diff options
| author | YamaArashi <shadow962@live.com> | 2016-01-06 01:47:28 -0800 |
|---|---|---|
| committer | YamaArashi <shadow962@live.com> | 2016-01-06 01:47:28 -0800 |
| commit | be8b04496302184c6e8f04d6179f9c3afc50aeb6 (patch) | |
| tree | 726e2468c0c07add773c0dbd86ab6386844259ae /gcc/reload1.c | |
initial commit
Diffstat (limited to 'gcc/reload1.c')
| -rwxr-xr-x | gcc/reload1.c | 10159 |
1 files changed, 10159 insertions, 0 deletions
diff --git a/gcc/reload1.c b/gcc/reload1.c new file mode 100755 index 0000000..08ca216 --- /dev/null +++ b/gcc/reload1.c @@ -0,0 +1,10159 @@ +/* Reload pseudo regs into hard regs for insns that require hard regs. + Copyright (C) 1987, 88, 89, 92-98, 1999 Free Software Foundation, Inc. + +This file is part of GNU CC. + +GNU CC is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU CC is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU CC; see the file COPYING. If not, write to +the Free Software Foundation, 59 Temple Place - Suite 330, +Boston, MA 02111-1307, USA. */ + + +#include "config.h" +#include "system.h" + +#include "machmode.h" +#include "hard-reg-set.h" +#include "rtl.h" +#include "obstack.h" +#include "insn-config.h" +#include "insn-flags.h" +#include "insn-codes.h" +#include "flags.h" +#include "expr.h" +#include "regs.h" +#include "basic-block.h" +#include "reload.h" +#include "recog.h" +#include "output.h" +#include "real.h" +#include "toplev.h" + +/* This file contains the reload pass of the compiler, which is + run after register allocation has been done. It checks that + each insn is valid (operands required to be in registers really + are in registers of the proper class) and fixes up invalid ones + by copying values temporarily into registers for the insns + that need them. + + The results of register allocation are described by the vector + reg_renumber; the insns still contain pseudo regs, but reg_renumber + can be used to find which hard reg, if any, a pseudo reg is in. + + The technique we always use is to free up a few hard regs that are + called ``reload regs'', and for each place where a pseudo reg + must be in a hard reg, copy it temporarily into one of the reload regs. + + Reload regs are allocated locally for every instruction that needs + reloads. When there are pseudos which are allocated to a register that + has been chosen as a reload reg, such pseudos must be ``spilled''. + This means that they go to other hard regs, or to stack slots if no other + available hard regs can be found. Spilling can invalidate more + insns, requiring additional need for reloads, so we must keep checking + until the process stabilizes. + + For machines with different classes of registers, we must keep track + of the register class needed for each reload, and make sure that + we allocate enough reload registers of each class. + + The file reload.c contains the code that checks one insn for + validity and reports the reloads that it needs. This file + is in charge of scanning the entire rtl code, accumulating the + reload needs, spilling, assigning reload registers to use for + fixing up each insn, and generating the new insns to copy values + into the reload registers. */ + + +#ifndef REGISTER_MOVE_COST +#define REGISTER_MOVE_COST(x, y) 2 +#endif + +/* During reload_as_needed, element N contains a REG rtx for the hard reg + into which reg N has been reloaded (perhaps for a previous insn). */ +static rtx *reg_last_reload_reg; + +/* Elt N nonzero if reg_last_reload_reg[N] has been set in this insn + for an output reload that stores into reg N. */ +static char *reg_has_output_reload; + +/* Indicates which hard regs are reload-registers for an output reload + in the current insn. */ +static HARD_REG_SET reg_is_output_reload; + +/* Element N is the constant value to which pseudo reg N is equivalent, + or zero if pseudo reg N is not equivalent to a constant. + find_reloads looks at this in order to replace pseudo reg N + with the constant it stands for. */ +rtx *reg_equiv_constant; + +/* Element N is a memory location to which pseudo reg N is equivalent, + prior to any register elimination (such as frame pointer to stack + pointer). Depending on whether or not it is a valid address, this value + is transferred to either reg_equiv_address or reg_equiv_mem. */ +rtx *reg_equiv_memory_loc; + +/* Element N is the address of stack slot to which pseudo reg N is equivalent. + This is used when the address is not valid as a memory address + (because its displacement is too big for the machine.) */ +rtx *reg_equiv_address; + +/* Element N is the memory slot to which pseudo reg N is equivalent, + or zero if pseudo reg N is not equivalent to a memory slot. */ +rtx *reg_equiv_mem; + +/* Widest width in which each pseudo reg is referred to (via subreg). */ +static int *reg_max_ref_width; + +/* Element N is the list of insns that initialized reg N from its equivalent + constant or memory slot. */ +static rtx *reg_equiv_init; + +/* Vector to remember old contents of reg_renumber before spilling. */ +static short *reg_old_renumber; + +/* During reload_as_needed, element N contains the last pseudo regno reloaded + into hard register N. If that pseudo reg occupied more than one register, + reg_reloaded_contents points to that pseudo for each spill register in + use; all of these must remain set for an inheritance to occur. */ +static int reg_reloaded_contents[FIRST_PSEUDO_REGISTER]; + +/* During reload_as_needed, element N contains the insn for which + hard register N was last used. Its contents are significant only + when reg_reloaded_valid is set for this register. */ +static rtx reg_reloaded_insn[FIRST_PSEUDO_REGISTER]; + +/* Indicate if reg_reloaded_insn / reg_reloaded_contents is valid */ +static HARD_REG_SET reg_reloaded_valid; +/* Indicate if the register was dead at the end of the reload. + This is only valid if reg_reloaded_contents is set and valid. */ +static HARD_REG_SET reg_reloaded_dead; + +/* Number of spill-regs so far; number of valid elements of spill_regs. */ +static int n_spills; + +/* In parallel with spill_regs, contains REG rtx's for those regs. + Holds the last rtx used for any given reg, or 0 if it has never + been used for spilling yet. This rtx is reused, provided it has + the proper mode. */ +static rtx spill_reg_rtx[FIRST_PSEUDO_REGISTER]; + +/* In parallel with spill_regs, contains nonzero for a spill reg + that was stored after the last time it was used. + The precise value is the insn generated to do the store. */ +static rtx spill_reg_store[FIRST_PSEUDO_REGISTER]; + +/* This is the register that was stored with spill_reg_store. This is a + copy of reload_out / reload_out_reg when the value was stored; if + reload_out is a MEM, spill_reg_stored_to will be set to reload_out_reg. */ +static rtx spill_reg_stored_to[FIRST_PSEUDO_REGISTER]; + +/* This table is the inverse mapping of spill_regs: + indexed by hard reg number, + it contains the position of that reg in spill_regs, + or -1 for something that is not in spill_regs. + + ?!? This is no longer accurate. */ +static short spill_reg_order[FIRST_PSEUDO_REGISTER]; + +/* This reg set indicates registers that can't be used as spill registers for + the currently processed insn. These are the hard registers which are live + during the insn, but not allocated to pseudos, as well as fixed + registers. */ +static HARD_REG_SET bad_spill_regs; + +/* These are the hard registers that can't be used as spill register for any + insn. This includes registers used for user variables and registers that + we can't eliminate. A register that appears in this set also can't be used + to retry register allocation. */ +static HARD_REG_SET bad_spill_regs_global; + +/* Describes order of use of registers for reloading + of spilled pseudo-registers. `n_spills' is the number of + elements that are actually valid; new ones are added at the end. + + Both spill_regs and spill_reg_order are used on two occasions: + once during find_reload_regs, where they keep track of the spill registers + for a single insn, but also during reload_as_needed where they show all + the registers ever used by reload. For the latter case, the information + is calculated during finish_spills. */ +static short spill_regs[FIRST_PSEUDO_REGISTER]; + +/* This vector of reg sets indicates, for each pseudo, which hard registers + may not be used for retrying global allocation because the register was + formerly spilled from one of them. If we allowed reallocating a pseudo to + a register that it was already allocated to, reload might not + terminate. */ +static HARD_REG_SET *pseudo_previous_regs; + +/* This vector of reg sets indicates, for each pseudo, which hard + registers may not be used for retrying global allocation because they + are used as spill registers during one of the insns in which the + pseudo is live. */ +static HARD_REG_SET *pseudo_forbidden_regs; + +/* All hard regs that have been used as spill registers for any insn are + marked in this set. */ +static HARD_REG_SET used_spill_regs; + +/* Index of last register assigned as a spill register. We allocate in + a round-robin fashion. */ +static int last_spill_reg; + +/* Describes order of preference for putting regs into spill_regs. + Contains the numbers of all the hard regs, in order most preferred first. + This order is different for each function. + It is set up by order_regs_for_reload. + Empty elements at the end contain -1. */ +static short potential_reload_regs[FIRST_PSEUDO_REGISTER]; + +/* Nonzero if indirect addressing is supported on the machine; this means + that spilling (REG n) does not require reloading it into a register in + order to do (MEM (REG n)) or (MEM (PLUS (REG n) (CONST_INT c))). The + value indicates the level of indirect addressing supported, e.g., two + means that (MEM (MEM (REG n))) is also valid if (REG n) does not get + a hard register. */ +static char spill_indirect_levels; + +/* Nonzero if indirect addressing is supported when the innermost MEM is + of the form (MEM (SYMBOL_REF sym)). It is assumed that the level to + which these are valid is the same as spill_indirect_levels, above. */ +char indirect_symref_ok; + +/* Nonzero if an address (plus (reg frame_pointer) (reg ...)) is valid. */ +char double_reg_address_ok; + +/* Record the stack slot for each spilled hard register. */ +static rtx spill_stack_slot[FIRST_PSEUDO_REGISTER]; + +/* Width allocated so far for that stack slot. */ +static int spill_stack_slot_width[FIRST_PSEUDO_REGISTER]; + +/* Record which pseudos needed to be spilled. */ +static regset spilled_pseudos; + +/* First uid used by insns created by reload in this function. + Used in find_equiv_reg. */ +int reload_first_uid; + +/* Flag set by local-alloc or global-alloc if anything is live in + a call-clobbered reg across calls. */ +int caller_save_needed; + +/* Set to 1 while reload_as_needed is operating. + Required by some machines to handle any generated moves differently. */ +int reload_in_progress = 0; + +/* These arrays record the insn_code of insns that may be needed to + perform input and output reloads of special objects. They provide a + place to pass a scratch register. */ +enum insn_code reload_in_optab[NUM_MACHINE_MODES]; +enum insn_code reload_out_optab[NUM_MACHINE_MODES]; + +/* This obstack is used for allocation of rtl during register elimination. + The allocated storage can be freed once find_reloads has processed the + insn. */ +struct obstack reload_obstack; + +/* Points to the beginning of the reload_obstack. All insn_chain structures + are allocated first. */ +char *reload_startobj; + +/* The point after all insn_chain structures. Used to quickly deallocate + memory used while processing one insn. */ +char *reload_firstobj; + +#define obstack_chunk_alloc xmalloc +#define obstack_chunk_free free + +/* List of labels that must never be deleted. */ +extern rtx forced_labels; + +/* List of insn_chain instructions, one for every insn that reload needs to + examine. */ +struct insn_chain *reload_insn_chain; + +#ifdef TREE_CODE +extern tree current_function_decl; +#else +extern union tree_node *current_function_decl; +#endif + +/* List of all insns needing reloads. */ +static struct insn_chain *insns_need_reload; + +/* This structure is used to record information about register eliminations. + Each array entry describes one possible way of eliminating a register + in favor of another. If there is more than one way of eliminating a + particular register, the most preferred should be specified first. */ + +struct elim_table +{ + int from; /* Register number to be eliminated. */ + int to; /* Register number used as replacement. */ + int initial_offset; /* Initial difference between values. */ + int can_eliminate; /* Non-zero if this elimination can be done. */ + int can_eliminate_previous; /* Value of CAN_ELIMINATE in previous scan over + insns made by reload. */ + int offset; /* Current offset between the two regs. */ + int previous_offset; /* Offset at end of previous insn. */ + int ref_outside_mem; /* "to" has been referenced outside a MEM. */ + rtx from_rtx; /* REG rtx for the register to be eliminated. + We cannot simply compare the number since + we might then spuriously replace a hard + register corresponding to a pseudo + assigned to the reg to be eliminated. */ + rtx to_rtx; /* REG rtx for the replacement. */ +}; + +static struct elim_table * reg_eliminate = 0; + +/* This is an intermediate structure to initialize the table. It has + exactly the members provided by ELIMINABLE_REGS. */ +static struct elim_table_1 +{ + int from; + int to; +} reg_eliminate_1[] = + +/* If a set of eliminable registers was specified, define the table from it. + Otherwise, default to the normal case of the frame pointer being + replaced by the stack pointer. */ + +#ifdef ELIMINABLE_REGS + ELIMINABLE_REGS; +#else + {{ FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM}}; +#endif + +#define NUM_ELIMINABLE_REGS (sizeof reg_eliminate_1/sizeof reg_eliminate_1[0]) + +/* Record the number of pending eliminations that have an offset not equal + to their initial offset. If non-zero, we use a new copy of each + replacement result in any insns encountered. */ +int num_not_at_initial_offset; + +/* Count the number of registers that we may be able to eliminate. */ +static int num_eliminable; +/* And the number of registers that are equivalent to a constant that + can be eliminated to frame_pointer / arg_pointer + constant. */ +static int num_eliminable_invariants; + +/* For each label, we record the offset of each elimination. If we reach + a label by more than one path and an offset differs, we cannot do the + elimination. This information is indexed by the number of the label. + The first table is an array of flags that records whether we have yet + encountered a label and the second table is an array of arrays, one + entry in the latter array for each elimination. */ + +static char *offsets_known_at; +static int (*offsets_at)[NUM_ELIMINABLE_REGS]; + +/* Number of labels in the current function. */ + +static int num_labels; + +struct hard_reg_n_uses +{ + int regno; + unsigned int uses; +}; + +static void maybe_fix_stack_asms PROTO((void)); +static void calculate_needs_all_insns PROTO((int)); +static void calculate_needs PROTO((struct insn_chain *)); +static void find_reload_regs PROTO((struct insn_chain *chain, + FILE *)); +static void find_tworeg_group PROTO((struct insn_chain *, int, + FILE *)); +static void find_group PROTO((struct insn_chain *, int, + FILE *)); +static int possible_group_p PROTO((struct insn_chain *, int)); +static void count_possible_groups PROTO((struct insn_chain *, int)); +static int modes_equiv_for_class_p PROTO((enum machine_mode, + enum machine_mode, + enum reg_class)); +static void delete_caller_save_insns PROTO((void)); + +static void spill_failure PROTO((rtx)); +static void new_spill_reg PROTO((struct insn_chain *, int, int, + int, FILE *)); +static void maybe_mark_pseudo_spilled PROTO((int)); +static void delete_dead_insn PROTO((rtx)); +static void alter_reg PROTO((int, int)); +static void set_label_offsets PROTO((rtx, rtx, int)); +static int eliminate_regs_in_insn PROTO((rtx, int)); +static void update_eliminable_offsets PROTO((void)); +static void mark_not_eliminable PROTO((rtx, rtx)); +static void set_initial_elim_offsets PROTO((void)); +static void verify_initial_elim_offsets PROTO((void)); +static void set_initial_label_offsets PROTO((void)); +static void set_offsets_for_label PROTO((rtx)); +static void init_elim_table PROTO((void)); +static void update_eliminables PROTO((HARD_REG_SET *)); +static void spill_hard_reg PROTO((int, FILE *, int)); +static int finish_spills PROTO((int, FILE *)); +static void ior_hard_reg_set PROTO((HARD_REG_SET *, HARD_REG_SET *)); +static void scan_paradoxical_subregs PROTO((rtx)); +static int hard_reg_use_compare PROTO((const GENERIC_PTR, const GENERIC_PTR)); +static void count_pseudo PROTO((struct hard_reg_n_uses *, int)); +static void order_regs_for_reload PROTO((struct insn_chain *)); +static void reload_as_needed PROTO((int)); +static void forget_old_reloads_1 PROTO((rtx, rtx)); +static int reload_reg_class_lower PROTO((const GENERIC_PTR, const GENERIC_PTR)); +static void mark_reload_reg_in_use PROTO((int, int, enum reload_type, + enum machine_mode)); +static void clear_reload_reg_in_use PROTO((int, int, enum reload_type, + enum machine_mode)); +static int reload_reg_free_p PROTO((int, int, enum reload_type)); +static int reload_reg_free_for_value_p PROTO((int, int, enum reload_type, rtx, rtx, int, int)); +static int reload_reg_reaches_end_p PROTO((int, int, enum reload_type)); +static int allocate_reload_reg PROTO((struct insn_chain *, int, int, + int)); +static void choose_reload_regs PROTO((struct insn_chain *)); +static void merge_assigned_reloads PROTO((rtx)); +static void emit_reload_insns PROTO((struct insn_chain *)); +static void delete_output_reload PROTO((rtx, int, int)); +static void delete_address_reloads PROTO((rtx, rtx)); +static void delete_address_reloads_1 PROTO((rtx, rtx, rtx)); +static rtx inc_for_reload PROTO((rtx, rtx, rtx, int)); +static int constraint_accepts_reg_p PROTO((char *, rtx)); +static void reload_cse_regs_1 PROTO((rtx)); +static void reload_cse_invalidate_regno PROTO((int, enum machine_mode, int)); +static int reload_cse_mem_conflict_p PROTO((rtx, rtx)); +static void reload_cse_invalidate_mem PROTO((rtx)); +static void reload_cse_invalidate_rtx PROTO((rtx, rtx)); +static int reload_cse_regno_equal_p PROTO((int, rtx, enum machine_mode)); +static int reload_cse_noop_set_p PROTO((rtx, rtx)); +static int reload_cse_simplify_set PROTO((rtx, rtx)); +static int reload_cse_simplify_operands PROTO((rtx)); +static void reload_cse_check_clobber PROTO((rtx, rtx)); +static void reload_cse_record_set PROTO((rtx, rtx)); +static void reload_combine PROTO((void)); +static void reload_combine_note_use PROTO((rtx *, rtx)); +static void reload_combine_note_store PROTO((rtx, rtx)); +static void reload_cse_move2add PROTO((rtx)); +static void move2add_note_store PROTO((rtx, rtx)); + +/* Initialize the reload pass once per compilation. */ + +void +init_reload () +{ + register int i; + + /* Often (MEM (REG n)) is still valid even if (REG n) is put on the stack. + Set spill_indirect_levels to the number of levels such addressing is + permitted, zero if it is not permitted at all. */ + + register rtx tem + = gen_rtx_MEM (Pmode, + gen_rtx_PLUS (Pmode, + gen_rtx_REG (Pmode, LAST_VIRTUAL_REGISTER + 1), + GEN_INT (4))); + spill_indirect_levels = 0; + + while (memory_address_p (QImode, tem)) + { + spill_indirect_levels++; + tem = gen_rtx_MEM (Pmode, tem); + } + + /* See if indirect addressing is valid for (MEM (SYMBOL_REF ...)). */ + + tem = gen_rtx_MEM (Pmode, gen_rtx_SYMBOL_REF (Pmode, "foo")); + indirect_symref_ok = memory_address_p (QImode, tem); + + /* See if reg+reg is a valid (and offsettable) address. */ + + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + { + tem = gen_rtx_PLUS (Pmode, + gen_rtx_REG (Pmode, HARD_FRAME_POINTER_REGNUM), + gen_rtx_REG (Pmode, i)); + /* This way, we make sure that reg+reg is an offsettable address. */ + tem = plus_constant (tem, 4); + + if (memory_address_p (QImode, tem)) + { + double_reg_address_ok = 1; + break; + } + } + + /* Initialize obstack for our rtl allocation. */ + gcc_obstack_init (&reload_obstack); + reload_startobj = (char *) obstack_alloc (&reload_obstack, 0); +} + +/* List of insn chains that are currently unused. */ +static struct insn_chain *unused_insn_chains = 0; + +/* Allocate an empty insn_chain structure. */ +struct insn_chain * +new_insn_chain () +{ + struct insn_chain *c; + + if (unused_insn_chains == 0) + { + c = obstack_alloc (&reload_obstack, sizeof (struct insn_chain)); + c->live_before = OBSTACK_ALLOC_REG_SET (&reload_obstack); + c->live_after = OBSTACK_ALLOC_REG_SET (&reload_obstack); + } + else + { + c = unused_insn_chains; + unused_insn_chains = c->next; + } + c->is_caller_save_insn = 0; + c->need_operand_change = 0; + c->need_reload = 0; + c->need_elim = 0; + return c; +} + +/* Small utility function to set all regs in hard reg set TO which are + allocated to pseudos in regset FROM. */ +void +compute_use_by_pseudos (to, from) + HARD_REG_SET *to; + regset from; +{ + int regno; + EXECUTE_IF_SET_IN_REG_SET + (from, FIRST_PSEUDO_REGISTER, regno, + { + int r = reg_renumber[regno]; + int nregs; + if (r < 0) + { + /* reload_combine uses the information from + basic_block_live_at_start, which might still contain registers + that have not actually been allocated since they have an + equivalence. */ + if (! reload_completed) + abort (); + } + else + { + nregs = HARD_REGNO_NREGS (r, PSEUDO_REGNO_MODE (regno)); + while (nregs-- > 0) + SET_HARD_REG_BIT (*to, r + nregs); + } + }); +} + +/* Global variables used by reload and its subroutines. */ + +/* Set during calculate_needs if an insn needs register elimination. */ +static int something_needs_elimination; +/* Set during calculate_needs if an insn needs an operand changed. */ +int something_needs_operands_changed; + +/* Nonzero means we couldn't get enough spill regs. */ +static int failure; + +/* Main entry point for the reload pass. + + FIRST is the first insn of the function being compiled. + + GLOBAL nonzero means we were called from global_alloc + and should attempt to reallocate any pseudoregs that we + displace from hard regs we will use for reloads. + If GLOBAL is zero, we do not have enough information to do that, + so any pseudo reg that is spilled must go to the stack. + + DUMPFILE is the global-reg debugging dump file stream, or 0. + If it is nonzero, messages are written to it to describe + which registers are seized as reload regs, which pseudo regs + are spilled from them, and where the pseudo regs are reallocated to. + + Return value is nonzero if reload failed + and we must not do any more for this function. */ + +int +reload (first, global, dumpfile) + rtx first; + int global; + FILE *dumpfile; +{ + register int i; + register rtx insn; + register struct elim_table *ep; + + /* The two pointers used to track the true location of the memory used + for label offsets. */ + char *real_known_ptr = NULL_PTR; + int (*real_at_ptr)[NUM_ELIMINABLE_REGS]; + + /* Make sure even insns with volatile mem refs are recognizable. */ + init_recog (); + + failure = 0; + + reload_firstobj = (char *) obstack_alloc (&reload_obstack, 0); + + /* Make sure that the last insn in the chain + is not something that needs reloading. */ + emit_note (NULL_PTR, NOTE_INSN_DELETED); + + /* Enable find_equiv_reg to distinguish insns made by reload. */ + reload_first_uid = get_max_uid (); + +#ifdef SECONDARY_MEMORY_NEEDED + /* Initialize the secondary memory table. */ + clear_secondary_mem (); +#endif + + /* We don't have a stack slot for any spill reg yet. */ + bzero ((char *) spill_stack_slot, sizeof spill_stack_slot); + bzero ((char *) spill_stack_slot_width, sizeof spill_stack_slot_width); + + /* Initialize the save area information for caller-save, in case some + are needed. */ + init_save_areas (); + + /* Compute which hard registers are now in use + as homes for pseudo registers. + This is done here rather than (eg) in global_alloc + because this point is reached even if not optimizing. */ + for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) + mark_home_live (i); + + /* A function that receives a nonlocal goto must save all call-saved + registers. */ + if (current_function_has_nonlocal_label) + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + { + if (! call_used_regs[i] && ! fixed_regs[i]) + regs_ever_live[i] = 1; + } + + /* Find all the pseudo registers that didn't get hard regs + but do have known equivalent constants or memory slots. + These include parameters (known equivalent to parameter slots) + and cse'd or loop-moved constant memory addresses. + + Record constant equivalents in reg_equiv_constant + so they will be substituted by find_reloads. + Record memory equivalents in reg_mem_equiv so they can + be substituted eventually by altering the REG-rtx's. */ + + reg_equiv_constant = (rtx *) xmalloc (max_regno * sizeof (rtx)); + bzero ((char *) reg_equiv_constant, max_regno * sizeof (rtx)); + reg_equiv_memory_loc = (rtx *) xmalloc (max_regno * sizeof (rtx)); + bzero ((char *) reg_equiv_memory_loc, max_regno * sizeof (rtx)); + reg_equiv_mem = (rtx *) xmalloc (max_regno * sizeof (rtx)); + bzero ((char *) reg_equiv_mem, max_regno * sizeof (rtx)); + reg_equiv_init = (rtx *) xmalloc (max_regno * sizeof (rtx)); + bzero ((char *) reg_equiv_init, max_regno * sizeof (rtx)); + reg_equiv_address = (rtx *) xmalloc (max_regno * sizeof (rtx)); + bzero ((char *) reg_equiv_address, max_regno * sizeof (rtx)); + reg_max_ref_width = (int *) xmalloc (max_regno * sizeof (int)); + bzero ((char *) reg_max_ref_width, max_regno * sizeof (int)); + reg_old_renumber = (short *) xmalloc (max_regno * sizeof (short)); + bcopy (reg_renumber, reg_old_renumber, max_regno * sizeof (short)); + pseudo_forbidden_regs + = (HARD_REG_SET *) xmalloc (max_regno * sizeof (HARD_REG_SET)); + pseudo_previous_regs + = (HARD_REG_SET *) xmalloc (max_regno * sizeof (HARD_REG_SET)); + + CLEAR_HARD_REG_SET (bad_spill_regs_global); + bzero ((char *) pseudo_previous_regs, max_regno * sizeof (HARD_REG_SET)); + + /* Look for REG_EQUIV notes; record what each pseudo is equivalent to. + Also find all paradoxical subregs and find largest such for each pseudo. + On machines with small register classes, record hard registers that + are used for user variables. These can never be used for spills. + Also look for a "constant" NOTE_INSN_SETJMP. This means that all + caller-saved registers must be marked live. */ + + num_eliminable_invariants = 0; + for (insn = first; insn; insn = NEXT_INSN (insn)) + { + rtx set = single_set (insn); + + if (GET_CODE (insn) == NOTE && CONST_CALL_P (insn) + && NOTE_LINE_NUMBER (insn) == NOTE_INSN_SETJMP) + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + if (! call_used_regs[i]) + regs_ever_live[i] = 1; + + if (set != 0 && GET_CODE (SET_DEST (set)) == REG) + { + rtx note = find_reg_note (insn, REG_EQUIV, NULL_RTX); + if (note +#ifdef LEGITIMATE_PIC_OPERAND_P + && (! function_invariant_p (XEXP (note, 0)) + || ! flag_pic + || LEGITIMATE_PIC_OPERAND_P (XEXP (note, 0))) +#endif + ) + { + rtx x = XEXP (note, 0); + i = REGNO (SET_DEST (set)); + if (i > LAST_VIRTUAL_REGISTER) + { + if (GET_CODE (x) == MEM) + { + /* If the operand is a PLUS, the MEM may be shared, + so make sure we have an unshared copy here. */ + if (GET_CODE (XEXP (x, 0)) == PLUS) + x = copy_rtx (x); + + reg_equiv_memory_loc[i] = x; + } + else if (function_invariant_p (x)) + { + if (GET_CODE (x) == PLUS) + { + /* This is PLUS of frame pointer and a constant, + and might be shared. Unshare it. */ + reg_equiv_constant[i] = copy_rtx (x); + num_eliminable_invariants++; + } + else if (x == frame_pointer_rtx + || x == arg_pointer_rtx) + { + reg_equiv_constant[i] = x; + num_eliminable_invariants++; + } + else if (LEGITIMATE_CONSTANT_P (x)) + reg_equiv_constant[i] = x; + else + reg_equiv_memory_loc[i] + = force_const_mem (GET_MODE (SET_DEST (set)), x); + } + else + continue; + + /* If this register is being made equivalent to a MEM + and the MEM is not SET_SRC, the equivalencing insn + is one with the MEM as a SET_DEST and it occurs later. + So don't mark this insn now. */ + if (GET_CODE (x) != MEM + || rtx_equal_p (SET_SRC (set), x)) + reg_equiv_init[i] + = gen_rtx_INSN_LIST (VOIDmode, insn, reg_equiv_init[i]); + } + } + } + + /* If this insn is setting a MEM from a register equivalent to it, + this is the equivalencing insn. */ + else if (set && GET_CODE (SET_DEST (set)) == MEM + && GET_CODE (SET_SRC (set)) == REG + && reg_equiv_memory_loc[REGNO (SET_SRC (set))] + && rtx_equal_p (SET_DEST (set), + reg_equiv_memory_loc[REGNO (SET_SRC (set))])) + reg_equiv_init[REGNO (SET_SRC (set))] + = gen_rtx_INSN_LIST (VOIDmode, insn, + reg_equiv_init[REGNO (SET_SRC (set))]); + + if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') + scan_paradoxical_subregs (PATTERN (insn)); + } + + init_elim_table (); + + num_labels = max_label_num () - get_first_label_num (); + + /* Allocate the tables used to store offset information at labels. */ + /* We used to use alloca here, but the size of what it would try to + allocate would occasionally cause it to exceed the stack limit and + cause a core dump. */ + real_known_ptr = xmalloc (num_labels); + real_at_ptr + = (int (*)[NUM_ELIMINABLE_REGS]) + xmalloc (num_labels * NUM_ELIMINABLE_REGS * sizeof (int)); + + offsets_known_at = real_known_ptr - get_first_label_num (); + offsets_at + = (int (*)[NUM_ELIMINABLE_REGS]) (real_at_ptr - get_first_label_num ()); + + /* Alter each pseudo-reg rtx to contain its hard reg number. + Assign stack slots to the pseudos that lack hard regs or equivalents. + Do not touch virtual registers. */ + + for (i = LAST_VIRTUAL_REGISTER + 1; i < max_regno; i++) + alter_reg (i, -1); + + /* If we have some registers we think can be eliminated, scan all insns to + see if there is an insn that sets one of these registers to something + other than itself plus a constant. If so, the register cannot be + eliminated. Doing this scan here eliminates an extra pass through the + main reload loop in the most common case where register elimination + cannot be done. */ + for (insn = first; insn && num_eliminable; insn = NEXT_INSN (insn)) + if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN + || GET_CODE (insn) == CALL_INSN) + note_stores (PATTERN (insn), mark_not_eliminable); + +#ifndef REGISTER_CONSTRAINTS + /* If all the pseudo regs have hard regs, + except for those that are never referenced, + we know that no reloads are needed. */ + /* But that is not true if there are register constraints, since + in that case some pseudos might be in the wrong kind of hard reg. */ + + for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) + if (reg_renumber[i] == -1 && REG_N_REFS (i) != 0) + break; + + if (i == max_regno && num_eliminable == 0 && ! caller_save_needed) + { + free (real_known_ptr); + free (real_at_ptr); + free (reg_equiv_constant); + free (reg_equiv_memory_loc); + free (reg_equiv_mem); + free (reg_equiv_init); + free (reg_equiv_address); + free (reg_max_ref_width); + free (reg_old_renumber); + free (pseudo_previous_regs); + free (pseudo_forbidden_regs); + return 0; + } +#endif + + maybe_fix_stack_asms (); + + insns_need_reload = 0; + something_needs_elimination = 0; + + /* Initialize to -1, which means take the first spill register. */ + last_spill_reg = -1; + + spilled_pseudos = ALLOCA_REG_SET (); + + /* Spill any hard regs that we know we can't eliminate. */ + CLEAR_HARD_REG_SET (used_spill_regs); + for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) + if (! ep->can_eliminate) + spill_hard_reg (ep->from, dumpfile, 1); + +#if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM + if (frame_pointer_needed) + spill_hard_reg (HARD_FRAME_POINTER_REGNUM, dumpfile, 1); +#endif + finish_spills (global, dumpfile); + + /* From now on, we may need to generate moves differently. We may also + allow modifications of insns which cause them to not be recognized. + Any such modifications will be cleaned up during reload itself. */ + reload_in_progress = 1; + + /* This loop scans the entire function each go-round + and repeats until one repetition spills no additional hard regs. */ + for (;;) + { + int something_changed; + int did_spill; + struct insn_chain *chain; + + HOST_WIDE_INT starting_frame_size; + + /* Round size of stack frame to BIGGEST_ALIGNMENT. This must be done + here because the stack size may be a part of the offset computation + for register elimination, and there might have been new stack slots + created in the last iteration of this loop. */ + assign_stack_local (BLKmode, 0, 0); + + starting_frame_size = get_frame_size (); + + set_initial_elim_offsets (); + set_initial_label_offsets (); + + /* For each pseudo register that has an equivalent location defined, + try to eliminate any eliminable registers (such as the frame pointer) + assuming initial offsets for the replacement register, which + is the normal case. + + If the resulting location is directly addressable, substitute + the MEM we just got directly for the old REG. + + If it is not addressable but is a constant or the sum of a hard reg + and constant, it is probably not addressable because the constant is + out of range, in that case record the address; we will generate + hairy code to compute the address in a register each time it is + needed. Similarly if it is a hard register, but one that is not + valid as an address register. + + If the location is not addressable, but does not have one of the + above forms, assign a stack slot. We have to do this to avoid the + potential of producing lots of reloads if, e.g., a location involves + a pseudo that didn't get a hard register and has an equivalent memory + location that also involves a pseudo that didn't get a hard register. + + Perhaps at some point we will improve reload_when_needed handling + so this problem goes away. But that's very hairy. */ + + for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) + if (reg_renumber[i] < 0 && reg_equiv_memory_loc[i]) + { + rtx x = eliminate_regs (reg_equiv_memory_loc[i], 0, NULL_RTX); + + if (strict_memory_address_p (GET_MODE (regno_reg_rtx[i]), + XEXP (x, 0))) + reg_equiv_mem[i] = x, reg_equiv_address[i] = 0; + else if (CONSTANT_P (XEXP (x, 0)) + || (GET_CODE (XEXP (x, 0)) == REG + && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER) + || (GET_CODE (XEXP (x, 0)) == PLUS + && GET_CODE (XEXP (XEXP (x, 0), 0)) == REG + && (REGNO (XEXP (XEXP (x, 0), 0)) + < FIRST_PSEUDO_REGISTER) + && CONSTANT_P (XEXP (XEXP (x, 0), 1)))) + reg_equiv_address[i] = XEXP (x, 0), reg_equiv_mem[i] = 0; + else + { + /* Make a new stack slot. Then indicate that something + changed so we go back and recompute offsets for + eliminable registers because the allocation of memory + below might change some offset. reg_equiv_{mem,address} + will be set up for this pseudo on the next pass around + the loop. */ + reg_equiv_memory_loc[i] = 0; + reg_equiv_init[i] = 0; + alter_reg (i, -1); + } + } + + if (caller_save_needed) + setup_save_areas (); + + /* If we allocated another stack slot, redo elimination bookkeeping. */ + if (starting_frame_size != get_frame_size ()) + continue; + + if (caller_save_needed) + { + save_call_clobbered_regs (); + /* That might have allocated new insn_chain structures. */ + reload_firstobj = (char *) obstack_alloc (&reload_obstack, 0); + } + + calculate_needs_all_insns (global); + + CLEAR_REG_SET (spilled_pseudos); + did_spill = 0; + + something_changed = 0; + + /* If we allocated any new memory locations, make another pass + since it might have changed elimination offsets. */ + if (starting_frame_size != get_frame_size ()) + something_changed = 1; + + { + HARD_REG_SET to_spill; + CLEAR_HARD_REG_SET (to_spill); + update_eliminables (&to_spill); + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + if (TEST_HARD_REG_BIT (to_spill, i)) + { + spill_hard_reg (i, dumpfile, 1); + did_spill = 1; + + /* Regardless of the state of spills, if we previously had + a register that we thought we could eliminate, but no can + not eliminate, we must run another pass. + + Consider pseudos which have an entry in reg_equiv_* which + reference an eliminable register. We must make another pass + to update reg_equiv_* so that we do not substitute in the + old value from when we thought the elimination could be + performed. */ + something_changed = 1; + } + } + + CLEAR_HARD_REG_SET (used_spill_regs); + /* Try to satisfy the needs for each insn. */ + for (chain = insns_need_reload; chain != 0; + chain = chain->next_need_reload) + find_reload_regs (chain, dumpfile); + + if (failure) + goto failed; + + if (insns_need_reload != 0 || did_spill) + something_changed |= finish_spills (global, dumpfile); + + if (! something_changed) + break; + + if (caller_save_needed) + delete_caller_save_insns (); + } + + /* If global-alloc was run, notify it of any register eliminations we have + done. */ + if (global) + for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) + if (ep->can_eliminate) + mark_elimination (ep->from, ep->to); + + /* If a pseudo has no hard reg, delete the insns that made the equivalence. + If that insn didn't set the register (i.e., it copied the register to + memory), just delete that insn instead of the equivalencing insn plus + anything now dead. If we call delete_dead_insn on that insn, we may + delete the insn that actually sets the register if the register dies + there and that is incorrect. */ + + for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) + { + if (reg_renumber[i] < 0 && reg_equiv_init[i] != 0) + { + rtx list; + for (list = reg_equiv_init[i]; list; list = XEXP (list, 1)) + { + rtx equiv_insn = XEXP (list, 0); + if (GET_CODE (equiv_insn) == NOTE) + continue; + if (reg_set_p (regno_reg_rtx[i], PATTERN (equiv_insn))) + delete_dead_insn (equiv_insn); + else + { + PUT_CODE (equiv_insn, NOTE); + NOTE_SOURCE_FILE (equiv_insn) = 0; + NOTE_LINE_NUMBER (equiv_insn) = NOTE_INSN_DELETED; + } + } + } + } + + /* Use the reload registers where necessary + by generating move instructions to move the must-be-register + values into or out of the reload registers. */ + + if (insns_need_reload != 0 || something_needs_elimination + || something_needs_operands_changed) + { + int old_frame_size = get_frame_size (); + + reload_as_needed (global); + + if (old_frame_size != get_frame_size ()) + abort (); + + if (num_eliminable) + verify_initial_elim_offsets (); + } + + /* If we were able to eliminate the frame pointer, show that it is no + longer live at the start of any basic block. If it ls live by + virtue of being in a pseudo, that pseudo will be marked live + and hence the frame pointer will be known to be live via that + pseudo. */ + + if (! frame_pointer_needed) + for (i = 0; i < n_basic_blocks; i++) + CLEAR_REGNO_REG_SET (basic_block_live_at_start[i], + HARD_FRAME_POINTER_REGNUM); + + /* Come here (with failure set nonzero) if we can't get enough spill regs + and we decide not to abort about it. */ + failed: + + reload_in_progress = 0; + + /* Now eliminate all pseudo regs by modifying them into + their equivalent memory references. + The REG-rtx's for the pseudos are modified in place, + so all insns that used to refer to them now refer to memory. + + For a reg that has a reg_equiv_address, all those insns + were changed by reloading so that no insns refer to it any longer; + but the DECL_RTL of a variable decl may refer to it, + and if so this causes the debugging info to mention the variable. */ + + for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) + { + rtx addr = 0; + int in_struct = 0; + int is_scalar; + int is_readonly = 0; + + if (reg_equiv_memory_loc[i]) + { + in_struct = MEM_IN_STRUCT_P (reg_equiv_memory_loc[i]); + is_scalar = MEM_SCALAR_P (reg_equiv_memory_loc[i]); + is_readonly = RTX_UNCHANGING_P (reg_equiv_memory_loc[i]); + } + + if (reg_equiv_mem[i]) + addr = XEXP (reg_equiv_mem[i], 0); + + if (reg_equiv_address[i]) + addr = reg_equiv_address[i]; + + if (addr) + { + if (reg_renumber[i] < 0) + { + rtx reg = regno_reg_rtx[i]; + XEXP (reg, 0) = addr; + REG_USERVAR_P (reg) = 0; + RTX_UNCHANGING_P (reg) = is_readonly; + MEM_IN_STRUCT_P (reg) = in_struct; + MEM_SCALAR_P (reg) = is_scalar; + /* We have no alias information about this newly created + MEM. */ + MEM_ALIAS_SET (reg) = 0; + PUT_CODE (reg, MEM); + } + else if (reg_equiv_mem[i]) + XEXP (reg_equiv_mem[i], 0) = addr; + } + } + + /* We must set reload_completed now since the cleanup_subreg_operands call + below will re-recognize each insn and reload may have generated insns + which are only valid during and after reload. */ + reload_completed = 1; + + /* Make a pass over all the insns and delete all USEs which we inserted + only to tag a REG_EQUAL note on them. Remove all REG_DEAD and REG_UNUSED + notes. Delete all CLOBBER insns and simplify (subreg (reg)) operands. + Also remove all REG_RETVAL and REG_LIBCALL notes since they are no longer + useful or accurate. */ + + for (insn = first; insn; insn = NEXT_INSN (insn)) + if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') + { + rtx *pnote; + + if ((GET_CODE (PATTERN (insn)) == USE + && find_reg_note (insn, REG_EQUAL, NULL_RTX)) + || GET_CODE (PATTERN (insn)) == CLOBBER) + { + PUT_CODE (insn, NOTE); + NOTE_SOURCE_FILE (insn) = 0; + NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; + continue; + } + + pnote = ®_NOTES (insn); + while (*pnote != 0) + { + if (REG_NOTE_KIND (*pnote) == REG_DEAD + || REG_NOTE_KIND (*pnote) == REG_UNUSED + || REG_NOTE_KIND (*pnote) == REG_RETVAL + || REG_NOTE_KIND (*pnote) == REG_LIBCALL) + *pnote = XEXP (*pnote, 1); + else + pnote = &XEXP (*pnote, 1); + } + + /* And simplify (subreg (reg)) if it appears as an operand. */ + cleanup_subreg_operands (insn); + } + + /* If we are doing stack checking, give a warning if this function's + frame size is larger than we expect. */ + if (flag_stack_check && ! STACK_CHECK_BUILTIN) + { + HOST_WIDE_INT size = get_frame_size () + STACK_CHECK_FIXED_FRAME_SIZE; + + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + if (regs_ever_live[i] && ! fixed_regs[i] && call_used_regs[i]) + size += UNITS_PER_WORD; + + if (size > STACK_CHECK_MAX_FRAME_SIZE) + warning ("frame size too large for reliable stack checking"); + } + + /* Indicate that we no longer have known memory locations or constants. */ + if (reg_equiv_constant) + free (reg_equiv_constant); + reg_equiv_constant = 0; + if (reg_equiv_memory_loc) + free (reg_equiv_memory_loc); + reg_equiv_memory_loc = 0; + + if (real_known_ptr) + free (real_known_ptr); + if (real_at_ptr) + free (real_at_ptr); + + free (reg_equiv_mem); + free (reg_equiv_init); + free (reg_equiv_address); + free (reg_max_ref_width); + free (reg_old_renumber); + free (pseudo_previous_regs); + free (pseudo_forbidden_regs); + + FREE_REG_SET (spilled_pseudos); + + CLEAR_HARD_REG_SET (used_spill_regs); + for (i = 0; i < n_spills; i++) + SET_HARD_REG_BIT (used_spill_regs, spill_regs[i]); + + /* Free all the insn_chain structures at once. */ + obstack_free (&reload_obstack, reload_startobj); + unused_insn_chains = 0; + + return failure; +} + +/* Yet another special case. Unfortunately, reg-stack forces people to + write incorrect clobbers in asm statements. These clobbers must not + cause the register to appear in bad_spill_regs, otherwise we'll call + fatal_insn later. We clear the corresponding regnos in the live + register sets to avoid this. + The whole thing is rather sick, I'm afraid. */ +static void +maybe_fix_stack_asms () +{ +#ifdef STACK_REGS + char *constraints[MAX_RECOG_OPERANDS]; + enum machine_mode operand_mode[MAX_RECOG_OPERANDS]; + struct insn_chain *chain; + + for (chain = reload_insn_chain; chain != 0; chain = chain->next) + { + int i, noperands; + HARD_REG_SET clobbered, allowed; + rtx pat; + + if (GET_RTX_CLASS (GET_CODE (chain->insn)) != 'i' + || (noperands = asm_noperands (PATTERN (chain->insn))) < 0) + continue; + pat = PATTERN (chain->insn); + if (GET_CODE (pat) != PARALLEL) + continue; + + CLEAR_HARD_REG_SET (clobbered); + CLEAR_HARD_REG_SET (allowed); + + /* First, make a mask of all stack regs that are clobbered. */ + for (i = 0; i < XVECLEN (pat, 0); i++) + { + rtx t = XVECEXP (pat, 0, i); + if (GET_CODE (t) == CLOBBER && STACK_REG_P (XEXP (t, 0))) + SET_HARD_REG_BIT (clobbered, REGNO (XEXP (t, 0))); + } + + /* Get the operand values and constraints out of the insn. */ + decode_asm_operands (pat, recog_operand, recog_operand_loc, + constraints, operand_mode); + + /* For every operand, see what registers are allowed. */ + for (i = 0; i < noperands; i++) + { + char *p = constraints[i]; + /* For every alternative, we compute the class of registers allowed + for reloading in CLS, and merge its contents into the reg set + ALLOWED. */ + int cls = (int) NO_REGS; + + for (;;) + { + char c = *p++; + + if (c == '\0' || c == ',' || c == '#') + { + /* End of one alternative - mark the regs in the current + class, and reset the class. */ + IOR_HARD_REG_SET (allowed, reg_class_contents[cls]); + cls = NO_REGS; + if (c == '#') + do { + c = *p++; + } while (c != '\0' && c != ','); + if (c == '\0') + break; + continue; + } + + switch (c) + { + case '=': case '+': case '*': case '%': case '?': case '!': + case '0': case '1': case '2': case '3': case '4': case 'm': + case '<': case '>': case 'V': case 'o': case '&': case 'E': + case 'F': case 's': case 'i': case 'n': case 'X': case 'I': + case 'J': case 'K': case 'L': case 'M': case 'N': case 'O': + case 'P': +#ifdef EXTRA_CONSTRAINT + case 'Q': case 'R': case 'S': case 'T': case 'U': +#endif + break; + + case 'p': + cls = (int) reg_class_subunion[cls][(int) BASE_REG_CLASS]; + break; + + case 'g': + case 'r': + cls = (int) reg_class_subunion[cls][(int) GENERAL_REGS]; + break; + + default: + cls = (int) reg_class_subunion[cls][(int) REG_CLASS_FROM_LETTER (c)]; + + } + } + } + /* Those of the registers which are clobbered, but allowed by the + constraints, must be usable as reload registers. So clear them + out of the life information. */ + AND_HARD_REG_SET (allowed, clobbered); + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + if (TEST_HARD_REG_BIT (allowed, i)) + { + CLEAR_REGNO_REG_SET (chain->live_before, i); + CLEAR_REGNO_REG_SET (chain->live_after, i); + } + } + +#endif +} + + +/* Walk the chain of insns, and determine for each whether it needs reloads + and/or eliminations. Build the corresponding insns_need_reload list, and + set something_needs_elimination as appropriate. */ +static void +calculate_needs_all_insns (global) + int global; +{ + struct insn_chain **pprev_reload = &insns_need_reload; + struct insn_chain **pchain; + + something_needs_elimination = 0; + + for (pchain = &reload_insn_chain; *pchain != 0; pchain = &(*pchain)->next) + { + rtx insn; + struct insn_chain *chain; + + chain = *pchain; + insn = chain->insn; + + /* If this is a label, a JUMP_INSN, or has REG_NOTES (which might + include REG_LABEL), we need to see what effects this has on the + known offsets at labels. */ + + if (GET_CODE (insn) == CODE_LABEL || GET_CODE (insn) == JUMP_INSN + || (GET_RTX_CLASS (GET_CODE (insn)) == 'i' + && REG_NOTES (insn) != 0)) + set_label_offsets (insn, insn, 0); + + if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') + { + rtx old_body = PATTERN (insn); + int old_code = INSN_CODE (insn); + rtx old_notes = REG_NOTES (insn); + int did_elimination = 0; + int operands_changed = 0; + rtx set = single_set (insn); + + /* Skip insns that only set an equivalence. */ + if (set && GET_CODE (SET_DEST (set)) == REG + && reg_renumber[REGNO (SET_DEST (set))] < 0 + && reg_equiv_constant[REGNO (SET_DEST (set))]) + { + /* Must clear out the shortcuts, in case they were set last + time through. */ + chain->need_elim = 0; + chain->need_reload = 0; + chain->need_operand_change = 0; + continue; + } + + /* If needed, eliminate any eliminable registers. */ + if (num_eliminable || num_eliminable_invariants) + did_elimination = eliminate_regs_in_insn (insn, 0); + + /* Analyze the instruction. */ + operands_changed = find_reloads (insn, 0, spill_indirect_levels, + global, spill_reg_order); + + /* If a no-op set needs more than one reload, this is likely + to be something that needs input address reloads. We + can't get rid of this cleanly later, and it is of no use + anyway, so discard it now. + We only do this when expensive_optimizations is enabled, + since this complements reload inheritance / output + reload deletion, and it can make debugging harder. */ + if (flag_expensive_optimizations && n_reloads > 1) + { + rtx set = single_set (insn); + if (set + && SET_SRC (set) == SET_DEST (set) + && GET_CODE (SET_SRC (set)) == REG + && REGNO (SET_SRC (set)) >= FIRST_PSEUDO_REGISTER) + { + PUT_CODE (insn, NOTE); + NOTE_SOURCE_FILE (insn) = 0; + NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; + continue; + } + } + if (num_eliminable) + update_eliminable_offsets (); + + /* Remember for later shortcuts which insns had any reloads or + register eliminations. */ + chain->need_elim = did_elimination; + chain->need_reload = n_reloads > 0; + chain->need_operand_change = operands_changed; + + /* Discard any register replacements done. */ + if (did_elimination) + { + obstack_free (&reload_obstack, reload_firstobj); + PATTERN (insn) = old_body; + INSN_CODE (insn) = old_code; + REG_NOTES (insn) = old_notes; + something_needs_elimination = 1; + } + + something_needs_operands_changed |= operands_changed; + + if (n_reloads != 0) + { + *pprev_reload = chain; + pprev_reload = &chain->next_need_reload; + + calculate_needs (chain); + } + } + } + *pprev_reload = 0; +} + +/* Compute the most additional registers needed by one instruction, + given by CHAIN. Collect information separately for each class of regs. + + To compute the number of reload registers of each class needed for an + insn, we must simulate what choose_reload_regs can do. We do this by + splitting an insn into an "input" and an "output" part. RELOAD_OTHER + reloads are used in both. The input part uses those reloads, + RELOAD_FOR_INPUT reloads, which must be live over the entire input section + of reloads, and the maximum of all the RELOAD_FOR_INPUT_ADDRESS and + RELOAD_FOR_OPERAND_ADDRESS reloads, which conflict with the inputs. + + The registers needed for output are RELOAD_OTHER and RELOAD_FOR_OUTPUT, + which are live for the entire output portion, and the maximum of all the + RELOAD_FOR_OUTPUT_ADDRESS reloads for each operand. + + The total number of registers needed is the maximum of the + inputs and outputs. */ + +static void +calculate_needs (chain) + struct insn_chain *chain; +{ + int i; + + /* Each `struct needs' corresponds to one RELOAD_... type. */ + struct { + struct needs other; + struct needs input; + struct needs output; + struct needs insn; + struct needs other_addr; + struct needs op_addr; + struct needs op_addr_reload; + struct needs in_addr[MAX_RECOG_OPERANDS]; + struct needs in_addr_addr[MAX_RECOG_OPERANDS]; + struct needs out_addr[MAX_RECOG_OPERANDS]; + struct needs out_addr_addr[MAX_RECOG_OPERANDS]; + } insn_needs; + + bzero ((char *) chain->group_size, sizeof chain->group_size); + for (i = 0; i < N_REG_CLASSES; i++) + chain->group_mode[i] = VOIDmode; + bzero ((char *) &insn_needs, sizeof insn_needs); + + /* Count each reload once in every class + containing the reload's own class. */ + + for (i = 0; i < n_reloads; i++) + { + register enum reg_class *p; + enum reg_class class = reload_reg_class[i]; + int size; + enum machine_mode mode; + struct needs *this_needs; + + /* Don't count the dummy reloads, for which one of the + regs mentioned in the insn can be used for reloading. + Don't count optional reloads. + Don't count reloads that got combined with others. */ + if (reload_reg_rtx[i] != 0 + || reload_optional[i] != 0 + || (reload_out[i] == 0 && reload_in[i] == 0 + && ! reload_secondary_p[i])) + continue; + + mode = reload_inmode[i]; + if (GET_MODE_SIZE (reload_outmode[i]) > GET_MODE_SIZE (mode)) + mode = reload_outmode[i]; + size = CLASS_MAX_NREGS (class, mode); + + /* Decide which time-of-use to count this reload for. */ + switch (reload_when_needed[i]) + { + case RELOAD_OTHER: + this_needs = &insn_needs.other; + break; + case RELOAD_FOR_INPUT: + this_needs = &insn_needs.input; + break; + case RELOAD_FOR_OUTPUT: + this_needs = &insn_needs.output; + break; + case RELOAD_FOR_INSN: + this_needs = &insn_needs.insn; + break; + case RELOAD_FOR_OTHER_ADDRESS: + this_needs = &insn_needs.other_addr; + break; + case RELOAD_FOR_INPUT_ADDRESS: + this_needs = &insn_needs.in_addr[reload_opnum[i]]; + break; + case RELOAD_FOR_INPADDR_ADDRESS: + this_needs = &insn_needs.in_addr_addr[reload_opnum[i]]; + break; + case RELOAD_FOR_OUTPUT_ADDRESS: + this_needs = &insn_needs.out_addr[reload_opnum[i]]; + break; + case RELOAD_FOR_OUTADDR_ADDRESS: + this_needs = &insn_needs.out_addr_addr[reload_opnum[i]]; + break; + case RELOAD_FOR_OPERAND_ADDRESS: + this_needs = &insn_needs.op_addr; + break; + case RELOAD_FOR_OPADDR_ADDR: + this_needs = &insn_needs.op_addr_reload; + break; + default: + abort(); + } + + if (size > 1) + { + enum machine_mode other_mode, allocate_mode; + + /* Count number of groups needed separately from + number of individual regs needed. */ + this_needs->groups[(int) class]++; + p = reg_class_superclasses[(int) class]; + while (*p != LIM_REG_CLASSES) + this_needs->groups[(int) *p++]++; + + /* Record size and mode of a group of this class. */ + /* If more than one size group is needed, + make all groups the largest needed size. */ + if (chain->group_size[(int) class] < size) + { + other_mode = chain->group_mode[(int) class]; + allocate_mode = mode; + + chain->group_size[(int) class] = size; + chain->group_mode[(int) class] = mode; + } + else + { + other_mode = mode; + allocate_mode = chain->group_mode[(int) class]; + } + + /* Crash if two dissimilar machine modes both need + groups of consecutive regs of the same class. */ + + if (other_mode != VOIDmode && other_mode != allocate_mode + && ! modes_equiv_for_class_p (allocate_mode, + other_mode, class)) + fatal_insn ("Two dissimilar machine modes both need groups of consecutive regs of the same class", + chain->insn); + } + else if (size == 1) + { + this_needs->regs[(unsigned char)reload_nongroup[i]][(int) class] += 1; + p = reg_class_superclasses[(int) class]; + while (*p != LIM_REG_CLASSES) + this_needs->regs[(unsigned char)reload_nongroup[i]][(int) *p++] += 1; + } + else + abort (); + } + + /* All reloads have been counted for this insn; + now merge the various times of use. + This sets insn_needs, etc., to the maximum total number + of registers needed at any point in this insn. */ + + for (i = 0; i < N_REG_CLASSES; i++) + { + int j, in_max, out_max; + + /* Compute normal and nongroup needs. */ + for (j = 0; j <= 1; j++) + { + int k; + for (in_max = 0, out_max = 0, k = 0; k < reload_n_operands; k++) + { + in_max = MAX (in_max, + (insn_needs.in_addr[k].regs[j][i] + + insn_needs.in_addr_addr[k].regs[j][i])); + out_max = MAX (out_max, insn_needs.out_addr[k].regs[j][i]); + out_max = MAX (out_max, + insn_needs.out_addr_addr[k].regs[j][i]); + } + + /* RELOAD_FOR_INSN reloads conflict with inputs, outputs, + and operand addresses but not things used to reload + them. Similarly, RELOAD_FOR_OPERAND_ADDRESS reloads + don't conflict with things needed to reload inputs or + outputs. */ + + in_max = MAX (MAX (insn_needs.op_addr.regs[j][i], + insn_needs.op_addr_reload.regs[j][i]), + in_max); + + out_max = MAX (out_max, insn_needs.insn.regs[j][i]); + + insn_needs.input.regs[j][i] + = MAX (insn_needs.input.regs[j][i] + + insn_needs.op_addr.regs[j][i] + + insn_needs.insn.regs[j][i], + in_max + insn_needs.input.regs[j][i]); + + insn_needs.output.regs[j][i] += out_max; + insn_needs.other.regs[j][i] + += MAX (MAX (insn_needs.input.regs[j][i], + insn_needs.output.regs[j][i]), + insn_needs.other_addr.regs[j][i]); + + } + + /* Now compute group needs. */ + for (in_max = 0, out_max = 0, j = 0; j < reload_n_operands; j++) + { + in_max = MAX (in_max, insn_needs.in_addr[j].groups[i]); + in_max = MAX (in_max, insn_needs.in_addr_addr[j].groups[i]); + out_max = MAX (out_max, insn_needs.out_addr[j].groups[i]); + out_max = MAX (out_max, insn_needs.out_addr_addr[j].groups[i]); + } + + in_max = MAX (MAX (insn_needs.op_addr.groups[i], + insn_needs.op_addr_reload.groups[i]), + in_max); + out_max = MAX (out_max, insn_needs.insn.groups[i]); + + insn_needs.input.groups[i] + = MAX (insn_needs.input.groups[i] + + insn_needs.op_addr.groups[i] + + insn_needs.insn.groups[i], + in_max + insn_needs.input.groups[i]); + + insn_needs.output.groups[i] += out_max; + insn_needs.other.groups[i] + += MAX (MAX (insn_needs.input.groups[i], + insn_needs.output.groups[i]), + insn_needs.other_addr.groups[i]); + } + + /* Record the needs for later. */ + chain->need = insn_needs.other; +} + +/* Find a group of exactly 2 registers. + + First try to fill out the group by spilling a single register which + would allow completion of the group. + + Then try to create a new group from a pair of registers, neither of + which are explicitly used. + + Then try to create a group from any pair of registers. */ + +static void +find_tworeg_group (chain, class, dumpfile) + struct insn_chain *chain; + int class; + FILE *dumpfile; +{ + int i; + /* First, look for a register that will complete a group. */ + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + { + int j, other; + + j = potential_reload_regs[i]; + if (j >= 0 && ! TEST_HARD_REG_BIT (bad_spill_regs, j) + && ((j > 0 && (other = j - 1, spill_reg_order[other] >= 0) + && TEST_HARD_REG_BIT (reg_class_contents[class], j) + && TEST_HARD_REG_BIT (reg_class_contents[class], other) + && HARD_REGNO_MODE_OK (other, chain->group_mode[class]) + && ! TEST_HARD_REG_BIT (chain->counted_for_nongroups, other) + /* We don't want one part of another group. + We could get "two groups" that overlap! */ + && ! TEST_HARD_REG_BIT (chain->counted_for_groups, other)) + || (j < FIRST_PSEUDO_REGISTER - 1 + && (other = j + 1, spill_reg_order[other] >= 0) + && TEST_HARD_REG_BIT (reg_class_contents[class], j) + && TEST_HARD_REG_BIT (reg_class_contents[class], other) + && HARD_REGNO_MODE_OK (j, chain->group_mode[class]) + && ! TEST_HARD_REG_BIT (chain->counted_for_nongroups, other) + && ! TEST_HARD_REG_BIT (chain->counted_for_groups, other)))) + { + register enum reg_class *p; + + /* We have found one that will complete a group, + so count off one group as provided. */ + chain->need.groups[class]--; + p = reg_class_superclasses[class]; + while (*p != LIM_REG_CLASSES) + { + if (chain->group_size [(int) *p] <= chain->group_size [class]) + chain->need.groups[(int) *p]--; + p++; + } + + /* Indicate both these regs are part of a group. */ + SET_HARD_REG_BIT (chain->counted_for_groups, j); + SET_HARD_REG_BIT (chain->counted_for_groups, other); + break; + } + } + /* We can't complete a group, so start one. */ + if (i == FIRST_PSEUDO_REGISTER) + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + { + int j, k; + j = potential_reload_regs[i]; + /* Verify that J+1 is a potential reload reg. */ + for (k = 0; k < FIRST_PSEUDO_REGISTER; k++) + if (potential_reload_regs[k] == j + 1) + break; + if (j >= 0 && j + 1 < FIRST_PSEUDO_REGISTER + && k < FIRST_PSEUDO_REGISTER + && spill_reg_order[j] < 0 && spill_reg_order[j + 1] < 0 + && TEST_HARD_REG_BIT (reg_class_contents[class], j) + && TEST_HARD_REG_BIT (reg_class_contents[class], j + 1) + && HARD_REGNO_MODE_OK (j, chain->group_mode[class]) + && ! TEST_HARD_REG_BIT (chain->counted_for_nongroups, j + 1) + && ! TEST_HARD_REG_BIT (bad_spill_regs, j + 1)) + break; + } + + /* I should be the index in potential_reload_regs + of the new reload reg we have found. */ + + new_spill_reg (chain, i, class, 0, dumpfile); +} + +/* Find a group of more than 2 registers. + Look for a sufficient sequence of unspilled registers, and spill them all + at once. */ + +static void +find_group (chain, class, dumpfile) + struct insn_chain *chain; + int class; + FILE *dumpfile; +{ + int i; + + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + { + int j = potential_reload_regs[i]; + + if (j >= 0 + && j + chain->group_size[class] <= FIRST_PSEUDO_REGISTER + && HARD_REGNO_MODE_OK (j, chain->group_mode[class])) + { + int k; + /* Check each reg in the sequence. */ + for (k = 0; k < chain->group_size[class]; k++) + if (! (spill_reg_order[j + k] < 0 + && ! TEST_HARD_REG_BIT (bad_spill_regs, j + k) + && TEST_HARD_REG_BIT (reg_class_contents[class], j + k))) + break; + /* We got a full sequence, so spill them all. */ + if (k == chain->group_size[class]) + { + register enum reg_class *p; + for (k = 0; k < chain->group_size[class]; k++) + { + int idx; + SET_HARD_REG_BIT (chain->counted_for_groups, j + k); + for (idx = 0; idx < FIRST_PSEUDO_REGISTER; idx++) + if (potential_reload_regs[idx] == j + k) + break; + new_spill_reg (chain, idx, class, 0, dumpfile); + } + + /* We have found one that will complete a group, + so count off one group as provided. */ + chain->need.groups[class]--; + p = reg_class_superclasses[class]; + while (*p != LIM_REG_CLASSES) + { + if (chain->group_size [(int) *p] + <= chain->group_size [class]) + chain->need.groups[(int) *p]--; + p++; + } + return; + } + } + } + /* There are no groups left. */ + spill_failure (chain->insn); + failure = 1; +} + +/* If pseudo REG conflicts with one of our reload registers, mark it as + spilled. */ +static void +maybe_mark_pseudo_spilled (reg) + int reg; +{ + int i; + int r = reg_renumber[reg]; + int nregs; + + if (r < 0) + abort (); + nregs = HARD_REGNO_NREGS (r, PSEUDO_REGNO_MODE (reg)); + for (i = 0; i < n_spills; i++) + if (r <= spill_regs[i] && r + nregs > spill_regs[i]) + { + SET_REGNO_REG_SET (spilled_pseudos, reg); + return; + } +} + +/* Find more reload regs to satisfy the remaining need of an insn, which + is given by CHAIN. + Do it by ascending class number, since otherwise a reg + might be spilled for a big class and might fail to count + for a smaller class even though it belongs to that class. + + Count spilled regs in `spills', and add entries to + `spill_regs' and `spill_reg_order'. + + ??? Note there is a problem here. + When there is a need for a group in a high-numbered class, + and also need for non-group regs that come from a lower class, + the non-group regs are chosen first. If there aren't many regs, + they might leave no room for a group. + + This was happening on the 386. To fix it, we added the code + that calls possible_group_p, so that the lower class won't + break up the last possible group. + + Really fixing the problem would require changes above + in counting the regs already spilled, and in choose_reload_regs. + It might be hard to avoid introducing bugs there. */ + +static void +find_reload_regs (chain, dumpfile) + struct insn_chain *chain; + FILE *dumpfile; +{ + int i, class; + short *group_needs = chain->need.groups; + short *simple_needs = chain->need.regs[0]; + short *nongroup_needs = chain->need.regs[1]; + + if (dumpfile) + fprintf (dumpfile, "Spilling for insn %d.\n", INSN_UID (chain->insn)); + + /* Compute the order of preference for hard registers to spill. + Store them by decreasing preference in potential_reload_regs. */ + + order_regs_for_reload (chain); + + /* So far, no hard regs have been spilled. */ + n_spills = 0; + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + spill_reg_order[i] = -1; + + CLEAR_HARD_REG_SET (chain->used_spill_regs); + CLEAR_HARD_REG_SET (chain->counted_for_groups); + CLEAR_HARD_REG_SET (chain->counted_for_nongroups); + + for (class = 0; class < N_REG_CLASSES; class++) + { + /* First get the groups of registers. + If we got single registers first, we might fragment + possible groups. */ + while (group_needs[class] > 0) + { + /* If any single spilled regs happen to form groups, + count them now. Maybe we don't really need + to spill another group. */ + count_possible_groups (chain, class); + + if (group_needs[class] <= 0) + break; + + /* Groups of size 2, the only groups used on most machines, + are treated specially. */ + if (chain->group_size[class] == 2) + find_tworeg_group (chain, class, dumpfile); + else + find_group (chain, class, dumpfile); + if (failure) + return; + } + + /* Now similarly satisfy all need for single registers. */ + + while (simple_needs[class] > 0 || nongroup_needs[class] > 0) + { + /* If we spilled enough regs, but they weren't counted + against the non-group need, see if we can count them now. + If so, we can avoid some actual spilling. */ + if (simple_needs[class] <= 0 && nongroup_needs[class] > 0) + for (i = 0; i < n_spills; i++) + { + int regno = spill_regs[i]; + if (TEST_HARD_REG_BIT (reg_class_contents[class], regno) + && !TEST_HARD_REG_BIT (chain->counted_for_groups, regno) + && !TEST_HARD_REG_BIT (chain->counted_for_nongroups, regno) + && nongroup_needs[class] > 0) + { + register enum reg_class *p; + + SET_HARD_REG_BIT (chain->counted_for_nongroups, regno); + nongroup_needs[class]--; + p = reg_class_superclasses[class]; + while (*p != LIM_REG_CLASSES) + nongroup_needs[(int) *p++]--; + } + } + + if (simple_needs[class] <= 0 && nongroup_needs[class] <= 0) + break; + + /* Consider the potential reload regs that aren't + yet in use as reload regs, in order of preference. + Find the most preferred one that's in this class. */ + + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + { + int regno = potential_reload_regs[i]; + if (regno >= 0 + && TEST_HARD_REG_BIT (reg_class_contents[class], regno) + /* If this reg will not be available for groups, + pick one that does not foreclose possible groups. + This is a kludge, and not very general, + but it should be sufficient to make the 386 work, + and the problem should not occur on machines with + more registers. */ + && (nongroup_needs[class] == 0 + || possible_group_p (chain, regno))) + break; + } + + /* If we couldn't get a register, try to get one even if we + might foreclose possible groups. This may cause problems + later, but that's better than aborting now, since it is + possible that we will, in fact, be able to form the needed + group even with this allocation. */ + + if (i >= FIRST_PSEUDO_REGISTER + && asm_noperands (chain->insn) < 0) + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + if (potential_reload_regs[i] >= 0 + && TEST_HARD_REG_BIT (reg_class_contents[class], + potential_reload_regs[i])) + break; + + /* I should be the index in potential_reload_regs + of the new reload reg we have found. */ + + new_spill_reg (chain, i, class, 1, dumpfile); + if (failure) + return; + } + } + + /* We know which hard regs to use, now mark the pseudos that live in them + as needing to be kicked out. */ + EXECUTE_IF_SET_IN_REG_SET + (chain->live_before, FIRST_PSEUDO_REGISTER, i, + { + maybe_mark_pseudo_spilled (i); + }); + EXECUTE_IF_SET_IN_REG_SET + (chain->live_after, FIRST_PSEUDO_REGISTER, i, + { + maybe_mark_pseudo_spilled (i); + }); + + IOR_HARD_REG_SET (used_spill_regs, chain->used_spill_regs); +} + +void +dump_needs (chain, dumpfile) + struct insn_chain *chain; + FILE *dumpfile; +{ + static char *reg_class_names[] = REG_CLASS_NAMES; + int i; + struct needs *n = &chain->need; + + for (i = 0; i < N_REG_CLASSES; i++) + { + if (n->regs[i][0] > 0) + fprintf (dumpfile, + ";; Need %d reg%s of class %s.\n", + n->regs[i][0], n->regs[i][0] == 1 ? "" : "s", + reg_class_names[i]); + if (n->regs[i][1] > 0) + fprintf (dumpfile, + ";; Need %d nongroup reg%s of class %s.\n", + n->regs[i][1], n->regs[i][1] == 1 ? "" : "s", + reg_class_names[i]); + if (n->groups[i] > 0) + fprintf (dumpfile, + ";; Need %d group%s (%smode) of class %s.\n", + n->groups[i], n->groups[i] == 1 ? "" : "s", + mode_name[(int) chain->group_mode[i]], + reg_class_names[i]); + } +} + +/* Delete all insns that were inserted by emit_caller_save_insns during + this iteration. */ +static void +delete_caller_save_insns () +{ + struct insn_chain *c = reload_insn_chain; + + while (c != 0) + { + while (c != 0 && c->is_caller_save_insn) + { + struct insn_chain *next = c->next; + rtx insn = c->insn; + + if (insn == BLOCK_HEAD (c->block)) + BLOCK_HEAD (c->block) = NEXT_INSN (insn); + if (insn == BLOCK_END (c->block)) + BLOCK_END (c->block) = PREV_INSN (insn); + if (c == reload_insn_chain) + reload_insn_chain = next; + + if (NEXT_INSN (insn) != 0) + PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); + if (PREV_INSN (insn) != 0) + NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); + + if (next) + next->prev = c->prev; + if (c->prev) + c->prev->next = next; + c->next = unused_insn_chains; + unused_insn_chains = c; + c = next; + } + if (c != 0) + c = c->next; + } +} + +/* Nonzero if, after spilling reg REGNO for non-groups, + it will still be possible to find a group if we still need one. */ + +static int +possible_group_p (chain, regno) + struct insn_chain *chain; + int regno; +{ + int i; + int class = (int) NO_REGS; + + for (i = 0; i < (int) N_REG_CLASSES; i++) + if (chain->need.groups[i] > 0) + { + class = i; + break; + } + + if (class == (int) NO_REGS) + return 1; + + /* Consider each pair of consecutive registers. */ + for (i = 0; i < FIRST_PSEUDO_REGISTER - 1; i++) + { + /* Ignore pairs that include reg REGNO. */ + if (i == regno || i + 1 == regno) + continue; + + /* Ignore pairs that are outside the class that needs the group. + ??? Here we fail to handle the case where two different classes + independently need groups. But this never happens with our + current machine descriptions. */ + if (! (TEST_HARD_REG_BIT (reg_class_contents[class], i) + && TEST_HARD_REG_BIT (reg_class_contents[class], i + 1))) + continue; + + /* A pair of consecutive regs we can still spill does the trick. */ + if (spill_reg_order[i] < 0 && spill_reg_order[i + 1] < 0 + && ! TEST_HARD_REG_BIT (bad_spill_regs, i) + && ! TEST_HARD_REG_BIT (bad_spill_regs, i + 1)) + return 1; + + /* A pair of one already spilled and one we can spill does it + provided the one already spilled is not otherwise reserved. */ + if (spill_reg_order[i] < 0 + && ! TEST_HARD_REG_BIT (bad_spill_regs, i) + && spill_reg_order[i + 1] >= 0 + && ! TEST_HARD_REG_BIT (chain->counted_for_groups, i + 1) + && ! TEST_HARD_REG_BIT (chain->counted_for_nongroups, i + 1)) + return 1; + if (spill_reg_order[i + 1] < 0 + && ! TEST_HARD_REG_BIT (bad_spill_regs, i + 1) + && spill_reg_order[i] >= 0 + && ! TEST_HARD_REG_BIT (chain->counted_for_groups, i) + && ! TEST_HARD_REG_BIT (chain->counted_for_nongroups, i)) + return 1; + } + + return 0; +} + +/* Count any groups of CLASS that can be formed from the registers recently + spilled. */ + +static void +count_possible_groups (chain, class) + struct insn_chain *chain; + int class; +{ + HARD_REG_SET new; + int i, j; + + /* Now find all consecutive groups of spilled registers + and mark each group off against the need for such groups. + But don't count them against ordinary need, yet. */ + + if (chain->group_size[class] == 0) + return; + + CLEAR_HARD_REG_SET (new); + + /* Make a mask of all the regs that are spill regs in class I. */ + for (i = 0; i < n_spills; i++) + { + int regno = spill_regs[i]; + + if (TEST_HARD_REG_BIT (reg_class_contents[class], regno) + && ! TEST_HARD_REG_BIT (chain->counted_for_groups, regno) + && ! TEST_HARD_REG_BIT (chain->counted_for_nongroups, regno)) + SET_HARD_REG_BIT (new, regno); + } + + /* Find each consecutive group of them. */ + for (i = 0; i < FIRST_PSEUDO_REGISTER && chain->need.groups[class] > 0; i++) + if (TEST_HARD_REG_BIT (new, i) + && i + chain->group_size[class] <= FIRST_PSEUDO_REGISTER + && HARD_REGNO_MODE_OK (i, chain->group_mode[class])) + { + for (j = 1; j < chain->group_size[class]; j++) + if (! TEST_HARD_REG_BIT (new, i + j)) + break; + + if (j == chain->group_size[class]) + { + /* We found a group. Mark it off against this class's need for + groups, and against each superclass too. */ + register enum reg_class *p; + + chain->need.groups[class]--; + p = reg_class_superclasses[class]; + while (*p != LIM_REG_CLASSES) + { + if (chain->group_size [(int) *p] <= chain->group_size [class]) + chain->need.groups[(int) *p]--; + p++; + } + + /* Don't count these registers again. */ + for (j = 0; j < chain->group_size[class]; j++) + SET_HARD_REG_BIT (chain->counted_for_groups, i + j); + } + + /* Skip to the last reg in this group. When i is incremented above, + it will then point to the first reg of the next possible group. */ + i += j - 1; + } +} + +/* ALLOCATE_MODE is a register mode that needs to be reloaded. OTHER_MODE is + another mode that needs to be reloaded for the same register class CLASS. + If any reg in CLASS allows ALLOCATE_MODE but not OTHER_MODE, fail. + ALLOCATE_MODE will never be smaller than OTHER_MODE. + + This code used to also fail if any reg in CLASS allows OTHER_MODE but not + ALLOCATE_MODE. This test is unnecessary, because we will never try to put + something of mode ALLOCATE_MODE into an OTHER_MODE register. Testing this + causes unnecessary failures on machines requiring alignment of register + groups when the two modes are different sizes, because the larger mode has + more strict alignment rules than the smaller mode. */ + +static int +modes_equiv_for_class_p (allocate_mode, other_mode, class) + enum machine_mode allocate_mode, other_mode; + enum reg_class class; +{ + register int regno; + for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) + { + if (TEST_HARD_REG_BIT (reg_class_contents[(int) class], regno) + && HARD_REGNO_MODE_OK (regno, allocate_mode) + && ! HARD_REGNO_MODE_OK (regno, other_mode)) + return 0; + } + return 1; +} + +/* Handle the failure to find a register to spill. + INSN should be one of the insns which needed this particular spill reg. */ + +static void +spill_failure (insn) + rtx insn; +{ + if (asm_noperands (PATTERN (insn)) >= 0) + error_for_asm (insn, "`asm' needs too many reloads"); + else + fatal_insn ("Unable to find a register to spill.", insn); +} + +/* Add a new register to the tables of available spill-registers. + CHAIN is the insn for which the register will be used; we decrease the + needs of that insn. + I is the index of this register in potential_reload_regs. + CLASS is the regclass whose need is being satisfied. + NONGROUP is 0 if this register is part of a group. + DUMPFILE is the same as the one that `reload' got. */ + +static void +new_spill_reg (chain, i, class, nongroup, dumpfile) + struct insn_chain *chain; + int i; + int class; + int nongroup; + FILE *dumpfile; +{ + register enum reg_class *p; + int regno = potential_reload_regs[i]; + + if (i >= FIRST_PSEUDO_REGISTER) + { + spill_failure (chain->insn); + failure = 1; + return; + } + + if (TEST_HARD_REG_BIT (bad_spill_regs, regno)) + { + static char *reg_class_names[] = REG_CLASS_NAMES; + + if (asm_noperands (PATTERN (chain->insn)) < 0) + { + /* The error message is still correct - we know only that it wasn't + an asm statement that caused the problem, but one of the global + registers declared by the users might have screwed us. */ + error ("fixed or forbidden register %d (%s) was spilled for class %s.", + regno, reg_names[regno], reg_class_names[class]); + error ("This may be due to a compiler bug or to impossible asm"); + error ("statements or clauses."); + fatal_insn ("This is the instruction:", chain->insn); + } + error_for_asm (chain->insn, "Invalid `asm' statement:"); + error_for_asm (chain->insn, + "fixed or forbidden register %d (%s) was spilled for class %s.", + regno, reg_names[regno], reg_class_names[class]); + failure = 1; + return; + } + + /* Make reg REGNO an additional reload reg. */ + + potential_reload_regs[i] = -1; + spill_regs[n_spills] = regno; + spill_reg_order[regno] = n_spills; + if (dumpfile) + fprintf (dumpfile, "Spilling reg %d.\n", regno); + SET_HARD_REG_BIT (chain->used_spill_regs, regno); + + /* Clear off the needs we just satisfied. */ + + chain->need.regs[0][class]--; + p = reg_class_superclasses[class]; + while (*p != LIM_REG_CLASSES) + chain->need.regs[0][(int) *p++]--; + + if (nongroup && chain->need.regs[1][class] > 0) + { + SET_HARD_REG_BIT (chain->counted_for_nongroups, regno); + chain->need.regs[1][class]--; + p = reg_class_superclasses[class]; + while (*p != LIM_REG_CLASSES) + chain->need.regs[1][(int) *p++]--; + } + + n_spills++; +} + +/* Delete an unneeded INSN and any previous insns who sole purpose is loading + data that is dead in INSN. */ + +static void +delete_dead_insn (insn) + rtx insn; +{ + rtx prev = prev_real_insn (insn); + rtx prev_dest; + + /* If the previous insn sets a register that dies in our insn, delete it + too. */ + if (prev && GET_CODE (PATTERN (prev)) == SET + && (prev_dest = SET_DEST (PATTERN (prev)), GET_CODE (prev_dest) == REG) + && reg_mentioned_p (prev_dest, PATTERN (insn)) + && find_regno_note (insn, REG_DEAD, REGNO (prev_dest)) + && ! side_effects_p (SET_SRC (PATTERN (prev)))) + delete_dead_insn (prev); + + PUT_CODE (insn, NOTE); + NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; + NOTE_SOURCE_FILE (insn) = 0; +} + +/* Modify the home of pseudo-reg I. + The new home is present in reg_renumber[I]. + + FROM_REG may be the hard reg that the pseudo-reg is being spilled from; + or it may be -1, meaning there is none or it is not relevant. + This is used so that all pseudos spilled from a given hard reg + can share one stack slot. */ + +static void +alter_reg (i, from_reg) + register int i; + int from_reg; +{ + /* When outputting an inline function, this can happen + for a reg that isn't actually used. */ + if (regno_reg_rtx[i] == 0) + return; + + /* If the reg got changed to a MEM at rtl-generation time, + ignore it. */ + if (GET_CODE (regno_reg_rtx[i]) != REG) + return; + + /* Modify the reg-rtx to contain the new hard reg + number or else to contain its pseudo reg number. */ + REGNO (regno_reg_rtx[i]) + = reg_renumber[i] >= 0 ? reg_renumber[i] : i; + + /* If we have a pseudo that is needed but has no hard reg or equivalent, + allocate a stack slot for it. */ + + if (reg_renumber[i] < 0 + && REG_N_REFS (i) > 0 + && reg_equiv_constant[i] == 0 + && reg_equiv_memory_loc[i] == 0) + { + register rtx x; + int inherent_size = PSEUDO_REGNO_BYTES (i); + int total_size = MAX (inherent_size, reg_max_ref_width[i]); + int adjust = 0; + + /* Each pseudo reg has an inherent size which comes from its own mode, + and a total size which provides room for paradoxical subregs + which refer to the pseudo reg in wider modes. + + We can use a slot already allocated if it provides both + enough inherent space and enough total space. + Otherwise, we allocate a new slot, making sure that it has no less + inherent space, and no less total space, then the previous slot. */ + if (from_reg == -1) + { + /* No known place to spill from => no slot to reuse. */ + x = assign_stack_local (GET_MODE (regno_reg_rtx[i]), total_size, + inherent_size == total_size ? 0 : -1); + if (BYTES_BIG_ENDIAN) + /* Cancel the big-endian correction done in assign_stack_local. + Get the address of the beginning of the slot. + This is so we can do a big-endian correction unconditionally + below. */ + adjust = inherent_size - total_size; + + RTX_UNCHANGING_P (x) = RTX_UNCHANGING_P (regno_reg_rtx[i]); + } + /* Reuse a stack slot if possible. */ + else if (spill_stack_slot[from_reg] != 0 + && spill_stack_slot_width[from_reg] >= total_size + && (GET_MODE_SIZE (GET_MODE (spill_stack_slot[from_reg])) + >= inherent_size)) + x = spill_stack_slot[from_reg]; + /* Allocate a bigger slot. */ + else + { + /* Compute maximum size needed, both for inherent size + and for total size. */ + enum machine_mode mode = GET_MODE (regno_reg_rtx[i]); + rtx stack_slot; + if (spill_stack_slot[from_reg]) + { + if (GET_MODE_SIZE (GET_MODE (spill_stack_slot[from_reg])) + > inherent_size) + mode = GET_MODE (spill_stack_slot[from_reg]); + if (spill_stack_slot_width[from_reg] > total_size) + total_size = spill_stack_slot_width[from_reg]; + } + /* Make a slot with that size. */ + x = assign_stack_local (mode, total_size, + inherent_size == total_size ? 0 : -1); + stack_slot = x; + if (BYTES_BIG_ENDIAN) + { + /* Cancel the big-endian correction done in assign_stack_local. + Get the address of the beginning of the slot. + This is so we can do a big-endian correction unconditionally + below. */ + adjust = GET_MODE_SIZE (mode) - total_size; + if (adjust) + stack_slot = gen_rtx_MEM (mode_for_size (total_size + * BITS_PER_UNIT, + MODE_INT, 1), + plus_constant (XEXP (x, 0), adjust)); + } + spill_stack_slot[from_reg] = stack_slot; + spill_stack_slot_width[from_reg] = total_size; + } + + /* On a big endian machine, the "address" of the slot + is the address of the low part that fits its inherent mode. */ + if (BYTES_BIG_ENDIAN && inherent_size < total_size) + adjust += (total_size - inherent_size); + + /* If we have any adjustment to make, or if the stack slot is the + wrong mode, make a new stack slot. */ + if (adjust != 0 || GET_MODE (x) != GET_MODE (regno_reg_rtx[i])) + { + x = gen_rtx_MEM (GET_MODE (regno_reg_rtx[i]), + plus_constant (XEXP (x, 0), adjust)); + + /* If this was shared among registers, must ensure we never + set it readonly since that can cause scheduling + problems. Note we would only have in this adjustment + case in any event, since the code above doesn't set it. */ + + if (from_reg == -1) + RTX_UNCHANGING_P (x) = RTX_UNCHANGING_P (regno_reg_rtx[i]); + } + + /* Save the stack slot for later. */ + reg_equiv_memory_loc[i] = x; + } +} + +/* Mark the slots in regs_ever_live for the hard regs + used by pseudo-reg number REGNO. */ + +void +mark_home_live (regno) + int regno; +{ + register int i, lim; + i = reg_renumber[regno]; + if (i < 0) + return; + lim = i + HARD_REGNO_NREGS (i, PSEUDO_REGNO_MODE (regno)); + while (i < lim) + regs_ever_live[i++] = 1; +} + +/* This function handles the tracking of elimination offsets around branches. + + X is a piece of RTL being scanned. + + INSN is the insn that it came from, if any. + + INITIAL_P is non-zero if we are to set the offset to be the initial + offset and zero if we are setting the offset of the label to be the + current offset. */ + +static void +set_label_offsets (x, insn, initial_p) + rtx x; + rtx insn; + int initial_p; +{ + enum rtx_code code = GET_CODE (x); + rtx tem; + unsigned int i; + struct elim_table *p; + + switch (code) + { + case LABEL_REF: + if (LABEL_REF_NONLOCAL_P (x)) + return; + + x = XEXP (x, 0); + + /* ... fall through ... */ + + case CODE_LABEL: + /* If we know nothing about this label, set the desired offsets. Note + that this sets the offset at a label to be the offset before a label + if we don't know anything about the label. This is not correct for + the label after a BARRIER, but is the best guess we can make. If + we guessed wrong, we will suppress an elimination that might have + been possible had we been able to guess correctly. */ + + if (! offsets_known_at[CODE_LABEL_NUMBER (x)]) + { + for (i = 0; i < NUM_ELIMINABLE_REGS; i++) + offsets_at[CODE_LABEL_NUMBER (x)][i] + = (initial_p ? reg_eliminate[i].initial_offset + : reg_eliminate[i].offset); + offsets_known_at[CODE_LABEL_NUMBER (x)] = 1; + } + + /* Otherwise, if this is the definition of a label and it is + preceded by a BARRIER, set our offsets to the known offset of + that label. */ + + else if (x == insn + && (tem = prev_nonnote_insn (insn)) != 0 + && GET_CODE (tem) == BARRIER) + set_offsets_for_label (insn); + else + /* If neither of the above cases is true, compare each offset + with those previously recorded and suppress any eliminations + where the offsets disagree. */ + + for (i = 0; i < NUM_ELIMINABLE_REGS; i++) + if (offsets_at[CODE_LABEL_NUMBER (x)][i] + != (initial_p ? reg_eliminate[i].initial_offset + : reg_eliminate[i].offset)) + reg_eliminate[i].can_eliminate = 0; + + return; + + case JUMP_INSN: + set_label_offsets (PATTERN (insn), insn, initial_p); + + /* ... fall through ... */ + + case INSN: + case CALL_INSN: + /* Any labels mentioned in REG_LABEL notes can be branched to indirectly + and hence must have all eliminations at their initial offsets. */ + for (tem = REG_NOTES (x); tem; tem = XEXP (tem, 1)) + if (REG_NOTE_KIND (tem) == REG_LABEL) + set_label_offsets (XEXP (tem, 0), insn, 1); + return; + + case ADDR_VEC: + case ADDR_DIFF_VEC: + /* Each of the labels in the address vector must be at their initial + offsets. We want the first field for ADDR_VEC and the second + field for ADDR_DIFF_VEC. */ + + for (i = 0; i < (unsigned) XVECLEN (x, code == ADDR_DIFF_VEC); i++) + set_label_offsets (XVECEXP (x, code == ADDR_DIFF_VEC, i), + insn, initial_p); + return; + + case SET: + /* We only care about setting PC. If the source is not RETURN, + IF_THEN_ELSE, or a label, disable any eliminations not at + their initial offsets. Similarly if any arm of the IF_THEN_ELSE + isn't one of those possibilities. For branches to a label, + call ourselves recursively. + + Note that this can disable elimination unnecessarily when we have + a non-local goto since it will look like a non-constant jump to + someplace in the current function. This isn't a significant + problem since such jumps will normally be when all elimination + pairs are back to their initial offsets. */ + + if (SET_DEST (x) != pc_rtx) + return; + + switch (GET_CODE (SET_SRC (x))) + { + case PC: + case RETURN: + return; + + case LABEL_REF: + set_label_offsets (XEXP (SET_SRC (x), 0), insn, initial_p); + return; + + case IF_THEN_ELSE: + tem = XEXP (SET_SRC (x), 1); + if (GET_CODE (tem) == LABEL_REF) + set_label_offsets (XEXP (tem, 0), insn, initial_p); + else if (GET_CODE (tem) != PC && GET_CODE (tem) != RETURN) + break; + + tem = XEXP (SET_SRC (x), 2); + if (GET_CODE (tem) == LABEL_REF) + set_label_offsets (XEXP (tem, 0), insn, initial_p); + else if (GET_CODE (tem) != PC && GET_CODE (tem) != RETURN) + break; + return; + + default: + break; + } + + /* If we reach here, all eliminations must be at their initial + offset because we are doing a jump to a variable address. */ + for (p = reg_eliminate; p < ®_eliminate[NUM_ELIMINABLE_REGS]; p++) + if (p->offset != p->initial_offset) + p->can_eliminate = 0; + break; + + default: + break; + } +} + +/* Used for communication between the next two function to properly share + the vector for an ASM_OPERANDS. */ + +static struct rtvec_def *old_asm_operands_vec, *new_asm_operands_vec; + +/* Scan X and replace any eliminable registers (such as fp) with a + replacement (such as sp), plus an offset. + + MEM_MODE is the mode of an enclosing MEM. We need this to know how + much to adjust a register for, e.g., PRE_DEC. Also, if we are inside a + MEM, we are allowed to replace a sum of a register and the constant zero + with the register, which we cannot do outside a MEM. In addition, we need + to record the fact that a register is referenced outside a MEM. + + If INSN is an insn, it is the insn containing X. If we replace a REG + in a SET_DEST with an equivalent MEM and INSN is non-zero, write a + CLOBBER of the pseudo after INSN so find_equiv_regs will know that + the REG is being modified. + + Alternatively, INSN may be a note (an EXPR_LIST or INSN_LIST). + That's used when we eliminate in expressions stored in notes. + This means, do not set ref_outside_mem even if the reference + is outside of MEMs. + + If we see a modification to a register we know about, take the + appropriate action (see case SET, below). + + REG_EQUIV_MEM and REG_EQUIV_ADDRESS contain address that have had + replacements done assuming all offsets are at their initial values. If + they are not, or if REG_EQUIV_ADDRESS is nonzero for a pseudo we + encounter, return the actual location so that find_reloads will do + the proper thing. */ + +rtx +eliminate_regs (x, mem_mode, insn) + rtx x; + enum machine_mode mem_mode; + rtx insn; +{ + enum rtx_code code = GET_CODE (x); + struct elim_table *ep; + int regno; + rtx new; + int i, j; + char *fmt; + int copied = 0; + + if (! current_function_decl) + return x; + + switch (code) + { + case CONST_INT: + case CONST_DOUBLE: + case CONST: + case SYMBOL_REF: + case CODE_LABEL: + case PC: + case CC0: + case ASM_INPUT: + case ADDR_VEC: + case ADDR_DIFF_VEC: + case RETURN: + return x; + + case ADDRESSOF: + /* This is only for the benefit of the debugging backends, which call + eliminate_regs on DECL_RTL; any ADDRESSOFs in the actual insns are + removed after CSE. */ + new = eliminate_regs (XEXP (x, 0), 0, insn); + if (GET_CODE (new) == MEM) + return XEXP (new, 0); + return x; + + case REG: + regno = REGNO (x); + + /* First handle the case where we encounter a bare register that + is eliminable. Replace it with a PLUS. */ + if (regno < FIRST_PSEUDO_REGISTER) + { + for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; + ep++) + if (ep->from_rtx == x && ep->can_eliminate) + { + if (! mem_mode + /* Refs inside notes don't count for this purpose. */ + && ! (insn != 0 && (GET_CODE (insn) == EXPR_LIST + || GET_CODE (insn) == INSN_LIST))) + ep->ref_outside_mem = 1; + return plus_constant (ep->to_rtx, ep->previous_offset); + } + + } + else if (reg_renumber[regno] < 0 && reg_equiv_constant + && reg_equiv_constant[regno] + && ! CONSTANT_P (reg_equiv_constant[regno])) + return eliminate_regs (copy_rtx (reg_equiv_constant[regno]), + mem_mode, insn); + return x; + + case PLUS: + /* If this is the sum of an eliminable register and a constant, rework + the sum. */ + if (GET_CODE (XEXP (x, 0)) == REG + && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER + && CONSTANT_P (XEXP (x, 1))) + { + for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; + ep++) + if (ep->from_rtx == XEXP (x, 0) && ep->can_eliminate) + { + if (! mem_mode + /* Refs inside notes don't count for this purpose. */ + && ! (insn != 0 && (GET_CODE (insn) == EXPR_LIST + || GET_CODE (insn) == INSN_LIST))) + ep->ref_outside_mem = 1; + + /* The only time we want to replace a PLUS with a REG (this + occurs when the constant operand of the PLUS is the negative + of the offset) is when we are inside a MEM. We won't want + to do so at other times because that would change the + structure of the insn in a way that reload can't handle. + We special-case the commonest situation in + eliminate_regs_in_insn, so just replace a PLUS with a + PLUS here, unless inside a MEM. */ + if (mem_mode != 0 && GET_CODE (XEXP (x, 1)) == CONST_INT + && INTVAL (XEXP (x, 1)) == - ep->previous_offset) + return ep->to_rtx; + else + return gen_rtx_PLUS (Pmode, ep->to_rtx, + plus_constant (XEXP (x, 1), + ep->previous_offset)); + } + + /* If the register is not eliminable, we are done since the other + operand is a constant. */ + return x; + } + + /* If this is part of an address, we want to bring any constant to the + outermost PLUS. We will do this by doing register replacement in + our operands and seeing if a constant shows up in one of them. + + We assume here this is part of an address (or a "load address" insn) + since an eliminable register is not likely to appear in any other + context. + + If we have (plus (eliminable) (reg)), we want to produce + (plus (plus (replacement) (reg) (const))). If this was part of a + normal add insn, (plus (replacement) (reg)) will be pushed as a + reload. This is the desired action. */ + + { + rtx new0 = eliminate_regs (XEXP (x, 0), mem_mode, insn); + rtx new1 = eliminate_regs (XEXP (x, 1), mem_mode, insn); + + if (new0 != XEXP (x, 0) || new1 != XEXP (x, 1)) + { + /* If one side is a PLUS and the other side is a pseudo that + didn't get a hard register but has a reg_equiv_constant, + we must replace the constant here since it may no longer + be in the position of any operand. */ + if (GET_CODE (new0) == PLUS && GET_CODE (new1) == REG + && REGNO (new1) >= FIRST_PSEUDO_REGISTER + && reg_renumber[REGNO (new1)] < 0 + && reg_equiv_constant != 0 + && reg_equiv_constant[REGNO (new1)] != 0) + new1 = reg_equiv_constant[REGNO (new1)]; + else if (GET_CODE (new1) == PLUS && GET_CODE (new0) == REG + && REGNO (new0) >= FIRST_PSEUDO_REGISTER + && reg_renumber[REGNO (new0)] < 0 + && reg_equiv_constant[REGNO (new0)] != 0) + new0 = reg_equiv_constant[REGNO (new0)]; + + new = form_sum (new0, new1); + + /* As above, if we are not inside a MEM we do not want to + turn a PLUS into something else. We might try to do so here + for an addition of 0 if we aren't optimizing. */ + if (! mem_mode && GET_CODE (new) != PLUS) + return gen_rtx_PLUS (GET_MODE (x), new, const0_rtx); + else + return new; + } + } + return x; + + case MULT: + /* If this is the product of an eliminable register and a + constant, apply the distribute law and move the constant out + so that we have (plus (mult ..) ..). This is needed in order + to keep load-address insns valid. This case is pathological. + We ignore the possibility of overflow here. */ + if (GET_CODE (XEXP (x, 0)) == REG + && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER + && GET_CODE (XEXP (x, 1)) == CONST_INT) + for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; + ep++) + if (ep->from_rtx == XEXP (x, 0) && ep->can_eliminate) + { + if (! mem_mode + /* Refs inside notes don't count for this purpose. */ + && ! (insn != 0 && (GET_CODE (insn) == EXPR_LIST + || GET_CODE (insn) == INSN_LIST))) + ep->ref_outside_mem = 1; + + return + plus_constant (gen_rtx_MULT (Pmode, ep->to_rtx, XEXP (x, 1)), + ep->previous_offset * INTVAL (XEXP (x, 1))); + } + + /* ... fall through ... */ + + case CALL: + case COMPARE: + case MINUS: + case DIV: case UDIV: + case MOD: case UMOD: + case AND: case IOR: case XOR: + case ROTATERT: case ROTATE: + case ASHIFTRT: case LSHIFTRT: case ASHIFT: + case NE: case EQ: + case GE: case GT: case GEU: case GTU: + case LE: case LT: case LEU: case LTU: + { + rtx new0 = eliminate_regs (XEXP (x, 0), mem_mode, insn); + rtx new1 + = XEXP (x, 1) ? eliminate_regs (XEXP (x, 1), mem_mode, insn) : 0; + + if (new0 != XEXP (x, 0) || new1 != XEXP (x, 1)) + return gen_rtx_fmt_ee (code, GET_MODE (x), new0, new1); + } + return x; + + case EXPR_LIST: + /* If we have something in XEXP (x, 0), the usual case, eliminate it. */ + if (XEXP (x, 0)) + { + new = eliminate_regs (XEXP (x, 0), mem_mode, insn); + if (new != XEXP (x, 0)) + x = gen_rtx_EXPR_LIST (REG_NOTE_KIND (x), new, XEXP (x, 1)); + } + + /* ... fall through ... */ + + case INSN_LIST: + /* Now do eliminations in the rest of the chain. If this was + an EXPR_LIST, this might result in allocating more memory than is + strictly needed, but it simplifies the code. */ + if (XEXP (x, 1)) + { + new = eliminate_regs (XEXP (x, 1), mem_mode, insn); + if (new != XEXP (x, 1)) + return gen_rtx_fmt_ee (GET_CODE (x), GET_MODE (x), XEXP (x, 0), new); + } + return x; + + case PRE_INC: + case POST_INC: + case PRE_DEC: + case POST_DEC: + for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) + if (ep->to_rtx == XEXP (x, 0)) + { + int size = GET_MODE_SIZE (mem_mode); + + /* If more bytes than MEM_MODE are pushed, account for them. */ +#ifdef PUSH_ROUNDING + if (ep->to_rtx == stack_pointer_rtx) + size = PUSH_ROUNDING (size); +#endif + if (code == PRE_DEC || code == POST_DEC) + ep->offset += size; + else + ep->offset -= size; + } + + /* Fall through to generic unary operation case. */ + case STRICT_LOW_PART: + case NEG: case NOT: + case SIGN_EXTEND: case ZERO_EXTEND: + case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE: + case FLOAT: case FIX: + case UNSIGNED_FIX: case UNSIGNED_FLOAT: + case ABS: + case SQRT: + case FFS: + new = eliminate_regs (XEXP (x, 0), mem_mode, insn); + if (new != XEXP (x, 0)) + return gen_rtx_fmt_e (code, GET_MODE (x), new); + return x; + + case SUBREG: + /* Similar to above processing, but preserve SUBREG_WORD. + Convert (subreg (mem)) to (mem) if not paradoxical. + Also, if we have a non-paradoxical (subreg (pseudo)) and the + pseudo didn't get a hard reg, we must replace this with the + eliminated version of the memory location because push_reloads + may do the replacement in certain circumstances. */ + if (GET_CODE (SUBREG_REG (x)) == REG + && (GET_MODE_SIZE (GET_MODE (x)) + <= GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))) + && reg_equiv_memory_loc != 0 + && reg_equiv_memory_loc[REGNO (SUBREG_REG (x))] != 0) + { +#if 0 + new = eliminate_regs (reg_equiv_memory_loc[REGNO (SUBREG_REG (x))], + mem_mode, insn); + + /* If we didn't change anything, we must retain the pseudo. */ + if (new == reg_equiv_memory_loc[REGNO (SUBREG_REG (x))]) + new = SUBREG_REG (x); + else + { + /* In this case, we must show that the pseudo is used in this + insn so that delete_output_reload will do the right thing. */ + if (insn != 0 && GET_CODE (insn) != EXPR_LIST + && GET_CODE (insn) != INSN_LIST) + REG_NOTES (emit_insn_before (gen_rtx_USE (VOIDmode, + SUBREG_REG (x)), + insn)) + = gen_rtx_EXPR_LIST (REG_EQUAL, new, NULL_RTX); + + /* Ensure NEW isn't shared in case we have to reload it. */ + new = copy_rtx (new); + } +#else + new = SUBREG_REG (x); +#endif + } + else + new = eliminate_regs (SUBREG_REG (x), mem_mode, insn); + + if (new != XEXP (x, 0)) + { + int x_size = GET_MODE_SIZE (GET_MODE (x)); + int new_size = GET_MODE_SIZE (GET_MODE (new)); + + if (GET_CODE (new) == MEM + && ((x_size < new_size +#ifdef WORD_REGISTER_OPERATIONS + /* On these machines, combine can create rtl of the form + (set (subreg:m1 (reg:m2 R) 0) ...) + where m1 < m2, and expects something interesting to + happen to the entire word. Moreover, it will use the + (reg:m2 R) later, expecting all bits to be preserved. + So if the number of words is the same, preserve the + subreg so that push_reloads can see it. */ + && ! ((x_size-1)/UNITS_PER_WORD == (new_size-1)/UNITS_PER_WORD) +#endif + ) + || (x_size == new_size)) + ) + { + int offset = SUBREG_WORD (x) * UNITS_PER_WORD; + enum machine_mode mode = GET_MODE (x); + + if (BYTES_BIG_ENDIAN) + offset += (MIN (UNITS_PER_WORD, + GET_MODE_SIZE (GET_MODE (new))) + - MIN (UNITS_PER_WORD, GET_MODE_SIZE (mode))); + + PUT_MODE (new, mode); + XEXP (new, 0) = plus_constant (XEXP (new, 0), offset); + return new; + } + else + return gen_rtx_SUBREG (GET_MODE (x), new, SUBREG_WORD (x)); + } + + return x; + + case USE: + /* If using a register that is the source of an eliminate we still + think can be performed, note it cannot be performed since we don't + know how this register is used. */ + for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) + if (ep->from_rtx == XEXP (x, 0)) + ep->can_eliminate = 0; + + new = eliminate_regs (XEXP (x, 0), mem_mode, insn); + if (new != XEXP (x, 0)) + return gen_rtx_fmt_e (code, GET_MODE (x), new); + return x; + + case CLOBBER: + /* If clobbering a register that is the replacement register for an + elimination we still think can be performed, note that it cannot + be performed. Otherwise, we need not be concerned about it. */ + for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) + if (ep->to_rtx == XEXP (x, 0)) + ep->can_eliminate = 0; + + new = eliminate_regs (XEXP (x, 0), mem_mode, insn); + if (new != XEXP (x, 0)) + return gen_rtx_fmt_e (code, GET_MODE (x), new); + return x; + + case ASM_OPERANDS: + { + rtx *temp_vec; + /* Properly handle sharing input and constraint vectors. */ + if (ASM_OPERANDS_INPUT_VEC (x) != old_asm_operands_vec) + { + /* When we come to a new vector not seen before, + scan all its elements; keep the old vector if none + of them changes; otherwise, make a copy. */ + old_asm_operands_vec = ASM_OPERANDS_INPUT_VEC (x); + temp_vec = (rtx *) alloca (XVECLEN (x, 3) * sizeof (rtx)); + for (i = 0; i < ASM_OPERANDS_INPUT_LENGTH (x); i++) + temp_vec[i] = eliminate_regs (ASM_OPERANDS_INPUT (x, i), + mem_mode, insn); + + for (i = 0; i < ASM_OPERANDS_INPUT_LENGTH (x); i++) + if (temp_vec[i] != ASM_OPERANDS_INPUT (x, i)) + break; + + if (i == ASM_OPERANDS_INPUT_LENGTH (x)) + new_asm_operands_vec = old_asm_operands_vec; + else + new_asm_operands_vec + = gen_rtvec_v (ASM_OPERANDS_INPUT_LENGTH (x), temp_vec); + } + + /* If we had to copy the vector, copy the entire ASM_OPERANDS. */ + if (new_asm_operands_vec == old_asm_operands_vec) + return x; + + new = gen_rtx_ASM_OPERANDS (VOIDmode, ASM_OPERANDS_TEMPLATE (x), + ASM_OPERANDS_OUTPUT_CONSTRAINT (x), + ASM_OPERANDS_OUTPUT_IDX (x), + new_asm_operands_vec, + ASM_OPERANDS_INPUT_CONSTRAINT_VEC (x), + ASM_OPERANDS_SOURCE_FILE (x), + ASM_OPERANDS_SOURCE_LINE (x)); + new->volatil = x->volatil; + return new; + } + + case SET: + /* Check for setting a register that we know about. */ + if (GET_CODE (SET_DEST (x)) == REG) + { + /* See if this is setting the replacement register for an + elimination. + + If DEST is the hard frame pointer, we do nothing because we + assume that all assignments to the frame pointer are for + non-local gotos and are being done at a time when they are valid + and do not disturb anything else. Some machines want to + eliminate a fake argument pointer (or even a fake frame pointer) + with either the real frame or the stack pointer. Assignments to + the hard frame pointer must not prevent this elimination. */ + + for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; + ep++) + if (ep->to_rtx == SET_DEST (x) + && SET_DEST (x) != hard_frame_pointer_rtx) + { + /* If it is being incremented, adjust the offset. Otherwise, + this elimination can't be done. */ + rtx src = SET_SRC (x); + + if (GET_CODE (src) == PLUS + && XEXP (src, 0) == SET_DEST (x) + && GET_CODE (XEXP (src, 1)) == CONST_INT) + ep->offset -= INTVAL (XEXP (src, 1)); + else + ep->can_eliminate = 0; + } + + /* Now check to see we are assigning to a register that can be + eliminated. If so, it must be as part of a PARALLEL, since we + will not have been called if this is a single SET. So indicate + that we can no longer eliminate this reg. */ + for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; + ep++) + if (ep->from_rtx == SET_DEST (x) && ep->can_eliminate) + ep->can_eliminate = 0; + } + + /* Now avoid the loop below in this common case. */ + { + rtx new0 = eliminate_regs (SET_DEST (x), 0, insn); + rtx new1 = eliminate_regs (SET_SRC (x), 0, insn); + + /* If SET_DEST changed from a REG to a MEM and INSN is an insn, + write a CLOBBER insn. */ + if (GET_CODE (SET_DEST (x)) == REG && GET_CODE (new0) == MEM + && insn != 0 && GET_CODE (insn) != EXPR_LIST + && GET_CODE (insn) != INSN_LIST) + emit_insn_after (gen_rtx_CLOBBER (VOIDmode, SET_DEST (x)), insn); + + if (new0 != SET_DEST (x) || new1 != SET_SRC (x)) + return gen_rtx_SET (VOIDmode, new0, new1); + } + + return x; + + case MEM: + /* This is only for the benefit of the debugging backends, which call + eliminate_regs on DECL_RTL; any ADDRESSOFs in the actual insns are + removed after CSE. */ + if (GET_CODE (XEXP (x, 0)) == ADDRESSOF) + return eliminate_regs (XEXP (XEXP (x, 0), 0), 0, insn); + + /* Our only special processing is to pass the mode of the MEM to our + recursive call and copy the flags. While we are here, handle this + case more efficiently. */ + new = eliminate_regs (XEXP (x, 0), GET_MODE (x), insn); + if (new != XEXP (x, 0)) + { + new = gen_rtx_MEM (GET_MODE (x), new); + new->volatil = x->volatil; + new->unchanging = x->unchanging; + new->in_struct = x->in_struct; + return new; + } + else + return x; + + default: + break; + } + + /* Process each of our operands recursively. If any have changed, make a + copy of the rtx. */ + fmt = GET_RTX_FORMAT (code); + for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++) + { + if (*fmt == 'e') + { + new = eliminate_regs (XEXP (x, i), mem_mode, insn); + if (new != XEXP (x, i) && ! copied) + { + rtx new_x = rtx_alloc (code); + bcopy ((char *) x, (char *) new_x, + (sizeof (*new_x) - sizeof (new_x->fld) + + sizeof (new_x->fld[0]) * GET_RTX_LENGTH (code))); + x = new_x; + copied = 1; + } + XEXP (x, i) = new; + } + else if (*fmt == 'E') + { + int copied_vec = 0; + for (j = 0; j < XVECLEN (x, i); j++) + { + new = eliminate_regs (XVECEXP (x, i, j), mem_mode, insn); + if (new != XVECEXP (x, i, j) && ! copied_vec) + { + rtvec new_v = gen_rtvec_vv (XVECLEN (x, i), + XVEC (x, i)->elem); + if (! copied) + { + rtx new_x = rtx_alloc (code); + bcopy ((char *) x, (char *) new_x, + (sizeof (*new_x) - sizeof (new_x->fld) + + (sizeof (new_x->fld[0]) + * GET_RTX_LENGTH (code)))); + x = new_x; + copied = 1; + } + XVEC (x, i) = new_v; + copied_vec = 1; + } + XVECEXP (x, i, j) = new; + } + } + } + + return x; +} + +/* Scan INSN and eliminate all eliminable registers in it. + + If REPLACE is nonzero, do the replacement destructively. Also + delete the insn as dead it if it is setting an eliminable register. + + If REPLACE is zero, do all our allocations in reload_obstack. + + If no eliminations were done and this insn doesn't require any elimination + processing (these are not identical conditions: it might be updating sp, + but not referencing fp; this needs to be seen during reload_as_needed so + that the offset between fp and sp can be taken into consideration), zero + is returned. Otherwise, 1 is returned. */ + +static int +eliminate_regs_in_insn (insn, replace) + rtx insn; + int replace; +{ + rtx old_body = PATTERN (insn); + rtx old_set = single_set (insn); + rtx new_body; + int val = 0; + struct elim_table *ep; + + if (! replace) + push_obstacks (&reload_obstack, &reload_obstack); + + if (old_set != 0 && GET_CODE (SET_DEST (old_set)) == REG + && REGNO (SET_DEST (old_set)) < FIRST_PSEUDO_REGISTER) + { + /* Check for setting an eliminable register. */ + for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) + if (ep->from_rtx == SET_DEST (old_set) && ep->can_eliminate) + { +#if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM + /* If this is setting the frame pointer register to the + hardware frame pointer register and this is an elimination + that will be done (tested above), this insn is really + adjusting the frame pointer downward to compensate for + the adjustment done before a nonlocal goto. */ + if (ep->from == FRAME_POINTER_REGNUM + && ep->to == HARD_FRAME_POINTER_REGNUM) + { + rtx src = SET_SRC (old_set); + int offset = 0, ok = 0; + rtx prev_insn, prev_set; + + if (src == ep->to_rtx) + offset = 0, ok = 1; + else if (GET_CODE (src) == PLUS + && GET_CODE (XEXP (src, 0)) == CONST_INT + && XEXP (src, 1) == ep->to_rtx) + offset = INTVAL (XEXP (src, 0)), ok = 1; + else if (GET_CODE (src) == PLUS + && GET_CODE (XEXP (src, 1)) == CONST_INT + && XEXP (src, 0) == ep->to_rtx) + offset = INTVAL (XEXP (src, 1)), ok = 1; + else if ((prev_insn = prev_nonnote_insn (insn)) != 0 + && (prev_set = single_set (prev_insn)) != 0 + && rtx_equal_p (SET_DEST (prev_set), src)) + { + src = SET_SRC (prev_set); + if (src == ep->to_rtx) + offset = 0, ok = 1; + else if (GET_CODE (src) == PLUS + && GET_CODE (XEXP (src, 0)) == CONST_INT + && XEXP (src, 1) == ep->to_rtx) + offset = INTVAL (XEXP (src, 0)), ok = 1; + else if (GET_CODE (src) == PLUS + && GET_CODE (XEXP (src, 1)) == CONST_INT + && XEXP (src, 0) == ep->to_rtx) + offset = INTVAL (XEXP (src, 1)), ok = 1; + } + + if (ok) + { + if (replace) + { + rtx src + = plus_constant (ep->to_rtx, offset - ep->offset); + + /* First see if this insn remains valid when we + make the change. If not, keep the INSN_CODE + the same and let reload fit it up. */ + validate_change (insn, &SET_SRC (old_set), src, 1); + validate_change (insn, &SET_DEST (old_set), + ep->to_rtx, 1); + if (! apply_change_group ()) + { + SET_SRC (old_set) = src; + SET_DEST (old_set) = ep->to_rtx; + } + } + + val = 1; + goto done; + } + } +#endif + + /* In this case this insn isn't serving a useful purpose. We + will delete it in reload_as_needed once we know that this + elimination is, in fact, being done. + + If REPLACE isn't set, we can't delete this insn, but needn't + process it since it won't be used unless something changes. */ + if (replace) + delete_dead_insn (insn); + val = 1; + goto done; + } + + /* Check for (set (reg) (plus (reg from) (offset))) where the offset + in the insn is the negative of the offset in FROM. Substitute + (set (reg) (reg to)) for the insn and change its code. + + We have to do this here, rather than in eliminate_regs, so that we can + change the insn code. */ + + if (GET_CODE (SET_SRC (old_set)) == PLUS + && GET_CODE (XEXP (SET_SRC (old_set), 0)) == REG + && GET_CODE (XEXP (SET_SRC (old_set), 1)) == CONST_INT) + for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; + ep++) + if (ep->from_rtx == XEXP (SET_SRC (old_set), 0) + && ep->can_eliminate) + { + /* We must stop at the first elimination that will be used. + If this one would replace the PLUS with a REG, do it + now. Otherwise, quit the loop and let eliminate_regs + do its normal replacement. */ + if (ep->offset == - INTVAL (XEXP (SET_SRC (old_set), 1))) + { + /* We assume here that we don't need a PARALLEL of + any CLOBBERs for this assignment. There's not + much we can do if we do need it. */ + PATTERN (insn) = gen_rtx_SET (VOIDmode, + SET_DEST (old_set), + ep->to_rtx); + INSN_CODE (insn) = -1; + val = 1; + goto done; + } + + break; + } + } + + old_asm_operands_vec = 0; + + /* Replace the body of this insn with a substituted form. If we changed + something, return non-zero. + + If we are replacing a body that was a (set X (plus Y Z)), try to + re-recognize the insn. We do this in case we had a simple addition + but now can do this as a load-address. This saves an insn in this + common case. */ + + new_body = eliminate_regs (old_body, 0, replace ? insn : NULL_RTX); + if (new_body != old_body) + { + /* If we aren't replacing things permanently and we changed something, + make another copy to ensure that all the RTL is new. Otherwise + things can go wrong if find_reload swaps commutative operands + and one is inside RTL that has been copied while the other is not. */ + + /* Don't copy an asm_operands because (1) there's no need and (2) + copy_rtx can't do it properly when there are multiple outputs. */ + if (! replace && asm_noperands (old_body) < 0) + new_body = copy_rtx (new_body); + + /* If we had a move insn but now we don't, rerecognize it. This will + cause spurious re-recognition if the old move had a PARALLEL since + the new one still will, but we can't call single_set without + having put NEW_BODY into the insn and the re-recognition won't + hurt in this rare case. */ + if (old_set != 0 + && ((GET_CODE (SET_SRC (old_set)) == REG + && (GET_CODE (new_body) != SET + || GET_CODE (SET_SRC (new_body)) != REG)) + /* If this was a load from or store to memory, compare + the MEM in recog_operand to the one in the insn. If they + are not equal, then rerecognize the insn. */ + || (old_set != 0 + && ((GET_CODE (SET_SRC (old_set)) == MEM + && SET_SRC (old_set) != recog_operand[1]) + || (GET_CODE (SET_DEST (old_set)) == MEM + && SET_DEST (old_set) != recog_operand[0]))) + /* If this was an add insn before, rerecognize. */ + || GET_CODE (SET_SRC (old_set)) == PLUS)) + { + if (! validate_change (insn, &PATTERN (insn), new_body, 0)) + /* If recognition fails, store the new body anyway. + It's normal to have recognition failures here + due to bizarre memory addresses; reloading will fix them. */ + PATTERN (insn) = new_body; + } + else + PATTERN (insn) = new_body; + + val = 1; + } + + /* Loop through all elimination pairs. See if any have changed. + + We also detect a cases where register elimination cannot be done, + namely, if a register would be both changed and referenced outside a MEM + in the resulting insn since such an insn is often undefined and, even if + not, we cannot know what meaning will be given to it. Note that it is + valid to have a register used in an address in an insn that changes it + (presumably with a pre- or post-increment or decrement). + + If anything changes, return nonzero. */ + + for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) + { + if (ep->previous_offset != ep->offset && ep->ref_outside_mem) + ep->can_eliminate = 0; + + ep->ref_outside_mem = 0; + + if (ep->previous_offset != ep->offset) + val = 1; + } + + done: + /* If we changed something, perform elimination in REG_NOTES. This is + needed even when REPLACE is zero because a REG_DEAD note might refer + to a register that we eliminate and could cause a different number + of spill registers to be needed in the final reload pass than in + the pre-passes. */ + if (val && REG_NOTES (insn) != 0) + REG_NOTES (insn) = eliminate_regs (REG_NOTES (insn), 0, REG_NOTES (insn)); + + if (! replace) + pop_obstacks (); + + return val; +} + +/* Loop through all elimination pairs. + Recalculate the number not at initial offset. + + Compute the maximum offset (minimum offset if the stack does not + grow downward) for each elimination pair. */ + +static void +update_eliminable_offsets () +{ + struct elim_table *ep; + + num_not_at_initial_offset = 0; + for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) + { + ep->previous_offset = ep->offset; + if (ep->can_eliminate && ep->offset != ep->initial_offset) + num_not_at_initial_offset++; + } +} + +/* Given X, a SET or CLOBBER of DEST, if DEST is the target of a register + replacement we currently believe is valid, mark it as not eliminable if X + modifies DEST in any way other than by adding a constant integer to it. + + If DEST is the frame pointer, we do nothing because we assume that + all assignments to the hard frame pointer are nonlocal gotos and are being + done at a time when they are valid and do not disturb anything else. + Some machines want to eliminate a fake argument pointer with either the + frame or stack pointer. Assignments to the hard frame pointer must not + prevent this elimination. + + Called via note_stores from reload before starting its passes to scan + the insns of the function. */ + +static void +mark_not_eliminable (dest, x) + rtx dest; + rtx x; +{ + register unsigned int i; + + /* A SUBREG of a hard register here is just changing its mode. We should + not see a SUBREG of an eliminable hard register, but check just in + case. */ + if (GET_CODE (dest) == SUBREG) + dest = SUBREG_REG (dest); + + if (dest == hard_frame_pointer_rtx) + return; + + for (i = 0; i < NUM_ELIMINABLE_REGS; i++) + if (reg_eliminate[i].can_eliminate && dest == reg_eliminate[i].to_rtx + && (GET_CODE (x) != SET + || GET_CODE (SET_SRC (x)) != PLUS + || XEXP (SET_SRC (x), 0) != dest + || GET_CODE (XEXP (SET_SRC (x), 1)) != CONST_INT)) + { + reg_eliminate[i].can_eliminate_previous + = reg_eliminate[i].can_eliminate = 0; + num_eliminable--; + } +} + +/* Verify that the initial elimination offsets did not change since the + last call to set_initial_elim_offsets. This is used to catch cases + where something illegal happened during reload_as_needed that could + cause incorrect code to be generated if we did not check for it. */ +static void +verify_initial_elim_offsets () +{ + int t; + +#ifdef ELIMINABLE_REGS + struct elim_table *ep; + + for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) + { + INITIAL_ELIMINATION_OFFSET (ep->from, ep->to, t); + if (t != ep->initial_offset) + abort (); + } +#else + INITIAL_FRAME_POINTER_OFFSET (t); + if (t != reg_eliminate[0].initial_offset) + abort (); +#endif +} + +/* Reset all offsets on eliminable registers to their initial values. */ +static void +set_initial_elim_offsets () +{ + struct elim_table *ep = reg_eliminate; + +#ifdef ELIMINABLE_REGS + for (; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) + { + INITIAL_ELIMINATION_OFFSET (ep->from, ep->to, ep->initial_offset); + ep->previous_offset = ep->offset = ep->initial_offset; + } +#else + INITIAL_FRAME_POINTER_OFFSET (ep->initial_offset); + ep->previous_offset = ep->offset = ep->initial_offset; +#endif + + num_not_at_initial_offset = 0; +} + +/* Initialize the known label offsets. + Set a known offset for each forced label to be at the initial offset + of each elimination. We do this because we assume that all + computed jumps occur from a location where each elimination is + at its initial offset. + For all other labels, show that we don't know the offsets. */ + +static void +set_initial_label_offsets () +{ + rtx x; + bzero ((char *) &offsets_known_at[get_first_label_num ()], num_labels); + + for (x = forced_labels; x; x = XEXP (x, 1)) + if (XEXP (x, 0)) + set_label_offsets (XEXP (x, 0), NULL_RTX, 1); +} + +/* Set all elimination offsets to the known values for the code label given + by INSN. */ +static void +set_offsets_for_label (insn) + rtx insn; +{ + unsigned int i; + int label_nr = CODE_LABEL_NUMBER (insn); + struct elim_table *ep; + + num_not_at_initial_offset = 0; + for (i = 0, ep = reg_eliminate; i < NUM_ELIMINABLE_REGS; ep++, i++) + { + ep->offset = ep->previous_offset = offsets_at[label_nr][i]; + if (ep->can_eliminate && ep->offset != ep->initial_offset) + num_not_at_initial_offset++; + } +} + +/* See if anything that happened changes which eliminations are valid. + For example, on the Sparc, whether or not the frame pointer can + be eliminated can depend on what registers have been used. We need + not check some conditions again (such as flag_omit_frame_pointer) + since they can't have changed. */ + +static void +update_eliminables (pset) + HARD_REG_SET *pset; +{ +#if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM + int previous_frame_pointer_needed = frame_pointer_needed; +#endif + struct elim_table *ep; + + for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) + if ((ep->from == HARD_FRAME_POINTER_REGNUM && FRAME_POINTER_REQUIRED) +#ifdef ELIMINABLE_REGS + || ! CAN_ELIMINATE (ep->from, ep->to) +#endif + ) + ep->can_eliminate = 0; + + /* Look for the case where we have discovered that we can't replace + register A with register B and that means that we will now be + trying to replace register A with register C. This means we can + no longer replace register C with register B and we need to disable + such an elimination, if it exists. This occurs often with A == ap, + B == sp, and C == fp. */ + + for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) + { + struct elim_table *op; + register int new_to = -1; + + if (! ep->can_eliminate && ep->can_eliminate_previous) + { + /* Find the current elimination for ep->from, if there is a + new one. */ + for (op = reg_eliminate; + op < ®_eliminate[NUM_ELIMINABLE_REGS]; op++) + if (op->from == ep->from && op->can_eliminate) + { + new_to = op->to; + break; + } + + /* See if there is an elimination of NEW_TO -> EP->TO. If so, + disable it. */ + for (op = reg_eliminate; + op < ®_eliminate[NUM_ELIMINABLE_REGS]; op++) + if (op->from == new_to && op->to == ep->to) + op->can_eliminate = 0; + } + } + + /* See if any registers that we thought we could eliminate the previous + time are no longer eliminable. If so, something has changed and we + must spill the register. Also, recompute the number of eliminable + registers and see if the frame pointer is needed; it is if there is + no elimination of the frame pointer that we can perform. */ + + frame_pointer_needed = 1; + for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) + { + if (ep->can_eliminate && ep->from == FRAME_POINTER_REGNUM + && ep->to != HARD_FRAME_POINTER_REGNUM) + frame_pointer_needed = 0; + + if (! ep->can_eliminate && ep->can_eliminate_previous) + { + ep->can_eliminate_previous = 0; + SET_HARD_REG_BIT (*pset, ep->from); + num_eliminable--; + } + } + +#if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM + /* If we didn't need a frame pointer last time, but we do now, spill + the hard frame pointer. */ + if (frame_pointer_needed && ! previous_frame_pointer_needed) + SET_HARD_REG_BIT (*pset, HARD_FRAME_POINTER_REGNUM); +#endif +} + +/* Initialize the table of registers to eliminate. */ +static void +init_elim_table () +{ + struct elim_table *ep; +#ifdef ELIMINABLE_REGS + struct elim_table_1 *ep1; +#endif + + if (!reg_eliminate) + { + reg_eliminate = (struct elim_table *) + xmalloc(sizeof(struct elim_table) * NUM_ELIMINABLE_REGS); + bzero ((PTR) reg_eliminate, + sizeof(struct elim_table) * NUM_ELIMINABLE_REGS); + } + + /* Does this function require a frame pointer? */ + + frame_pointer_needed = (! flag_omit_frame_pointer +#ifdef EXIT_IGNORE_STACK + /* ?? If EXIT_IGNORE_STACK is set, we will not save + and restore sp for alloca. So we can't eliminate + the frame pointer in that case. At some point, + we should improve this by emitting the + sp-adjusting insns for this case. */ + || (current_function_calls_alloca + && EXIT_IGNORE_STACK) +#endif + || FRAME_POINTER_REQUIRED); + + num_eliminable = 0; + +#ifdef ELIMINABLE_REGS + for (ep = reg_eliminate, ep1 = reg_eliminate_1; + ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++, ep1++) + { + ep->from = ep1->from; + ep->to = ep1->to; + ep->can_eliminate = ep->can_eliminate_previous + = (CAN_ELIMINATE (ep->from, ep->to) + && ! (ep->to == STACK_POINTER_REGNUM && frame_pointer_needed)); + } +#else + reg_eliminate[0].from = reg_eliminate_1[0].from; + reg_eliminate[0].to = reg_eliminate_1[0].to; + reg_eliminate[0].can_eliminate = reg_eliminate[0].can_eliminate_previous + = ! frame_pointer_needed; +#endif + + /* Count the number of eliminable registers and build the FROM and TO + REG rtx's. Note that code in gen_rtx will cause, e.g., + gen_rtx (REG, Pmode, STACK_POINTER_REGNUM) to equal stack_pointer_rtx. + We depend on this. */ + for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) + { + num_eliminable += ep->can_eliminate; + ep->from_rtx = gen_rtx_REG (Pmode, ep->from); + ep->to_rtx = gen_rtx_REG (Pmode, ep->to); + } +} + +/* Kick all pseudos out of hard register REGNO. + If DUMPFILE is nonzero, log actions taken on that file. + + If CANT_ELIMINATE is nonzero, it means that we are doing this spill + because we found we can't eliminate some register. In the case, no pseudos + are allowed to be in the register, even if they are only in a block that + doesn't require spill registers, unlike the case when we are spilling this + hard reg to produce another spill register. + + Return nonzero if any pseudos needed to be kicked out. */ + +static void +spill_hard_reg (regno, dumpfile, cant_eliminate) + register int regno; + FILE *dumpfile; + int cant_eliminate; +{ + register int i; + + if (cant_eliminate) + { + SET_HARD_REG_BIT (bad_spill_regs_global, regno); + regs_ever_live[regno] = 1; + } + + /* Spill every pseudo reg that was allocated to this reg + or to something that overlaps this reg. */ + + for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) + if (reg_renumber[i] >= 0 + && reg_renumber[i] <= regno + && (reg_renumber[i] + + HARD_REGNO_NREGS (reg_renumber[i], + PSEUDO_REGNO_MODE (i)) + > regno)) + SET_REGNO_REG_SET (spilled_pseudos, i); +} + +/* I'm getting weird preprocessor errors if I use IOR_HARD_REG_SET + from within EXECUTE_IF_SET_IN_REG_SET. Hence this awkwardness. */ +static void +ior_hard_reg_set (set1, set2) + HARD_REG_SET *set1, *set2; +{ + IOR_HARD_REG_SET (*set1, *set2); +} + +/* After find_reload_regs has been run for all insn that need reloads, + and/or spill_hard_regs was called, this function is used to actually + spill pseudo registers and try to reallocate them. It also sets up the + spill_regs array for use by choose_reload_regs. */ + +static int +finish_spills (global, dumpfile) + int global; + FILE *dumpfile; +{ + struct insn_chain *chain; + int something_changed = 0; + int i; + + /* Build the spill_regs array for the function. */ + /* If there are some registers still to eliminate and one of the spill regs + wasn't ever used before, additional stack space may have to be + allocated to store this register. Thus, we may have changed the offset + between the stack and frame pointers, so mark that something has changed. + + One might think that we need only set VAL to 1 if this is a call-used + register. However, the set of registers that must be saved by the + prologue is not identical to the call-used set. For example, the + register used by the call insn for the return PC is a call-used register, + but must be saved by the prologue. */ + + n_spills = 0; + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + if (TEST_HARD_REG_BIT (used_spill_regs, i)) + { + spill_reg_order[i] = n_spills; + spill_regs[n_spills++] = i; + if (num_eliminable && ! regs_ever_live[i]) + something_changed = 1; + regs_ever_live[i] = 1; + } + else + spill_reg_order[i] = -1; + + for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) + if (REGNO_REG_SET_P (spilled_pseudos, i)) + { + /* Record the current hard register the pseudo is allocated to in + pseudo_previous_regs so we avoid reallocating it to the same + hard reg in a later pass. */ + if (reg_renumber[i] < 0) + abort (); + SET_HARD_REG_BIT (pseudo_previous_regs[i], reg_renumber[i]); + /* Mark it as no longer having a hard register home. */ + reg_renumber[i] = -1; + /* We will need to scan everything again. */ + something_changed = 1; + } + + /* Retry global register allocation if possible. */ + if (global) + { + bzero ((char *) pseudo_forbidden_regs, max_regno * sizeof (HARD_REG_SET)); + /* For every insn that needs reloads, set the registers used as spill + regs in pseudo_forbidden_regs for every pseudo live across the + insn. */ + for (chain = insns_need_reload; chain; chain = chain->next_need_reload) + { + EXECUTE_IF_SET_IN_REG_SET + (chain->live_before, FIRST_PSEUDO_REGISTER, i, + { + ior_hard_reg_set (pseudo_forbidden_regs + i, + &chain->used_spill_regs); + }); + EXECUTE_IF_SET_IN_REG_SET + (chain->live_after, FIRST_PSEUDO_REGISTER, i, + { + ior_hard_reg_set (pseudo_forbidden_regs + i, + &chain->used_spill_regs); + }); + } + + /* Retry allocating the spilled pseudos. For each reg, merge the + various reg sets that indicate which hard regs can't be used, + and call retry_global_alloc. + We change spill_pseudos here to only contain pseudos that did not + get a new hard register. */ + for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) + if (reg_old_renumber[i] != reg_renumber[i]) + { + HARD_REG_SET forbidden; + COPY_HARD_REG_SET (forbidden, bad_spill_regs_global); + IOR_HARD_REG_SET (forbidden, pseudo_forbidden_regs[i]); + IOR_HARD_REG_SET (forbidden, pseudo_previous_regs[i]); + retry_global_alloc (i, forbidden); + if (reg_renumber[i] >= 0) + CLEAR_REGNO_REG_SET (spilled_pseudos, i); + } + } + + /* Fix up the register information in the insn chain. + This involves deleting those of the spilled pseudos which did not get + a new hard register home from the live_{before,after} sets. */ + for (chain = reload_insn_chain; chain; chain = chain->next) + { + HARD_REG_SET used_by_pseudos; + HARD_REG_SET used_by_pseudos2; + + AND_COMPL_REG_SET (chain->live_before, spilled_pseudos); + AND_COMPL_REG_SET (chain->live_after, spilled_pseudos); + + /* Mark any unallocated hard regs as available for spills. That + makes inheritance work somewhat better. */ + if (chain->need_reload) + { + REG_SET_TO_HARD_REG_SET (used_by_pseudos, chain->live_before); + REG_SET_TO_HARD_REG_SET (used_by_pseudos2, chain->live_after); + IOR_HARD_REG_SET (used_by_pseudos, used_by_pseudos2); + + /* Save the old value for the sanity test below. */ + COPY_HARD_REG_SET (used_by_pseudos2, chain->used_spill_regs); + + compute_use_by_pseudos (&used_by_pseudos, chain->live_before); + compute_use_by_pseudos (&used_by_pseudos, chain->live_after); + COMPL_HARD_REG_SET (chain->used_spill_regs, used_by_pseudos); + AND_HARD_REG_SET (chain->used_spill_regs, used_spill_regs); + + /* Make sure we only enlarge the set. */ + GO_IF_HARD_REG_SUBSET (used_by_pseudos2, chain->used_spill_regs, ok); + abort (); + ok:; + } + } + + /* Let alter_reg modify the reg rtx's for the modified pseudos. */ + for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) + { + int regno = reg_renumber[i]; + if (reg_old_renumber[i] == regno) + continue; + + alter_reg (i, reg_old_renumber[i]); + reg_old_renumber[i] = regno; + if (dumpfile) + { + if (regno == -1) + fprintf (dumpfile, " Register %d now on stack.\n\n", i); + else + fprintf (dumpfile, " Register %d now in %d.\n\n", + i, reg_renumber[i]); + } + } + + return something_changed; +} + +/* Find all paradoxical subregs within X and update reg_max_ref_width. + Also mark any hard registers used to store user variables as + forbidden from being used for spill registers. */ + +static void +scan_paradoxical_subregs (x) + register rtx x; +{ + register int i; + register char *fmt; + register enum rtx_code code = GET_CODE (x); + + switch (code) + { + case REG: +#if 0 + if (SMALL_REGISTER_CLASSES && REGNO (x) < FIRST_PSEUDO_REGISTER + && REG_USERVAR_P (x)) + SET_HARD_REG_BIT (bad_spill_regs_global, REGNO (x)); +#endif + return; + + case CONST_INT: + case CONST: + case SYMBOL_REF: + case LABEL_REF: + case CONST_DOUBLE: + case CC0: + case PC: + case USE: + case CLOBBER: + return; + + case SUBREG: + if (GET_CODE (SUBREG_REG (x)) == REG + && GET_MODE_SIZE (GET_MODE (x)) > GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))) + reg_max_ref_width[REGNO (SUBREG_REG (x))] + = GET_MODE_SIZE (GET_MODE (x)); + return; + + default: + break; + } + + fmt = GET_RTX_FORMAT (code); + for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) + { + if (fmt[i] == 'e') + scan_paradoxical_subregs (XEXP (x, i)); + else if (fmt[i] == 'E') + { + register int j; + for (j = XVECLEN (x, i) - 1; j >=0; j--) + scan_paradoxical_subregs (XVECEXP (x, i, j)); + } + } +} + +static int +hard_reg_use_compare (p1p, p2p) + const GENERIC_PTR p1p; + const GENERIC_PTR p2p; +{ + struct hard_reg_n_uses *p1 = (struct hard_reg_n_uses *)p1p; + struct hard_reg_n_uses *p2 = (struct hard_reg_n_uses *)p2p; + int bad1 = TEST_HARD_REG_BIT (bad_spill_regs, p1->regno); + int bad2 = TEST_HARD_REG_BIT (bad_spill_regs, p2->regno); + if (bad1 && bad2) + return p1->regno - p2->regno; + if (bad1) + return 1; + if (bad2) + return -1; + if (p1->uses > p2->uses) + return 1; + if (p1->uses < p2->uses) + return -1; + /* If regs are equally good, sort by regno, + so that the results of qsort leave nothing to chance. */ + return p1->regno - p2->regno; +} + +/* Used for communication between order_regs_for_reload and count_pseudo. + Used to avoid counting one pseudo twice. */ +static regset pseudos_counted; + +/* Update the costs in N_USES, considering that pseudo REG is live. */ +static void +count_pseudo (n_uses, reg) + struct hard_reg_n_uses *n_uses; + int reg; +{ + int r = reg_renumber[reg]; + int nregs; + + if (REGNO_REG_SET_P (pseudos_counted, reg)) + return; + SET_REGNO_REG_SET (pseudos_counted, reg); + + if (r < 0) + abort (); + + nregs = HARD_REGNO_NREGS (r, PSEUDO_REGNO_MODE (reg)); + while (nregs-- > 0) + n_uses[r++].uses += REG_N_REFS (reg); +} +/* Choose the order to consider regs for use as reload registers + based on how much trouble would be caused by spilling one. + Store them in order of decreasing preference in potential_reload_regs. */ + +static void +order_regs_for_reload (chain) + struct insn_chain *chain; +{ + register int i; + register int o = 0; + struct hard_reg_n_uses hard_reg_n_uses[FIRST_PSEUDO_REGISTER]; + + pseudos_counted = ALLOCA_REG_SET (); + + COPY_HARD_REG_SET (bad_spill_regs, bad_spill_regs_global); + + /* Count number of uses of each hard reg by pseudo regs allocated to it + and then order them by decreasing use. */ + + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + { + int j; + + hard_reg_n_uses[i].regno = i; + hard_reg_n_uses[i].uses = 0; + + /* Test the various reasons why we can't use a register for + spilling in this insn. */ + if (fixed_regs[i] + || REGNO_REG_SET_P (chain->live_before, i) + || REGNO_REG_SET_P (chain->live_after, i)) + { + SET_HARD_REG_BIT (bad_spill_regs, i); + continue; + } + + /* Now find out which pseudos are allocated to it, and update + hard_reg_n_uses. */ + CLEAR_REG_SET (pseudos_counted); + + EXECUTE_IF_SET_IN_REG_SET + (chain->live_before, FIRST_PSEUDO_REGISTER, j, + { + count_pseudo (hard_reg_n_uses, j); + }); + EXECUTE_IF_SET_IN_REG_SET + (chain->live_after, FIRST_PSEUDO_REGISTER, j, + { + count_pseudo (hard_reg_n_uses, j); + }); + } + + FREE_REG_SET (pseudos_counted); + + /* Prefer registers not so far used, for use in temporary loading. + Among them, if REG_ALLOC_ORDER is defined, use that order. + Otherwise, prefer registers not preserved by calls. */ + +/* CYGNUS LOCAL z8k */ +#ifdef RELOAD_ALLOC_ORDER + /* ??? This is a hack. This will give poor code, but is used for the + z8k because it is currently the only way to ensure that we will be + able to satisfy all of the reloads. Possible other solutions: + - make reload keep track of how many groups of each size are needed, + instead of just remembering the maximum group size + - improve code for making group 4 reloads + -- try looking for combinations of single register spills and potential + reload regs (sample uncompleted code exists for this) + -- try expanding an existing group 2 reload to a group 4 reload + -- unallocate a group 2 reload, try to allocate the group 4 reload, + then reallocate the group 2 reload, if one step fails then all do + - add code to deal with overlapping register groups(?). */ + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + potential_reload_regs[i] = reload_alloc_order[i]; +#else +/* END CYGNUS LOCAL */ + + +#ifdef REG_ALLOC_ORDER + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + { + int regno = reg_alloc_order[i]; + + if (hard_reg_n_uses[regno].uses == 0 + && ! TEST_HARD_REG_BIT (bad_spill_regs, regno)) + potential_reload_regs[o++] = regno; + } +#else + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + { + if (hard_reg_n_uses[i].uses == 0 && call_used_regs[i] + && ! TEST_HARD_REG_BIT (bad_spill_regs, i)) + potential_reload_regs[o++] = i; + } + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + { + if (hard_reg_n_uses[i].uses == 0 && ! call_used_regs[i] + && ! TEST_HARD_REG_BIT (bad_spill_regs, i)) + potential_reload_regs[o++] = i; + } +#endif + + qsort (hard_reg_n_uses, FIRST_PSEUDO_REGISTER, + sizeof hard_reg_n_uses[0], hard_reg_use_compare); + + /* Now add the regs that are already used, + preferring those used less often. The fixed and otherwise forbidden + registers will be at the end of this list. */ + + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + if (hard_reg_n_uses[i].uses != 0 + && ! TEST_HARD_REG_BIT (bad_spill_regs, hard_reg_n_uses[i].regno)) + potential_reload_regs[o++] = hard_reg_n_uses[i].regno; + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + if (TEST_HARD_REG_BIT (bad_spill_regs, hard_reg_n_uses[i].regno)) + potential_reload_regs[o++] = hard_reg_n_uses[i].regno; +/* CYGNUS LOCAL z8k */ +#endif +/* END CYGNUS LOCAL */ +} + +/* Reload pseudo-registers into hard regs around each insn as needed. + Additional register load insns are output before the insn that needs it + and perhaps store insns after insns that modify the reloaded pseudo reg. + + reg_last_reload_reg and reg_reloaded_contents keep track of + which registers are already available in reload registers. + We update these for the reloads that we perform, + as the insns are scanned. */ + +static void +reload_as_needed (live_known) + int live_known; +{ + struct insn_chain *chain; +#if defined (AUTO_INC_DEC) || defined (INSN_CLOBBERS_REGNO_P) + register int i; +#endif + rtx x; + + bzero ((char *) spill_reg_rtx, sizeof spill_reg_rtx); + bzero ((char *) spill_reg_store, sizeof spill_reg_store); + reg_last_reload_reg = (rtx *) alloca (max_regno * sizeof (rtx)); + bzero ((char *) reg_last_reload_reg, max_regno * sizeof (rtx)); + reg_has_output_reload = (char *) alloca (max_regno); + CLEAR_HARD_REG_SET (reg_reloaded_valid); + + set_initial_elim_offsets (); + + for (chain = reload_insn_chain; chain; chain = chain->next) + { + rtx prev; + rtx insn = chain->insn; + rtx old_next = NEXT_INSN (insn); + + /* If we pass a label, copy the offsets from the label information + into the current offsets of each elimination. */ + if (GET_CODE (insn) == CODE_LABEL) + set_offsets_for_label (insn); + + else if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') + { + rtx oldpat = PATTERN (insn); + + /* If this is a USE and CLOBBER of a MEM, ensure that any + references to eliminable registers have been removed. */ + + if ((GET_CODE (PATTERN (insn)) == USE + || GET_CODE (PATTERN (insn)) == CLOBBER) + && GET_CODE (XEXP (PATTERN (insn), 0)) == MEM) + XEXP (XEXP (PATTERN (insn), 0), 0) + = eliminate_regs (XEXP (XEXP (PATTERN (insn), 0), 0), + GET_MODE (XEXP (PATTERN (insn), 0)), + NULL_RTX); + + /* If we need to do register elimination processing, do so. + This might delete the insn, in which case we are done. */ + if ((num_eliminable || num_eliminable_invariants) && chain->need_elim) + { + eliminate_regs_in_insn (insn, 1); + if (GET_CODE (insn) == NOTE) + { + update_eliminable_offsets (); + continue; + } + } + + /* If need_elim is nonzero but need_reload is zero, one might think + that we could simply set n_reloads to 0. However, find_reloads + could have done some manipulation of the insn (such as swapping + commutative operands), and these manipulations are lost during + the first pass for every insn that needs register elimination. + So the actions of find_reloads must be redone here. */ + + if (! chain->need_elim && ! chain->need_reload + && ! chain->need_operand_change) + n_reloads = 0; + /* First find the pseudo regs that must be reloaded for this insn. + This info is returned in the tables reload_... (see reload.h). + Also modify the body of INSN by substituting RELOAD + rtx's for those pseudo regs. */ + else + { + bzero (reg_has_output_reload, max_regno); + CLEAR_HARD_REG_SET (reg_is_output_reload); + + find_reloads (insn, 1, spill_indirect_levels, live_known, + spill_reg_order); + } + + if (num_eliminable && chain->need_elim) + update_eliminable_offsets (); + + if (n_reloads > 0) + { + rtx next = NEXT_INSN (insn); + rtx p; + + prev = PREV_INSN (insn); + + /* Now compute which reload regs to reload them into. Perhaps + reusing reload regs from previous insns, or else output + load insns to reload them. Maybe output store insns too. + Record the choices of reload reg in reload_reg_rtx. */ + choose_reload_regs (chain); + + /* Merge any reloads that we didn't combine for fear of + increasing the number of spill registers needed but now + discover can be safely merged. */ + if (SMALL_REGISTER_CLASSES) + merge_assigned_reloads (insn); + + /* Generate the insns to reload operands into or out of + their reload regs. */ + emit_reload_insns (chain); + + /* Substitute the chosen reload regs from reload_reg_rtx + into the insn's body (or perhaps into the bodies of other + load and store insn that we just made for reloading + and that we moved the structure into). */ + subst_reloads (); + + /* If this was an ASM, make sure that all the reload insns + we have generated are valid. If not, give an error + and delete them. */ + + if (asm_noperands (PATTERN (insn)) >= 0) + for (p = NEXT_INSN (prev); p != next; p = NEXT_INSN (p)) + if (p != insn && GET_RTX_CLASS (GET_CODE (p)) == 'i' + && (recog_memoized (p) < 0 + || (extract_insn (p), ! constrain_operands (1)))) + { + error_for_asm (insn, + "`asm' operand requires impossible reload"); + PUT_CODE (p, NOTE); + NOTE_SOURCE_FILE (p) = 0; + NOTE_LINE_NUMBER (p) = NOTE_INSN_DELETED; + } + } + /* Any previously reloaded spilled pseudo reg, stored in this insn, + is no longer validly lying around to save a future reload. + Note that this does not detect pseudos that were reloaded + for this insn in order to be stored in + (obeying register constraints). That is correct; such reload + registers ARE still valid. */ + note_stores (oldpat, forget_old_reloads_1); + + /* There may have been CLOBBER insns placed after INSN. So scan + between INSN and NEXT and use them to forget old reloads. */ + for (x = NEXT_INSN (insn); x != old_next; x = NEXT_INSN (x)) + if (GET_CODE (x) == INSN && GET_CODE (PATTERN (x)) == CLOBBER) + note_stores (PATTERN (x), forget_old_reloads_1); + +#ifdef AUTO_INC_DEC + /* Likewise for regs altered by auto-increment in this insn. + REG_INC notes have been changed by reloading: + find_reloads_address_1 records substitutions for them, + which have been performed by subst_reloads above. */ + for (i = n_reloads - 1; i >= 0; i--) + { + rtx in_reg = reload_in_reg[i]; + if (in_reg) + { + enum rtx_code code = GET_CODE (in_reg); + /* PRE_INC / PRE_DEC will have the reload register ending up + with the same value as the stack slot, but that doesn't + hold true for POST_INC / POST_DEC. Either we have to + convert the memory access to a true POST_INC / POST_DEC, + or we can't use the reload register for inheritance. */ + if ((code == POST_INC || code == POST_DEC) + && TEST_HARD_REG_BIT (reg_reloaded_valid, + REGNO (reload_reg_rtx[i])) + /* Make sure it is the inc/dec pseudo, and not + some other (e.g. output operand) pseudo. */ + && (reg_reloaded_contents[REGNO (reload_reg_rtx[i])] + == REGNO (XEXP (in_reg, 0)))) + + { + rtx reload_reg = reload_reg_rtx[i]; + enum machine_mode mode = GET_MODE (reload_reg); + int n = 0; + rtx p; + + for (p = PREV_INSN (old_next); p != prev; p = PREV_INSN (p)) + { + /* We really want to ignore REG_INC notes here, so + use PATTERN (p) as argument to reg_set_p . */ + if (reg_set_p (reload_reg, PATTERN (p))) + break; + n = count_occurrences (PATTERN (p), reload_reg); + if (! n) + continue; + if (n == 1) + { + n = validate_replace_rtx (reload_reg, + gen_rtx (code, mode, + reload_reg), + p); + + /* We must also verify that the constraints + are met after the replacement. */ + extract_insn (p); + if (n) + n = constrain_operands (1); + else + break; + + /* If the constraints were not met, then + undo the replacement. */ + if (!n) + { + validate_replace_rtx (gen_rtx (code, mode, + reload_reg), + reload_reg, p); + break; + } + + } + break; + } + if (n == 1) + REG_NOTES (p) = gen_rtx_EXPR_LIST (REG_INC, reload_reg, + REG_NOTES (p)); + else + forget_old_reloads_1 (XEXP (in_reg, 0), NULL_RTX); + } + } + } +#if 0 /* ??? Is this code obsolete now? Need to check carefully. */ + /* Likewise for regs altered by auto-increment in this insn. + But note that the reg-notes are not changed by reloading: + they still contain the pseudo-regs, not the spill regs. */ + for (x = REG_NOTES (insn); x; x = XEXP (x, 1)) + if (REG_NOTE_KIND (x) == REG_INC) + { + /* See if this pseudo reg was reloaded in this insn. + If so, its last-reload info is still valid + because it is based on this insn's reload. */ + for (i = 0; i < n_reloads; i++) + if (reload_out[i] == XEXP (x, 0)) + break; + + if (i == n_reloads) + forget_old_reloads_1 (XEXP (x, 0), NULL_RTX); + } +#endif +#endif + } + /* A reload reg's contents are unknown after a label. */ + if (GET_CODE (insn) == CODE_LABEL) + CLEAR_HARD_REG_SET (reg_reloaded_valid); + + /* Don't assume a reload reg is still good after a call insn + if it is a call-used reg. */ + else if (GET_CODE (insn) == CALL_INSN) + AND_COMPL_HARD_REG_SET(reg_reloaded_valid, call_used_reg_set); + + /* In case registers overlap, allow certain insns to invalidate + particular hard registers. */ + +#ifdef INSN_CLOBBERS_REGNO_P + for (i = 0 ; i < FIRST_PSEUDO_REGISTER; i++) + if (TEST_HARD_REG_BIT (reg_reloaded_valid, i) + && INSN_CLOBBERS_REGNO_P (insn, i)) + CLEAR_HARD_REG_BIT (reg_reloaded_valid, i); +#endif + +#ifdef USE_C_ALLOCA + alloca (0); +#endif + } +} + +/* Discard all record of any value reloaded from X, + or reloaded in X from someplace else; + unless X is an output reload reg of the current insn. + + X may be a hard reg (the reload reg) + or it may be a pseudo reg that was reloaded from. */ + +static void +forget_old_reloads_1 (x, ignored) + rtx x; + rtx ignored ATTRIBUTE_UNUSED; +{ + register int regno; + int nr; + int offset = 0; + + /* note_stores does give us subregs of hard regs. */ + while (GET_CODE (x) == SUBREG) + { + offset += SUBREG_WORD (x); + x = SUBREG_REG (x); + } + + if (GET_CODE (x) != REG) + return; + + regno = REGNO (x) + offset; + + if (regno >= FIRST_PSEUDO_REGISTER) + nr = 1; + else + { + int i; + nr = HARD_REGNO_NREGS (regno, GET_MODE (x)); + /* Storing into a spilled-reg invalidates its contents. + This can happen if a block-local pseudo is allocated to that reg + and it wasn't spilled because this block's total need is 0. + Then some insn might have an optional reload and use this reg. */ + for (i = 0; i < nr; i++) + /* But don't do this if the reg actually serves as an output + reload reg in the current instruction. */ + if (n_reloads == 0 + || ! TEST_HARD_REG_BIT (reg_is_output_reload, regno + i)) + CLEAR_HARD_REG_BIT (reg_reloaded_valid, regno + i); + } + + /* Since value of X has changed, + forget any value previously copied from it. */ + + while (nr-- > 0) + /* But don't forget a copy if this is the output reload + that establishes the copy's validity. */ + if (n_reloads == 0 || reg_has_output_reload[regno + nr] == 0) + reg_last_reload_reg[regno + nr] = 0; +} + +/* For each reload, the mode of the reload register. */ +static enum machine_mode reload_mode[MAX_RELOADS]; + +/* For each reload, the largest number of registers it will require. */ +static int reload_nregs[MAX_RELOADS]; + +/* Comparison function for qsort to decide which of two reloads + should be handled first. *P1 and *P2 are the reload numbers. */ + +static int +reload_reg_class_lower (r1p, r2p) + const GENERIC_PTR r1p; + const GENERIC_PTR r2p; +{ + register int r1 = *(short *)r1p, r2 = *(short *)r2p; + register int t; + + /* Consider required reloads before optional ones. */ + t = reload_optional[r1] - reload_optional[r2]; + if (t != 0) + return t; + + /* Count all solitary classes before non-solitary ones. */ + t = ((reg_class_size[(int) reload_reg_class[r2]] == 1) + - (reg_class_size[(int) reload_reg_class[r1]] == 1)); + if (t != 0) + return t; + + /* Aside from solitaires, consider all multi-reg groups first. */ + t = reload_nregs[r2] - reload_nregs[r1]; + if (t != 0) + return t; + + /* Consider reloads in order of increasing reg-class number. */ + t = (int) reload_reg_class[r1] - (int) reload_reg_class[r2]; + if (t != 0) + return t; + + /* If reloads are equally urgent, sort by reload number, + so that the results of qsort leave nothing to chance. */ + return r1 - r2; +} + +/* The following HARD_REG_SETs indicate when each hard register is + used for a reload of various parts of the current insn. */ + +/* If reg is in use as a reload reg for a RELOAD_OTHER reload. */ +static HARD_REG_SET reload_reg_used; +/* If reg is in use for a RELOAD_FOR_INPUT_ADDRESS reload for operand I. */ +static HARD_REG_SET reload_reg_used_in_input_addr[MAX_RECOG_OPERANDS]; +/* If reg is in use for a RELOAD_FOR_INPADDR_ADDRESS reload for operand I. */ +static HARD_REG_SET reload_reg_used_in_inpaddr_addr[MAX_RECOG_OPERANDS]; +/* If reg is in use for a RELOAD_FOR_OUTPUT_ADDRESS reload for operand I. */ +static HARD_REG_SET reload_reg_used_in_output_addr[MAX_RECOG_OPERANDS]; +/* If reg is in use for a RELOAD_FOR_OUTADDR_ADDRESS reload for operand I. */ +static HARD_REG_SET reload_reg_used_in_outaddr_addr[MAX_RECOG_OPERANDS]; +/* If reg is in use for a RELOAD_FOR_INPUT reload for operand I. */ +static HARD_REG_SET reload_reg_used_in_input[MAX_RECOG_OPERANDS]; +/* If reg is in use for a RELOAD_FOR_OUTPUT reload for operand I. */ +static HARD_REG_SET reload_reg_used_in_output[MAX_RECOG_OPERANDS]; +/* If reg is in use for a RELOAD_FOR_OPERAND_ADDRESS reload. */ +static HARD_REG_SET reload_reg_used_in_op_addr; +/* If reg is in use for a RELOAD_FOR_OPADDR_ADDR reload. */ +static HARD_REG_SET reload_reg_used_in_op_addr_reload; +/* If reg is in use for a RELOAD_FOR_INSN reload. */ +static HARD_REG_SET reload_reg_used_in_insn; +/* If reg is in use for a RELOAD_FOR_OTHER_ADDRESS reload. */ +static HARD_REG_SET reload_reg_used_in_other_addr; + +/* If reg is in use as a reload reg for any sort of reload. */ +static HARD_REG_SET reload_reg_used_at_all; + +/* If reg is use as an inherited reload. We just mark the first register + in the group. */ +static HARD_REG_SET reload_reg_used_for_inherit; + +/* Records which hard regs are used in any way, either as explicit use or + by being allocated to a pseudo during any point of the current insn. */ +static HARD_REG_SET reg_used_in_insn; + +/* Mark reg REGNO as in use for a reload of the sort spec'd by OPNUM and + TYPE. MODE is used to indicate how many consecutive regs are + actually used. */ + +static void +mark_reload_reg_in_use (regno, opnum, type, mode) + int regno; + int opnum; + enum reload_type type; + enum machine_mode mode; +{ + int nregs = HARD_REGNO_NREGS (regno, mode); + int i; + + for (i = regno; i < nregs + regno; i++) + { + switch (type) + { + case RELOAD_OTHER: + SET_HARD_REG_BIT (reload_reg_used, i); + break; + + case RELOAD_FOR_INPUT_ADDRESS: + SET_HARD_REG_BIT (reload_reg_used_in_input_addr[opnum], i); + break; + + case RELOAD_FOR_INPADDR_ADDRESS: + SET_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[opnum], i); + break; + + case RELOAD_FOR_OUTPUT_ADDRESS: + SET_HARD_REG_BIT (reload_reg_used_in_output_addr[opnum], i); + break; + + case RELOAD_FOR_OUTADDR_ADDRESS: + SET_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[opnum], i); + break; + + case RELOAD_FOR_OPERAND_ADDRESS: + SET_HARD_REG_BIT (reload_reg_used_in_op_addr, i); + break; + + case RELOAD_FOR_OPADDR_ADDR: + SET_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, i); + break; + + case RELOAD_FOR_OTHER_ADDRESS: + SET_HARD_REG_BIT (reload_reg_used_in_other_addr, i); + break; + + case RELOAD_FOR_INPUT: + SET_HARD_REG_BIT (reload_reg_used_in_input[opnum], i); + break; + + case RELOAD_FOR_OUTPUT: + SET_HARD_REG_BIT (reload_reg_used_in_output[opnum], i); + break; + + case RELOAD_FOR_INSN: + SET_HARD_REG_BIT (reload_reg_used_in_insn, i); + break; + } + + SET_HARD_REG_BIT (reload_reg_used_at_all, i); + } +} + +/* Similarly, but show REGNO is no longer in use for a reload. */ + +static void +clear_reload_reg_in_use (regno, opnum, type, mode) + int regno; + int opnum; + enum reload_type type; + enum machine_mode mode; +{ + int nregs = HARD_REGNO_NREGS (regno, mode); + int start_regno, end_regno; + int i; + /* A complication is that for some reload types, inheritance might + allow multiple reloads of the same types to share a reload register. + We set check_opnum if we have to check only reloads with the same + operand number, and check_any if we have to check all reloads. */ + int check_opnum = 0; + int check_any = 0; + HARD_REG_SET *used_in_set; + + switch (type) + { + case RELOAD_OTHER: + used_in_set = &reload_reg_used; + break; + + case RELOAD_FOR_INPUT_ADDRESS: + used_in_set = &reload_reg_used_in_input_addr[opnum]; + break; + + case RELOAD_FOR_INPADDR_ADDRESS: + check_opnum = 1; + used_in_set = &reload_reg_used_in_inpaddr_addr[opnum]; + break; + + case RELOAD_FOR_OUTPUT_ADDRESS: + used_in_set = &reload_reg_used_in_output_addr[opnum]; + break; + + case RELOAD_FOR_OUTADDR_ADDRESS: + check_opnum = 1; + used_in_set = &reload_reg_used_in_outaddr_addr[opnum]; + break; + + case RELOAD_FOR_OPERAND_ADDRESS: + used_in_set = &reload_reg_used_in_op_addr; + break; + + case RELOAD_FOR_OPADDR_ADDR: + check_any = 1; + used_in_set = &reload_reg_used_in_op_addr_reload; + break; + + case RELOAD_FOR_OTHER_ADDRESS: + used_in_set = &reload_reg_used_in_other_addr; + check_any = 1; + break; + + case RELOAD_FOR_INPUT: + used_in_set = &reload_reg_used_in_input[opnum]; + break; + + case RELOAD_FOR_OUTPUT: + used_in_set = &reload_reg_used_in_output[opnum]; + break; + + case RELOAD_FOR_INSN: + used_in_set = &reload_reg_used_in_insn; + break; + default: + abort (); + } + /* We resolve conflicts with remaining reloads of the same type by + excluding the intervals of of reload registers by them from the + interval of freed reload registers. Since we only keep track of + one set of interval bounds, we might have to exclude somewhat + more then what would be necessary if we used a HARD_REG_SET here. + But this should only happen very infrequently, so there should + be no reason to worry about it. */ + + start_regno = regno; + end_regno = regno + nregs; + if (check_opnum || check_any) + { + for (i = n_reloads - 1; i >= 0; i--) + { + if (reload_when_needed[i] == type + && (check_any || reload_opnum[i] == opnum) + && reload_reg_rtx[i]) + { + int conflict_start = true_regnum (reload_reg_rtx[i]); + int conflict_end + = (conflict_start + + HARD_REGNO_NREGS (conflict_start, reload_mode[i])); + + /* If there is an overlap with the first to-be-freed register, + adjust the interval start. */ + if (conflict_start <= start_regno && conflict_end > start_regno) + start_regno = conflict_end; + /* Otherwise, if there is a conflict with one of the other + to-be-freed registers, adjust the interval end. */ + if (conflict_start > start_regno && conflict_start < end_regno) + end_regno = conflict_start; + } + } + } + for (i = start_regno; i < end_regno; i++) + CLEAR_HARD_REG_BIT (*used_in_set, i); +} + +/* 1 if reg REGNO is free as a reload reg for a reload of the sort + specified by OPNUM and TYPE. */ + +static int +reload_reg_free_p (regno, opnum, type) + int regno; + int opnum; + enum reload_type type; +{ + int i; + + /* In use for a RELOAD_OTHER means it's not available for anything. */ + if (TEST_HARD_REG_BIT (reload_reg_used, regno)) + return 0; + + switch (type) + { + case RELOAD_OTHER: + /* In use for anything means we can't use it for RELOAD_OTHER. */ + if (TEST_HARD_REG_BIT (reload_reg_used_in_other_addr, regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)) + return 0; + + for (i = 0; i < reload_n_operands; i++) + if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)) + return 0; + + return 1; + + case RELOAD_FOR_INPUT: + if (TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)) + return 0; + + if (TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno)) + return 0; + + /* If it is used for some other input, can't use it. */ + for (i = 0; i < reload_n_operands; i++) + if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)) + return 0; + + /* If it is used in a later operand's address, can't use it. */ + for (i = opnum + 1; i < reload_n_operands; i++) + if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno)) + return 0; + + return 1; + + case RELOAD_FOR_INPUT_ADDRESS: + /* Can't use a register if it is used for an input address for this + operand or used as an input in an earlier one. */ + if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[opnum], regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[opnum], regno)) + return 0; + + for (i = 0; i < opnum; i++) + if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)) + return 0; + + return 1; + + case RELOAD_FOR_INPADDR_ADDRESS: + /* Can't use a register if it is used for an input address + for this operand or used as an input in an earlier + one. */ + if (TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[opnum], regno)) + return 0; + + for (i = 0; i < opnum; i++) + if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)) + return 0; + + return 1; + + case RELOAD_FOR_OUTPUT_ADDRESS: + /* Can't use a register if it is used for an output address for this + operand or used as an output in this or a later operand. */ + if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[opnum], regno)) + return 0; + + for (i = opnum; i < reload_n_operands; i++) + if (TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)) + return 0; + + return 1; + + case RELOAD_FOR_OUTADDR_ADDRESS: + /* Can't use a register if it is used for an output address + for this operand or used as an output in this or a + later operand. */ + if (TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[opnum], regno)) + return 0; + + for (i = opnum; i < reload_n_operands; i++) + if (TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)) + return 0; + + return 1; + + case RELOAD_FOR_OPERAND_ADDRESS: + for (i = 0; i < reload_n_operands; i++) + if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)) + return 0; + + return (! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno) + && ! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)); + + case RELOAD_FOR_OPADDR_ADDR: + for (i = 0; i < reload_n_operands; i++) + if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)) + return 0; + + return (!TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno)); + + case RELOAD_FOR_OUTPUT: + /* This cannot share a register with RELOAD_FOR_INSN reloads, other + outputs, or an operand address for this or an earlier output. */ + if (TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)) + return 0; + + for (i = 0; i < reload_n_operands; i++) + if (TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)) + return 0; + + for (i = 0; i <= opnum; i++) + if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)) + return 0; + + return 1; + + case RELOAD_FOR_INSN: + for (i = 0; i < reload_n_operands; i++) + if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)) + return 0; + + return (! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno) + && ! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)); + + case RELOAD_FOR_OTHER_ADDRESS: + return ! TEST_HARD_REG_BIT (reload_reg_used_in_other_addr, regno); + } + abort (); +} + +/* Return 1 if the value in reload reg REGNO, as used by a reload + needed for the part of the insn specified by OPNUM and TYPE, + is still available in REGNO at the end of the insn. + + We can assume that the reload reg was already tested for availability + at the time it is needed, and we should not check this again, + in case the reg has already been marked in use. */ + +static int +reload_reg_reaches_end_p (regno, opnum, type) + int regno; + int opnum; + enum reload_type type; +{ + int i; + + switch (type) + { + case RELOAD_OTHER: + /* Since a RELOAD_OTHER reload claims the reg for the entire insn, + its value must reach the end. */ + return 1; + + /* If this use is for part of the insn, + its value reaches if no subsequent part uses the same register. + Just like the above function, don't try to do this with lots + of fallthroughs. */ + + case RELOAD_FOR_OTHER_ADDRESS: + /* Here we check for everything else, since these don't conflict + with anything else and everything comes later. */ + + for (i = 0; i < reload_n_operands; i++) + if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)) + return 0; + + return (! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno) + && ! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno) + && ! TEST_HARD_REG_BIT (reload_reg_used, regno)); + + case RELOAD_FOR_INPUT_ADDRESS: + case RELOAD_FOR_INPADDR_ADDRESS: + /* Similar, except that we check only for this and subsequent inputs + and the address of only subsequent inputs and we do not need + to check for RELOAD_OTHER objects since they are known not to + conflict. */ + + for (i = opnum; i < reload_n_operands; i++) + if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)) + return 0; + + for (i = opnum + 1; i < reload_n_operands; i++) + if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno)) + return 0; + + for (i = 0; i < reload_n_operands; i++) + if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)) + return 0; + + if (TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno)) + return 0; + + return (! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno) + && ! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)); + + case RELOAD_FOR_INPUT: + /* Similar to input address, except we start at the next operand for + both input and input address and we do not check for + RELOAD_FOR_OPERAND_ADDRESS and RELOAD_FOR_INSN since these + would conflict. */ + + for (i = opnum + 1; i < reload_n_operands; i++) + if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)) + return 0; + + /* ... fall through ... */ + + case RELOAD_FOR_OPERAND_ADDRESS: + /* Check outputs and their addresses. */ + + for (i = 0; i < reload_n_operands; i++) + if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)) + return 0; + + return 1; + + case RELOAD_FOR_OPADDR_ADDR: + for (i = 0; i < reload_n_operands; i++) + if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)) + return 0; + + return (! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno) + && !TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)); + + case RELOAD_FOR_INSN: + /* These conflict with other outputs with RELOAD_OTHER. So + we need only check for output addresses. */ + + opnum = -1; + + /* ... fall through ... */ + + case RELOAD_FOR_OUTPUT: + case RELOAD_FOR_OUTPUT_ADDRESS: + case RELOAD_FOR_OUTADDR_ADDRESS: + /* We already know these can't conflict with a later output. So the + only thing to check are later output addresses. */ + for (i = opnum + 1; i < reload_n_operands; i++) + if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno) + || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)) + return 0; + + return 1; + } + + abort (); +} + +/* Return 1 if the reloads denoted by R1 and R2 cannot share a register. + Return 0 otherwise. + + This function uses the same algorithm as reload_reg_free_p above. */ + +int +reloads_conflict (r1, r2) + int r1, r2; +{ + enum reload_type r1_type = reload_when_needed[r1]; + enum reload_type r2_type = reload_when_needed[r2]; + int r1_opnum = reload_opnum[r1]; + int r2_opnum = reload_opnum[r2]; + + /* RELOAD_OTHER conflicts with everything. */ + if (r2_type == RELOAD_OTHER) + return 1; + + /* Otherwise, check conflicts differently for each type. */ + + switch (r1_type) + { + case RELOAD_FOR_INPUT: + return (r2_type == RELOAD_FOR_INSN + || r2_type == RELOAD_FOR_OPERAND_ADDRESS + || r2_type == RELOAD_FOR_OPADDR_ADDR + || r2_type == RELOAD_FOR_INPUT + || ((r2_type == RELOAD_FOR_INPUT_ADDRESS + || r2_type == RELOAD_FOR_INPADDR_ADDRESS) + && r2_opnum > r1_opnum)); + + case RELOAD_FOR_INPUT_ADDRESS: + return ((r2_type == RELOAD_FOR_INPUT_ADDRESS && r1_opnum == r2_opnum) + || (r2_type == RELOAD_FOR_INPUT && r2_opnum < r1_opnum)); + + case RELOAD_FOR_INPADDR_ADDRESS: + return ((r2_type == RELOAD_FOR_INPADDR_ADDRESS && r1_opnum == r2_opnum) + || (r2_type == RELOAD_FOR_INPUT && r2_opnum < r1_opnum)); + + case RELOAD_FOR_OUTPUT_ADDRESS: + return ((r2_type == RELOAD_FOR_OUTPUT_ADDRESS && r2_opnum == r1_opnum) + || (r2_type == RELOAD_FOR_OUTPUT && r2_opnum >= r1_opnum)); + + case RELOAD_FOR_OUTADDR_ADDRESS: + return ((r2_type == RELOAD_FOR_OUTADDR_ADDRESS && r2_opnum == r1_opnum) + || (r2_type == RELOAD_FOR_OUTPUT && r2_opnum >= r1_opnum)); + + case RELOAD_FOR_OPERAND_ADDRESS: + return (r2_type == RELOAD_FOR_INPUT || r2_type == RELOAD_FOR_INSN + || r2_type == RELOAD_FOR_OPERAND_ADDRESS); + + case RELOAD_FOR_OPADDR_ADDR: + return (r2_type == RELOAD_FOR_INPUT + || r2_type == RELOAD_FOR_OPADDR_ADDR); + + case RELOAD_FOR_OUTPUT: + return (r2_type == RELOAD_FOR_INSN || r2_type == RELOAD_FOR_OUTPUT + || ((r2_type == RELOAD_FOR_OUTPUT_ADDRESS + || r2_type == RELOAD_FOR_OUTADDR_ADDRESS) + && r2_opnum >= r1_opnum)); + + case RELOAD_FOR_INSN: + return (r2_type == RELOAD_FOR_INPUT || r2_type == RELOAD_FOR_OUTPUT + || r2_type == RELOAD_FOR_INSN + || r2_type == RELOAD_FOR_OPERAND_ADDRESS); + + case RELOAD_FOR_OTHER_ADDRESS: + return r2_type == RELOAD_FOR_OTHER_ADDRESS; + + case RELOAD_OTHER: + return 1; + + default: + abort (); + } +} + +/* Vector of reload-numbers showing the order in which the reloads should + be processed. */ +short reload_order[MAX_RELOADS]; + +/* Indexed by reload number, 1 if incoming value + inherited from previous insns. */ +char reload_inherited[MAX_RELOADS]; + +/* For an inherited reload, this is the insn the reload was inherited from, + if we know it. Otherwise, this is 0. */ +rtx reload_inheritance_insn[MAX_RELOADS]; + +/* If non-zero, this is a place to get the value of the reload, + rather than using reload_in. */ +rtx reload_override_in[MAX_RELOADS]; + +/* For each reload, the hard register number of the register used, + or -1 if we did not need a register for this reload. */ +int reload_spill_index[MAX_RELOADS]; + +/* Return 1 if the value in reload reg REGNO, as used by a reload + needed for the part of the insn specified by OPNUM and TYPE, + may be used to load VALUE into it. + + Other read-only reloads with the same value do not conflict + unless OUT is non-zero and these other reloads have to live while + output reloads live. + If OUT is CONST0_RTX, this is a special case: it means that the + test should not be for using register REGNO as reload register, but + for copying from register REGNO into the reload register. + + RELOADNUM is the number of the reload we want to load this value for; + a reload does not conflict with itself. + + When IGNORE_ADDRESS_RELOADS is set, we can not have conflicts with + reloads that load an address for the very reload we are considering. + + The caller has to make sure that there is no conflict with the return + register. */ +static int +reload_reg_free_for_value_p (regno, opnum, type, value, out, reloadnum, + ignore_address_reloads) + int regno; + int opnum; + enum reload_type type; + rtx value, out; + int reloadnum; + int ignore_address_reloads; +{ + int time1; + int i; + int copy = 0; + + if (out == const0_rtx) + { + copy = 1; + out = NULL_RTX; + } + + /* We use some pseudo 'time' value to check if the lifetimes of the + new register use would overlap with the one of a previous reload + that is not read-only or uses a different value. + The 'time' used doesn't have to be linear in any shape or form, just + monotonic. + Some reload types use different 'buckets' for each operand. + So there are MAX_RECOG_OPERANDS different time values for each + such reload type. + We compute TIME1 as the time when the register for the prospective + new reload ceases to be live, and TIME2 for each existing + reload as the time when that the reload register of that reload + becomes live. + Where there is little to be gained by exact lifetime calculations, + we just make conservative assumptions, i.e. a longer lifetime; + this is done in the 'default:' cases. */ + switch (type) + { + case RELOAD_FOR_OTHER_ADDRESS: + time1 = 0; + break; + case RELOAD_OTHER: + time1 = copy ? 1 : MAX_RECOG_OPERANDS * 5 + 5; + break; + /* For each input, we might have a sequence of RELOAD_FOR_INPADDR_ADDRESS, + RELOAD_FOR_INPUT_ADDRESS and RELOAD_FOR_INPUT. By adding 0 / 1 / 2 , + respectively, to the time values for these, we get distinct time + values. To get distinct time values for each operand, we have to + multiply opnum by at least three. We round that up to four because + multiply by four is often cheaper. */ + case RELOAD_FOR_INPADDR_ADDRESS: + time1 = opnum * 4 + 2; + break; + case RELOAD_FOR_INPUT_ADDRESS: + time1 = opnum * 4 + 3; + break; + case RELOAD_FOR_INPUT: + /* All RELOAD_FOR_INPUT reloads remain live till the instruction + executes (inclusive). */ + time1 = copy ? opnum * 4 + 4 : MAX_RECOG_OPERANDS * 4 + 3; + break; + case RELOAD_FOR_OPADDR_ADDR: + /* opnum * 4 + 4 + <= (MAX_RECOG_OPERANDS - 1) * 4 + 4 == MAX_RECOG_OPERANDS * 4 */ + time1 = MAX_RECOG_OPERANDS * 4 + 1; + break; + case RELOAD_FOR_OPERAND_ADDRESS: + /* RELOAD_FOR_OPERAND_ADDRESS reloads are live even while the insn + is executed. */ + time1 = copy ? MAX_RECOG_OPERANDS * 4 + 2 : MAX_RECOG_OPERANDS * 4 + 3; + break; + case RELOAD_FOR_OUTADDR_ADDRESS: + time1 = MAX_RECOG_OPERANDS * 4 + 4 + opnum; + break; + case RELOAD_FOR_OUTPUT_ADDRESS: + time1 = MAX_RECOG_OPERANDS * 4 + 5 + opnum; + break; + default: + time1 = MAX_RECOG_OPERANDS * 5 + 5; + } + + for (i = 0; i < n_reloads; i++) + { + rtx reg = reload_reg_rtx[i]; + if (reg && GET_CODE (reg) == REG + && ((unsigned) regno - true_regnum (reg) + <= HARD_REGNO_NREGS (REGNO (reg), GET_MODE (reg)) - (unsigned)1) + && i != reloadnum) + { + if (! reload_in[i] || ! rtx_equal_p (reload_in[i], value) + || reload_out[i] || out) + { + int time2; + switch (reload_when_needed[i]) + { + case RELOAD_FOR_OTHER_ADDRESS: + time2 = 0; + break; + case RELOAD_FOR_INPADDR_ADDRESS: + /* find_reloads makes sure that a + RELOAD_FOR_{INP,OP,OUT}ADDR_ADDRESS reload is only used + by at most one - the first - + RELOAD_FOR_{INPUT,OPERAND,OUTPUT}_ADDRESS . If the + address reload is inherited, the address address reload + goes away, so we can ignore this conflict. */ + if (type == RELOAD_FOR_INPUT_ADDRESS && reloadnum == i + 1 + && ignore_address_reloads + /* Unless the RELOAD_FOR_INPUT is an auto_inc expression. + Then the address address is still needed to store + back the new address. */ + && ! reload_out[reloadnum]) + continue; + /* Likewise, if a RELOAD_FOR_INPUT can inherit a value, its + RELOAD_FOR_INPUT_ADDRESS / RELOAD_FOR_INPADDR_ADDRESS + reloads go away. */ + if (type == RELOAD_FOR_INPUT && opnum == reload_opnum[i] + && ignore_address_reloads + /* Unless we are reloading an auto_inc expression. */ + && ! reload_out[reloadnum]) + continue; + time2 = reload_opnum[i] * 4 + 2; + break; + case RELOAD_FOR_INPUT_ADDRESS: + if (type == RELOAD_FOR_INPUT && opnum == reload_opnum[i] + && ignore_address_reloads + && ! reload_out[reloadnum]) + continue; + time2 = reload_opnum[i] * 4 + 3; + break; + case RELOAD_FOR_INPUT: + time2 = reload_opnum[i] * 4 + 4; + break; + /* reload_opnum[i] * 4 + 4 <= (MAX_RECOG_OPERAND - 1) * 4 + 4 + == MAX_RECOG_OPERAND * 4 */ + case RELOAD_FOR_OPADDR_ADDR: + if (type == RELOAD_FOR_OPERAND_ADDRESS && reloadnum == i + 1 + && ignore_address_reloads + && ! reload_out[reloadnum]) + continue; + time2 = MAX_RECOG_OPERANDS * 4 + 1; + break; + case RELOAD_FOR_OPERAND_ADDRESS: + time2 = MAX_RECOG_OPERANDS * 4 + 2; + break; + case RELOAD_FOR_INSN: + time2 = MAX_RECOG_OPERANDS * 4 + 3; + break; + case RELOAD_FOR_OUTPUT: + /* All RELOAD_FOR_OUTPUT reloads become live just after the + instruction is executed. */ + time2 = MAX_RECOG_OPERANDS * 4 + 4; + break; + /* The first RELOAD_FOR_OUTADDR_ADDRESS reload conflicts with + the RELOAD_FOR_OUTPUT reloads, so assign it the same time + value. */ + case RELOAD_FOR_OUTADDR_ADDRESS: + if (type == RELOAD_FOR_OUTPUT_ADDRESS && reloadnum == i + 1 + && ignore_address_reloads + && ! reload_out[reloadnum]) + continue; + time2 = MAX_RECOG_OPERANDS * 4 + 4 + reload_opnum[i]; + break; + case RELOAD_FOR_OUTPUT_ADDRESS: + time2 = MAX_RECOG_OPERANDS * 4 + 5 + reload_opnum[i]; + break; + case RELOAD_OTHER: + /* If there is no conflict in the input part, handle this + like an output reload. */ + if (! reload_in[i] || rtx_equal_p (reload_in[i], value)) + { + time2 = MAX_RECOG_OPERANDS * 4 + 4; + break; + } + time2 = 1; + /* RELOAD_OTHER might be live beyond instruction execution, + but this is not obvious when we set time2 = 1. So check + here if there might be a problem with the new reload + clobbering the register used by the RELOAD_OTHER. */ + if (out) + return 0; + break; + default: + return 0; + } + if ((time1 >= time2 + && (! reload_in[i] || reload_out[i] + || ! rtx_equal_p (reload_in[i], value))) + || (out && reload_out_reg[reloadnum] + && time2 >= MAX_RECOG_OPERANDS * 4 + 3)) + return 0; + } + } + } + return 1; +} + +/* Find a spill register to use as a reload register for reload R. + LAST_RELOAD is non-zero if this is the last reload for the insn being + processed. + + Set reload_reg_rtx[R] to the register allocated. + + If NOERROR is nonzero, we return 1 if successful, + or 0 if we couldn't find a spill reg and we didn't change anything. */ + +static int +allocate_reload_reg (chain, r, last_reload, noerror) + struct insn_chain *chain; + int r; + int last_reload; + int noerror; +{ + rtx insn = chain->insn; + int i, pass, count, regno; + rtx new; + + /* If we put this reload ahead, thinking it is a group, + then insist on finding a group. Otherwise we can grab a + reg that some other reload needs. + (That can happen when we have a 68000 DATA_OR_FP_REG + which is a group of data regs or one fp reg.) + We need not be so restrictive if there are no more reloads + for this insn. + + ??? Really it would be nicer to have smarter handling + for that kind of reg class, where a problem like this is normal. + Perhaps those classes should be avoided for reloading + by use of more alternatives. */ + + int force_group = reload_nregs[r] > 1 && ! last_reload; + + /* If we want a single register and haven't yet found one, + take any reg in the right class and not in use. + If we want a consecutive group, here is where we look for it. + + We use two passes so we can first look for reload regs to + reuse, which are already in use for other reloads in this insn, + and only then use additional registers. + I think that maximizing reuse is needed to make sure we don't + run out of reload regs. Suppose we have three reloads, and + reloads A and B can share regs. These need two regs. + Suppose A and B are given different regs. + That leaves none for C. */ + for (pass = 0; pass < 2; pass++) + { + /* I is the index in spill_regs. + We advance it round-robin between insns to use all spill regs + equally, so that inherited reloads have a chance + of leapfrogging each other. Don't do this, however, when we have + group needs and failure would be fatal; if we only have a relatively + small number of spill registers, and more than one of them has + group needs, then by starting in the middle, we may end up + allocating the first one in such a way that we are not left with + sufficient groups to handle the rest. */ + +/* CYGNUS LOCAL z8k */ +#ifndef RELOAD_ALLOC_ORDER + /* If RELOAD_ALLOC_ORDER is defined, then we must always take spill + registers in that defined order, so this round-robin must be + disabled. */ +/* END CYGNUS LOCAL */ + + if (noerror || ! force_group) + i = last_spill_reg; + else +/* CYGNUS LOCAL z8k */ +#endif +/* END CYGNUS LOCAL */ + i = -1; + + for (count = 0; count < n_spills; count++) + { + int class = (int) reload_reg_class[r]; + int regnum; + + i++; + if (i >= n_spills) + i -= n_spills; + regnum = spill_regs[i]; + + if ((reload_reg_free_p (regnum, reload_opnum[r], + reload_when_needed[r]) + || (reload_in[r] + /* We check reload_reg_used to make sure we + don't clobber the return register. */ + && ! TEST_HARD_REG_BIT (reload_reg_used, regnum) + && reload_reg_free_for_value_p (regnum, + reload_opnum[r], + reload_when_needed[r], + reload_in[r], + reload_out[r], r, 1))) + && TEST_HARD_REG_BIT (reg_class_contents[class], regnum) + && HARD_REGNO_MODE_OK (regnum, reload_mode[r]) + /* Look first for regs to share, then for unshared. But + don't share regs used for inherited reloads; they are + the ones we want to preserve. */ + && (pass + || (TEST_HARD_REG_BIT (reload_reg_used_at_all, + regnum) + && ! TEST_HARD_REG_BIT (reload_reg_used_for_inherit, + regnum)))) + { + int nr = HARD_REGNO_NREGS (regnum, reload_mode[r]); + /* Avoid the problem where spilling a GENERAL_OR_FP_REG + (on 68000) got us two FP regs. If NR is 1, + we would reject both of them. */ + if (force_group) + nr = CLASS_MAX_NREGS (reload_reg_class[r], reload_mode[r]); + /* If we need only one reg, we have already won. */ + if (nr == 1) + { + /* But reject a single reg if we demand a group. */ + if (force_group) + continue; + break; + } + /* Otherwise check that as many consecutive regs as we need + are available here. + Also, don't use for a group registers that are + needed for nongroups. */ + if (! TEST_HARD_REG_BIT (chain->counted_for_nongroups, regnum)) + while (nr > 1) + { + regno = regnum + nr - 1; + if (!(TEST_HARD_REG_BIT (reg_class_contents[class], regno) + && spill_reg_order[regno] >= 0 + && reload_reg_free_p (regno, reload_opnum[r], + reload_when_needed[r]) + && ! TEST_HARD_REG_BIT (chain->counted_for_nongroups, + regno))) + break; + nr--; + } + if (nr == 1) + break; + } + } + + /* If we found something on pass 1, omit pass 2. */ + if (count < n_spills) + break; + } + + /* We should have found a spill register by now. */ + if (count == n_spills) + { + if (noerror) + return 0; + goto failure; + } + + /* I is the index in SPILL_REG_RTX of the reload register we are to + allocate. Get an rtx for it and find its register number. */ + + new = spill_reg_rtx[i]; + + if (new == 0 || GET_MODE (new) != reload_mode[r]) + spill_reg_rtx[i] = new + = gen_rtx_REG (reload_mode[r], spill_regs[i]); + + regno = true_regnum (new); + + /* Detect when the reload reg can't hold the reload mode. + This used to be one `if', but Sequent compiler can't handle that. */ + if (HARD_REGNO_MODE_OK (regno, reload_mode[r])) + { + enum machine_mode test_mode = VOIDmode; + if (reload_in[r]) + test_mode = GET_MODE (reload_in[r]); + /* If reload_in[r] has VOIDmode, it means we will load it + in whatever mode the reload reg has: to wit, reload_mode[r]. + We have already tested that for validity. */ + /* Aside from that, we need to test that the expressions + to reload from or into have modes which are valid for this + reload register. Otherwise the reload insns would be invalid. */ + if (! (reload_in[r] != 0 && test_mode != VOIDmode + && ! HARD_REGNO_MODE_OK (regno, test_mode))) + if (! (reload_out[r] != 0 + && ! HARD_REGNO_MODE_OK (regno, GET_MODE (reload_out[r])))) + { + /* The reg is OK. */ + last_spill_reg = i; + + /* Mark as in use for this insn the reload regs we use + for this. */ + mark_reload_reg_in_use (spill_regs[i], reload_opnum[r], + reload_when_needed[r], reload_mode[r]); + + reload_reg_rtx[r] = new; + reload_spill_index[r] = spill_regs[i]; + return 1; + } + } + + /* The reg is not OK. */ + if (noerror) + return 0; + + failure: + if (asm_noperands (PATTERN (insn)) < 0) + /* It's the compiler's fault. */ + fatal_insn ("Could not find a spill register", insn); + + /* It's the user's fault; the operand's mode and constraint + don't match. Disable this reload so we don't crash in final. */ + error_for_asm (insn, + "`asm' operand constraint incompatible with operand size"); + reload_in[r] = 0; + reload_out[r] = 0; + reload_reg_rtx[r] = 0; + reload_optional[r] = 1; + reload_secondary_p[r] = 1; + + return 1; +} + +/* Assign hard reg targets for the pseudo-registers we must reload + into hard regs for this insn. + Also output the instructions to copy them in and out of the hard regs. + + For machines with register classes, we are responsible for + finding a reload reg in the proper class. */ + +static void +choose_reload_regs (chain) + struct insn_chain *chain; +{ + rtx insn = chain->insn; + register int i, j; + int max_group_size = 1; + enum reg_class group_class = NO_REGS; + int inheritance; + int pass; + + rtx save_reload_reg_rtx[MAX_RELOADS]; + char save_reload_inherited[MAX_RELOADS]; + rtx save_reload_inheritance_insn[MAX_RELOADS]; + rtx save_reload_override_in[MAX_RELOADS]; + int save_reload_spill_index[MAX_RELOADS]; + HARD_REG_SET save_reload_reg_used; + HARD_REG_SET save_reload_reg_used_in_input_addr[MAX_RECOG_OPERANDS]; + HARD_REG_SET save_reload_reg_used_in_inpaddr_addr[MAX_RECOG_OPERANDS]; + HARD_REG_SET save_reload_reg_used_in_output_addr[MAX_RECOG_OPERANDS]; + HARD_REG_SET save_reload_reg_used_in_outaddr_addr[MAX_RECOG_OPERANDS]; + HARD_REG_SET save_reload_reg_used_in_input[MAX_RECOG_OPERANDS]; + HARD_REG_SET save_reload_reg_used_in_output[MAX_RECOG_OPERANDS]; + HARD_REG_SET save_reload_reg_used_in_op_addr; + HARD_REG_SET save_reload_reg_used_in_op_addr_reload; + HARD_REG_SET save_reload_reg_used_in_insn; + HARD_REG_SET save_reload_reg_used_in_other_addr; + HARD_REG_SET save_reload_reg_used_at_all; + + bzero (reload_inherited, MAX_RELOADS); + bzero ((char *) reload_inheritance_insn, MAX_RELOADS * sizeof (rtx)); + bzero ((char *) reload_override_in, MAX_RELOADS * sizeof (rtx)); + + CLEAR_HARD_REG_SET (reload_reg_used); + CLEAR_HARD_REG_SET (reload_reg_used_at_all); + CLEAR_HARD_REG_SET (reload_reg_used_in_op_addr); + CLEAR_HARD_REG_SET (reload_reg_used_in_op_addr_reload); + CLEAR_HARD_REG_SET (reload_reg_used_in_insn); + CLEAR_HARD_REG_SET (reload_reg_used_in_other_addr); + + CLEAR_HARD_REG_SET (reg_used_in_insn); + { + HARD_REG_SET tmp; + REG_SET_TO_HARD_REG_SET (tmp, chain->live_before); + IOR_HARD_REG_SET (reg_used_in_insn, tmp); + REG_SET_TO_HARD_REG_SET (tmp, chain->live_after); + IOR_HARD_REG_SET (reg_used_in_insn, tmp); + compute_use_by_pseudos (®_used_in_insn, chain->live_before); + compute_use_by_pseudos (®_used_in_insn, chain->live_after); + } + for (i = 0; i < reload_n_operands; i++) + { + CLEAR_HARD_REG_SET (reload_reg_used_in_output[i]); + CLEAR_HARD_REG_SET (reload_reg_used_in_input[i]); + CLEAR_HARD_REG_SET (reload_reg_used_in_input_addr[i]); + CLEAR_HARD_REG_SET (reload_reg_used_in_inpaddr_addr[i]); + CLEAR_HARD_REG_SET (reload_reg_used_in_output_addr[i]); + CLEAR_HARD_REG_SET (reload_reg_used_in_outaddr_addr[i]); + } + + IOR_COMPL_HARD_REG_SET (reload_reg_used, chain->used_spill_regs); + +#if 0 /* Not needed, now that we can always retry without inheritance. */ + /* See if we have more mandatory reloads than spill regs. + If so, then we cannot risk optimizations that could prevent + reloads from sharing one spill register. + + Since we will try finding a better register than reload_reg_rtx + unless it is equal to reload_in or reload_out, count such reloads. */ + + { + int tem = 0; + for (j = 0; j < n_reloads; j++) + if (! reload_optional[j] + && (reload_in[j] != 0 || reload_out[j] != 0 || reload_secondary_p[j]) + && (reload_reg_rtx[j] == 0 + || (! rtx_equal_p (reload_reg_rtx[j], reload_in[j]) + && ! rtx_equal_p (reload_reg_rtx[j], reload_out[j])))) + tem++; + if (tem > n_spills) + must_reuse = 1; + } +#endif + + /* In order to be certain of getting the registers we need, + we must sort the reloads into order of increasing register class. + Then our grabbing of reload registers will parallel the process + that provided the reload registers. + + Also note whether any of the reloads wants a consecutive group of regs. + If so, record the maximum size of the group desired and what + register class contains all the groups needed by this insn. */ + + for (j = 0; j < n_reloads; j++) + { + reload_order[j] = j; + reload_spill_index[j] = -1; + + reload_mode[j] + = (reload_inmode[j] == VOIDmode + || (GET_MODE_SIZE (reload_outmode[j]) + > GET_MODE_SIZE (reload_inmode[j]))) + ? reload_outmode[j] : reload_inmode[j]; + + reload_nregs[j] = CLASS_MAX_NREGS (reload_reg_class[j], reload_mode[j]); + + if (reload_nregs[j] > 1) + { + max_group_size = MAX (reload_nregs[j], max_group_size); + group_class = reg_class_superunion[(int)reload_reg_class[j]][(int)group_class]; + } + + /* If we have already decided to use a certain register, + don't use it in another way. */ + if (reload_reg_rtx[j]) + mark_reload_reg_in_use (REGNO (reload_reg_rtx[j]), reload_opnum[j], + reload_when_needed[j], reload_mode[j]); + } + + if (n_reloads > 1) + qsort (reload_order, n_reloads, sizeof (short), reload_reg_class_lower); + + bcopy ((char *) reload_reg_rtx, (char *) save_reload_reg_rtx, + sizeof reload_reg_rtx); + bcopy (reload_inherited, save_reload_inherited, sizeof reload_inherited); + bcopy ((char *) reload_inheritance_insn, + (char *) save_reload_inheritance_insn, + sizeof reload_inheritance_insn); + bcopy ((char *) reload_override_in, (char *) save_reload_override_in, + sizeof reload_override_in); + bcopy ((char *) reload_spill_index, (char *) save_reload_spill_index, + sizeof reload_spill_index); + COPY_HARD_REG_SET (save_reload_reg_used, reload_reg_used); + COPY_HARD_REG_SET (save_reload_reg_used_at_all, reload_reg_used_at_all); + COPY_HARD_REG_SET (save_reload_reg_used_in_op_addr, + reload_reg_used_in_op_addr); + + COPY_HARD_REG_SET (save_reload_reg_used_in_op_addr_reload, + reload_reg_used_in_op_addr_reload); + + COPY_HARD_REG_SET (save_reload_reg_used_in_insn, + reload_reg_used_in_insn); + COPY_HARD_REG_SET (save_reload_reg_used_in_other_addr, + reload_reg_used_in_other_addr); + + for (i = 0; i < reload_n_operands; i++) + { + COPY_HARD_REG_SET (save_reload_reg_used_in_output[i], + reload_reg_used_in_output[i]); + COPY_HARD_REG_SET (save_reload_reg_used_in_input[i], + reload_reg_used_in_input[i]); + COPY_HARD_REG_SET (save_reload_reg_used_in_input_addr[i], + reload_reg_used_in_input_addr[i]); + COPY_HARD_REG_SET (save_reload_reg_used_in_inpaddr_addr[i], + reload_reg_used_in_inpaddr_addr[i]); + COPY_HARD_REG_SET (save_reload_reg_used_in_output_addr[i], + reload_reg_used_in_output_addr[i]); + COPY_HARD_REG_SET (save_reload_reg_used_in_outaddr_addr[i], + reload_reg_used_in_outaddr_addr[i]); + } + + /* If -O, try first with inheritance, then turning it off. + If not -O, don't do inheritance. + Using inheritance when not optimizing leads to paradoxes + with fp on the 68k: fp numbers (not NaNs) fail to be equal to themselves + because one side of the comparison might be inherited. */ + + for (inheritance = optimize > 0; inheritance >= 0; inheritance--) + { + /* Process the reloads in order of preference just found. + Beyond this point, subregs can be found in reload_reg_rtx. + + This used to look for an existing reloaded home for all + of the reloads, and only then perform any new reloads. + But that could lose if the reloads were done out of reg-class order + because a later reload with a looser constraint might have an old + home in a register needed by an earlier reload with a tighter constraint. + + To solve this, we make two passes over the reloads, in the order + described above. In the first pass we try to inherit a reload + from a previous insn. If there is a later reload that needs a + class that is a proper subset of the class being processed, we must + also allocate a spill register during the first pass. + + Then make a second pass over the reloads to allocate any reloads + that haven't been given registers yet. */ + + CLEAR_HARD_REG_SET (reload_reg_used_for_inherit); + + for (j = 0; j < n_reloads; j++) + { + register int r = reload_order[j]; + + /* Ignore reloads that got marked inoperative. */ + if (reload_out[r] == 0 && reload_in[r] == 0 + && ! reload_secondary_p[r]) + continue; + + /* If find_reloads chose to use reload_in or reload_out as a reload + register, we don't need to chose one. Otherwise, try even if it + found one since we might save an insn if we find the value lying + around. + Try also when reload_in is a pseudo without a hard reg. */ + if (reload_in[r] != 0 && reload_reg_rtx[r] != 0 + && (rtx_equal_p (reload_in[r], reload_reg_rtx[r]) + || (rtx_equal_p (reload_out[r], reload_reg_rtx[r]) + && GET_CODE (reload_in[r]) != MEM + && true_regnum (reload_in[r]) < FIRST_PSEUDO_REGISTER))) + continue; + +#if 0 /* No longer needed for correct operation. + It might give better code, or might not; worth an experiment? */ + /* If this is an optional reload, we can't inherit from earlier insns + until we are sure that any non-optional reloads have been allocated. + The following code takes advantage of the fact that optional reloads + are at the end of reload_order. */ + if (reload_optional[r] != 0) + for (i = 0; i < j; i++) + if ((reload_out[reload_order[i]] != 0 + || reload_in[reload_order[i]] != 0 + || reload_secondary_p[reload_order[i]]) + && ! reload_optional[reload_order[i]] + && reload_reg_rtx[reload_order[i]] == 0) + allocate_reload_reg (chain, reload_order[i], 0, inheritance); +#endif + + /* First see if this pseudo is already available as reloaded + for a previous insn. We cannot try to inherit for reloads + that are smaller than the maximum number of registers needed + for groups unless the register we would allocate cannot be used + for the groups. + + We could check here to see if this is a secondary reload for + an object that is already in a register of the desired class. + This would avoid the need for the secondary reload register. + But this is complex because we can't easily determine what + objects might want to be loaded via this reload. So let a + register be allocated here. In `emit_reload_insns' we suppress + one of the loads in the case described above. */ + + if (inheritance) + { + int word = 0; + register int regno = -1; + enum machine_mode mode; + + if (reload_in[r] == 0) + ; + else if (GET_CODE (reload_in[r]) == REG) + { + regno = REGNO (reload_in[r]); + mode = GET_MODE (reload_in[r]); + } + else if (GET_CODE (reload_in_reg[r]) == REG) + { + regno = REGNO (reload_in_reg[r]); + mode = GET_MODE (reload_in_reg[r]); + } + else if (GET_CODE (reload_in_reg[r]) == SUBREG + && GET_CODE (SUBREG_REG (reload_in_reg[r])) == REG) + { + word = SUBREG_WORD (reload_in_reg[r]); + regno = REGNO (SUBREG_REG (reload_in_reg[r])); + if (regno < FIRST_PSEUDO_REGISTER) + regno += word; + mode = GET_MODE (reload_in_reg[r]); + } +#ifdef AUTO_INC_DEC + else if ((GET_CODE (reload_in_reg[r]) == PRE_INC + || GET_CODE (reload_in_reg[r]) == PRE_DEC + || GET_CODE (reload_in_reg[r]) == POST_INC + || GET_CODE (reload_in_reg[r]) == POST_DEC) + && GET_CODE (XEXP (reload_in_reg[r], 0)) == REG) + { + regno = REGNO (XEXP (reload_in_reg[r], 0)); + mode = GET_MODE (XEXP (reload_in_reg[r], 0)); + reload_out[r] = reload_in[r]; + } +#endif +#if 0 + /* This won't work, since REGNO can be a pseudo reg number. + Also, it takes much more hair to keep track of all the things + that can invalidate an inherited reload of part of a pseudoreg. */ + else if (GET_CODE (reload_in[r]) == SUBREG + && GET_CODE (SUBREG_REG (reload_in[r])) == REG) + regno = REGNO (SUBREG_REG (reload_in[r])) + SUBREG_WORD (reload_in[r]); +#endif + + if (regno >= 0 && reg_last_reload_reg[regno] != 0) + { + enum reg_class class = reload_reg_class[r], last_class; + rtx last_reg = reg_last_reload_reg[regno]; + + i = REGNO (last_reg) + word; + last_class = REGNO_REG_CLASS (i); + if ((GET_MODE_SIZE (GET_MODE (last_reg)) + >= GET_MODE_SIZE (mode) + word * UNITS_PER_WORD) + && reg_reloaded_contents[i] == regno + && TEST_HARD_REG_BIT (reg_reloaded_valid, i) + && HARD_REGNO_MODE_OK (i, reload_mode[r]) + && (TEST_HARD_REG_BIT (reg_class_contents[(int) class], i) + /* Even if we can't use this register as a reload + register, we might use it for reload_override_in, + if copying it to the desired class is cheap + enough. */ + || ((REGISTER_MOVE_COST (last_class, class) + < MEMORY_MOVE_COST (mode, class, 1)) +#ifdef SECONDARY_INPUT_RELOAD_CLASS + && (SECONDARY_INPUT_RELOAD_CLASS (class, mode, + last_reg) + == NO_REGS) +#endif +#ifdef SECONDARY_MEMORY_NEEDED + && ! SECONDARY_MEMORY_NEEDED (last_class, class, + mode) +#endif + )) + + && (reload_nregs[r] == max_group_size + || ! TEST_HARD_REG_BIT (reg_class_contents[(int) group_class], + i)) + && reload_reg_free_for_value_p (i, reload_opnum[r], + reload_when_needed[r], + reload_in[r], + const0_rtx, r, 1)) + { + /* If a group is needed, verify that all the subsequent + registers still have their values intact. */ + int nr + = HARD_REGNO_NREGS (i, reload_mode[r]); + int k; + + for (k = 1; k < nr; k++) + if (reg_reloaded_contents[i + k] != regno + || ! TEST_HARD_REG_BIT (reg_reloaded_valid, i + k)) + break; + + if (k == nr) + { + int i1; + + last_reg = (GET_MODE (last_reg) == mode + ? last_reg : gen_rtx_REG (mode, i)); + + /* We found a register that contains the + value we need. If this register is the + same as an `earlyclobber' operand of the + current insn, just mark it as a place to + reload from since we can't use it as the + reload register itself. */ + + for (i1 = 0; i1 < n_earlyclobbers; i1++) + if (reg_overlap_mentioned_for_reload_p + (reg_last_reload_reg[regno], + reload_earlyclobbers[i1])) + break; + + if (i1 != n_earlyclobbers + || ! (reload_reg_free_for_value_p + (i, reload_opnum[r], reload_when_needed[r], + reload_in[r], reload_out[r], r, 1)) + /* Don't use it if we'd clobber a pseudo reg. */ + || (TEST_HARD_REG_BIT (reg_used_in_insn, i) + && reload_out[r] + && ! TEST_HARD_REG_BIT (reg_reloaded_dead, i)) + /* Don't clobber the frame pointer. */ + || (i == HARD_FRAME_POINTER_REGNUM + && reload_out[r]) + /* Don't really use the inherited spill reg + if we need it wider than we've got it. */ + || (GET_MODE_SIZE (reload_mode[r]) + > GET_MODE_SIZE (mode)) + || ! TEST_HARD_REG_BIT (reg_class_contents[(int) reload_reg_class[r]], + i) + + /* If find_reloads chose reload_out as reload + register, stay with it - that leaves the + inherited register for subsequent reloads. */ + || (reload_out[r] && reload_reg_rtx[r] + && rtx_equal_p (reload_out[r], + reload_reg_rtx[r]))) + { + reload_override_in[r] = last_reg; + reload_inheritance_insn[r] + = reg_reloaded_insn[i]; + } + else + { + int k; + /* We can use this as a reload reg. */ + /* Mark the register as in use for this part of + the insn. */ + mark_reload_reg_in_use (i, + reload_opnum[r], + reload_when_needed[r], + reload_mode[r]); + reload_reg_rtx[r] = last_reg; + reload_inherited[r] = 1; + reload_inheritance_insn[r] + = reg_reloaded_insn[i]; + reload_spill_index[r] = i; + for (k = 0; k < nr; k++) + SET_HARD_REG_BIT (reload_reg_used_for_inherit, + i + k); + } + } + } + } + } + + /* Here's another way to see if the value is already lying around. */ + if (inheritance + && reload_in[r] != 0 + && ! reload_inherited[r] + && reload_out[r] == 0 + && (CONSTANT_P (reload_in[r]) + || GET_CODE (reload_in[r]) == PLUS + || GET_CODE (reload_in[r]) == REG + || GET_CODE (reload_in[r]) == MEM) + && (reload_nregs[r] == max_group_size + || ! reg_classes_intersect_p (reload_reg_class[r], group_class))) + { + register rtx equiv + = find_equiv_reg (reload_in[r], insn, reload_reg_class[r], + -1, NULL_PTR, 0, reload_mode[r]); + int regno; + + if (equiv != 0) + { + if (GET_CODE (equiv) == REG) + regno = REGNO (equiv); + else if (GET_CODE (equiv) == SUBREG) + { + /* This must be a SUBREG of a hard register. + Make a new REG since this might be used in an + address and not all machines support SUBREGs + there. */ + regno = REGNO (SUBREG_REG (equiv)) + SUBREG_WORD (equiv); + equiv = gen_rtx_REG (reload_mode[r], regno); + } + else + abort (); + } + + /* If we found a spill reg, reject it unless it is free + and of the desired class. */ + if (equiv != 0 + && ((TEST_HARD_REG_BIT (reload_reg_used_at_all, regno) + && ! reload_reg_free_for_value_p (regno, reload_opnum[r], + reload_when_needed[r], + reload_in[r], + reload_out[r], r, 1)) + || ! TEST_HARD_REG_BIT (reg_class_contents[(int) reload_reg_class[r]], + regno))) + equiv = 0; + + if (equiv != 0 && ! HARD_REGNO_MODE_OK (regno, reload_mode[r])) + equiv = 0; + + /* We found a register that contains the value we need. + If this register is the same as an `earlyclobber' operand + of the current insn, just mark it as a place to reload from + since we can't use it as the reload register itself. */ + + if (equiv != 0) + for (i = 0; i < n_earlyclobbers; i++) + if (reg_overlap_mentioned_for_reload_p (equiv, + reload_earlyclobbers[i])) + { + reload_override_in[r] = equiv; + equiv = 0; + break; + } + + /* If the equiv register we have found is explicitly clobbered + in the current insn, it depends on the reload type if we + can use it, use it for reload_override_in, or not at all. + In particular, we then can't use EQUIV for a + RELOAD_FOR_OUTPUT_ADDRESS reload. */ + + if (equiv != 0 && regno_clobbered_p (regno, insn)) + { + switch (reload_when_needed[r]) + { + case RELOAD_FOR_OTHER_ADDRESS: + case RELOAD_FOR_INPADDR_ADDRESS: + case RELOAD_FOR_INPUT_ADDRESS: + case RELOAD_FOR_OPADDR_ADDR: + break; + case RELOAD_OTHER: + case RELOAD_FOR_INPUT: + case RELOAD_FOR_OPERAND_ADDRESS: + reload_override_in[r] = equiv; + /* Fall through. */ + default: + equiv = 0; + break; + } + } + + /* If we found an equivalent reg, say no code need be generated + to load it, and use it as our reload reg. */ + if (equiv != 0 && regno != HARD_FRAME_POINTER_REGNUM) + { + int nr = HARD_REGNO_NREGS (regno, reload_mode[r]); + int k; + reload_reg_rtx[r] = equiv; + reload_inherited[r] = 1; + + /* If reg_reloaded_valid is not set for this register, + there might be a stale spill_reg_store lying around. + We must clear it, since otherwise emit_reload_insns + might delete the store. */ + if (! TEST_HARD_REG_BIT (reg_reloaded_valid, regno)) + spill_reg_store[regno] = NULL_RTX; + /* If any of the hard registers in EQUIV are spill + registers, mark them as in use for this insn. */ + for (k = 0; k < nr; k++) + { + i = spill_reg_order[regno + k]; + if (i >= 0) + { + mark_reload_reg_in_use (regno, reload_opnum[r], + reload_when_needed[r], + reload_mode[r]); + SET_HARD_REG_BIT (reload_reg_used_for_inherit, + regno + k); + } + } + } + } + + /* If we found a register to use already, or if this is an optional + reload, we are done. */ + if (reload_reg_rtx[r] != 0 || reload_optional[r] != 0) + continue; + +#if 0 /* No longer needed for correct operation. Might or might not + give better code on the average. Want to experiment? */ + + /* See if there is a later reload that has a class different from our + class that intersects our class or that requires less register + than our reload. If so, we must allocate a register to this + reload now, since that reload might inherit a previous reload + and take the only available register in our class. Don't do this + for optional reloads since they will force all previous reloads + to be allocated. Also don't do this for reloads that have been + turned off. */ + + for (i = j + 1; i < n_reloads; i++) + { + int s = reload_order[i]; + + if ((reload_in[s] == 0 && reload_out[s] == 0 + && ! reload_secondary_p[s]) + || reload_optional[s]) + continue; + + if ((reload_reg_class[s] != reload_reg_class[r] + && reg_classes_intersect_p (reload_reg_class[r], + reload_reg_class[s])) + || reload_nregs[s] < reload_nregs[r]) + break; + } + + if (i == n_reloads) + continue; + + allocate_reload_reg (chain, r, j == n_reloads - 1, inheritance); +#endif + } + + /* Now allocate reload registers for anything non-optional that + didn't get one yet. */ + for (j = 0; j < n_reloads; j++) + { + register int r = reload_order[j]; + + /* Ignore reloads that got marked inoperative. */ + if (reload_out[r] == 0 && reload_in[r] == 0 && ! reload_secondary_p[r]) + continue; + + /* Skip reloads that already have a register allocated or are + optional. */ + if (reload_reg_rtx[r] != 0 || reload_optional[r]) + continue; + + if (! allocate_reload_reg (chain, r, j == n_reloads - 1, inheritance)) + break; + } + + /* If that loop got all the way, we have won. */ + if (j == n_reloads) + break; + + /* Loop around and try without any inheritance. */ + /* First undo everything done by the failed attempt + to allocate with inheritance. */ + bcopy ((char *) save_reload_reg_rtx, (char *) reload_reg_rtx, + sizeof reload_reg_rtx); + bcopy ((char *) save_reload_inherited, (char *) reload_inherited, + sizeof reload_inherited); + bcopy ((char *) save_reload_inheritance_insn, + (char *) reload_inheritance_insn, + sizeof reload_inheritance_insn); + bcopy ((char *) save_reload_override_in, (char *) reload_override_in, + sizeof reload_override_in); + bcopy ((char *) save_reload_spill_index, (char *) reload_spill_index, + sizeof reload_spill_index); + COPY_HARD_REG_SET (reload_reg_used, save_reload_reg_used); + COPY_HARD_REG_SET (reload_reg_used_at_all, save_reload_reg_used_at_all); + COPY_HARD_REG_SET (reload_reg_used_in_op_addr, + save_reload_reg_used_in_op_addr); + COPY_HARD_REG_SET (reload_reg_used_in_op_addr_reload, + save_reload_reg_used_in_op_addr_reload); + COPY_HARD_REG_SET (reload_reg_used_in_insn, + save_reload_reg_used_in_insn); + COPY_HARD_REG_SET (reload_reg_used_in_other_addr, + save_reload_reg_used_in_other_addr); + + for (i = 0; i < reload_n_operands; i++) + { + COPY_HARD_REG_SET (reload_reg_used_in_input[i], + save_reload_reg_used_in_input[i]); + COPY_HARD_REG_SET (reload_reg_used_in_output[i], + save_reload_reg_used_in_output[i]); + COPY_HARD_REG_SET (reload_reg_used_in_input_addr[i], + save_reload_reg_used_in_input_addr[i]); + COPY_HARD_REG_SET (reload_reg_used_in_inpaddr_addr[i], + save_reload_reg_used_in_inpaddr_addr[i]); + COPY_HARD_REG_SET (reload_reg_used_in_output_addr[i], + save_reload_reg_used_in_output_addr[i]); + COPY_HARD_REG_SET (reload_reg_used_in_outaddr_addr[i], + save_reload_reg_used_in_outaddr_addr[i]); + } + } + + /* If we thought we could inherit a reload, because it seemed that + nothing else wanted the same reload register earlier in the insn, + verify that assumption, now that all reloads have been assigned. + Likewise for reloads where reload_override_in has been set. */ + + /* If doing expensive optimizations, do one preliminary pass that doesn't + cancel any inheritance, but removes reloads that have been needed only + for reloads that we know can be inherited. */ + for (pass = flag_expensive_optimizations; pass >= 0; pass--) + { + for (j = 0; j < n_reloads; j++) + { + register int r = reload_order[j]; + rtx check_reg; + int check_regnum, nr, cant_inherit; + + if (reload_inherited[r] && reload_reg_rtx[r]) + check_reg = reload_reg_rtx[r]; + else if (reload_override_in[r] + && (GET_CODE (reload_override_in[r]) == REG + || GET_CODE (reload_override_in[r]) == SUBREG)) + check_reg = reload_override_in[r]; + else + continue; + + /* ??? reload_reg_free_for_value_p does not correctly handle + multi-word hard registers, so we loop and call it for each + individual hard register. All other places in reload that + call this function will also have to be fixed. */ + check_regnum = true_regnum (check_reg); + nr = HARD_REGNO_NREGS (check_regnum, reload_mode[r]); + cant_inherit = 0; + for (i = check_regnum + nr - 1; i >= check_regnum; i--) + if (! reload_reg_free_for_value_p (i, reload_opnum[r], + reload_when_needed[r], + reload_in[r], + (reload_inherited[r] + ? reload_out[r] : const0_rtx), + r, 1)) + { + cant_inherit = 1; + break; + } + + if (cant_inherit) + { + if (pass) + continue; + reload_inherited[r] = 0; + reload_override_in[r] = 0; + } + /* If we can inherit a RELOAD_FOR_INPUT, or can use a + reload_override_in, then we do not need its related + RELOAD_FOR_INPUT_ADDRESS / RELOAD_FOR_INPADDR_ADDRESS reloads; + likewise for other reload types. + We handle this by removing a reload when its only replacement + is mentioned in reload_in of the reload we are going to inherit. + A special case are auto_inc expressions; even if the input is + inherited, we still need the address for the output. We can + recognize them because they have RELOAD_OUT set but not + RELOAD_OUT_REG. + If we suceeded removing some reload and we are doing a preliminary + pass just to remove such reloads, make another pass, since the + removal of one reload might allow us to inherit another one. */ + else if ((! reload_out[r] || reload_out_reg[r]) + && remove_address_replacements (reload_in[r]) && pass) + pass = 2; + } + } + + /* Now that reload_override_in is known valid, + actually override reload_in. */ + for (j = 0; j < n_reloads; j++) + if (reload_override_in[j]) + reload_in[j] = reload_override_in[j]; + + /* If this reload won't be done because it has been cancelled or is + optional and not inherited, clear reload_reg_rtx so other + routines (such as subst_reloads) don't get confused. */ + for (j = 0; j < n_reloads; j++) + if (reload_reg_rtx[j] != 0 + && ((reload_optional[j] && ! reload_inherited[j]) + || (reload_in[j] == 0 && reload_out[j] == 0 + && ! reload_secondary_p[j]))) + { + int regno = true_regnum (reload_reg_rtx[j]); + + if (spill_reg_order[regno] >= 0) + clear_reload_reg_in_use (regno, reload_opnum[j], + reload_when_needed[j], reload_mode[j]); + reload_reg_rtx[j] = 0; + } + + /* Record which pseudos and which spill regs have output reloads. */ + for (j = 0; j < n_reloads; j++) + { + register int r = reload_order[j]; + + i = reload_spill_index[r]; + + /* I is nonneg if this reload uses a register. + If reload_reg_rtx[r] is 0, this is an optional reload + that we opted to ignore. */ + if (reload_out_reg[r] != 0 && GET_CODE (reload_out_reg[r]) == REG + && reload_reg_rtx[r] != 0) + { + register int nregno = REGNO (reload_out_reg[r]); + int nr = 1; + + if (nregno < FIRST_PSEUDO_REGISTER) + nr = HARD_REGNO_NREGS (nregno, reload_mode[r]); + + while (--nr >= 0) + reg_has_output_reload[nregno + nr] = 1; + + if (i >= 0) + { + nr = HARD_REGNO_NREGS (i, reload_mode[r]); + while (--nr >= 0) + SET_HARD_REG_BIT (reg_is_output_reload, i + nr); + } + + if (reload_when_needed[r] != RELOAD_OTHER + && reload_when_needed[r] != RELOAD_FOR_OUTPUT + && reload_when_needed[r] != RELOAD_FOR_INSN) + abort (); + } + } +} + +/* Deallocate the reload register for reload R. This is called from + remove_address_replacements. */ +void +deallocate_reload_reg (r) + int r; +{ + int regno; + + if (! reload_reg_rtx[r]) + return; + regno = true_regnum (reload_reg_rtx[r]); + reload_reg_rtx[r] = 0; + if (spill_reg_order[regno] >= 0) + clear_reload_reg_in_use (regno, reload_opnum[r], reload_when_needed[r], + reload_mode[r]); + reload_spill_index[r] = -1; +} + +/* If SMALL_REGISTER_CLASSES is non-zero, we may not have merged two + reloads of the same item for fear that we might not have enough reload + registers. However, normally they will get the same reload register + and hence actually need not be loaded twice. + + Here we check for the most common case of this phenomenon: when we have + a number of reloads for the same object, each of which were allocated + the same reload_reg_rtx, that reload_reg_rtx is not used for any other + reload, and is not modified in the insn itself. If we find such, + merge all the reloads and set the resulting reload to RELOAD_OTHER. + This will not increase the number of spill registers needed and will + prevent redundant code. */ + +static void +merge_assigned_reloads (insn) + rtx insn; +{ + int i, j; + + /* Scan all the reloads looking for ones that only load values and + are not already RELOAD_OTHER and ones whose reload_reg_rtx are + assigned and not modified by INSN. */ + + for (i = 0; i < n_reloads; i++) + { + int conflicting_input = 0; + int max_input_address_opnum = -1; + int min_conflicting_input_opnum = MAX_RECOG_OPERANDS; + + if (reload_in[i] == 0 || reload_when_needed[i] == RELOAD_OTHER + || reload_out[i] != 0 || reload_reg_rtx[i] == 0 + || reg_set_p (reload_reg_rtx[i], insn)) + continue; + + /* Look at all other reloads. Ensure that the only use of this + reload_reg_rtx is in a reload that just loads the same value + as we do. Note that any secondary reloads must be of the identical + class since the values, modes, and result registers are the + same, so we need not do anything with any secondary reloads. */ + + for (j = 0; j < n_reloads; j++) + { + if (i == j || reload_reg_rtx[j] == 0 + || ! reg_overlap_mentioned_p (reload_reg_rtx[j], + reload_reg_rtx[i])) + continue; + + if (reload_when_needed[j] == RELOAD_FOR_INPUT_ADDRESS + && reload_opnum[j] > max_input_address_opnum) + max_input_address_opnum = reload_opnum[j]; + + /* If the reload regs aren't exactly the same (e.g, different modes) + or if the values are different, we can't merge this reload. + But if it is an input reload, we might still merge + RELOAD_FOR_INPUT_ADDRESS and RELOAD_FOR_OTHER_ADDRESS reloads. */ + + if (! rtx_equal_p (reload_reg_rtx[i], reload_reg_rtx[j]) + || reload_out[j] != 0 || reload_in[j] == 0 + || ! rtx_equal_p (reload_in[i], reload_in[j])) + { + if (reload_when_needed[j] != RELOAD_FOR_INPUT + || ((reload_when_needed[i] != RELOAD_FOR_INPUT_ADDRESS + || reload_opnum[i] > reload_opnum[j]) + && reload_when_needed[i] != RELOAD_FOR_OTHER_ADDRESS)) + break; + conflicting_input = 1; + if (min_conflicting_input_opnum > reload_opnum[j]) + min_conflicting_input_opnum = reload_opnum[j]; + } + } + + /* If all is OK, merge the reloads. Only set this to RELOAD_OTHER if + we, in fact, found any matching reloads. */ + + if (j == n_reloads + && max_input_address_opnum <= min_conflicting_input_opnum) + { + for (j = 0; j < n_reloads; j++) + if (i != j && reload_reg_rtx[j] != 0 + && rtx_equal_p (reload_reg_rtx[i], reload_reg_rtx[j]) + && (! conflicting_input + || reload_when_needed[j] == RELOAD_FOR_INPUT_ADDRESS + || reload_when_needed[j] == RELOAD_FOR_OTHER_ADDRESS)) + { + reload_when_needed[i] = RELOAD_OTHER; + reload_in[j] = 0; + reload_spill_index[j] = -1; + transfer_replacements (i, j); + } + + /* If this is now RELOAD_OTHER, look for any reloads that load + parts of this operand and set them to RELOAD_FOR_OTHER_ADDRESS + if they were for inputs, RELOAD_OTHER for outputs. Note that + this test is equivalent to looking for reloads for this operand + number. */ + + if (reload_when_needed[i] == RELOAD_OTHER) + for (j = 0; j < n_reloads; j++) + if (reload_in[j] != 0 + && reload_when_needed[i] != RELOAD_OTHER + && reg_overlap_mentioned_for_reload_p (reload_in[j], + reload_in[i])) + reload_when_needed[j] + = ((reload_when_needed[i] == RELOAD_FOR_INPUT_ADDRESS + || reload_when_needed[i] == RELOAD_FOR_INPADDR_ADDRESS) + ? RELOAD_FOR_OTHER_ADDRESS : RELOAD_OTHER); + } + } +} + + +/* Output insns to reload values in and out of the chosen reload regs. */ + +static void +emit_reload_insns (chain) + struct insn_chain *chain; +{ + rtx insn = chain->insn; + + register int j; + rtx input_reload_insns[MAX_RECOG_OPERANDS]; + rtx other_input_address_reload_insns = 0; + rtx other_input_reload_insns = 0; + rtx input_address_reload_insns[MAX_RECOG_OPERANDS]; + rtx inpaddr_address_reload_insns[MAX_RECOG_OPERANDS]; + rtx output_reload_insns[MAX_RECOG_OPERANDS]; + rtx output_address_reload_insns[MAX_RECOG_OPERANDS]; + rtx outaddr_address_reload_insns[MAX_RECOG_OPERANDS]; + rtx operand_reload_insns = 0; + rtx other_operand_reload_insns = 0; + rtx other_output_reload_insns[MAX_RECOG_OPERANDS]; + rtx following_insn = NEXT_INSN (insn); + rtx before_insn = PREV_INSN (insn); + int special; + /* Values to be put in spill_reg_store are put here first. */ + rtx new_spill_reg_store[FIRST_PSEUDO_REGISTER]; + HARD_REG_SET reg_reloaded_died; + + CLEAR_HARD_REG_SET (reg_reloaded_died); + + for (j = 0; j < reload_n_operands; j++) + input_reload_insns[j] = input_address_reload_insns[j] + = inpaddr_address_reload_insns[j] + = output_reload_insns[j] = output_address_reload_insns[j] + = outaddr_address_reload_insns[j] + = other_output_reload_insns[j] = 0; + + /* Now output the instructions to copy the data into and out of the + reload registers. Do these in the order that the reloads were reported, + since reloads of base and index registers precede reloads of operands + and the operands may need the base and index registers reloaded. */ + + for (j = 0; j < n_reloads; j++) + { + register rtx old; + rtx oldequiv_reg = 0; + rtx this_reload_insn = 0; + int expect_occurrences = 1; + + if (reload_reg_rtx[j] + && REGNO (reload_reg_rtx[j]) < FIRST_PSEUDO_REGISTER) + new_spill_reg_store[REGNO (reload_reg_rtx[j])] = 0; + + old = (reload_in[j] && GET_CODE (reload_in[j]) == MEM + ? reload_in_reg[j] : reload_in[j]); + + if (old != 0 + /* AUTO_INC reloads need to be handled even if inherited. We got an + AUTO_INC reload if reload_out is set but reload_out_reg isn't. */ + && (! reload_inherited[j] || (reload_out[j] && ! reload_out_reg[j])) + && ! rtx_equal_p (reload_reg_rtx[j], old) + && reload_reg_rtx[j] != 0) + { + register rtx reloadreg = reload_reg_rtx[j]; + rtx oldequiv = 0; + enum machine_mode mode; + rtx *where; + + /* Determine the mode to reload in. + This is very tricky because we have three to choose from. + There is the mode the insn operand wants (reload_inmode[J]). + There is the mode of the reload register RELOADREG. + There is the intrinsic mode of the operand, which we could find + by stripping some SUBREGs. + It turns out that RELOADREG's mode is irrelevant: + we can change that arbitrarily. + + Consider (SUBREG:SI foo:QI) as an operand that must be SImode; + then the reload reg may not support QImode moves, so use SImode. + If foo is in memory due to spilling a pseudo reg, this is safe, + because the QImode value is in the least significant part of a + slot big enough for a SImode. If foo is some other sort of + memory reference, then it is impossible to reload this case, + so previous passes had better make sure this never happens. + + Then consider a one-word union which has SImode and one of its + members is a float, being fetched as (SUBREG:SF union:SI). + We must fetch that as SFmode because we could be loading into + a float-only register. In this case OLD's mode is correct. + + Consider an immediate integer: it has VOIDmode. Here we need + to get a mode from something else. + + In some cases, there is a fourth mode, the operand's + containing mode. If the insn specifies a containing mode for + this operand, it overrides all others. + + I am not sure whether the algorithm here is always right, + but it does the right things in those cases. */ + + mode = GET_MODE (old); + if (mode == VOIDmode) + mode = reload_inmode[j]; + +#ifdef SECONDARY_INPUT_RELOAD_CLASS + /* If we need a secondary register for this operation, see if + the value is already in a register in that class. Don't + do this if the secondary register will be used as a scratch + register. */ + + if (reload_secondary_in_reload[j] >= 0 + && reload_secondary_in_icode[j] == CODE_FOR_nothing + && optimize) + oldequiv + = find_equiv_reg (old, insn, + reload_reg_class[reload_secondary_in_reload[j]], + -1, NULL_PTR, 0, mode); +#endif + + /* If reloading from memory, see if there is a register + that already holds the same value. If so, reload from there. + We can pass 0 as the reload_reg_p argument because + any other reload has either already been emitted, + in which case find_equiv_reg will see the reload-insn, + or has yet to be emitted, in which case it doesn't matter + because we will use this equiv reg right away. */ + + if (oldequiv == 0 && optimize + && (GET_CODE (old) == MEM + || (GET_CODE (old) == REG + && REGNO (old) >= FIRST_PSEUDO_REGISTER + && reg_renumber[REGNO (old)] < 0))) + oldequiv = find_equiv_reg (old, insn, ALL_REGS, + -1, NULL_PTR, 0, mode); + + if (oldequiv) + { + int regno = true_regnum (oldequiv); + + /* Don't use OLDEQUIV if any other reload changes it at an + earlier stage of this insn or at this stage. */ + if (! reload_reg_free_for_value_p (regno, reload_opnum[j], + reload_when_needed[j], + reload_in[j], const0_rtx, j, + 0)) + oldequiv = 0; + + /* If it is no cheaper to copy from OLDEQUIV into the + reload register than it would be to move from memory, + don't use it. Likewise, if we need a secondary register + or memory. */ + + if (oldequiv != 0 + && ((REGNO_REG_CLASS (regno) != reload_reg_class[j] + && (REGISTER_MOVE_COST (REGNO_REG_CLASS (regno), + reload_reg_class[j]) + >= MEMORY_MOVE_COST (mode, reload_reg_class[j], 1))) +#ifdef SECONDARY_INPUT_RELOAD_CLASS + || (SECONDARY_INPUT_RELOAD_CLASS (reload_reg_class[j], + mode, oldequiv) + != NO_REGS) +#endif +#ifdef SECONDARY_MEMORY_NEEDED + || SECONDARY_MEMORY_NEEDED (REGNO_REG_CLASS (regno), + reload_reg_class[j], + mode) +#endif + )) + oldequiv = 0; + } + + /* delete_output_reload is only invoked properly if old contains + the original pseudo register. Since this is replaced with a + hard reg when RELOAD_OVERRIDE_IN is set, see if we can + find the pseudo in RELOAD_IN_REG. */ + if (oldequiv == 0 + && reload_override_in[j] + && GET_CODE (reload_in_reg[j]) == REG) + { + oldequiv = old; + old = reload_in_reg[j]; + } + if (oldequiv == 0) + oldequiv = old; + else if (GET_CODE (oldequiv) == REG) + oldequiv_reg = oldequiv; + else if (GET_CODE (oldequiv) == SUBREG) + oldequiv_reg = SUBREG_REG (oldequiv); + + /* If we are reloading from a register that was recently stored in + with an output-reload, see if we can prove there was + actually no need to store the old value in it. */ + + if (optimize && GET_CODE (oldequiv) == REG + && REGNO (oldequiv) < FIRST_PSEUDO_REGISTER + && spill_reg_store[REGNO (oldequiv)] + && GET_CODE (old) == REG + && (dead_or_set_p (insn, spill_reg_stored_to[REGNO (oldequiv)]) + || rtx_equal_p (spill_reg_stored_to[REGNO (oldequiv)], + reload_out_reg[j]))) + delete_output_reload (insn, j, REGNO (oldequiv)); + + /* Encapsulate both RELOADREG and OLDEQUIV into that mode, + then load RELOADREG from OLDEQUIV. Note that we cannot use + gen_lowpart_common since it can do the wrong thing when + RELOADREG has a multi-word mode. Note that RELOADREG + must always be a REG here. */ + + if (GET_MODE (reloadreg) != mode) + reloadreg = gen_rtx_REG (mode, REGNO (reloadreg)); + while (GET_CODE (oldequiv) == SUBREG && GET_MODE (oldequiv) != mode) + oldequiv = SUBREG_REG (oldequiv); + if (GET_MODE (oldequiv) != VOIDmode + && mode != GET_MODE (oldequiv)) + oldequiv = gen_rtx_SUBREG (mode, oldequiv, 0); + + /* Switch to the right place to emit the reload insns. */ + switch (reload_when_needed[j]) + { + case RELOAD_OTHER: + where = &other_input_reload_insns; + break; + case RELOAD_FOR_INPUT: + where = &input_reload_insns[reload_opnum[j]]; + break; + case RELOAD_FOR_INPUT_ADDRESS: + where = &input_address_reload_insns[reload_opnum[j]]; + break; + case RELOAD_FOR_INPADDR_ADDRESS: + where = &inpaddr_address_reload_insns[reload_opnum[j]]; + break; + case RELOAD_FOR_OUTPUT_ADDRESS: + where = &output_address_reload_insns[reload_opnum[j]]; + break; + case RELOAD_FOR_OUTADDR_ADDRESS: + where = &outaddr_address_reload_insns[reload_opnum[j]]; + break; + case RELOAD_FOR_OPERAND_ADDRESS: + where = &operand_reload_insns; + break; + case RELOAD_FOR_OPADDR_ADDR: + where = &other_operand_reload_insns; + break; + case RELOAD_FOR_OTHER_ADDRESS: + where = &other_input_address_reload_insns; + break; + default: + abort (); + } + + push_to_sequence (*where); + special = 0; + + /* Auto-increment addresses must be reloaded in a special way. */ + if (reload_out[j] && ! reload_out_reg[j]) + { + /* We are not going to bother supporting the case where a + incremented register can't be copied directly from + OLDEQUIV since this seems highly unlikely. */ + if (reload_secondary_in_reload[j] >= 0) + abort (); + + if (reload_inherited[j]) + oldequiv = reloadreg; + + old = XEXP (reload_in_reg[j], 0); + + if (optimize && GET_CODE (oldequiv) == REG + && REGNO (oldequiv) < FIRST_PSEUDO_REGISTER + && spill_reg_store[REGNO (oldequiv)] + && GET_CODE (old) == REG + && (dead_or_set_p (insn, + spill_reg_stored_to[REGNO (oldequiv)]) + || rtx_equal_p (spill_reg_stored_to[REGNO (oldequiv)], + old))) + delete_output_reload (insn, j, REGNO (oldequiv)); + + /* Prevent normal processing of this reload. */ + special = 1; + /* Output a special code sequence for this case. */ + new_spill_reg_store[REGNO (reloadreg)] + = inc_for_reload (reloadreg, oldequiv, reload_out[j], + reload_inc[j]); + } + + /* If we are reloading a pseudo-register that was set by the previous + insn, see if we can get rid of that pseudo-register entirely + by redirecting the previous insn into our reload register. */ + + else if (optimize && GET_CODE (old) == REG + && REGNO (old) >= FIRST_PSEUDO_REGISTER + && dead_or_set_p (insn, old) + /* This is unsafe if some other reload + uses the same reg first. */ + && reload_reg_free_for_value_p (REGNO (reloadreg), + reload_opnum[j], + reload_when_needed[j], + old, reload_out[j], + j, 0)) + { + rtx temp = PREV_INSN (insn); + while (temp && GET_CODE (temp) == NOTE) + temp = PREV_INSN (temp); + if (temp + && GET_CODE (temp) == INSN + && GET_CODE (PATTERN (temp)) == SET + && SET_DEST (PATTERN (temp)) == old + /* Make sure we can access insn_operand_constraint. */ + && asm_noperands (PATTERN (temp)) < 0 + /* This is unsafe if prev insn rejects our reload reg. */ + && constraint_accepts_reg_p (insn_operand_constraint[recog_memoized (temp)][0], + reloadreg) + /* This is unsafe if operand occurs more than once in current + insn. Perhaps some occurrences aren't reloaded. */ + && count_occurrences (PATTERN (insn), old) == 1 + /* Don't risk splitting a matching pair of operands. */ + && ! reg_mentioned_p (old, SET_SRC (PATTERN (temp)))) + { + /* Store into the reload register instead of the pseudo. */ + SET_DEST (PATTERN (temp)) = reloadreg; + + /* If the previous insn is an output reload, the source is + a reload register, and its spill_reg_store entry will + contain the previous destination. This is now + invalid. */ + if (GET_CODE (SET_SRC (PATTERN (temp))) == REG + && REGNO (SET_SRC (PATTERN (temp))) < FIRST_PSEUDO_REGISTER) + { + spill_reg_store[REGNO (SET_SRC (PATTERN (temp)))] = 0; + spill_reg_stored_to[REGNO (SET_SRC (PATTERN (temp)))] = 0; + } + + /* If these are the only uses of the pseudo reg, + pretend for GDB it lives in the reload reg we used. */ + if (REG_N_DEATHS (REGNO (old)) == 1 + && REG_N_SETS (REGNO (old)) == 1) + { + reg_renumber[REGNO (old)] = REGNO (reload_reg_rtx[j]); + alter_reg (REGNO (old), -1); + } + special = 1; + } + } + + /* We can't do that, so output an insn to load RELOADREG. */ + + if (! special) + { +#ifdef SECONDARY_INPUT_RELOAD_CLASS + rtx second_reload_reg = 0; + enum insn_code icode; + + /* If we have a secondary reload, pick up the secondary register + and icode, if any. If OLDEQUIV and OLD are different or + if this is an in-out reload, recompute whether or not we + still need a secondary register and what the icode should + be. If we still need a secondary register and the class or + icode is different, go back to reloading from OLD if using + OLDEQUIV means that we got the wrong type of register. We + cannot have different class or icode due to an in-out reload + because we don't make such reloads when both the input and + output need secondary reload registers. */ + + if (reload_secondary_in_reload[j] >= 0) + { + int secondary_reload = reload_secondary_in_reload[j]; + rtx real_oldequiv = oldequiv; + rtx real_old = old; + + /* If OLDEQUIV is a pseudo with a MEM, get the real MEM + and similarly for OLD. + See comments in get_secondary_reload in reload.c. */ + /* If it is a pseudo that cannot be replaced with its + equivalent MEM, we must fall back to reload_in, which + will have all the necessary substitutions registered. + Likewise for a pseudo that can't be replaced with its + equivalent constant. */ + + if (GET_CODE (oldequiv) == REG + && REGNO (oldequiv) >= FIRST_PSEUDO_REGISTER + && (reg_equiv_memory_loc[REGNO (oldequiv)] != 0 + || reg_equiv_constant[REGNO (oldequiv)] != 0)) + { + if (! reg_equiv_mem[REGNO (oldequiv)] + || num_not_at_initial_offset) + real_oldequiv = reload_in[j]; + else + real_oldequiv = reg_equiv_mem[REGNO (oldequiv)]; + } + + if (GET_CODE (old) == REG + && REGNO (old) >= FIRST_PSEUDO_REGISTER + && (reg_equiv_memory_loc[REGNO (old)] != 0 + || reg_equiv_constant[REGNO (old)] != 0)) + { + if (! reg_equiv_mem[REGNO (old)] + || num_not_at_initial_offset) + real_old = reload_in[j]; + else + real_old = reg_equiv_mem[REGNO (old)]; + } + + second_reload_reg = reload_reg_rtx[secondary_reload]; + icode = reload_secondary_in_icode[j]; + + if ((old != oldequiv && ! rtx_equal_p (old, oldequiv)) + || (reload_in[j] != 0 && reload_out[j] != 0)) + { + enum reg_class new_class + = SECONDARY_INPUT_RELOAD_CLASS (reload_reg_class[j], + mode, real_oldequiv); + + if (new_class == NO_REGS) + second_reload_reg = 0; + else + { + enum insn_code new_icode; + enum machine_mode new_mode; + + if (! TEST_HARD_REG_BIT (reg_class_contents[(int) new_class], + REGNO (second_reload_reg))) + oldequiv = old, real_oldequiv = real_old; + else + { + new_icode = reload_in_optab[(int) mode]; + if (new_icode != CODE_FOR_nothing + && ((insn_operand_predicate[(int) new_icode][0] + && ! ((*insn_operand_predicate[(int) new_icode][0]) + (reloadreg, mode))) + || (insn_operand_predicate[(int) new_icode][1] + && ! ((*insn_operand_predicate[(int) new_icode][1]) + (real_oldequiv, mode))))) + new_icode = CODE_FOR_nothing; + + if (new_icode == CODE_FOR_nothing) + new_mode = mode; + else + new_mode = insn_operand_mode[(int) new_icode][2]; + + if (GET_MODE (second_reload_reg) != new_mode) + { + if (!HARD_REGNO_MODE_OK (REGNO (second_reload_reg), + new_mode)) + oldequiv = old, real_oldequiv = real_old; + else + second_reload_reg + = gen_rtx_REG (new_mode, + REGNO (second_reload_reg)); + } + } + } + } + + /* If we still need a secondary reload register, check + to see if it is being used as a scratch or intermediate + register and generate code appropriately. If we need + a scratch register, use REAL_OLDEQUIV since the form of + the insn may depend on the actual address if it is + a MEM. */ + + if (second_reload_reg) + { + if (icode != CODE_FOR_nothing) + { + emit_insn (GEN_FCN (icode) (reloadreg, real_oldequiv, + second_reload_reg)); + special = 1; + } + else + { + /* See if we need a scratch register to load the + intermediate register (a tertiary reload). */ + enum insn_code tertiary_icode + = reload_secondary_in_icode[secondary_reload]; + + if (tertiary_icode != CODE_FOR_nothing) + { + rtx third_reload_reg + = reload_reg_rtx[reload_secondary_in_reload[secondary_reload]]; + + emit_insn ((GEN_FCN (tertiary_icode) + (second_reload_reg, real_oldequiv, + third_reload_reg))); + } + else + gen_reload (second_reload_reg, real_oldequiv, + reload_opnum[j], + reload_when_needed[j]); + + oldequiv = second_reload_reg; + } + } + } +#endif + + if (! special && ! rtx_equal_p (reloadreg, oldequiv)) + { + rtx real_oldequiv = oldequiv; + + if ((GET_CODE (oldequiv) == REG + && REGNO (oldequiv) >= FIRST_PSEUDO_REGISTER + && (reg_equiv_memory_loc[REGNO (oldequiv)] != 0 + || reg_equiv_constant[REGNO (oldequiv)] != 0)) + || (GET_CODE (oldequiv) == SUBREG + && GET_CODE (SUBREG_REG (oldequiv)) == REG + && (REGNO (SUBREG_REG (oldequiv)) + >= FIRST_PSEUDO_REGISTER) + && ((reg_equiv_memory_loc + [REGNO (SUBREG_REG (oldequiv))] != 0) + || (reg_equiv_constant + [REGNO (SUBREG_REG (oldequiv))] != 0)))) + real_oldequiv = reload_in[j]; + gen_reload (reloadreg, real_oldequiv, reload_opnum[j], + reload_when_needed[j]); + } + + } + + this_reload_insn = get_last_insn (); + /* End this sequence. */ + *where = get_insns (); + end_sequence (); + + /* Update reload_override_in so that delete_address_reloads_1 + can see the actual register usage. */ + if (oldequiv_reg) + reload_override_in[j] = oldequiv; + } + + /* When inheriting a wider reload, we have a MEM in reload_in[j], + e.g. inheriting a SImode output reload for + (mem:HI (plus:SI (reg:SI 14 fp) (const_int 10))) */ + if (optimize && reload_inherited[j] && reload_in[j] + && GET_CODE (reload_in[j]) == MEM + && GET_CODE (reload_in_reg[j]) == MEM + && reload_spill_index[j] >= 0 + && TEST_HARD_REG_BIT (reg_reloaded_valid, reload_spill_index[j])) + { + expect_occurrences + = count_occurrences (PATTERN (insn), reload_in[j]) == 1 ? 0 : -1; + reload_in[j] + = regno_reg_rtx[reg_reloaded_contents[reload_spill_index[j]]]; + } + + /* If we are reloading a register that was recently stored in with an + output-reload, see if we can prove there was + actually no need to store the old value in it. */ + + if (optimize + && (reload_inherited[j] || reload_override_in[j]) + && reload_reg_rtx[j] + && GET_CODE (reload_reg_rtx[j]) == REG + && spill_reg_store[REGNO (reload_reg_rtx[j])] != 0 +#if 0 + /* There doesn't seem to be any reason to restrict this to pseudos + and doing so loses in the case where we are copying from a + register of the wrong class. */ + && REGNO (spill_reg_stored_to[REGNO (reload_reg_rtx[j])]) + >= FIRST_PSEUDO_REGISTER +#endif + /* The insn might have already some references to stackslots + replaced by MEMs, while reload_out_reg still names the + original pseudo. */ + && (dead_or_set_p (insn, + spill_reg_stored_to[REGNO (reload_reg_rtx[j])]) + || rtx_equal_p (spill_reg_stored_to[REGNO (reload_reg_rtx[j])], + reload_out_reg[j]))) + delete_output_reload (insn, j, REGNO (reload_reg_rtx[j])); + + /* Input-reloading is done. Now do output-reloading, + storing the value from the reload-register after the main insn + if reload_out[j] is nonzero. + + ??? At some point we need to support handling output reloads of + JUMP_INSNs or insns that set cc0. */ + + /* If this is an output reload that stores something that is + not loaded in this same reload, see if we can eliminate a previous + store. */ + { + rtx pseudo = reload_out_reg[j]; + + if (pseudo + && GET_CODE (pseudo) == REG + && ! rtx_equal_p (reload_in_reg[j], pseudo) + && REGNO (pseudo) >= FIRST_PSEUDO_REGISTER + && reg_last_reload_reg[REGNO (pseudo)]) + { + int pseudo_no = REGNO (pseudo); + int last_regno = REGNO (reg_last_reload_reg[pseudo_no]); + + /* We don't need to test full validity of last_regno for + inherit here; we only want to know if the store actually + matches the pseudo. */ + if (reg_reloaded_contents[last_regno] == pseudo_no + && spill_reg_store[last_regno] + && rtx_equal_p (pseudo, spill_reg_stored_to[last_regno])) + delete_output_reload (insn, j, last_regno); + } + } + + old = reload_out_reg[j]; + if (old != 0 + && reload_reg_rtx[j] != old + && reload_reg_rtx[j] != 0) + { + register rtx reloadreg = reload_reg_rtx[j]; +#ifdef SECONDARY_OUTPUT_RELOAD_CLASS + register rtx second_reloadreg = 0; +#endif + rtx note, p; + enum machine_mode mode; + int special = 0; + + /* An output operand that dies right away does need a reload, + but need not be copied from it. Show the new location in the + REG_UNUSED note. */ + if ((GET_CODE (old) == REG || GET_CODE (old) == SCRATCH) + && (note = find_reg_note (insn, REG_UNUSED, old)) != 0) + { + XEXP (note, 0) = reload_reg_rtx[j]; + continue; + } + /* Likewise for a SUBREG of an operand that dies. */ + else if (GET_CODE (old) == SUBREG + && GET_CODE (SUBREG_REG (old)) == REG + && 0 != (note = find_reg_note (insn, REG_UNUSED, + SUBREG_REG (old)))) + { + XEXP (note, 0) = gen_lowpart_common (GET_MODE (old), + reload_reg_rtx[j]); + continue; + } + else if (GET_CODE (old) == SCRATCH) + /* If we aren't optimizing, there won't be a REG_UNUSED note, + but we don't want to make an output reload. */ + continue; + +#if 0 + /* Strip off of OLD any size-increasing SUBREGs such as + (SUBREG:SI foo:QI 0). */ + + while (GET_CODE (old) == SUBREG && SUBREG_WORD (old) == 0 + && (GET_MODE_SIZE (GET_MODE (old)) + > GET_MODE_SIZE (GET_MODE (SUBREG_REG (old))))) + old = SUBREG_REG (old); +#endif + + /* If is a JUMP_INSN, we can't support output reloads yet. */ + if (GET_CODE (insn) == JUMP_INSN) + abort (); + + if (reload_when_needed[j] == RELOAD_OTHER) + start_sequence (); + else + push_to_sequence (output_reload_insns[reload_opnum[j]]); + + old = reload_out[j]; + + /* Determine the mode to reload in. + See comments above (for input reloading). */ + + mode = GET_MODE (old); + if (mode == VOIDmode) + { + /* VOIDmode should never happen for an output. */ + if (asm_noperands (PATTERN (insn)) < 0) + /* It's the compiler's fault. */ + fatal_insn ("VOIDmode on an output", insn); + error_for_asm (insn, "output operand is constant in `asm'"); + /* Prevent crash--use something we know is valid. */ + mode = word_mode; + old = gen_rtx_REG (mode, REGNO (reloadreg)); + } + + if (GET_MODE (reloadreg) != mode) + reloadreg = gen_rtx_REG (mode, REGNO (reloadreg)); + +#ifdef SECONDARY_OUTPUT_RELOAD_CLASS + + /* If we need two reload regs, set RELOADREG to the intermediate + one, since it will be stored into OLD. We might need a secondary + register only for an input reload, so check again here. */ + + if (reload_secondary_out_reload[j] >= 0) + { + rtx real_old = old; + + if (GET_CODE (old) == REG && REGNO (old) >= FIRST_PSEUDO_REGISTER + && reg_equiv_mem[REGNO (old)] != 0) + real_old = reg_equiv_mem[REGNO (old)]; + + if((SECONDARY_OUTPUT_RELOAD_CLASS (reload_reg_class[j], + mode, real_old) + != NO_REGS)) + { + second_reloadreg = reloadreg; + reloadreg = reload_reg_rtx[reload_secondary_out_reload[j]]; + + /* See if RELOADREG is to be used as a scratch register + or as an intermediate register. */ + if (reload_secondary_out_icode[j] != CODE_FOR_nothing) + { + emit_insn ((GEN_FCN (reload_secondary_out_icode[j]) + (real_old, second_reloadreg, reloadreg))); + special = 1; + } + else + { + /* See if we need both a scratch and intermediate reload + register. */ + + int secondary_reload = reload_secondary_out_reload[j]; + enum insn_code tertiary_icode + = reload_secondary_out_icode[secondary_reload]; + + if (GET_MODE (reloadreg) != mode) + reloadreg = gen_rtx_REG (mode, REGNO (reloadreg)); + + if (tertiary_icode != CODE_FOR_nothing) + { + rtx third_reloadreg + = reload_reg_rtx[reload_secondary_out_reload[secondary_reload]]; + rtx tem; + + /* Copy primary reload reg to secondary reload reg. + (Note that these have been swapped above, then + secondary reload reg to OLD using our insn. */ + + /* If REAL_OLD is a paradoxical SUBREG, remove it + and try to put the opposite SUBREG on + RELOADREG. */ + if (GET_CODE (real_old) == SUBREG + && (GET_MODE_SIZE (GET_MODE (real_old)) + > GET_MODE_SIZE (GET_MODE (SUBREG_REG (real_old)))) + && 0 != (tem = gen_lowpart_common + (GET_MODE (SUBREG_REG (real_old)), + reloadreg))) + real_old = SUBREG_REG (real_old), reloadreg = tem; + + gen_reload (reloadreg, second_reloadreg, + reload_opnum[j], reload_when_needed[j]); + emit_insn ((GEN_FCN (tertiary_icode) + (real_old, reloadreg, third_reloadreg))); + special = 1; + } + + else + /* Copy between the reload regs here and then to + OUT later. */ + + gen_reload (reloadreg, second_reloadreg, + reload_opnum[j], reload_when_needed[j]); + } + } + } +#endif + + /* Output the last reload insn. */ + if (! special) + { + rtx set; + + /* Don't output the last reload if OLD is not the dest of + INSN and is in the src and is clobbered by INSN. */ + if (! flag_expensive_optimizations + || GET_CODE (old) != REG + || !(set = single_set (insn)) + || rtx_equal_p (old, SET_DEST (set)) + || !reg_mentioned_p (old, SET_SRC (set)) + || !regno_clobbered_p (REGNO (old), insn)) + gen_reload (old, reloadreg, reload_opnum[j], + reload_when_needed[j]); + } + + /* Look at all insns we emitted, just to be safe. */ + for (p = get_insns (); p; p = NEXT_INSN (p)) + if (GET_RTX_CLASS (GET_CODE (p)) == 'i') + { + rtx pat = PATTERN (p); + + /* If this output reload doesn't come from a spill reg, + clear any memory of reloaded copies of the pseudo reg. + If this output reload comes from a spill reg, + reg_has_output_reload will make this do nothing. */ + note_stores (pat, forget_old_reloads_1); + + if (reg_mentioned_p (reload_reg_rtx[j], pat)) + { + rtx set = single_set (insn); + if (reload_spill_index[j] < 0 + && set + && SET_SRC (set) == reload_reg_rtx[j]) + { + int src = REGNO (SET_SRC (set)); + + reload_spill_index[j] = src; + SET_HARD_REG_BIT (reg_is_output_reload, src); + if (find_regno_note (insn, REG_DEAD, src)) + SET_HARD_REG_BIT (reg_reloaded_died, src); + } + if (REGNO (reload_reg_rtx[j]) < FIRST_PSEUDO_REGISTER) + { + int s = reload_secondary_out_reload[j]; + set = single_set (p); + /* If this reload copies only to the secondary reload + register, the secondary reload does the actual + store. */ + if (s >= 0 && set == NULL_RTX) + ; /* We can't tell what function the secondary reload + has and where the actual store to the pseudo is + made; leave new_spill_reg_store alone. */ + else if (s >= 0 + && SET_SRC (set) == reload_reg_rtx[j] + && SET_DEST (set) == reload_reg_rtx[s]) + { + /* Usually the next instruction will be the + secondary reload insn; if we can confirm + that it is, setting new_spill_reg_store to + that insn will allow an extra optimization. */ + rtx s_reg = reload_reg_rtx[s]; + rtx next = NEXT_INSN (p); + reload_out[s] = reload_out[j]; + reload_out_reg[s] = reload_out_reg[j]; + set = single_set (next); + if (set && SET_SRC (set) == s_reg + && ! new_spill_reg_store[REGNO (s_reg)]) + { + SET_HARD_REG_BIT (reg_is_output_reload, + REGNO (s_reg)); + new_spill_reg_store[REGNO (s_reg)] = next; + } + } + else + new_spill_reg_store[REGNO (reload_reg_rtx[j])] = p; + } + } + } + + if (reload_when_needed[j] == RELOAD_OTHER) + { + emit_insns (other_output_reload_insns[reload_opnum[j]]); + other_output_reload_insns[reload_opnum[j]] = get_insns (); + } + else + output_reload_insns[reload_opnum[j]] = get_insns (); + + end_sequence (); + } + } + + /* Now write all the insns we made for reloads in the order expected by + the allocation functions. Prior to the insn being reloaded, we write + the following reloads: + + RELOAD_FOR_OTHER_ADDRESS reloads for input addresses. + + RELOAD_OTHER reloads. + + For each operand, any RELOAD_FOR_INPADDR_ADDRESS reloads followed + by any RELOAD_FOR_INPUT_ADDRESS reloads followed by the + RELOAD_FOR_INPUT reload for the operand. + + RELOAD_FOR_OPADDR_ADDRS reloads. + + RELOAD_FOR_OPERAND_ADDRESS reloads. + + After the insn being reloaded, we write the following: + + For each operand, any RELOAD_FOR_OUTADDR_ADDRESS reloads followed + by any RELOAD_FOR_OUTPUT_ADDRESS reload followed by the + RELOAD_FOR_OUTPUT reload, followed by any RELOAD_OTHER output + reloads for the operand. The RELOAD_OTHER output reloads are + output in descending order by reload number. */ + + emit_insns_before (other_input_address_reload_insns, insn); + emit_insns_before (other_input_reload_insns, insn); + + for (j = 0; j < reload_n_operands; j++) + { + emit_insns_before (inpaddr_address_reload_insns[j], insn); + emit_insns_before (input_address_reload_insns[j], insn); + emit_insns_before (input_reload_insns[j], insn); + } + + emit_insns_before (other_operand_reload_insns, insn); + emit_insns_before (operand_reload_insns, insn); + + for (j = 0; j < reload_n_operands; j++) + { + emit_insns_before (outaddr_address_reload_insns[j], following_insn); + emit_insns_before (output_address_reload_insns[j], following_insn); + emit_insns_before (output_reload_insns[j], following_insn); + emit_insns_before (other_output_reload_insns[j], following_insn); + } + + /* Keep basic block info up to date. */ + if (n_basic_blocks) + { + if (BLOCK_HEAD (chain->block) == insn) + BLOCK_HEAD (chain->block) = NEXT_INSN (before_insn); + if (BLOCK_END (chain->block) == insn) + BLOCK_END (chain->block) = PREV_INSN (following_insn); + } + + /* For all the spill regs newly reloaded in this instruction, + record what they were reloaded from, so subsequent instructions + can inherit the reloads. + + Update spill_reg_store for the reloads of this insn. + Copy the elements that were updated in the loop above. */ + + for (j = 0; j < n_reloads; j++) + { + register int r = reload_order[j]; + register int i = reload_spill_index[r]; + + /* If this is a non-inherited input reload from a pseudo, we must + clear any memory of a previous store to the same pseudo. Only do + something if there will not be an output reload for the pseudo + being reloaded. */ + if (reload_in_reg[r] != 0 + && ! (reload_inherited[r] || reload_override_in[r])) + { + rtx reg = reload_in_reg[r]; + + if (GET_CODE (reg) == SUBREG) + reg = SUBREG_REG (reg); + + if (GET_CODE (reg) == REG + && REGNO (reg) >= FIRST_PSEUDO_REGISTER + && ! reg_has_output_reload[REGNO (reg)]) + { + int nregno = REGNO (reg); + + if (reg_last_reload_reg[nregno]) + { + int last_regno = REGNO (reg_last_reload_reg[nregno]); + + if (reg_reloaded_contents[last_regno] == nregno) + spill_reg_store[last_regno] = 0; + } + } + } + + /* I is nonneg if this reload used a register. + If reload_reg_rtx[r] is 0, this is an optional reload + that we opted to ignore. */ + + if (i >= 0 && reload_reg_rtx[r] != 0) + { + int nr + = HARD_REGNO_NREGS (i, GET_MODE (reload_reg_rtx[r])); + int k; + int part_reaches_end = 0; + int all_reaches_end = 1; + + /* For a multi register reload, we need to check if all or part + of the value lives to the end. */ + for (k = 0; k < nr; k++) + { + if (reload_reg_reaches_end_p (i + k, reload_opnum[r], + reload_when_needed[r])) + part_reaches_end = 1; + else + all_reaches_end = 0; + } + + /* Ignore reloads that don't reach the end of the insn in + entirety. */ + if (all_reaches_end) + { + /* First, clear out memory of what used to be in this spill reg. + If consecutive registers are used, clear them all. */ + + for (k = 0; k < nr; k++) + CLEAR_HARD_REG_BIT (reg_reloaded_valid, i + k); + + /* Maybe the spill reg contains a copy of reload_out. */ + if (reload_out[r] != 0 + && (GET_CODE (reload_out[r]) == REG +#ifdef AUTO_INC_DEC + || ! reload_out_reg[r] +#endif + || GET_CODE (reload_out_reg[r]) == REG)) + { + rtx out = (GET_CODE (reload_out[r]) == REG + ? reload_out[r] + : reload_out_reg[r] + ? reload_out_reg[r] +/* AUTO_INC */ : XEXP (reload_in_reg[r], 0)); + register int nregno = REGNO (out); + int nnr = (nregno >= FIRST_PSEUDO_REGISTER ? 1 + : HARD_REGNO_NREGS (nregno, + GET_MODE (reload_reg_rtx[r]))); + + spill_reg_store[i] = new_spill_reg_store[i]; + spill_reg_stored_to[i] = out; + reg_last_reload_reg[nregno] = reload_reg_rtx[r]; + + /* If NREGNO is a hard register, it may occupy more than + one register. If it does, say what is in the + rest of the registers assuming that both registers + agree on how many words the object takes. If not, + invalidate the subsequent registers. */ + + if (nregno < FIRST_PSEUDO_REGISTER) + for (k = 1; k < nnr; k++) + reg_last_reload_reg[nregno + k] + = (nr == nnr + ? gen_rtx_REG (reg_raw_mode[REGNO (reload_reg_rtx[r]) + k], + REGNO (reload_reg_rtx[r]) + k) + : 0); + + /* Now do the inverse operation. */ + for (k = 0; k < nr; k++) + { + CLEAR_HARD_REG_BIT (reg_reloaded_dead, i + k); + reg_reloaded_contents[i + k] + = (nregno >= FIRST_PSEUDO_REGISTER || nr != nnr + ? nregno + : nregno + k); + reg_reloaded_insn[i + k] = insn; + SET_HARD_REG_BIT (reg_reloaded_valid, i + k); + } + } + + /* Maybe the spill reg contains a copy of reload_in. Only do + something if there will not be an output reload for + the register being reloaded. */ + else if (reload_out_reg[r] == 0 + && reload_in[r] != 0 + && ((GET_CODE (reload_in[r]) == REG + && REGNO (reload_in[r]) >= FIRST_PSEUDO_REGISTER + && ! reg_has_output_reload[REGNO (reload_in[r])]) + || (GET_CODE (reload_in_reg[r]) == REG + && ! reg_has_output_reload[REGNO (reload_in_reg[r])])) + && ! reg_set_p (reload_reg_rtx[r], PATTERN (insn))) + { + register int nregno; + int nnr; + + if (GET_CODE (reload_in[r]) == REG + && REGNO (reload_in[r]) >= FIRST_PSEUDO_REGISTER) + nregno = REGNO (reload_in[r]); + else if (GET_CODE (reload_in_reg[r]) == REG) + nregno = REGNO (reload_in_reg[r]); + else + nregno = REGNO (XEXP (reload_in_reg[r], 0)); + + nnr = (nregno >= FIRST_PSEUDO_REGISTER ? 1 + : HARD_REGNO_NREGS (nregno, + GET_MODE (reload_reg_rtx[r]))); + + reg_last_reload_reg[nregno] = reload_reg_rtx[r]; + + if (nregno < FIRST_PSEUDO_REGISTER) + for (k = 1; k < nnr; k++) + reg_last_reload_reg[nregno + k] + = (nr == nnr + ? gen_rtx_REG (reg_raw_mode[REGNO (reload_reg_rtx[r]) + k], + REGNO (reload_reg_rtx[r]) + k) + : 0); + + /* Unless we inherited this reload, show we haven't + recently done a store. + Previous stores of inherited auto_inc expressions + also have to be discarded. */ + if (! reload_inherited[r] + || (reload_out[r] && ! reload_out_reg[r])) + spill_reg_store[i] = 0; + + for (k = 0; k < nr; k++) + { + CLEAR_HARD_REG_BIT (reg_reloaded_dead, i + k); + reg_reloaded_contents[i + k] + = (nregno >= FIRST_PSEUDO_REGISTER || nr != nnr + ? nregno + : nregno + k); + reg_reloaded_insn[i + k] = insn; + SET_HARD_REG_BIT (reg_reloaded_valid, i + k); + } + } + } + + /* However, if part of the reload reaches the end, then we must + invalidate the old info for the part that survives to the end. */ + else if (part_reaches_end) + { + for (k = 0; k < nr; k++) + if (reload_reg_reaches_end_p (i + k, + reload_opnum[r], + reload_when_needed[r])) + CLEAR_HARD_REG_BIT (reg_reloaded_valid, i + k); + } + } + + /* The following if-statement was #if 0'd in 1.34 (or before...). + It's reenabled in 1.35 because supposedly nothing else + deals with this problem. */ + + /* If a register gets output-reloaded from a non-spill register, + that invalidates any previous reloaded copy of it. + But forget_old_reloads_1 won't get to see it, because + it thinks only about the original insn. So invalidate it here. */ + if (i < 0 && reload_out[r] != 0 + && (GET_CODE (reload_out[r]) == REG + || (GET_CODE (reload_out[r]) == MEM + && GET_CODE (reload_out_reg[r]) == REG))) + { + rtx out = (GET_CODE (reload_out[r]) == REG + ? reload_out[r] : reload_out_reg[r]); + register int nregno = REGNO (out); + if (nregno >= FIRST_PSEUDO_REGISTER) + { + rtx src_reg, store_insn; + + reg_last_reload_reg[nregno] = 0; + + /* If we can find a hard register that is stored, record + the storing insn so that we may delete this insn with + delete_output_reload. */ + src_reg = reload_reg_rtx[r]; + + /* If this is an optional reload, try to find the source reg + from an input reload. */ + if (! src_reg) + { + rtx set = single_set (insn); + if (set && SET_DEST (set) == reload_out[r]) + { + int k; + + src_reg = SET_SRC (set); + store_insn = insn; + for (k = 0; k < n_reloads; k++) + { + if (reload_in[k] == src_reg) + { + src_reg = reload_reg_rtx[k]; + break; + } + } + } + } + else + store_insn = new_spill_reg_store[REGNO (src_reg)]; + if (src_reg && GET_CODE (src_reg) == REG + && REGNO (src_reg) < FIRST_PSEUDO_REGISTER) + { + int src_regno = REGNO (src_reg); + int nr = HARD_REGNO_NREGS (src_regno, reload_mode[r]); + /* The place where to find a death note varies with + PRESERVE_DEATH_INFO_REGNO_P . The condition is not + necessarily checked exactly in the code that moves + notes, so just check both locations. */ + rtx note = find_regno_note (insn, REG_DEAD, src_regno); + if (! note) + note = find_regno_note (store_insn, REG_DEAD, src_regno); + while (nr-- > 0) + { + spill_reg_store[src_regno + nr] = store_insn; + spill_reg_stored_to[src_regno + nr] = out; + reg_reloaded_contents[src_regno + nr] = nregno; + reg_reloaded_insn[src_regno + nr] = store_insn; + CLEAR_HARD_REG_BIT (reg_reloaded_dead, src_regno + nr); + SET_HARD_REG_BIT (reg_reloaded_valid, src_regno + nr); + SET_HARD_REG_BIT (reg_is_output_reload, src_regno + nr); + if (note) + SET_HARD_REG_BIT (reg_reloaded_died, src_regno); + else + CLEAR_HARD_REG_BIT (reg_reloaded_died, src_regno); + } + reg_last_reload_reg[nregno] = src_reg; + } + } + else + { + int num_regs = HARD_REGNO_NREGS (nregno,GET_MODE (reload_out[r])); + + while (num_regs-- > 0) + reg_last_reload_reg[nregno + num_regs] = 0; + } + } + } + IOR_HARD_REG_SET (reg_reloaded_dead, reg_reloaded_died); +} + +/* Emit code to perform a reload from IN (which may be a reload register) to + OUT (which may also be a reload register). IN or OUT is from operand + OPNUM with reload type TYPE. + + Returns first insn emitted. */ + +rtx +gen_reload (out, in, opnum, type) + rtx out; + rtx in; + int opnum; + enum reload_type type; +{ + rtx last = get_last_insn (); + rtx tem; + + /* If IN is a paradoxical SUBREG, remove it and try to put the + opposite SUBREG on OUT. Likewise for a paradoxical SUBREG on OUT. */ + if (GET_CODE (in) == SUBREG + && (GET_MODE_SIZE (GET_MODE (in)) + > GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))) + && (tem = gen_lowpart_common (GET_MODE (SUBREG_REG (in)), out)) != 0) + in = SUBREG_REG (in), out = tem; + else if (GET_CODE (out) == SUBREG + && (GET_MODE_SIZE (GET_MODE (out)) + > GET_MODE_SIZE (GET_MODE (SUBREG_REG (out)))) + && (tem = gen_lowpart_common (GET_MODE (SUBREG_REG (out)), in)) != 0) + out = SUBREG_REG (out), in = tem; + + /* How to do this reload can get quite tricky. Normally, we are being + asked to reload a simple operand, such as a MEM, a constant, or a pseudo + register that didn't get a hard register. In that case we can just + call emit_move_insn. + + We can also be asked to reload a PLUS that adds a register or a MEM to + another register, constant or MEM. This can occur during frame pointer + elimination and while reloading addresses. This case is handled by + trying to emit a single insn to perform the add. If it is not valid, + we use a two insn sequence. + + Finally, we could be called to handle an 'o' constraint by putting + an address into a register. In that case, we first try to do this + with a named pattern of "reload_load_address". If no such pattern + exists, we just emit a SET insn and hope for the best (it will normally + be valid on machines that use 'o'). + + This entire process is made complex because reload will never + process the insns we generate here and so we must ensure that + they will fit their constraints and also by the fact that parts of + IN might be being reloaded separately and replaced with spill registers. + Because of this, we are, in some sense, just guessing the right approach + here. The one listed above seems to work. + + ??? At some point, this whole thing needs to be rethought. */ + + if (GET_CODE (in) == PLUS + && (GET_CODE (XEXP (in, 0)) == REG + || GET_CODE (XEXP (in, 0)) == SUBREG + || GET_CODE (XEXP (in, 0)) == MEM) + && (GET_CODE (XEXP (in, 1)) == REG + || GET_CODE (XEXP (in, 1)) == SUBREG + || CONSTANT_P (XEXP (in, 1)) + || GET_CODE (XEXP (in, 1)) == MEM)) + { + /* We need to compute the sum of a register or a MEM and another + register, constant, or MEM, and put it into the reload + register. The best possible way of doing this is if the machine + has a three-operand ADD insn that accepts the required operands. + + The simplest approach is to try to generate such an insn and see if it + is recognized and matches its constraints. If so, it can be used. + + It might be better not to actually emit the insn unless it is valid, + but we need to pass the insn as an operand to `recog' and + `extract_insn' and it is simpler to emit and then delete the insn if + not valid than to dummy things up. */ + + rtx op0, op1, tem, insn; + int code; + + op0 = find_replacement (&XEXP (in, 0)); + op1 = find_replacement (&XEXP (in, 1)); + + /* Since constraint checking is strict, commutativity won't be + checked, so we need to do that here to avoid spurious failure + if the add instruction is two-address and the second operand + of the add is the same as the reload reg, which is frequently + the case. If the insn would be A = B + A, rearrange it so + it will be A = A + B as constrain_operands expects. */ + + if (GET_CODE (XEXP (in, 1)) == REG + && REGNO (out) == REGNO (XEXP (in, 1))) + tem = op0, op0 = op1, op1 = tem; + + if (op0 != XEXP (in, 0) || op1 != XEXP (in, 1)) + in = gen_rtx_PLUS (GET_MODE (in), op0, op1); + + insn = emit_insn (gen_rtx_SET (VOIDmode, out, in)); + code = recog_memoized (insn); + + if (code >= 0) + { + extract_insn (insn); + /* We want constrain operands to treat this insn strictly in + its validity determination, i.e., the way it would after reload + has completed. */ + if (constrain_operands (1)) + return insn; + } + + delete_insns_since (last); + + /* If that failed, we must use a conservative two-insn sequence. + use move to copy constant, MEM, or pseudo register to the reload + register since "move" will be able to handle an arbitrary operand, + unlike add which can't, in general. Then add the registers. + + If there is another way to do this for a specific machine, a + DEFINE_PEEPHOLE should be specified that recognizes the sequence + we emit below. */ + + if (CONSTANT_P (op1) || GET_CODE (op1) == MEM || GET_CODE (op1) == SUBREG + || (GET_CODE (op1) == REG + && REGNO (op1) >= FIRST_PSEUDO_REGISTER)) + tem = op0, op0 = op1, op1 = tem; + + gen_reload (out, op0, opnum, type); + + /* If OP0 and OP1 are the same, we can use OUT for OP1. + This fixes a problem on the 32K where the stack pointer cannot + be used as an operand of an add insn. */ + + if (rtx_equal_p (op0, op1)) + op1 = out; + + insn = emit_insn (gen_add2_insn (out, op1)); + + /* If that failed, copy the address register to the reload register. + Then add the constant to the reload register. */ + + code = recog_memoized (insn); + + if (code >= 0) + { + extract_insn (insn); + /* We want constrain operands to treat this insn strictly in + its validity determination, i.e., the way it would after reload + has completed. */ + if (constrain_operands (1)) + { + /* Add a REG_EQUIV note so that find_equiv_reg can find it. */ + REG_NOTES (insn) + = gen_rtx_EXPR_LIST (REG_EQUIV, in, REG_NOTES (insn)); + return insn; + } + } + + delete_insns_since (last); + + gen_reload (out, op1, opnum, type); + insn = emit_insn (gen_add2_insn (out, op0)); + REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_EQUIV, in, REG_NOTES (insn)); + } + +#ifdef SECONDARY_MEMORY_NEEDED + /* If we need a memory location to do the move, do it that way. */ + else if (GET_CODE (in) == REG && REGNO (in) < FIRST_PSEUDO_REGISTER + && GET_CODE (out) == REG && REGNO (out) < FIRST_PSEUDO_REGISTER + && SECONDARY_MEMORY_NEEDED (REGNO_REG_CLASS (REGNO (in)), + REGNO_REG_CLASS (REGNO (out)), + GET_MODE (out))) + { + /* Get the memory to use and rewrite both registers to its mode. */ + rtx loc = get_secondary_mem (in, GET_MODE (out), opnum, type); + + if (GET_MODE (loc) != GET_MODE (out)) + out = gen_rtx_REG (GET_MODE (loc), REGNO (out)); + + if (GET_MODE (loc) != GET_MODE (in)) + in = gen_rtx_REG (GET_MODE (loc), REGNO (in)); + + gen_reload (loc, in, opnum, type); + gen_reload (out, loc, opnum, type); + } +#endif + + /* If IN is a simple operand, use gen_move_insn. */ + else if (GET_RTX_CLASS (GET_CODE (in)) == 'o' || GET_CODE (in) == SUBREG) + emit_insn (gen_move_insn (out, in)); + +#ifdef HAVE_reload_load_address + else if (HAVE_reload_load_address) + emit_insn (gen_reload_load_address (out, in)); +#endif + + /* Otherwise, just write (set OUT IN) and hope for the best. */ + else + emit_insn (gen_rtx_SET (VOIDmode, out, in)); + + /* Return the first insn emitted. + We can not just return get_last_insn, because there may have + been multiple instructions emitted. Also note that gen_move_insn may + emit more than one insn itself, so we can not assume that there is one + insn emitted per emit_insn_before call. */ + + return last ? NEXT_INSN (last) : get_insns (); +} + +/* Delete a previously made output-reload + whose result we now believe is not needed. + First we double-check. + + INSN is the insn now being processed. + LAST_RELOAD_REG is the hard register number for which we want to delete + the last output reload. + J is the reload-number that originally used REG. The caller has made + certain that reload J doesn't use REG any longer for input. */ + +static void +delete_output_reload (insn, j, last_reload_reg) + rtx insn; + int j; + int last_reload_reg; +{ + rtx output_reload_insn = spill_reg_store[last_reload_reg]; + rtx reg = spill_reg_stored_to[last_reload_reg]; + int k; + int n_occurrences; + int n_inherited = 0; + register rtx i1; + rtx substed; + + /* Get the raw pseudo-register referred to. */ + + while (GET_CODE (reg) == SUBREG) + reg = SUBREG_REG (reg); + substed = reg_equiv_memory_loc[REGNO (reg)]; + + /* This is unsafe if the operand occurs more often in the current + insn than it is inherited. */ + for (k = n_reloads - 1; k >= 0; k--) + { + rtx reg2 = reload_in[k]; + if (! reg2) + continue; + if (GET_CODE (reg2) == MEM || reload_override_in[k]) + reg2 = reload_in_reg[k]; +#ifdef AUTO_INC_DEC + if (reload_out[k] && ! reload_out_reg[k]) + reg2 = XEXP (reload_in_reg[k], 0); +#endif + while (GET_CODE (reg2) == SUBREG) + reg2 = SUBREG_REG (reg2); + if (rtx_equal_p (reg2, reg)) + { + if (reload_inherited[k] || reload_override_in[k] || k == j) + { + n_inherited++; + reg2 = reload_out_reg[k]; + if (! reg2) + continue; + while (GET_CODE (reg2) == SUBREG) + reg2 = XEXP (reg2, 0); + if (rtx_equal_p (reg2, reg)) + n_inherited++; + } + else + return; + } + } + n_occurrences = count_occurrences (PATTERN (insn), reg); + if (substed) + n_occurrences += count_occurrences (PATTERN (insn), substed); + if (n_occurrences > n_inherited) + return; + + /* If the pseudo-reg we are reloading is no longer referenced + anywhere between the store into it and here, + and no jumps or labels intervene, then the value can get + here through the reload reg alone. + Otherwise, give up--return. */ + for (i1 = NEXT_INSN (output_reload_insn); + i1 != insn; i1 = NEXT_INSN (i1)) + { + if (GET_CODE (i1) == CODE_LABEL || GET_CODE (i1) == JUMP_INSN) + return; + if ((GET_CODE (i1) == INSN || GET_CODE (i1) == CALL_INSN) + && reg_mentioned_p (reg, PATTERN (i1))) + { + /* If this is USE in front of INSN, we only have to check that + there are no more references than accounted for by inheritance. */ + while (GET_CODE (i1) == INSN && GET_CODE (PATTERN (i1)) == USE) + { + n_occurrences += rtx_equal_p (reg, XEXP (PATTERN (i1), 0)) != 0; + i1 = NEXT_INSN (i1); + } + if (n_occurrences <= n_inherited && i1 == insn) + break; + return; + } + } + + /* The caller has already checked that REG dies or is set in INSN. + It has also checked that we are optimizing, and thus some inaccurancies + in the debugging information are acceptable. + So we could just delete output_reload_insn. + But in some cases we can improve the debugging information without + sacrificing optimization - maybe even improving the code: + See if the pseudo reg has been completely replaced + with reload regs. If so, delete the store insn + and forget we had a stack slot for the pseudo. */ + if (reload_out[j] != reload_in[j] + && REG_N_DEATHS (REGNO (reg)) == 1 + && REG_N_SETS (REGNO (reg)) == 1 + && REG_BASIC_BLOCK (REGNO (reg)) >= 0 + && find_regno_note (insn, REG_DEAD, REGNO (reg))) + { + rtx i2; + + /* We know that it was used only between here + and the beginning of the current basic block. + (We also know that the last use before INSN was + the output reload we are thinking of deleting, but never mind that.) + Search that range; see if any ref remains. */ + for (i2 = PREV_INSN (insn); i2; i2 = PREV_INSN (i2)) + { + rtx set = single_set (i2); + + /* Uses which just store in the pseudo don't count, + since if they are the only uses, they are dead. */ + if (set != 0 && SET_DEST (set) == reg) + continue; + if (GET_CODE (i2) == CODE_LABEL + || GET_CODE (i2) == JUMP_INSN) + break; + if ((GET_CODE (i2) == INSN || GET_CODE (i2) == CALL_INSN) + && reg_mentioned_p (reg, PATTERN (i2))) + { + /* Some other ref remains; just delete the output reload we + know to be dead. */ + delete_address_reloads (output_reload_insn, insn); + PUT_CODE (output_reload_insn, NOTE); + NOTE_SOURCE_FILE (output_reload_insn) = 0; + NOTE_LINE_NUMBER (output_reload_insn) = NOTE_INSN_DELETED; + return; + } + } + + /* Delete the now-dead stores into this pseudo. */ + for (i2 = PREV_INSN (insn); i2; i2 = PREV_INSN (i2)) + { + rtx set = single_set (i2); + + if (set != 0 && SET_DEST (set) == reg) + { + delete_address_reloads (i2, insn); + /* This might be a basic block head, + thus don't use delete_insn. */ + PUT_CODE (i2, NOTE); + NOTE_SOURCE_FILE (i2) = 0; + NOTE_LINE_NUMBER (i2) = NOTE_INSN_DELETED; + } + if (GET_CODE (i2) == CODE_LABEL + || GET_CODE (i2) == JUMP_INSN) + break; + } + + /* For the debugging info, + say the pseudo lives in this reload reg. */ + reg_renumber[REGNO (reg)] = REGNO (reload_reg_rtx[j]); + alter_reg (REGNO (reg), -1); + } + delete_address_reloads (output_reload_insn, insn); + PUT_CODE (output_reload_insn, NOTE); + NOTE_SOURCE_FILE (output_reload_insn) = 0; + NOTE_LINE_NUMBER (output_reload_insn) = NOTE_INSN_DELETED; + +} + +/* We are going to delete DEAD_INSN. Recursively delete loads of + reload registers used in DEAD_INSN that are not used till CURRENT_INSN. + CURRENT_INSN is being reloaded, so we have to check its reloads too. */ +static void +delete_address_reloads (dead_insn, current_insn) + rtx dead_insn, current_insn; +{ + rtx set = single_set (dead_insn); + rtx set2, dst, prev, next; + if (set) + { + rtx dst = SET_DEST (set); + if (GET_CODE (dst) == MEM) + delete_address_reloads_1 (dead_insn, XEXP (dst, 0), current_insn); + } + /* If we deleted the store from a reloaded post_{in,de}c expression, + we can delete the matching adds. */ + prev = PREV_INSN (dead_insn); + next = NEXT_INSN (dead_insn); + if (! prev || ! next) + return; + set = single_set (next); + set2 = single_set (prev); + if (! set || ! set2 + || GET_CODE (SET_SRC (set)) != PLUS || GET_CODE (SET_SRC (set2)) != PLUS + || GET_CODE (XEXP (SET_SRC (set), 1)) != CONST_INT + || GET_CODE (XEXP (SET_SRC (set2), 1)) != CONST_INT) + return; + dst = SET_DEST (set); + if (! rtx_equal_p (dst, SET_DEST (set2)) + || ! rtx_equal_p (dst, XEXP (SET_SRC (set), 0)) + || ! rtx_equal_p (dst, XEXP (SET_SRC (set2), 0)) + || (INTVAL (XEXP (SET_SRC (set), 1)) + != - INTVAL (XEXP (SET_SRC (set2), 1)))) + return; + delete_insn (prev); + delete_insn (next); +} + +/* Subfunction of delete_address_reloads: process registers found in X. */ +static void +delete_address_reloads_1 (dead_insn, x, current_insn) + rtx dead_insn, x, current_insn; +{ + rtx prev, set, dst, i2; + int i, j; + enum rtx_code code = GET_CODE (x); + + if (code != REG) + { + char *fmt= GET_RTX_FORMAT (code); + for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) + { + if (fmt[i] == 'e') + delete_address_reloads_1 (dead_insn, XEXP (x, i), current_insn); + else if (fmt[i] == 'E') + { + for (j = XVECLEN (x, i) - 1; j >=0; j--) + delete_address_reloads_1 (dead_insn, XVECEXP (x, i, j), + current_insn); + } + } + return; + } + + if (spill_reg_order[REGNO (x)] < 0) + return; + + /* Scan backwards for the insn that sets x. This might be a way back due + to inheritance. */ + for (prev = PREV_INSN (dead_insn); prev; prev = PREV_INSN (prev)) + { + code = GET_CODE (prev); + if (code == CODE_LABEL || code == JUMP_INSN) + return; + if (GET_RTX_CLASS (code) != 'i') + continue; + if (reg_set_p (x, PATTERN (prev))) + break; + if (reg_referenced_p (x, PATTERN (prev))) + return; + } + if (! prev || INSN_UID (prev) < reload_first_uid) + return; + /* Check that PREV only sets the reload register. */ + set = single_set (prev); + if (! set) + return; + dst = SET_DEST (set); + if (GET_CODE (dst) != REG + || ! rtx_equal_p (dst, x)) + return; + if (! reg_set_p (dst, PATTERN (dead_insn))) + { + /* Check if DST was used in a later insn - + it might have been inherited. */ + for (i2 = NEXT_INSN (dead_insn); i2; i2 = NEXT_INSN (i2)) + { + if (GET_CODE (i2) == CODE_LABEL) + break; + if (GET_RTX_CLASS (GET_CODE (i2)) != 'i') + continue; + if (reg_referenced_p (dst, PATTERN (i2))) + { + /* If there is a reference to the register in the current insn, + it might be loaded in a non-inherited reload. If no other + reload uses it, that means the register is set before + referenced. */ + if (i2 == current_insn) + { + for (j = n_reloads - 1; j >= 0; j--) + if ((reload_reg_rtx[j] == dst && reload_inherited[j]) + || reload_override_in[j] == dst) + return; + for (j = n_reloads - 1; j >= 0; j--) + if (reload_in[j] && reload_reg_rtx[j] == dst) + break; + if (j >= 0) + break; + } + return; + } + if (GET_CODE (i2) == JUMP_INSN) + break; + if (reg_set_p (dst, PATTERN (i2))) + break; + /* If DST is still live at CURRENT_INSN, check if it is used for + any reload. */ + if (i2 == current_insn) + { + for (j = n_reloads - 1; j >= 0; j--) + if ((reload_reg_rtx[j] == dst && reload_inherited[j]) + || reload_override_in[j] == dst) + return; + /* ??? We can't finish the loop here, because dst might be + allocated to a pseudo in this block if no reload in this + block needs any of the clsses containing DST - see + spill_hard_reg. There is no easy way to tell this, so we + have to scan till the end of the basic block. */ + } + } + } + delete_address_reloads_1 (prev, SET_SRC (set), current_insn); + reg_reloaded_contents[REGNO (dst)] = -1; + /* Can't use delete_insn here because PREV might be a basic block head. */ + PUT_CODE (prev, NOTE); + NOTE_LINE_NUMBER (prev) = NOTE_INSN_DELETED; + NOTE_SOURCE_FILE (prev) = 0; +} + +/* Output reload-insns to reload VALUE into RELOADREG. + VALUE is an autoincrement or autodecrement RTX whose operand + is a register or memory location; + so reloading involves incrementing that location. + IN is either identical to VALUE, or some cheaper place to reload from. + + INC_AMOUNT is the number to increment or decrement by (always positive). + This cannot be deduced from VALUE. + + Return the instruction that stores into RELOADREG. */ + +static rtx +inc_for_reload (reloadreg, in, value, inc_amount) + rtx reloadreg; + rtx in, value; + int inc_amount; +{ + /* REG or MEM to be copied and incremented. */ + rtx incloc = XEXP (value, 0); + /* Nonzero if increment after copying. */ + int post = (GET_CODE (value) == POST_DEC || GET_CODE (value) == POST_INC); + rtx last; + rtx inc; + rtx add_insn; + int code; + rtx store; + rtx real_in = in == value ? XEXP (in, 0) : in; + + /* No hard register is equivalent to this register after + inc/dec operation. If REG_LAST_RELOAD_REG were non-zero, + we could inc/dec that register as well (maybe even using it for + the source), but I'm not sure it's worth worrying about. */ + if (GET_CODE (incloc) == REG) + reg_last_reload_reg[REGNO (incloc)] = 0; + + if (GET_CODE (value) == PRE_DEC || GET_CODE (value) == POST_DEC) + inc_amount = - inc_amount; + + inc = GEN_INT (inc_amount); + + /* If this is post-increment, first copy the location to the reload reg. */ + if (post && real_in != reloadreg) + emit_insn (gen_move_insn (reloadreg, real_in)); + + if (in == value) + { + /* See if we can directly increment INCLOC. Use a method similar to + that in gen_reload. */ + + last = get_last_insn (); + add_insn = emit_insn (gen_rtx_SET (VOIDmode, incloc, + gen_rtx_PLUS (GET_MODE (incloc), + incloc, inc))); + + code = recog_memoized (add_insn); + if (code >= 0) + { + extract_insn (add_insn); + if (constrain_operands (1)) + { + /* If this is a pre-increment and we have incremented the value + where it lives, copy the incremented value to RELOADREG to + be used as an address. */ + + if (! post) + emit_insn (gen_move_insn (reloadreg, incloc)); + + return add_insn; + } + } + delete_insns_since (last); + } + + /* If couldn't do the increment directly, must increment in RELOADREG. + The way we do this depends on whether this is pre- or post-increment. + For pre-increment, copy INCLOC to the reload register, increment it + there, then save back. */ + + if (! post) + { + if (in != reloadreg) + emit_insn (gen_move_insn (reloadreg, real_in)); + emit_insn (gen_add2_insn (reloadreg, inc)); + store = emit_insn (gen_move_insn (incloc, reloadreg)); + } + else + { + /* Postincrement. + Because this might be a jump insn or a compare, and because RELOADREG + may not be available after the insn in an input reload, we must do + the incrementation before the insn being reloaded for. + + We have already copied IN to RELOADREG. Increment the copy in + RELOADREG, save that back, then decrement RELOADREG so it has + the original value. */ + + emit_insn (gen_add2_insn (reloadreg, inc)); + store = emit_insn (gen_move_insn (incloc, reloadreg)); + emit_insn (gen_add2_insn (reloadreg, GEN_INT (-inc_amount))); + } + + return store; +} + +/* Return 1 if we are certain that the constraint-string STRING allows + the hard register REG. Return 0 if we can't be sure of this. */ + +static int +constraint_accepts_reg_p (string, reg) + char *string; + rtx reg; +{ + int value = 0; + int regno = true_regnum (reg); + int c; + + /* Initialize for first alternative. */ + value = 0; + /* Check that each alternative contains `g' or `r'. */ + while (1) + switch (c = *string++) + { + case 0: + /* If an alternative lacks `g' or `r', we lose. */ + return value; + case ',': + /* If an alternative lacks `g' or `r', we lose. */ + if (value == 0) + return 0; + /* Initialize for next alternative. */ + value = 0; + break; + case 'g': + case 'r': + /* Any general reg wins for this alternative. */ + if (TEST_HARD_REG_BIT (reg_class_contents[(int) GENERAL_REGS], regno)) + value = 1; + break; + default: + /* Any reg in specified class wins for this alternative. */ + { + enum reg_class class = REG_CLASS_FROM_LETTER (c); + + if (TEST_HARD_REG_BIT (reg_class_contents[(int) class], regno)) + value = 1; + } + } +} + +/* Return the number of places FIND appears within X, but don't count + an occurrence if some SET_DEST is FIND. */ + +int +count_occurrences (x, find) + register rtx x, find; +{ + register int i, j; + register enum rtx_code code; + register char *format_ptr; + int count; + + if (x == find) + return 1; + if (x == 0) + return 0; + + code = GET_CODE (x); + + switch (code) + { + case REG: + case QUEUED: + case CONST_INT: + case CONST_DOUBLE: + case SYMBOL_REF: + case CODE_LABEL: + case PC: + case CC0: + return 0; + + case MEM: + if (GET_CODE (find) == MEM && rtx_equal_p (x, find)) + return 1; + break; + case SET: + if (SET_DEST (x) == find) + return count_occurrences (SET_SRC (x), find); + break; + + default: + break; + } + + format_ptr = GET_RTX_FORMAT (code); + count = 0; + + for (i = 0; i < GET_RTX_LENGTH (code); i++) + { + switch (*format_ptr++) + { + case 'e': + count += count_occurrences (XEXP (x, i), find); + break; + + case 'E': + if (XVEC (x, i) != NULL) + { + for (j = 0; j < XVECLEN (x, i); j++) + count += count_occurrences (XVECEXP (x, i, j), find); + } + break; + } + } + return count; +} + +/* This array holds values which are equivalent to a hard register + during reload_cse_regs. Each array element is an EXPR_LIST of + values. Each time a hard register is set, we set the corresponding + array element to the value. Each time a hard register is copied + into memory, we add the memory location to the corresponding array + element. We don't store values or memory addresses with side + effects in this array. + + If the value is a CONST_INT, then the mode of the containing + EXPR_LIST is the mode in which that CONST_INT was referenced. + + We sometimes clobber a specific entry in a list. In that case, we + just set XEXP (list-entry, 0) to 0. */ + +static rtx *reg_values; + +/* This is a preallocated REG rtx which we use as a temporary in + reload_cse_invalidate_regno, so that we don't need to allocate a + new one each time through a loop in that function. */ + +static rtx invalidate_regno_rtx; + +/* Invalidate any entries in reg_values which depend on REGNO, + including those for REGNO itself. This is called if REGNO is + changing. If CLOBBER is true, then always forget anything we + currently know about REGNO. MODE is the mode of the assignment to + REGNO, which is used to determine how many hard registers are being + changed. If MODE is VOIDmode, then only REGNO is being changed; + this is used when invalidating call clobbered registers across a + call. */ + +static void +reload_cse_invalidate_regno (regno, mode, clobber) + int regno; + enum machine_mode mode; + int clobber; +{ + int endregno; + register int i; + + /* Our callers don't always go through true_regnum; we may see a + pseudo-register here from a CLOBBER or the like. We probably + won't ever see a pseudo-register that has a real register number, + for we check anyhow for safety. */ + if (regno >= FIRST_PSEUDO_REGISTER) + regno = reg_renumber[regno]; + if (regno < 0) + return; + + if (mode == VOIDmode) + endregno = regno + 1; + else + endregno = regno + HARD_REGNO_NREGS (regno, mode); + + if (clobber) + for (i = regno; i < endregno; i++) + reg_values[i] = 0; + + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + { + rtx x; + + for (x = reg_values[i]; x; x = XEXP (x, 1)) + { + if (XEXP (x, 0) != 0 + && refers_to_regno_p (regno, endregno, XEXP (x, 0), NULL_PTR)) + { + /* If this is the only entry on the list, clear + reg_values[i]. Otherwise, just clear this entry on + the list. */ + if (XEXP (x, 1) == 0 && x == reg_values[i]) + { + reg_values[i] = 0; + break; + } + XEXP (x, 0) = 0; + } + } + } + + /* We must look at earlier registers, in case REGNO is part of a + multi word value but is not the first register. If an earlier + register has a value in a mode which overlaps REGNO, then we must + invalidate that earlier register. Note that we do not need to + check REGNO or later registers (we must not check REGNO itself, + because we would incorrectly conclude that there was a conflict). */ + + for (i = 0; i < regno; i++) + { + rtx x; + + for (x = reg_values[i]; x; x = XEXP (x, 1)) + { + if (XEXP (x, 0) != 0) + { + PUT_MODE (invalidate_regno_rtx, GET_MODE (x)); + REGNO (invalidate_regno_rtx) = i; + if (refers_to_regno_p (regno, endregno, invalidate_regno_rtx, + NULL_PTR)) + { + reload_cse_invalidate_regno (i, VOIDmode, 1); + break; + } + } + } + } +} + +/* The memory at address MEM_BASE is being changed. + Return whether this change will invalidate VAL. */ + +static int +reload_cse_mem_conflict_p (mem_base, val) + rtx mem_base; + rtx val; +{ + enum rtx_code code; + char *fmt; + int i; + + code = GET_CODE (val); + switch (code) + { + /* Get rid of a few simple cases quickly. */ + case REG: + case PC: + case CC0: + case SCRATCH: + case CONST: + case CONST_INT: + case CONST_DOUBLE: + case SYMBOL_REF: + case LABEL_REF: + return 0; + + case MEM: + if (GET_MODE (mem_base) == BLKmode + || GET_MODE (val) == BLKmode) + return 1; + if (anti_dependence (val, mem_base)) + return 1; + /* The address may contain nested MEMs. */ + break; + + default: + break; + } + + fmt = GET_RTX_FORMAT (code); + + for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) + { + if (fmt[i] == 'e') + { + if (reload_cse_mem_conflict_p (mem_base, XEXP (val, i))) + return 1; + } + else if (fmt[i] == 'E') + { + int j; + + for (j = 0; j < XVECLEN (val, i); j++) + if (reload_cse_mem_conflict_p (mem_base, XVECEXP (val, i, j))) + return 1; + } + } + + return 0; +} + +/* Invalidate any entries in reg_values which are changed because of a + store to MEM_RTX. If this is called because of a non-const call + instruction, MEM_RTX is (mem:BLK const0_rtx). */ + +static void +reload_cse_invalidate_mem (mem_rtx) + rtx mem_rtx; +{ + register int i; + + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + { + rtx x; + + for (x = reg_values[i]; x; x = XEXP (x, 1)) + { + if (XEXP (x, 0) != 0 + && reload_cse_mem_conflict_p (mem_rtx, XEXP (x, 0))) + { + /* If this is the only entry on the list, clear + reg_values[i]. Otherwise, just clear this entry on + the list. */ + if (XEXP (x, 1) == 0 && x == reg_values[i]) + { + reg_values[i] = 0; + break; + } + XEXP (x, 0) = 0; + } + } + } +} + +/* Invalidate DEST, which is being assigned to or clobbered. The + second parameter exists so that this function can be passed to + note_stores; it is ignored. */ + +static void +reload_cse_invalidate_rtx (dest, ignore) + rtx dest; + rtx ignore ATTRIBUTE_UNUSED; +{ + while (GET_CODE (dest) == STRICT_LOW_PART + || GET_CODE (dest) == SIGN_EXTRACT + || GET_CODE (dest) == ZERO_EXTRACT + || GET_CODE (dest) == SUBREG) + dest = XEXP (dest, 0); + + if (GET_CODE (dest) == REG) + reload_cse_invalidate_regno (REGNO (dest), GET_MODE (dest), 1); + else if (GET_CODE (dest) == MEM) + reload_cse_invalidate_mem (dest); +} + +/* Do a very simple CSE pass over the hard registers. + + This function detects no-op moves where we happened to assign two + different pseudo-registers to the same hard register, and then + copied one to the other. Reload will generate a useless + instruction copying a register to itself. + + This function also detects cases where we load a value from memory + into two different registers, and (if memory is more expensive than + registers) changes it to simply copy the first register into the + second register. + + Another optimization is performed that scans the operands of each + instruction to see whether the value is already available in a + hard register. It then replaces the operand with the hard register + if possible, much like an optional reload would. */ + +static void +reload_cse_regs_1 (first) + rtx first; +{ + char *firstobj; + rtx callmem; + register int i; + rtx insn; + + init_alias_analysis (); + + reg_values = (rtx *) alloca (FIRST_PSEUDO_REGISTER * sizeof (rtx)); + bzero ((char *)reg_values, FIRST_PSEUDO_REGISTER * sizeof (rtx)); + + /* Create our EXPR_LIST structures on reload_obstack, so that we can + free them when we are done. */ + push_obstacks (&reload_obstack, &reload_obstack); + firstobj = (char *) obstack_alloc (&reload_obstack, 0); + + /* We pass this to reload_cse_invalidate_mem to invalidate all of + memory for a non-const call instruction. */ + callmem = gen_rtx_MEM (BLKmode, const0_rtx); + + /* This is used in reload_cse_invalidate_regno to avoid consing a + new REG in a loop in that function. */ + invalidate_regno_rtx = gen_rtx_REG (VOIDmode, 0); + + for (insn = first; insn; insn = NEXT_INSN (insn)) + { + rtx body; + + if (GET_CODE (insn) == CODE_LABEL) + { + /* Forget all the register values at a code label. We don't + try to do anything clever around jumps. */ + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + reg_values[i] = 0; + + continue; + } + +#ifdef NON_SAVING_SETJMP + if (NON_SAVING_SETJMP && GET_CODE (insn) == NOTE + && NOTE_LINE_NUMBER (insn) == NOTE_INSN_SETJMP) + { + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + reg_values[i] = 0; + + continue; + } +#endif + + if (GET_RTX_CLASS (GET_CODE (insn)) != 'i') + continue; + + /* If this is a call instruction, forget anything stored in a + call clobbered register, or, if this is not a const call, in + memory. */ + if (GET_CODE (insn) == CALL_INSN) + { + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + if (call_used_regs[i]) + reload_cse_invalidate_regno (i, VOIDmode, 1); + + if (! CONST_CALL_P (insn)) + reload_cse_invalidate_mem (callmem); + } + + body = PATTERN (insn); + if (GET_CODE (body) == SET) + { + int count = 0; + if (reload_cse_noop_set_p (body, insn)) + { + /* If this sets the return value of the function, we must keep + a USE around, in case this is in a different basic block + than the final USE. Otherwise, we could loose important + register lifeness information on SMALL_REGISTER_CLASSES + machines, where return registers might be used as spills: + subsequent passes assume that spill registers are dead at + the end of a basic block. */ + if (REG_FUNCTION_VALUE_P (SET_DEST (body))) + { + pop_obstacks (); + PATTERN (insn) = gen_rtx_USE (VOIDmode, SET_DEST (body)); + INSN_CODE (insn) = -1; + REG_NOTES (insn) = NULL_RTX; + push_obstacks (&reload_obstack, &reload_obstack); + } + else + { + PUT_CODE (insn, NOTE); + NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; + NOTE_SOURCE_FILE (insn) = 0; + } + + /* We're done with this insn. */ + continue; + } + + /* It's not a no-op, but we can try to simplify it. */ + count += reload_cse_simplify_set (body, insn); + + if (count > 0) + apply_change_group (); + else + reload_cse_simplify_operands (insn); + + reload_cse_record_set (body, body); + } + else if (GET_CODE (body) == PARALLEL) + { + int count = 0; + rtx value = NULL_RTX; + + /* If every action in a PARALLEL is a noop, we can delete + the entire PARALLEL. */ + for (i = XVECLEN (body, 0) - 1; i >= 0; --i) + { + rtx part = XVECEXP (body, 0, i); + if (GET_CODE (part) == SET) + { + if (! reload_cse_noop_set_p (part, insn)) + break; + if (REG_FUNCTION_VALUE_P (SET_DEST (part))) + { + if (value) + break; + value = SET_DEST (part); + } + } + else if (GET_CODE (part) != CLOBBER) + break; + } + if (i < 0) + { + if (value) + { + pop_obstacks (); + PATTERN (insn) = gen_rtx_USE (VOIDmode, value); + INSN_CODE (insn) = -1; + REG_NOTES (insn) = NULL_RTX; + push_obstacks (&reload_obstack, &reload_obstack); + } + else + { + PUT_CODE (insn, NOTE); + NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; + NOTE_SOURCE_FILE (insn) = 0; + } + + /* We're done with this insn. */ + continue; + } + + /* It's not a no-op, but we can try to simplify it. */ + for (i = XVECLEN (body, 0) - 1; i >= 0; --i) + if (GET_CODE (XVECEXP (body, 0, i)) == SET) + count += reload_cse_simplify_set (XVECEXP (body, 0, i), insn); + + if (count > 0) + apply_change_group (); + else + reload_cse_simplify_operands (insn); + + /* Look through the PARALLEL and record the values being + set, if possible. Also handle any CLOBBERs. */ + for (i = XVECLEN (body, 0) - 1; i >= 0; --i) + { + rtx x = XVECEXP (body, 0, i); + + if (GET_CODE (x) == SET) + reload_cse_record_set (x, body); + else + note_stores (x, reload_cse_invalidate_rtx); + } + } + else + note_stores (body, reload_cse_invalidate_rtx); + +#ifdef AUTO_INC_DEC + /* Clobber any registers which appear in REG_INC notes. We + could keep track of the changes to their values, but it is + unlikely to help. */ + { + rtx x; + + for (x = REG_NOTES (insn); x; x = XEXP (x, 1)) + if (REG_NOTE_KIND (x) == REG_INC) + reload_cse_invalidate_rtx (XEXP (x, 0), NULL_RTX); + } +#endif + + /* Look for any CLOBBERs in CALL_INSN_FUNCTION_USAGE, but only + after we have processed the insn. */ + if (GET_CODE (insn) == CALL_INSN) + { + rtx x; + + for (x = CALL_INSN_FUNCTION_USAGE (insn); x; x = XEXP (x, 1)) + if (GET_CODE (XEXP (x, 0)) == CLOBBER) + reload_cse_invalidate_rtx (XEXP (XEXP (x, 0), 0), NULL_RTX); + } + } + + /* Free all the temporary structures we created, and go back to the + regular obstacks. */ + obstack_free (&reload_obstack, firstobj); + pop_obstacks (); +} + +/* Call cse / combine like post-reload optimization phases. + FIRST is the first instruction. */ +void +reload_cse_regs (first) + rtx first; +{ + reload_cse_regs_1 (first); + reload_combine (); + reload_cse_move2add (first); + if (flag_expensive_optimizations) + reload_cse_regs_1 (first); +} + +/* Return whether the values known for REGNO are equal to VAL. MODE + is the mode of the object that VAL is being copied to; this matters + if VAL is a CONST_INT. */ + +static int +reload_cse_regno_equal_p (regno, val, mode) + int regno; + rtx val; + enum machine_mode mode; +{ + rtx x; + + if (val == 0) + return 0; + + for (x = reg_values[regno]; x; x = XEXP (x, 1)) + if (XEXP (x, 0) != 0 + && rtx_equal_p (XEXP (x, 0), val) + && (! flag_float_store || GET_CODE (XEXP (x, 0)) != MEM + || GET_MODE_CLASS (GET_MODE (x)) != MODE_FLOAT) + && (GET_CODE (val) != CONST_INT + || mode == GET_MODE (x) + || (GET_MODE_SIZE (mode) < GET_MODE_SIZE (GET_MODE (x)) + /* On a big endian machine if the value spans more than + one register then this register holds the high part of + it and we can't use it. + + ??? We should also compare with the high part of the + value. */ + && !(WORDS_BIG_ENDIAN + && HARD_REGNO_NREGS (regno, GET_MODE (x)) > 1) + && TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (mode), + GET_MODE_BITSIZE (GET_MODE (x)))))) + return 1; + + return 0; +} + +/* See whether a single set is a noop. SET is the set instruction we + are should check, and INSN is the instruction from which it came. */ + +static int +reload_cse_noop_set_p (set, insn) + rtx set; + rtx insn; +{ + rtx src, dest; + enum machine_mode dest_mode; + int dreg, sreg; + int ret; + + src = SET_SRC (set); + dest = SET_DEST (set); + dest_mode = GET_MODE (dest); + + if (side_effects_p (src)) + return 0; + + dreg = true_regnum (dest); + sreg = true_regnum (src); + + /* Check for setting a register to itself. In this case, we don't + have to worry about REG_DEAD notes. */ + if (dreg >= 0 && dreg == sreg) + return 1; + + ret = 0; + if (dreg >= 0) + { + /* Check for setting a register to itself. */ + if (dreg == sreg) + ret = 1; + + /* Check for setting a register to a value which we already know + is in the register. */ + else if (reload_cse_regno_equal_p (dreg, src, dest_mode)) + ret = 1; + + /* Check for setting a register DREG to another register SREG + where SREG is equal to a value which is already in DREG. */ + else if (sreg >= 0) + { + rtx x; + + for (x = reg_values[sreg]; x; x = XEXP (x, 1)) + { + rtx tmp; + + if (XEXP (x, 0) == 0) + continue; + + if (dest_mode == GET_MODE (x)) + tmp = XEXP (x, 0); + else if (GET_MODE_BITSIZE (dest_mode) + < GET_MODE_BITSIZE (GET_MODE (x))) + tmp = gen_lowpart_common (dest_mode, XEXP (x, 0)); + else + continue; + + if (tmp + && reload_cse_regno_equal_p (dreg, tmp, dest_mode)) + { + ret = 1; + break; + } + } + } + } + else if (GET_CODE (dest) == MEM) + { + /* Check for storing a register to memory when we know that the + register is equivalent to the memory location. */ + if (sreg >= 0 + && reload_cse_regno_equal_p (sreg, dest, dest_mode) + && ! side_effects_p (dest)) + ret = 1; + } + + return ret; +} + +/* Try to simplify a single SET instruction. SET is the set pattern. + INSN is the instruction it came from. + This function only handles one case: if we set a register to a value + which is not a register, we try to find that value in some other register + and change the set into a register copy. */ + +static int +reload_cse_simplify_set (set, insn) + rtx set; + rtx insn; +{ + int dreg; + rtx src; + enum machine_mode dest_mode; + enum reg_class dclass; + register int i; + + dreg = true_regnum (SET_DEST (set)); + if (dreg < 0) + return 0; + + src = SET_SRC (set); + if (side_effects_p (src) || true_regnum (src) >= 0) + return 0; + + dclass = REGNO_REG_CLASS (dreg); + + /* If memory loads are cheaper than register copies, don't change them. */ + if (GET_CODE (src) == MEM + && MEMORY_MOVE_COST (GET_MODE (src), dclass, 1) < 2) + return 0; + + /* If the constant is cheaper than a register, don't change it. */ + if (CONSTANT_P (src) + && rtx_cost (src, SET) < 2) + return 0; + + dest_mode = GET_MODE (SET_DEST (set)); + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + { + if (i != dreg + && REGISTER_MOVE_COST (REGNO_REG_CLASS (i), dclass) == 2 + && reload_cse_regno_equal_p (i, src, dest_mode)) + { + int validated; + + /* Pop back to the real obstacks while changing the insn. */ + pop_obstacks (); + + validated = validate_change (insn, &SET_SRC (set), + gen_rtx_REG (dest_mode, i), 1); + + /* Go back to the obstack we are using for temporary + storage. */ + push_obstacks (&reload_obstack, &reload_obstack); + + if (validated) + return 1; + } + } + return 0; +} + +/* Try to replace operands in INSN with equivalent values that are already + in registers. This can be viewed as optional reloading. + + For each non-register operand in the insn, see if any hard regs are + known to be equivalent to that operand. Record the alternatives which + can accept these hard registers. Among all alternatives, select the + ones which are better or equal to the one currently matching, where + "better" is in terms of '?' and '!' constraints. Among the remaining + alternatives, select the one which replaces most operands with + hard registers. */ + +static int +reload_cse_simplify_operands (insn) + rtx insn; +{ +#ifdef REGISTER_CONSTRAINTS + int i,j; + + char *constraints[MAX_RECOG_OPERANDS]; + + /* Vector recording how bad an alternative is. */ + int *alternative_reject; + /* Vector recording how many registers can be introduced by choosing + this alternative. */ + int *alternative_nregs; + /* Array of vectors recording, for each operand and each alternative, + which hard register to substitute, or -1 if the operand should be + left as it is. */ + int *op_alt_regno[MAX_RECOG_OPERANDS]; + /* Array of alternatives, sorted in order of decreasing desirability. */ + int *alternative_order; + rtx reg = gen_rtx_REG (VOIDmode, -1); + + extract_insn (insn); + + if (recog_n_alternatives == 0 || recog_n_operands == 0) + return 0; + + /* Figure out which alternative currently matches. */ + if (! constrain_operands (1)) + fatal_insn_not_found (insn); + + alternative_reject = (int *) alloca (recog_n_alternatives * sizeof (int)); + alternative_nregs = (int *) alloca (recog_n_alternatives * sizeof (int)); + alternative_order = (int *) alloca (recog_n_alternatives * sizeof (int)); + bzero ((char *)alternative_reject, recog_n_alternatives * sizeof (int)); + bzero ((char *)alternative_nregs, recog_n_alternatives * sizeof (int)); + + for (i = 0; i < recog_n_operands; i++) + { + enum machine_mode mode; + int regno; + char *p; + + op_alt_regno[i] = (int *) alloca (recog_n_alternatives * sizeof (int)); + for (j = 0; j < recog_n_alternatives; j++) + op_alt_regno[i][j] = -1; + + p = constraints[i] = recog_constraints[i]; + mode = recog_operand_mode[i]; + + /* Add the reject values for each alternative given by the constraints + for this operand. */ + j = 0; + while (*p != '\0') + { + char c = *p++; + if (c == ',') + j++; + else if (c == '?') + alternative_reject[j] += 3; + else if (c == '!') + alternative_reject[j] += 300; + } + + /* We won't change operands which are already registers. We + also don't want to modify output operands. */ + regno = true_regnum (recog_operand[i]); + if (regno >= 0 + || constraints[i][0] == '=' + || constraints[i][0] == '+') + continue; + + for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) + { + int class = (int) NO_REGS; + + if (! reload_cse_regno_equal_p (regno, recog_operand[i], mode)) + continue; + + REGNO (reg) = regno; + PUT_MODE (reg, mode); + + /* We found a register equal to this operand. Now look for all + alternatives that can accept this register and have not been + assigned a register they can use yet. */ + j = 0; + p = constraints[i]; + for (;;) + { + char c = *p++; + + switch (c) + { + case '=': case '+': case '?': + case '#': case '&': case '!': + case '*': case '%': + case '0': case '1': case '2': case '3': case '4': + case 'm': case '<': case '>': case 'V': case 'o': + case 'E': case 'F': case 'G': case 'H': + case 's': case 'i': case 'n': + case 'I': case 'J': case 'K': case 'L': + case 'M': case 'N': case 'O': case 'P': +#ifdef EXTRA_CONSTRAINT + case 'Q': case 'R': case 'S': case 'T': case 'U': +#endif + case 'p': case 'X': + /* These don't say anything we care about. */ + break; + + case 'g': case 'r': + class = reg_class_subunion[(int) class][(int) GENERAL_REGS]; + break; + + default: + class + = reg_class_subunion[(int) class][(int) REG_CLASS_FROM_LETTER ((unsigned char)c)]; + break; + + case ',': case '\0': + /* See if REGNO fits this alternative, and set it up as the + replacement register if we don't have one for this + alternative yet and the operand being replaced is not + a cheap CONST_INT. */ + if (op_alt_regno[i][j] == -1 + && reg_fits_class_p (reg, class, 0, mode) + && (GET_CODE (recog_operand[i]) != CONST_INT + || rtx_cost (recog_operand[i], SET) > rtx_cost (reg, SET))) + { + alternative_nregs[j]++; + op_alt_regno[i][j] = regno; + } + j++; + break; + } + + if (c == '\0') + break; + } + } + } + + /* Record all alternatives which are better or equal to the currently + matching one in the alternative_order array. */ + for (i = j = 0; i < recog_n_alternatives; i++) + if (alternative_reject[i] <= alternative_reject[which_alternative]) + alternative_order[j++] = i; + recog_n_alternatives = j; + + /* Sort it. Given a small number of alternatives, a dumb algorithm + won't hurt too much. */ + for (i = 0; i < recog_n_alternatives - 1; i++) + { + int best = i; + int best_reject = alternative_reject[alternative_order[i]]; + int best_nregs = alternative_nregs[alternative_order[i]]; + int tmp; + + for (j = i + 1; j < recog_n_alternatives; j++) + { + int this_reject = alternative_reject[alternative_order[j]]; + int this_nregs = alternative_nregs[alternative_order[j]]; + + if (this_reject < best_reject + || (this_reject == best_reject && this_nregs < best_nregs)) + { + best = j; + best_reject = this_reject; + best_nregs = this_nregs; + } + } + + tmp = alternative_order[best]; + alternative_order[best] = alternative_order[i]; + alternative_order[i] = tmp; + } + + /* Substitute the operands as determined by op_alt_regno for the best + alternative. */ + j = alternative_order[0]; + + /* Pop back to the real obstacks while changing the insn. */ + pop_obstacks (); + + for (i = 0; i < recog_n_operands; i++) + { + enum machine_mode mode = recog_operand_mode[i]; + if (op_alt_regno[i][j] == -1) + continue; + + validate_change (insn, recog_operand_loc[i], + gen_rtx_REG (mode, op_alt_regno[i][j]), 1); + } + + for (i = recog_n_dups - 1; i >= 0; i--) + { + int op = recog_dup_num[i]; + enum machine_mode mode = recog_operand_mode[op]; + + if (op_alt_regno[op][j] == -1) + continue; + + validate_change (insn, recog_dup_loc[i], + gen_rtx_REG (mode, op_alt_regno[op][j]), 1); + } + + /* Go back to the obstack we are using for temporary + storage. */ + push_obstacks (&reload_obstack, &reload_obstack); + + return apply_change_group (); +#else + return 0; +#endif +} + +/* These two variables are used to pass information from + reload_cse_record_set to reload_cse_check_clobber. */ + +static int reload_cse_check_clobbered; +static rtx reload_cse_check_src; + +/* See if DEST overlaps with RELOAD_CSE_CHECK_SRC. If it does, set + RELOAD_CSE_CHECK_CLOBBERED. This is called via note_stores. The + second argument, which is passed by note_stores, is ignored. */ + +static void +reload_cse_check_clobber (dest, ignore) + rtx dest; + rtx ignore ATTRIBUTE_UNUSED; +{ + if (reg_overlap_mentioned_p (dest, reload_cse_check_src)) + reload_cse_check_clobbered = 1; +} + +/* Record the result of a SET instruction. SET is the set pattern. + BODY is the pattern of the insn that it came from. */ + +static void +reload_cse_record_set (set, body) + rtx set; + rtx body; +{ + rtx dest, src, x; + int dreg, sreg; + enum machine_mode dest_mode; + + dest = SET_DEST (set); + src = SET_SRC (set); + dreg = true_regnum (dest); + sreg = true_regnum (src); + dest_mode = GET_MODE (dest); + + /* Some machines don't define AUTO_INC_DEC, but they still use push + instructions. We need to catch that case here in order to + invalidate the stack pointer correctly. Note that invalidating + the stack pointer is different from invalidating DEST. */ + x = dest; + while (GET_CODE (x) == SUBREG + || GET_CODE (x) == ZERO_EXTRACT + || GET_CODE (x) == SIGN_EXTRACT + || GET_CODE (x) == STRICT_LOW_PART) + x = XEXP (x, 0); + if (push_operand (x, GET_MODE (x))) + { + reload_cse_invalidate_rtx (stack_pointer_rtx, NULL_RTX); + reload_cse_invalidate_rtx (dest, NULL_RTX); + return; + } + + /* We can only handle an assignment to a register, or a store of a + register to a memory location. For other cases, we just clobber + the destination. We also have to just clobber if there are side + effects in SRC or DEST. */ + if ((dreg < 0 && GET_CODE (dest) != MEM) + || side_effects_p (src) + || side_effects_p (dest)) + { + reload_cse_invalidate_rtx (dest, NULL_RTX); + return; + } + +#ifdef HAVE_cc0 + /* We don't try to handle values involving CC, because it's a pain + to keep track of when they have to be invalidated. */ + if (reg_mentioned_p (cc0_rtx, src) + || reg_mentioned_p (cc0_rtx, dest)) + { + reload_cse_invalidate_rtx (dest, NULL_RTX); + return; + } +#endif + + /* If BODY is a PARALLEL, then we need to see whether the source of + SET is clobbered by some other instruction in the PARALLEL. */ + if (GET_CODE (body) == PARALLEL) + { + int i; + + for (i = XVECLEN (body, 0) - 1; i >= 0; --i) + { + rtx x; + + x = XVECEXP (body, 0, i); + if (x == set) + continue; + + reload_cse_check_clobbered = 0; + reload_cse_check_src = src; + note_stores (x, reload_cse_check_clobber); + if (reload_cse_check_clobbered) + { + reload_cse_invalidate_rtx (dest, NULL_RTX); + return; + } + } + } + + if (dreg >= 0) + { + int i; + + /* This is an assignment to a register. Update the value we + have stored for the register. */ + if (sreg >= 0) + { + rtx x; + + /* This is a copy from one register to another. Any values + which were valid for SREG are now valid for DREG. If the + mode changes, we use gen_lowpart_common to extract only + the part of the value that is copied. */ + reg_values[dreg] = 0; + for (x = reg_values[sreg]; x; x = XEXP (x, 1)) + { + rtx tmp; + + if (XEXP (x, 0) == 0) + continue; + if (dest_mode == GET_MODE (XEXP (x, 0))) + tmp = XEXP (x, 0); + else if (GET_MODE_BITSIZE (dest_mode) + > GET_MODE_BITSIZE (GET_MODE (XEXP (x, 0)))) + continue; + else + tmp = gen_lowpart_common (dest_mode, XEXP (x, 0)); + if (tmp) + reg_values[dreg] = gen_rtx_EXPR_LIST (dest_mode, tmp, + reg_values[dreg]); + } + } + else + reg_values[dreg] = gen_rtx_EXPR_LIST (dest_mode, src, NULL_RTX); + + /* We've changed DREG, so invalidate any values held by other + registers that depend upon it. */ + reload_cse_invalidate_regno (dreg, dest_mode, 0); + + /* If this assignment changes more than one hard register, + forget anything we know about the others. */ + for (i = 1; i < HARD_REGNO_NREGS (dreg, dest_mode); i++) + reg_values[dreg + i] = 0; + } + else if (GET_CODE (dest) == MEM) + { + /* Invalidate conflicting memory locations. */ + reload_cse_invalidate_mem (dest); + + /* If we're storing a register to memory, add DEST to the list + in REG_VALUES. */ + if (sreg >= 0 && ! side_effects_p (dest)) + reg_values[sreg] = gen_rtx_EXPR_LIST (dest_mode, dest, + reg_values[sreg]); + } + else + { + /* We should have bailed out earlier. */ + abort (); + } +} + +/* If reload couldn't use reg+reg+offset addressing, try to use reg+reg + addressing now. + This code might also be useful when reload gave up on reg+reg addresssing + because of clashes between the return register and INDEX_REG_CLASS. */ + +/* The maximum number of uses of a register we can keep track of to + replace them with reg+reg addressing. */ +#define RELOAD_COMBINE_MAX_USES 6 + +/* INSN is the insn where a register has ben used, and USEP points to the + location of the register within the rtl. */ +struct reg_use { rtx insn, *usep; }; + +/* If the register is used in some unknown fashion, USE_INDEX is negative. + If it is dead, USE_INDEX is RELOAD_COMBINE_MAX_USES, and STORE_RUID + indicates where it becomes live again. + Otherwise, USE_INDEX is the index of the last encountered use of the + register (which is first among these we have seen since we scan backwards), + OFFSET contains the constant offset that is added to the register in + all encountered uses, and USE_RUID indicates the first encountered, i.e. + last, of these uses. + STORE_RUID is always meaningful if we only want to use a value in a + register in a different place: it denotes the next insn in the insn + stream (i.e. the last ecountered) that sets or clobbers the register. */ +static struct + { + struct reg_use reg_use[RELOAD_COMBINE_MAX_USES]; + int use_index; + rtx offset; + int store_ruid; + int use_ruid; + } reg_state[FIRST_PSEUDO_REGISTER]; + +/* Reverse linear uid. This is increased in reload_combine while scanning + the instructions from last to first. It is used to set last_label_ruid + and the store_ruid / use_ruid fields in reg_state. */ +static int reload_combine_ruid; + +#define LABEL_LIVE(LABEL) \ + (label_live[CODE_LABEL_NUMBER (LABEL) - min_labelno]) + +static void +reload_combine () +{ + rtx insn, set; + int first_index_reg = 1, last_index_reg = 0; + int i; + int last_label_ruid; + int min_labelno, n_labels; + HARD_REG_SET ever_live_at_start, *label_live; + + /* If reg+reg can be used in offsetable memory adresses, the main chunk of + reload has already used it where appropriate, so there is no use in + trying to generate it now. */ + if (double_reg_address_ok && INDEX_REG_CLASS != NO_REGS) + return; + + /* To avoid wasting too much time later searching for an index register, + determine the minimum and maximum index register numbers. */ + for (i = FIRST_PSEUDO_REGISTER - 1; i >= 0; --i) + { + if (TEST_HARD_REG_BIT (reg_class_contents[INDEX_REG_CLASS], i)) + { + if (! last_index_reg) + last_index_reg = i; + first_index_reg = i; + } + } + /* If no index register is available, we can quit now. */ + if (first_index_reg > last_index_reg) + return; + + /* Set up LABEL_LIVE and EVER_LIVE_AT_START. The register lifetime + information is a bit fuzzy immediately after reload, but it's + still good enough to determine which registers are live at a jump + destination. */ + min_labelno = get_first_label_num (); + n_labels = max_label_num () - min_labelno; + label_live = (HARD_REG_SET *) xmalloc (n_labels * sizeof (HARD_REG_SET)); + CLEAR_HARD_REG_SET (ever_live_at_start); + for (i = n_basic_blocks - 1; i >= 0; i--) + { + insn = BLOCK_HEAD (i); + if (GET_CODE (insn) == CODE_LABEL) + { + HARD_REG_SET live; + + REG_SET_TO_HARD_REG_SET (live, basic_block_live_at_start[i]); + compute_use_by_pseudos (&live, basic_block_live_at_start[i]); + COPY_HARD_REG_SET (LABEL_LIVE (insn), live); + IOR_HARD_REG_SET (ever_live_at_start, live); + } + } + + /* Initialize last_label_ruid, reload_combine_ruid and reg_state. */ + last_label_ruid = reload_combine_ruid = 0; + for (i = FIRST_PSEUDO_REGISTER - 1; i >= 0; --i) + { + reg_state[i].store_ruid = reload_combine_ruid; + if (fixed_regs[i]) + reg_state[i].use_index = -1; + else + reg_state[i].use_index = RELOAD_COMBINE_MAX_USES; + } + + for (insn = get_last_insn (); insn; insn = PREV_INSN (insn)) + { + rtx note; + + /* We cannot do our optimization across labels. Invalidating all the use + information we have would be costly, so we just note where the label + is and then later disable any optimization that would cross it. */ + if (GET_CODE (insn) == CODE_LABEL) + last_label_ruid = reload_combine_ruid; + if (GET_CODE (insn) == BARRIER) + { + for (i = FIRST_PSEUDO_REGISTER - 1; i >= 0; --i) + reg_state[i].use_index = RELOAD_COMBINE_MAX_USES; + } + if (GET_RTX_CLASS (GET_CODE (insn)) != 'i') + continue; + reload_combine_ruid++; + + /* Look for (set (REGX) (CONST_INT)) + (set (REGX) (PLUS (REGX) (REGY))) + ... + ... (MEM (REGX)) ... + and convert it to + (set (REGZ) (CONST_INT)) + ... + ... (MEM (PLUS (REGZ) (REGY)))... . + + First, check that we have (set (REGX) (PLUS (REGX) (REGY))) + and that we know all uses of REGX before it dies. */ + set = single_set (insn); + if (set != NULL_RTX + && GET_CODE (SET_DEST (set)) == REG + && (HARD_REGNO_NREGS (REGNO (SET_DEST (set)), + GET_MODE (SET_DEST (set))) + == 1) + && GET_CODE (SET_SRC (set)) == PLUS + && GET_CODE (XEXP (SET_SRC (set), 1)) == REG + && rtx_equal_p (XEXP (SET_SRC (set), 0), SET_DEST (set)) + && last_label_ruid < reg_state[REGNO (SET_DEST (set))].use_ruid) + { + rtx reg = SET_DEST (set); + rtx plus = SET_SRC (set); + rtx base = XEXP (plus, 1); + rtx prev = prev_nonnote_insn (insn); + rtx prev_set = prev ? single_set (prev) : NULL_RTX; + int regno = REGNO (reg); + rtx const_reg; + rtx reg_sum = NULL_RTX; + + /* Now, we need an index register. + We'll set index_reg to this index register, const_reg to the + register that is to be loaded with the constant + (denoted as REGZ in the substitution illustration above), + and reg_sum to the register-register that we want to use to + substitute uses of REG (typically in MEMs) with. + First check REG and BASE for being index registers; + we can use them even if they are not dead. */ + if (TEST_HARD_REG_BIT (reg_class_contents[INDEX_REG_CLASS], regno) + || TEST_HARD_REG_BIT (reg_class_contents[INDEX_REG_CLASS], + REGNO (base))) + { + const_reg = reg; + reg_sum = plus; + } + else + { + /* Otherwise, look for a free index register. Since we have + checked above that neiter REG nor BASE are index registers, + if we find anything at all, it will be different from these + two registers. */ + for (i = first_index_reg; i <= last_index_reg; i++) + { + if (TEST_HARD_REG_BIT (reg_class_contents[INDEX_REG_CLASS], i) + && reg_state[i].use_index == RELOAD_COMBINE_MAX_USES + && reg_state[i].store_ruid <= reg_state[regno].use_ruid + && HARD_REGNO_NREGS (i, GET_MODE (reg)) == 1) + { + rtx index_reg = gen_rtx_REG (GET_MODE (reg), i); + const_reg = index_reg; + reg_sum = gen_rtx_PLUS (GET_MODE (reg), index_reg, base); + break; + } + } + } + /* Check that PREV_SET is indeed (set (REGX) (CONST_INT)) and that + (REGY), i.e. BASE, is not clobbered before the last use we'll + create. */ + if (prev_set + && GET_CODE (SET_SRC (prev_set)) == CONST_INT + && rtx_equal_p (SET_DEST (prev_set), reg) + && reg_state[regno].use_index >= 0 + && reg_state[REGNO (base)].store_ruid <= reg_state[regno].use_ruid + && reg_sum) + { + int i; + + /* Change destination register and - if necessary - the + constant value in PREV, the constant loading instruction. */ + validate_change (prev, &SET_DEST (prev_set), const_reg, 1); + if (reg_state[regno].offset != const0_rtx) + validate_change (prev, + &SET_SRC (prev_set), + GEN_INT (INTVAL (SET_SRC (prev_set)) + + INTVAL (reg_state[regno].offset)), + 1); + /* Now for every use of REG that we have recorded, replace REG + with REG_SUM. */ + for (i = reg_state[regno].use_index; + i < RELOAD_COMBINE_MAX_USES; i++) + validate_change (reg_state[regno].reg_use[i].insn, + reg_state[regno].reg_use[i].usep, + reg_sum, 1); + + if (apply_change_group ()) + { + rtx *np; + + /* Delete the reg-reg addition. */ + PUT_CODE (insn, NOTE); + NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; + NOTE_SOURCE_FILE (insn) = 0; + + if (reg_state[regno].offset != const0_rtx) + { + /* Previous REG_EQUIV / REG_EQUAL notes for PREV + are now invalid. */ + for (np = ®_NOTES (prev); *np; ) + { + if (REG_NOTE_KIND (*np) == REG_EQUAL + || REG_NOTE_KIND (*np) == REG_EQUIV) + *np = XEXP (*np, 1); + else + np = &XEXP (*np, 1); + } + } + reg_state[regno].use_index = RELOAD_COMBINE_MAX_USES; + reg_state[REGNO (const_reg)].store_ruid = reload_combine_ruid; + continue; + } + } + } + note_stores (PATTERN (insn), reload_combine_note_store); + if (GET_CODE (insn) == CALL_INSN) + { + rtx link; + + for (i = FIRST_PSEUDO_REGISTER - 1; i >= 0; --i) + { + if (call_used_regs[i]) + { + reg_state[i].use_index = RELOAD_COMBINE_MAX_USES; + reg_state[i].store_ruid = reload_combine_ruid; + } + } + for (link = CALL_INSN_FUNCTION_USAGE (insn); link; + link = XEXP (link, 1)) + { + rtx use = XEXP (link, 0); + int regno = REGNO (XEXP (use, 0)); + if (GET_CODE (use) == CLOBBER) + { + reg_state[regno].use_index = RELOAD_COMBINE_MAX_USES; + reg_state[regno].store_ruid = reload_combine_ruid; + } + else + reg_state[regno].use_index = -1; + } + } + if (GET_CODE (insn) == JUMP_INSN && GET_CODE (PATTERN (insn)) != RETURN) + { + /* Non-spill registers might be used at the call destination in + some unknown fashion, so we have to mark the unknown use. */ + HARD_REG_SET *live; + if ((condjump_p (insn) || condjump_in_parallel_p (insn)) + && JUMP_LABEL (insn)) + live = &LABEL_LIVE (JUMP_LABEL (insn)); + else + live = &ever_live_at_start; + for (i = FIRST_PSEUDO_REGISTER - 1; i >= 0; --i) + { + if (TEST_HARD_REG_BIT (*live, i)) + reg_state[i].use_index = -1; + } + } + reload_combine_note_use (&PATTERN (insn), insn); + for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) + { + if (REG_NOTE_KIND (note) == REG_INC + && GET_CODE (XEXP (note, 0)) == REG) + { + int regno = REGNO (XEXP (note, 0)); + + reg_state[regno].store_ruid = reload_combine_ruid; + reg_state[regno].use_index = -1; + } + } + } + free (label_live); +} + +/* Check if DST is a register or a subreg of a register; if it is, + update reg_state[regno].store_ruid and reg_state[regno].use_index + accordingly. Called via note_stores from reload_combine. */ +static void +reload_combine_note_store (dst, set) + rtx dst, set; +{ + int regno = 0; + int i; + unsigned size = GET_MODE_SIZE (GET_MODE (dst)); + + if (GET_CODE (dst) == SUBREG) + { + regno = SUBREG_WORD (dst); + dst = SUBREG_REG (dst); + } + if (GET_CODE (dst) != REG) + return; + regno += REGNO (dst); + + /* note_stores might have stripped a STRICT_LOW_PART, so we have to be + careful with registers / register parts that are not full words. + + Similarly for ZERO_EXTRACT and SIGN_EXTRACT. */ + if (GET_CODE (set) != SET + || GET_CODE (SET_DEST (set)) == ZERO_EXTRACT + || GET_CODE (SET_DEST (set)) == SIGN_EXTRACT + || GET_CODE (SET_DEST (set)) == STRICT_LOW_PART) + { + for (i = (size - 1) / UNITS_PER_WORD + regno; i >= regno; i--) + { + reg_state[i].use_index = -1; + reg_state[i].store_ruid = reload_combine_ruid; + } + } + else + { + for (i = (size - 1) / UNITS_PER_WORD + regno; i >= regno; i--) + { + reg_state[i].store_ruid = reload_combine_ruid; + reg_state[i].use_index = RELOAD_COMBINE_MAX_USES; + } + } +} + +/* XP points to a piece of rtl that has to be checked for any uses of + registers. + *XP is the pattern of INSN, or a part of it. + Called from reload_combine, and recursively by itself. */ +static void +reload_combine_note_use (xp, insn) + rtx *xp, insn; +{ + rtx x = *xp; + enum rtx_code code = x->code; + char *fmt; + int i, j; + rtx offset = const0_rtx; /* For the REG case below. */ + + switch (code) + { + case SET: + if (GET_CODE (SET_DEST (x)) == REG) + { + reload_combine_note_use (&SET_SRC (x), insn); + return; + } + break; + + case CLOBBER: + if (GET_CODE (SET_DEST (x)) == REG) + return; + break; + + case PLUS: + /* We are interested in (plus (reg) (const_int)) . */ + if (GET_CODE (XEXP (x, 0)) != REG || GET_CODE (XEXP (x, 1)) != CONST_INT) + break; + offset = XEXP (x, 1); + x = XEXP (x, 0); + /* Fall through. */ + case REG: + { + int regno = REGNO (x); + int use_index; + + /* Some spurious USEs of pseudo registers might remain. + Just ignore them. */ + if (regno >= FIRST_PSEUDO_REGISTER) + return; + + /* If this register is already used in some unknown fashion, we + can't do anything. + If we decrement the index from zero to -1, we can't store more + uses, so this register becomes used in an unknown fashion. */ + use_index = --reg_state[regno].use_index; + if (use_index < 0) + return; + + if (use_index != RELOAD_COMBINE_MAX_USES - 1) + { + /* We have found another use for a register that is already + used later. Check if the offsets match; if not, mark the + register as used in an unknown fashion. */ + if (! rtx_equal_p (offset, reg_state[regno].offset)) + { + reg_state[regno].use_index = -1; + return; + } + } + else + { + /* This is the first use of this register we have seen since we + marked it as dead. */ + reg_state[regno].offset = offset; + reg_state[regno].use_ruid = reload_combine_ruid; + } + reg_state[regno].reg_use[use_index].insn = insn; + reg_state[regno].reg_use[use_index].usep = xp; + return; + } + + default: + break; + } + + /* Recursively process the components of X. */ + fmt = GET_RTX_FORMAT (code); + for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) + { + if (fmt[i] == 'e') + reload_combine_note_use (&XEXP (x, i), insn); + else if (fmt[i] == 'E') + { + for (j = XVECLEN (x, i) - 1; j >= 0; j--) + reload_combine_note_use (&XVECEXP (x, i, j), insn); + } + } +} + +/* See if we can reduce the cost of a constant by replacing a move with + an add. */ +/* We cannot do our optimization across labels. Invalidating all the + information about register contents we have would be costly, so we + use last_label_luid (local variable of reload_cse_move2add) to note + where the label is and then later disable any optimization that would + cross it. + reg_offset[n] / reg_base_reg[n] / reg_mode[n] are only valid if + reg_set_luid[n] is larger than last_label_luid[n] . */ +static int reg_set_luid[FIRST_PSEUDO_REGISTER]; +/* reg_offset[n] has to be CONST_INT for it and reg_base_reg[n] / + reg_mode[n] to be valid. + If reg_offset[n] is a CONST_INT and reg_base_reg[n] is negative, register n + has been set to reg_offset[n] in mode reg_mode[n] . + If reg_offset[n] is a CONST_INT and reg_base_reg[n] is non-negative, + register n has been set to the sum of reg_offset[n] and register + reg_base_reg[n], calculated in mode reg_mode[n] . */ +static rtx reg_offset[FIRST_PSEUDO_REGISTER]; +static int reg_base_reg[FIRST_PSEUDO_REGISTER]; +static enum machine_mode reg_mode[FIRST_PSEUDO_REGISTER]; +/* move2add_luid is linearily increased while scanning the instructions + from first to last. It is used to set reg_set_luid in + reload_cse_move2add and move2add_note_store. */ +static int move2add_luid; + +static void +reload_cse_move2add (first) + rtx first; +{ + int i; + rtx insn; + int last_label_luid; + + for (i = FIRST_PSEUDO_REGISTER-1; i >= 0; i--) + reg_set_luid[i] = 0; + + last_label_luid = 0; + move2add_luid = 1; + for (insn = first; insn; insn = NEXT_INSN (insn), move2add_luid++) + { + rtx pat, note; + + if (GET_CODE (insn) == CODE_LABEL) + last_label_luid = move2add_luid; + if (GET_RTX_CLASS (GET_CODE (insn)) != 'i') + continue; + pat = PATTERN (insn); + /* For simplicity, we only perform this optimization on + straightforward SETs. */ + if (GET_CODE (pat) == SET + && GET_CODE (SET_DEST (pat)) == REG) + { + rtx reg = SET_DEST (pat); + int regno = REGNO (reg); + rtx src = SET_SRC (pat); + + /* Check if we have valid information on the contents of this + register in the mode of REG. */ + /* ??? We don't know how zero / sign extension is handled, hence + we can't go from a narrower to a wider mode. */ + if (reg_set_luid[regno] > last_label_luid + && (GET_MODE_SIZE (GET_MODE (reg)) + <= GET_MODE_SIZE (reg_mode[regno])) + && GET_CODE (reg_offset[regno]) == CONST_INT) + { + /* Try to transform (set (REGX) (CONST_INT A)) + ... + (set (REGX) (CONST_INT B)) + to + (set (REGX) (CONST_INT A)) + ... + (set (REGX) (plus (REGX) (CONST_INT B-A))) */ + + if (GET_CODE (src) == CONST_INT && reg_base_reg[regno] < 0) + { + int success = 0; + rtx new_src = GEN_INT (INTVAL (src) + - INTVAL (reg_offset[regno])); + /* (set (reg) (plus (reg) (const_int 0))) is not canonical; + use (set (reg) (reg)) instead. + We don't delete this insn, nor do we convert it into a + note, to avoid losing register notes or the return + value flag. jump2 already knowns how to get rid of + no-op moves. */ + if (new_src == const0_rtx) + success = validate_change (insn, &SET_SRC (pat), reg, 0); + else if (rtx_cost (new_src, PLUS) < rtx_cost (src, SET) + && have_add2_insn (GET_MODE (reg))) + success = validate_change (insn, &PATTERN (insn), + gen_add2_insn (reg, new_src), 0); + reg_set_luid[regno] = move2add_luid; + reg_mode[regno] = GET_MODE (reg); + reg_offset[regno] = src; + continue; + } + + /* Try to transform (set (REGX) (REGY)) + (set (REGX) (PLUS (REGX) (CONST_INT A))) + ... + (set (REGX) (REGY)) + (set (REGX) (PLUS (REGX) (CONST_INT B))) + to + (REGX) (REGY)) + (set (REGX) (PLUS (REGX) (CONST_INT A))) + ... + (set (REGX) (plus (REGX) (CONST_INT B-A))) */ + else if (GET_CODE (src) == REG + && reg_base_reg[regno] == REGNO (src) + && reg_set_luid[regno] > reg_set_luid[REGNO (src)]) + { + rtx next = next_nonnote_insn (insn); + rtx set; + if (next) + set = single_set (next); + if (next + && set + && SET_DEST (set) == reg + && GET_CODE (SET_SRC (set)) == PLUS + && XEXP (SET_SRC (set), 0) == reg + && GET_CODE (XEXP (SET_SRC (set), 1)) == CONST_INT) + { + rtx src3 = XEXP (SET_SRC (set), 1); + rtx new_src = GEN_INT (INTVAL (src3) + - INTVAL (reg_offset[regno])); + int success = 0; + + if (new_src == const0_rtx) + /* See above why we create (set (reg) (reg)) here. */ + success + = validate_change (next, &SET_SRC (set), reg, 0); + else if ((rtx_cost (new_src, PLUS) + < 2 + rtx_cost (src3, SET)) + && have_add2_insn (GET_MODE (reg))) + success + = validate_change (next, &PATTERN (next), + gen_add2_insn (reg, new_src), 0); + if (success) + { + /* INSN might be the first insn in a basic block + if the preceding insn is a conditional jump + or a possible-throwing call. */ + PUT_CODE (insn, NOTE); + NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; + NOTE_SOURCE_FILE (insn) = 0; + } + insn = next; + reg_set_luid[regno] = move2add_luid; + reg_mode[regno] = GET_MODE (reg); + reg_offset[regno] = src3; + continue; + } + } + } + } + + for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) + { + if (REG_NOTE_KIND (note) == REG_INC + && GET_CODE (XEXP (note, 0)) == REG) + { + /* Indicate that this register has been recently written to, + but the exact contents are not available. */ + int regno = REGNO (XEXP (note, 0)); + if (regno < FIRST_PSEUDO_REGISTER) + { + reg_set_luid[regno] = move2add_luid; + reg_offset[regno] = note; + } + } + } + note_stores (PATTERN (insn), move2add_note_store); + /* If this is a CALL_INSN, all call used registers are stored with + unknown values. */ + if (GET_CODE (insn) == CALL_INSN) + { + for (i = FIRST_PSEUDO_REGISTER-1; i >= 0; i--) + { + if (call_used_regs[i]) + { + reg_set_luid[i] = move2add_luid; + reg_offset[i] = insn; /* Invalidate contents. */ + } + } + } + } +} + +/* SET is a SET or CLOBBER that sets DST. + Update reg_set_luid, reg_offset and reg_base_reg accordingly. + Called from reload_cse_move2add via note_stores. */ +static void +move2add_note_store (dst, set) + rtx dst, set; +{ + int regno = 0; + int i; + + enum machine_mode mode = GET_MODE (dst); + if (GET_CODE (dst) == SUBREG) + { + regno = SUBREG_WORD (dst); + dst = SUBREG_REG (dst); + } + if (GET_CODE (dst) != REG) + return; + + regno += REGNO (dst); + + if (HARD_REGNO_NREGS (regno, mode) == 1 && GET_CODE (set) == SET + && GET_CODE (SET_DEST (set)) != ZERO_EXTRACT + && GET_CODE (SET_DEST (set)) != SIGN_EXTRACT + && GET_CODE (SET_DEST (set)) != STRICT_LOW_PART) + { + rtx src = SET_SRC (set); + + reg_mode[regno] = mode; + switch (GET_CODE (src)) + { + case PLUS: + { + rtx src0 = XEXP (src, 0); + if (GET_CODE (src0) == REG) + { + if (REGNO (src0) != regno + || reg_offset[regno] != const0_rtx) + { + reg_base_reg[regno] = REGNO (src0); + reg_set_luid[regno] = move2add_luid; + } + reg_offset[regno] = XEXP (src, 1); + break; + } + reg_set_luid[regno] = move2add_luid; + reg_offset[regno] = set; /* Invalidate contents. */ + break; + } + + case REG: + reg_base_reg[regno] = REGNO (SET_SRC (set)); + reg_offset[regno] = const0_rtx; + reg_set_luid[regno] = move2add_luid; + break; + + default: + reg_base_reg[regno] = -1; + reg_offset[regno] = SET_SRC (set); + reg_set_luid[regno] = move2add_luid; + break; + } + } + else + { + for (i = regno + HARD_REGNO_NREGS (regno, mode) - 1; i >= regno; i--) + { + /* Indicate that this register has been recently written to, + but the exact contents are not available. */ + reg_set_luid[i] = move2add_luid; + reg_offset[i] = dst; + } + } +} |