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Diffstat (limited to 'gcc/explow.c')
| -rwxr-xr-x | gcc/explow.c | 1546 |
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diff --git a/gcc/explow.c b/gcc/explow.c new file mode 100755 index 0000000..9be9e79 --- /dev/null +++ b/gcc/explow.c @@ -0,0 +1,1546 @@ +/* Subroutines for manipulating rtx's in semantically interesting ways. + Copyright (C) 1987, 91, 94-97, 1998 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 "rtl.h" +#include "tree.h" +#include "flags.h" +#include "expr.h" +#include "hard-reg-set.h" +#include "insn-config.h" +#include "recog.h" +#include "insn-flags.h" +#include "insn-codes.h" + +#if !defined PREFERRED_STACK_BOUNDARY && defined STACK_BOUNDARY +#define PREFERRED_STACK_BOUNDARY STACK_BOUNDARY +#endif + +static rtx break_out_memory_refs PROTO((rtx)); +static void emit_stack_probe PROTO((rtx)); +/* Return an rtx for the sum of X and the integer C. + + This function should be used via the `plus_constant' macro. */ + +rtx +plus_constant_wide (x, c) + register rtx x; + register HOST_WIDE_INT c; +{ + register RTX_CODE code; + register enum machine_mode mode; + register rtx tem; + int all_constant = 0; + + if (c == 0) + return x; + + restart: + + code = GET_CODE (x); + mode = GET_MODE (x); + switch (code) + { + case CONST_INT: + return GEN_INT (INTVAL (x) + c); + + case CONST_DOUBLE: + { + HOST_WIDE_INT l1 = CONST_DOUBLE_LOW (x); + HOST_WIDE_INT h1 = CONST_DOUBLE_HIGH (x); + HOST_WIDE_INT l2 = c; + HOST_WIDE_INT h2 = c < 0 ? ~0 : 0; + HOST_WIDE_INT lv, hv; + + add_double (l1, h1, l2, h2, &lv, &hv); + + return immed_double_const (lv, hv, VOIDmode); + } + + case MEM: + /* If this is a reference to the constant pool, try replacing it with + a reference to a new constant. If the resulting address isn't + valid, don't return it because we have no way to validize it. */ + if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF + && CONSTANT_POOL_ADDRESS_P (XEXP (x, 0))) + { + /* Any rtl we create here must go in a saveable obstack, since + we might have been called from within combine. */ + push_obstacks_nochange (); + rtl_in_saveable_obstack (); + tem + = force_const_mem (GET_MODE (x), + plus_constant (get_pool_constant (XEXP (x, 0)), + c)); + pop_obstacks (); + if (memory_address_p (GET_MODE (tem), XEXP (tem, 0))) + return tem; + } + break; + + case CONST: + /* If adding to something entirely constant, set a flag + so that we can add a CONST around the result. */ + x = XEXP (x, 0); + all_constant = 1; + goto restart; + + case SYMBOL_REF: + case LABEL_REF: + all_constant = 1; + break; + + case PLUS: + /* The interesting case is adding the integer to a sum. + Look for constant term in the sum and combine + with C. For an integer constant term, we make a combined + integer. For a constant term that is not an explicit integer, + we cannot really combine, but group them together anyway. + + Restart or use a recursive call in case the remaining operand is + something that we handle specially, such as a SYMBOL_REF. + + We may not immediately return from the recursive call here, lest + all_constant gets lost. */ + + if (GET_CODE (XEXP (x, 1)) == CONST_INT) + { + c += INTVAL (XEXP (x, 1)); + x = XEXP (x, 0); + goto restart; + } + else if (CONSTANT_P (XEXP (x, 0))) + { + x = gen_rtx_PLUS (mode, + plus_constant (XEXP (x, 0), c), + XEXP (x, 1)); + c = 0; + } + else if (CONSTANT_P (XEXP (x, 1))) + { + x = gen_rtx_PLUS (mode, + XEXP (x, 0), + plus_constant (XEXP (x, 1), c)); + c = 0; + } + break; + + default: + break; + } + + if (c != 0) + x = gen_rtx_PLUS (mode, x, GEN_INT (c)); + + if (GET_CODE (x) == SYMBOL_REF || GET_CODE (x) == LABEL_REF) + return x; + else if (all_constant) + return gen_rtx_CONST (mode, x); + else + return x; +} + +/* This is the same as `plus_constant', except that it handles LO_SUM. + + This function should be used via the `plus_constant_for_output' macro. */ + +rtx +plus_constant_for_output_wide (x, c) + register rtx x; + register HOST_WIDE_INT c; +{ + register enum machine_mode mode = GET_MODE (x); + + if (GET_CODE (x) == LO_SUM) + return gen_rtx_LO_SUM (mode, XEXP (x, 0), + plus_constant_for_output (XEXP (x, 1), c)); + + else + return plus_constant (x, c); +} + +/* If X is a sum, return a new sum like X but lacking any constant terms. + Add all the removed constant terms into *CONSTPTR. + X itself is not altered. The result != X if and only if + it is not isomorphic to X. */ + +rtx +eliminate_constant_term (x, constptr) + rtx x; + rtx *constptr; +{ + register rtx x0, x1; + rtx tem; + + if (GET_CODE (x) != PLUS) + return x; + + /* First handle constants appearing at this level explicitly. */ + if (GET_CODE (XEXP (x, 1)) == CONST_INT + && 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x), *constptr, + XEXP (x, 1))) + && GET_CODE (tem) == CONST_INT) + { + *constptr = tem; + return eliminate_constant_term (XEXP (x, 0), constptr); + } + + tem = const0_rtx; + x0 = eliminate_constant_term (XEXP (x, 0), &tem); + x1 = eliminate_constant_term (XEXP (x, 1), &tem); + if ((x1 != XEXP (x, 1) || x0 != XEXP (x, 0)) + && 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x), + *constptr, tem)) + && GET_CODE (tem) == CONST_INT) + { + *constptr = tem; + return gen_rtx_PLUS (GET_MODE (x), x0, x1); + } + + return x; +} + +/* Returns the insn that next references REG after INSN, or 0 + if REG is clobbered before next referenced or we cannot find + an insn that references REG in a straight-line piece of code. */ + +rtx +find_next_ref (reg, insn) + rtx reg; + rtx insn; +{ + rtx next; + + for (insn = NEXT_INSN (insn); insn; insn = next) + { + next = NEXT_INSN (insn); + if (GET_CODE (insn) == NOTE) + continue; + if (GET_CODE (insn) == CODE_LABEL + || GET_CODE (insn) == BARRIER) + return 0; + if (GET_CODE (insn) == INSN + || GET_CODE (insn) == JUMP_INSN + || GET_CODE (insn) == CALL_INSN) + { + if (reg_set_p (reg, insn)) + return 0; + if (reg_mentioned_p (reg, PATTERN (insn))) + return insn; + if (GET_CODE (insn) == JUMP_INSN) + { + if (simplejump_p (insn)) + next = JUMP_LABEL (insn); + else + return 0; + } + if (GET_CODE (insn) == CALL_INSN + && REGNO (reg) < FIRST_PSEUDO_REGISTER + && call_used_regs[REGNO (reg)]) + return 0; + } + else + abort (); + } + return 0; +} + +/* Return an rtx for the size in bytes of the value of EXP. */ + +rtx +expr_size (exp) + tree exp; +{ + tree size = size_in_bytes (TREE_TYPE (exp)); + + if (TREE_CODE (size) != INTEGER_CST + && contains_placeholder_p (size)) + size = build (WITH_RECORD_EXPR, sizetype, size, exp); + + return expand_expr (size, NULL_RTX, TYPE_MODE (sizetype), + EXPAND_MEMORY_USE_BAD); +} + +/* Return a copy of X in which all memory references + and all constants that involve symbol refs + have been replaced with new temporary registers. + Also emit code to load the memory locations and constants + into those registers. + + If X contains no such constants or memory references, + X itself (not a copy) is returned. + + If a constant is found in the address that is not a legitimate constant + in an insn, it is left alone in the hope that it might be valid in the + address. + + X may contain no arithmetic except addition, subtraction and multiplication. + Values returned by expand_expr with 1 for sum_ok fit this constraint. */ + +static rtx +break_out_memory_refs (x) + register rtx x; +{ + if (GET_CODE (x) == MEM + || (CONSTANT_P (x) && CONSTANT_ADDRESS_P (x) + && GET_MODE (x) != VOIDmode)) + x = force_reg (GET_MODE (x), x); + else if (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS + || GET_CODE (x) == MULT) + { + register rtx op0 = break_out_memory_refs (XEXP (x, 0)); + register rtx op1 = break_out_memory_refs (XEXP (x, 1)); + + if (op0 != XEXP (x, 0) || op1 != XEXP (x, 1)) + x = gen_rtx_fmt_ee (GET_CODE (x), Pmode, op0, op1); + } + + return x; +} + +#ifdef POINTERS_EXTEND_UNSIGNED + +/* Given X, a memory address in ptr_mode, convert it to an address + in Pmode, or vice versa (TO_MODE says which way). We take advantage of + the fact that pointers are not allowed to overflow by commuting arithmetic + operations over conversions so that address arithmetic insns can be + used. */ + +rtx +convert_memory_address (to_mode, x) + enum machine_mode to_mode; + rtx x; +{ + enum machine_mode from_mode = to_mode == ptr_mode ? Pmode : ptr_mode; + rtx temp; + + /* Here we handle some special cases. If none of them apply, fall through + to the default case. */ + switch (GET_CODE (x)) + { + case CONST_INT: + case CONST_DOUBLE: + return x; + + case LABEL_REF: + temp = gen_rtx_LABEL_REF (to_mode, XEXP (x, 0)); + LABEL_REF_NONLOCAL_P (temp) = LABEL_REF_NONLOCAL_P (x); + return temp; + + case SYMBOL_REF: + temp = gen_rtx_SYMBOL_REF (to_mode, XSTR (x, 0)); + SYMBOL_REF_FLAG (temp) = SYMBOL_REF_FLAG (x); + CONSTANT_POOL_ADDRESS_P (temp) = CONSTANT_POOL_ADDRESS_P (x); + return temp; + + case CONST: + return gen_rtx_CONST (to_mode, + convert_memory_address (to_mode, XEXP (x, 0))); + + case PLUS: + case MULT: + /* For addition the second operand is a small constant, we can safely + permute the conversion and addition operation. We can always safely + permute them if we are making the address narrower. In addition, + always permute the operations if this is a constant. */ + if (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (from_mode) + || (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 1)) == CONST_INT + && (INTVAL (XEXP (x, 1)) + 20000 < 40000 + || CONSTANT_P (XEXP (x, 0))))) + return gen_rtx_fmt_ee (GET_CODE (x), to_mode, + convert_memory_address (to_mode, XEXP (x, 0)), + convert_memory_address (to_mode, XEXP (x, 1))); + break; + + default: + break; + } + + return convert_modes (to_mode, from_mode, + x, POINTERS_EXTEND_UNSIGNED); +} +#endif + +/* Given a memory address or facsimile X, construct a new address, + currently equivalent, that is stable: future stores won't change it. + + X must be composed of constants, register and memory references + combined with addition, subtraction and multiplication: + in other words, just what you can get from expand_expr if sum_ok is 1. + + Works by making copies of all regs and memory locations used + by X and combining them the same way X does. + You could also stabilize the reference to this address + by copying the address to a register with copy_to_reg; + but then you wouldn't get indexed addressing in the reference. */ + +rtx +copy_all_regs (x) + register rtx x; +{ + if (GET_CODE (x) == REG) + { + if (REGNO (x) != FRAME_POINTER_REGNUM +#if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM + && REGNO (x) != HARD_FRAME_POINTER_REGNUM +#endif + ) + x = copy_to_reg (x); + } + else if (GET_CODE (x) == MEM) + x = copy_to_reg (x); + else if (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS + || GET_CODE (x) == MULT) + { + register rtx op0 = copy_all_regs (XEXP (x, 0)); + register rtx op1 = copy_all_regs (XEXP (x, 1)); + if (op0 != XEXP (x, 0) || op1 != XEXP (x, 1)) + x = gen_rtx_fmt_ee (GET_CODE (x), Pmode, op0, op1); + } + return x; +} + +/* Return something equivalent to X but valid as a memory address + for something of mode MODE. When X is not itself valid, this + works by copying X or subexpressions of it into registers. */ + +rtx +memory_address (mode, x) + enum machine_mode mode; + register rtx x; +{ + register rtx oldx = x; + + if (GET_CODE (x) == ADDRESSOF) + return x; + +#ifdef POINTERS_EXTEND_UNSIGNED + if (GET_MODE (x) == ptr_mode) + x = convert_memory_address (Pmode, x); +#endif + + /* By passing constant addresses thru registers + we get a chance to cse them. */ + if (! cse_not_expected && CONSTANT_P (x) && CONSTANT_ADDRESS_P (x)) + x = force_reg (Pmode, x); + + /* Accept a QUEUED that refers to a REG + even though that isn't a valid address. + On attempting to put this in an insn we will call protect_from_queue + which will turn it into a REG, which is valid. */ + else if (GET_CODE (x) == QUEUED + && GET_CODE (QUEUED_VAR (x)) == REG) + ; + + /* We get better cse by rejecting indirect addressing at this stage. + Let the combiner create indirect addresses where appropriate. + For now, generate the code so that the subexpressions useful to share + are visible. But not if cse won't be done! */ + else + { + if (! cse_not_expected && GET_CODE (x) != REG) + x = break_out_memory_refs (x); + + /* At this point, any valid address is accepted. */ + GO_IF_LEGITIMATE_ADDRESS (mode, x, win); + + /* If it was valid before but breaking out memory refs invalidated it, + use it the old way. */ + if (memory_address_p (mode, oldx)) + goto win2; + + /* Perform machine-dependent transformations on X + in certain cases. This is not necessary since the code + below can handle all possible cases, but machine-dependent + transformations can make better code. */ + LEGITIMIZE_ADDRESS (x, oldx, mode, win); + + /* PLUS and MULT can appear in special ways + as the result of attempts to make an address usable for indexing. + Usually they are dealt with by calling force_operand, below. + But a sum containing constant terms is special + if removing them makes the sum a valid address: + then we generate that address in a register + and index off of it. We do this because it often makes + shorter code, and because the addresses thus generated + in registers often become common subexpressions. */ + if (GET_CODE (x) == PLUS) + { + rtx constant_term = const0_rtx; + rtx y = eliminate_constant_term (x, &constant_term); + if (constant_term == const0_rtx + || ! memory_address_p (mode, y)) + x = force_operand (x, NULL_RTX); + else + { + y = gen_rtx_PLUS (GET_MODE (x), copy_to_reg (y), constant_term); + if (! memory_address_p (mode, y)) + x = force_operand (x, NULL_RTX); + else + x = y; + } + } + + else if (GET_CODE (x) == MULT || GET_CODE (x) == MINUS) + x = force_operand (x, NULL_RTX); + + /* If we have a register that's an invalid address, + it must be a hard reg of the wrong class. Copy it to a pseudo. */ + else if (GET_CODE (x) == REG) + x = copy_to_reg (x); + + /* Last resort: copy the value to a register, since + the register is a valid address. */ + else + x = force_reg (Pmode, x); + + goto done; + + win2: + x = oldx; + win: + if (flag_force_addr && ! cse_not_expected && GET_CODE (x) != REG + /* Don't copy an addr via a reg if it is one of our stack slots. */ + && ! (GET_CODE (x) == PLUS + && (XEXP (x, 0) == virtual_stack_vars_rtx + || XEXP (x, 0) == virtual_incoming_args_rtx))) + { + if (general_operand (x, Pmode)) + x = force_reg (Pmode, x); + else + x = force_operand (x, NULL_RTX); + } + } + + done: + + /* If we didn't change the address, we are done. Otherwise, mark + a reg as a pointer if we have REG or REG + CONST_INT. */ + if (oldx == x) + return x; + else if (GET_CODE (x) == REG) + mark_reg_pointer (x, 1); + else if (GET_CODE (x) == PLUS + && GET_CODE (XEXP (x, 0)) == REG + && GET_CODE (XEXP (x, 1)) == CONST_INT) + mark_reg_pointer (XEXP (x, 0), 1); + + /* OLDX may have been the address on a temporary. Update the address + to indicate that X is now used. */ + update_temp_slot_address (oldx, x); + + return x; +} + +/* Like `memory_address' but pretend `flag_force_addr' is 0. */ + +rtx +memory_address_noforce (mode, x) + enum machine_mode mode; + rtx x; +{ + int ambient_force_addr = flag_force_addr; + rtx val; + + flag_force_addr = 0; + val = memory_address (mode, x); + flag_force_addr = ambient_force_addr; + return val; +} + +/* Convert a mem ref into one with a valid memory address. + Pass through anything else unchanged. */ + +rtx +validize_mem (ref) + rtx ref; +{ + if (GET_CODE (ref) != MEM) + return ref; + if (memory_address_p (GET_MODE (ref), XEXP (ref, 0))) + return ref; + /* Don't alter REF itself, since that is probably a stack slot. */ + return change_address (ref, GET_MODE (ref), XEXP (ref, 0)); +} + +/* Return a modified copy of X with its memory address copied + into a temporary register to protect it from side effects. + If X is not a MEM, it is returned unchanged (and not copied). + Perhaps even if it is a MEM, if there is no need to change it. */ + +rtx +stabilize (x) + rtx x; +{ + register rtx addr; + if (GET_CODE (x) != MEM) + return x; + addr = XEXP (x, 0); + if (rtx_unstable_p (addr)) + { + rtx temp = copy_all_regs (addr); + rtx mem; + if (GET_CODE (temp) != REG) + temp = copy_to_reg (temp); + mem = gen_rtx_MEM (GET_MODE (x), temp); + + /* Mark returned memref with in_struct if it's in an array or + structure. Copy const and volatile from original memref. */ + + RTX_UNCHANGING_P (mem) = RTX_UNCHANGING_P (x); + MEM_COPY_ATTRIBUTES (mem, x); + if (GET_CODE (addr) == PLUS) + MEM_SET_IN_STRUCT_P (mem, 1); + + /* Since the new MEM is just like the old X, it can alias only + the things that X could. */ + MEM_ALIAS_SET (mem) = MEM_ALIAS_SET (x); + + /* CYGNUS LOCAL unaligned-pointers */ + MEM_UNALIGNED_P (mem) = MEM_UNALIGNED_P (x); + /* END CYGNUS LOCAL */ + return mem; + } + return x; +} + +/* Copy the value or contents of X to a new temp reg and return that reg. */ + +rtx +copy_to_reg (x) + rtx x; +{ + register rtx temp = gen_reg_rtx (GET_MODE (x)); + + /* If not an operand, must be an address with PLUS and MULT so + do the computation. */ + if (! general_operand (x, VOIDmode)) + x = force_operand (x, temp); + + if (x != temp) + emit_move_insn (temp, x); + + return temp; +} + +/* Like copy_to_reg but always give the new register mode Pmode + in case X is a constant. */ + +rtx +copy_addr_to_reg (x) + rtx x; +{ + return copy_to_mode_reg (Pmode, x); +} + +/* Like copy_to_reg but always give the new register mode MODE + in case X is a constant. */ + +rtx +copy_to_mode_reg (mode, x) + enum machine_mode mode; + rtx x; +{ + register rtx temp = gen_reg_rtx (mode); + + /* If not an operand, must be an address with PLUS and MULT so + do the computation. */ + if (! general_operand (x, VOIDmode)) + x = force_operand (x, temp); + + if (GET_MODE (x) != mode && GET_MODE (x) != VOIDmode) + abort (); + if (x != temp) + emit_move_insn (temp, x); + return temp; +} + +/* Load X into a register if it is not already one. + Use mode MODE for the register. + X should be valid for mode MODE, but it may be a constant which + is valid for all integer modes; that's why caller must specify MODE. + + The caller must not alter the value in the register we return, + since we mark it as a "constant" register. */ + +rtx +force_reg (mode, x) + enum machine_mode mode; + rtx x; +{ + register rtx temp, insn, set; + + if (GET_CODE (x) == REG) + return x; + temp = gen_reg_rtx (mode); + insn = emit_move_insn (temp, x); + + /* Let optimizers know that TEMP's value never changes + and that X can be substituted for it. Don't get confused + if INSN set something else (such as a SUBREG of TEMP). */ + if (CONSTANT_P (x) + && (set = single_set (insn)) != 0 + && SET_DEST (set) == temp) + { + rtx note = find_reg_note (insn, REG_EQUAL, NULL_RTX); + + if (note) + XEXP (note, 0) = x; + else + REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_EQUAL, x, REG_NOTES (insn)); + } + return temp; +} + +/* If X is a memory ref, copy its contents to a new temp reg and return + that reg. Otherwise, return X. */ + +rtx +force_not_mem (x) + rtx x; +{ + register rtx temp; + if (GET_CODE (x) != MEM || GET_MODE (x) == BLKmode) + return x; + temp = gen_reg_rtx (GET_MODE (x)); + emit_move_insn (temp, x); + return temp; +} + +/* Copy X to TARGET (if it's nonzero and a reg) + or to a new temp reg and return that reg. + MODE is the mode to use for X in case it is a constant. */ + +rtx +copy_to_suggested_reg (x, target, mode) + rtx x, target; + enum machine_mode mode; +{ + register rtx temp; + + if (target && GET_CODE (target) == REG) + temp = target; + else + temp = gen_reg_rtx (mode); + + emit_move_insn (temp, x); + return temp; +} + +/* Return the mode to use to store a scalar of TYPE and MODE. + PUNSIGNEDP points to the signedness of the type and may be adjusted + to show what signedness to use on extension operations. + + FOR_CALL is non-zero if this call is promoting args for a call. */ + +enum machine_mode +promote_mode (type, mode, punsignedp, for_call) + tree type; + enum machine_mode mode; + int *punsignedp; + int for_call ATTRIBUTE_UNUSED; +{ + enum tree_code code = TREE_CODE (type); + int unsignedp = *punsignedp; + +#ifdef PROMOTE_FOR_CALL_ONLY + if (! for_call) + return mode; +#endif + + switch (code) + { +#ifdef PROMOTE_MODE + case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE: + case CHAR_TYPE: case REAL_TYPE: case OFFSET_TYPE: + PROMOTE_MODE (mode, unsignedp, type); + break; +#endif + +#ifdef POINTERS_EXTEND_UNSIGNED + case REFERENCE_TYPE: + case POINTER_TYPE: + mode = Pmode; + unsignedp = POINTERS_EXTEND_UNSIGNED; + break; +#endif + + default: + break; + } + + *punsignedp = unsignedp; + return mode; +} + +/* Adjust the stack pointer by ADJUST (an rtx for a number of bytes). + This pops when ADJUST is positive. ADJUST need not be constant. */ + +void +adjust_stack (adjust) + rtx adjust; +{ + rtx temp; + adjust = protect_from_queue (adjust, 0); + + if (adjust == const0_rtx) + return; + + temp = expand_binop (Pmode, +#ifdef STACK_GROWS_DOWNWARD + add_optab, +#else + sub_optab, +#endif + stack_pointer_rtx, adjust, stack_pointer_rtx, 0, + OPTAB_LIB_WIDEN); + + if (temp != stack_pointer_rtx) + emit_move_insn (stack_pointer_rtx, temp); +} + +/* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes). + This pushes when ADJUST is positive. ADJUST need not be constant. */ + +void +anti_adjust_stack (adjust) + rtx adjust; +{ + rtx temp; + adjust = protect_from_queue (adjust, 0); + + if (adjust == const0_rtx) + return; + + temp = expand_binop (Pmode, +#ifdef STACK_GROWS_DOWNWARD + sub_optab, +#else + add_optab, +#endif + stack_pointer_rtx, adjust, stack_pointer_rtx, 0, + OPTAB_LIB_WIDEN); + + if (temp != stack_pointer_rtx) + emit_move_insn (stack_pointer_rtx, temp); +} + +/* Round the size of a block to be pushed up to the boundary required + by this machine. SIZE is the desired size, which need not be constant. */ + +rtx +round_push (size) + rtx size; +{ +#ifdef PREFERRED_STACK_BOUNDARY + int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT; + if (align == 1) + return size; + if (GET_CODE (size) == CONST_INT) + { + int new = (INTVAL (size) + align - 1) / align * align; + if (INTVAL (size) != new) + size = GEN_INT (new); + } + else + { + /* CEIL_DIV_EXPR needs to worry about the addition overflowing, + but we know it can't. So add ourselves and then do + TRUNC_DIV_EXPR. */ + size = expand_binop (Pmode, add_optab, size, GEN_INT (align - 1), + NULL_RTX, 1, OPTAB_LIB_WIDEN); + size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size, GEN_INT (align), + NULL_RTX, 1); + size = expand_mult (Pmode, size, GEN_INT (align), NULL_RTX, 1); + } +#endif /* PREFERRED_STACK_BOUNDARY */ + return size; +} + +/* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer + to a previously-created save area. If no save area has been allocated, + this function will allocate one. If a save area is specified, it + must be of the proper mode. + + The insns are emitted after insn AFTER, if nonzero, otherwise the insns + are emitted at the current position. */ + +void +emit_stack_save (save_level, psave, after) + enum save_level save_level; + rtx *psave; + rtx after; +{ + rtx sa = *psave; + /* The default is that we use a move insn and save in a Pmode object. */ + rtx (*fcn) PROTO ((rtx, rtx)) = gen_move_insn; + enum machine_mode mode = STACK_SAVEAREA_MODE (save_level); + + /* See if this machine has anything special to do for this kind of save. */ + switch (save_level) + { +#ifdef HAVE_save_stack_block + case SAVE_BLOCK: + if (HAVE_save_stack_block) + fcn = gen_save_stack_block; + break; +#endif +#ifdef HAVE_save_stack_function + case SAVE_FUNCTION: + if (HAVE_save_stack_function) + fcn = gen_save_stack_function; + break; +#endif +#ifdef HAVE_save_stack_nonlocal + case SAVE_NONLOCAL: + if (HAVE_save_stack_nonlocal) + fcn = gen_save_stack_nonlocal; + break; +#endif + default: + break; + } + + /* If there is no save area and we have to allocate one, do so. Otherwise + verify the save area is the proper mode. */ + + if (sa == 0) + { + if (mode != VOIDmode) + { + if (save_level == SAVE_NONLOCAL) + *psave = sa = assign_stack_local (mode, GET_MODE_SIZE (mode), 0); + else + *psave = sa = gen_reg_rtx (mode); + } + } + else + { + if (mode == VOIDmode || GET_MODE (sa) != mode) + abort (); + } + + if (after) + { + rtx seq; + + start_sequence (); + /* We must validize inside the sequence, to ensure that any instructions + created by the validize call also get moved to the right place. */ + if (sa != 0) + sa = validize_mem (sa); + emit_insn (fcn (sa, stack_pointer_rtx)); + seq = gen_sequence (); + end_sequence (); + emit_insn_after (seq, after); + } + else + { + if (sa != 0) + sa = validize_mem (sa); + emit_insn (fcn (sa, stack_pointer_rtx)); + } +} + +/* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save + area made by emit_stack_save. If it is zero, we have nothing to do. + + Put any emitted insns after insn AFTER, if nonzero, otherwise at + current position. */ + +void +emit_stack_restore (save_level, sa, after) + enum save_level save_level; + rtx after; + rtx sa; +{ + /* The default is that we use a move insn. */ + rtx (*fcn) PROTO ((rtx, rtx)) = gen_move_insn; + + /* See if this machine has anything special to do for this kind of save. */ + switch (save_level) + { +#ifdef HAVE_restore_stack_block + case SAVE_BLOCK: + if (HAVE_restore_stack_block) + fcn = gen_restore_stack_block; + break; +#endif +#ifdef HAVE_restore_stack_function + case SAVE_FUNCTION: + if (HAVE_restore_stack_function) + fcn = gen_restore_stack_function; + break; +#endif +#ifdef HAVE_restore_stack_nonlocal + case SAVE_NONLOCAL: + if (HAVE_restore_stack_nonlocal) + fcn = gen_restore_stack_nonlocal; + break; +#endif + default: + break; + } + + if (sa != 0) + sa = validize_mem (sa); + + if (after) + { + rtx seq; + + start_sequence (); + emit_insn (fcn (stack_pointer_rtx, sa)); + seq = gen_sequence (); + end_sequence (); + emit_insn_after (seq, after); + } + else + emit_insn (fcn (stack_pointer_rtx, sa)); +} + +#ifdef SETJMP_VIA_SAVE_AREA +/* Optimize RTL generated by allocate_dynamic_stack_space for targets + where SETJMP_VIA_SAVE_AREA is true. The problem is that on these + platforms, the dynamic stack space used can corrupt the original + frame, thus causing a crash if a longjmp unwinds to it. */ + +void +optimize_save_area_alloca (insns) + rtx insns; +{ + rtx insn; + + for (insn = insns; insn; insn = NEXT_INSN(insn)) + { + rtx note; + + if (GET_CODE (insn) != INSN) + continue; + + for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) + { + if (REG_NOTE_KIND (note) != REG_SAVE_AREA) + continue; + + if (!current_function_calls_setjmp) + { + rtx pat = PATTERN (insn); + + /* If we do not see the note in a pattern matching + these precise characteristics, we did something + entirely wrong in allocate_dynamic_stack_space. + + Note, one way this could happen is if SETJMP_VIA_SAVE_AREA + was defined on a machine where stacks grow towards higher + addresses. + + Right now only supported port with stack that grow upward + is the HPPA and it does not define SETJMP_VIA_SAVE_AREA. */ + if (GET_CODE (pat) != SET + || SET_DEST (pat) != stack_pointer_rtx + || GET_CODE (SET_SRC (pat)) != MINUS + || XEXP (SET_SRC (pat), 0) != stack_pointer_rtx) + abort (); + + /* This will now be transformed into a (set REG REG) + so we can just blow away all the other notes. */ + XEXP (SET_SRC (pat), 1) = XEXP (note, 0); + REG_NOTES (insn) = NULL_RTX; + } + else + { + /* setjmp was called, we must remove the REG_SAVE_AREA + note so that later passes do not get confused by its + presence. */ + if (note == REG_NOTES (insn)) + { + REG_NOTES (insn) = XEXP (note, 1); + } + else + { + rtx srch; + + for (srch = REG_NOTES (insn); srch; srch = XEXP (srch, 1)) + if (XEXP (srch, 1) == note) + break; + + if (srch == NULL_RTX) + abort(); + + XEXP (srch, 1) = XEXP (note, 1); + } + } + /* Once we've seen the note of interest, we need not look at + the rest of them. */ + break; + } + } +} +#endif /* SETJMP_VIA_SAVE_AREA */ + +/* Return an rtx representing the address of an area of memory dynamically + pushed on the stack. This region of memory is always aligned to + a multiple of BIGGEST_ALIGNMENT. + + Any required stack pointer alignment is preserved. + + SIZE is an rtx representing the size of the area. + TARGET is a place in which the address can be placed. + + KNOWN_ALIGN is the alignment (in bits) that we know SIZE has. */ + +rtx +allocate_dynamic_stack_space (size, target, known_align) + rtx size; + rtx target; + int known_align; +{ +#ifdef SETJMP_VIA_SAVE_AREA + rtx setjmpless_size = NULL_RTX; +#endif + + /* If we're asking for zero bytes, it doesn't matter what we point + to since we can't dereference it. But return a reasonable + address anyway. */ + if (size == const0_rtx) + return virtual_stack_dynamic_rtx; + + /* Otherwise, show we're calling alloca or equivalent. */ + current_function_calls_alloca = 1; + + /* Ensure the size is in the proper mode. */ + if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode) + size = convert_to_mode (Pmode, size, 1); + + /* We will need to ensure that the address we return is aligned to + BIGGEST_ALIGNMENT. If STACK_DYNAMIC_OFFSET is defined, we don't + always know its final value at this point in the compilation (it + might depend on the size of the outgoing parameter lists, for + example), so we must align the value to be returned in that case. + (Note that STACK_DYNAMIC_OFFSET will have a default non-zero value if + STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined). + We must also do an alignment operation on the returned value if + the stack pointer alignment is less strict that BIGGEST_ALIGNMENT. + + If we have to align, we must leave space in SIZE for the hole + that might result from the alignment operation. */ + +#if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET) || ! defined (PREFERRED_STACK_BOUNDARY) +#define MUST_ALIGN 1 +#else +#define MUST_ALIGN (PREFERRED_STACK_BOUNDARY < BIGGEST_ALIGNMENT) +#endif + + if (MUST_ALIGN) + { + if (GET_CODE (size) == CONST_INT) + size = GEN_INT (INTVAL (size) + + (BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1)); + else + size = expand_binop (Pmode, add_optab, size, + GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1), + NULL_RTX, 1, OPTAB_LIB_WIDEN); + } + +#ifdef SETJMP_VIA_SAVE_AREA + /* If setjmp restores regs from a save area in the stack frame, + avoid clobbering the reg save area. Note that the offset of + virtual_incoming_args_rtx includes the preallocated stack args space. + It would be no problem to clobber that, but it's on the wrong side + of the old save area. */ + { + rtx dynamic_offset + = expand_binop (Pmode, sub_optab, virtual_stack_dynamic_rtx, + stack_pointer_rtx, NULL_RTX, 1, OPTAB_LIB_WIDEN); + + if (!current_function_calls_setjmp) + { + int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT; + + /* See optimize_save_area_alloca to understand what is being + set up here. */ + +#if !defined(PREFERRED_STACK_BOUNDARY) || !defined(MUST_ALIGN) || (PREFERRED_STACK_BOUNDARY != BIGGEST_ALIGNMENT) + /* If anyone creates a target with these characteristics, let them + know that our optimization cannot work correctly in such a case. */ + abort(); +#endif + + if (GET_CODE (size) == CONST_INT) + { + int new = INTVAL (size) / align * align; + + if (INTVAL (size) != new) + setjmpless_size = GEN_INT (new); + else + setjmpless_size = size; + } + else + { + /* Since we know overflow is not possible, we avoid using + CEIL_DIV_EXPR and use TRUNC_DIV_EXPR instead. */ + setjmpless_size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size, + GEN_INT (align), NULL_RTX, 1); + setjmpless_size = expand_mult (Pmode, setjmpless_size, + GEN_INT (align), NULL_RTX, 1); + } + /* Our optimization works based upon being able to perform a simple + transformation of this RTL into a (set REG REG) so make sure things + did in fact end up in a REG. */ + if (!arith_operand (setjmpless_size, Pmode)) + setjmpless_size = force_reg (Pmode, setjmpless_size); + } + + size = expand_binop (Pmode, add_optab, size, dynamic_offset, + NULL_RTX, 1, OPTAB_LIB_WIDEN); + } +#endif /* SETJMP_VIA_SAVE_AREA */ + + /* Round the size to a multiple of the required stack alignment. + Since the stack if presumed to be rounded before this allocation, + this will maintain the required alignment. + + If the stack grows downward, we could save an insn by subtracting + SIZE from the stack pointer and then aligning the stack pointer. + The problem with this is that the stack pointer may be unaligned + between the execution of the subtraction and alignment insns and + some machines do not allow this. Even on those that do, some + signal handlers malfunction if a signal should occur between those + insns. Since this is an extremely rare event, we have no reliable + way of knowing which systems have this problem. So we avoid even + momentarily mis-aligning the stack. */ + +#ifdef PREFERRED_STACK_BOUNDARY + /* If we added a variable amount to SIZE, + we can no longer assume it is aligned. */ +#if !defined (SETJMP_VIA_SAVE_AREA) + if (MUST_ALIGN || known_align % PREFERRED_STACK_BOUNDARY != 0) +#endif + size = round_push (size); +#endif + + do_pending_stack_adjust (); + + /* If needed, check that we have the required amount of stack. Take into + account what has already been checked. */ + if (flag_stack_check && ! STACK_CHECK_BUILTIN) + probe_stack_range (STACK_CHECK_MAX_FRAME_SIZE + STACK_CHECK_PROTECT, size); + + /* Don't use a TARGET that isn't a pseudo. */ + if (target == 0 || GET_CODE (target) != REG + || REGNO (target) < FIRST_PSEUDO_REGISTER) + target = gen_reg_rtx (Pmode); + + mark_reg_pointer (target, known_align / BITS_PER_UNIT); + + /* Perform the required allocation from the stack. Some systems do + this differently than simply incrementing/decrementing from the + stack pointer, such as acquiring the space by calling malloc(). */ +#ifdef HAVE_allocate_stack + if (HAVE_allocate_stack) + { + enum machine_mode mode = STACK_SIZE_MODE; + + if (insn_operand_predicate[(int) CODE_FOR_allocate_stack][0] + && ! ((*insn_operand_predicate[(int) CODE_FOR_allocate_stack][0]) + (target, Pmode))) + target = copy_to_mode_reg (Pmode, target); + size = convert_modes (mode, ptr_mode, size, 1); + if (insn_operand_predicate[(int) CODE_FOR_allocate_stack][1] + && ! ((*insn_operand_predicate[(int) CODE_FOR_allocate_stack][1]) + (size, mode))) + size = copy_to_mode_reg (mode, size); + + emit_insn (gen_allocate_stack (target, size)); + } + else +#endif + { +#ifndef STACK_GROWS_DOWNWARD + emit_move_insn (target, virtual_stack_dynamic_rtx); +#endif + size = convert_modes (Pmode, ptr_mode, size, 1); + anti_adjust_stack (size); +#ifdef SETJMP_VIA_SAVE_AREA + if (setjmpless_size != NULL_RTX) + { + rtx note_target = get_last_insn (); + + REG_NOTES (note_target) + = gen_rtx_EXPR_LIST (REG_SAVE_AREA, setjmpless_size, + REG_NOTES (note_target)); + } +#endif /* SETJMP_VIA_SAVE_AREA */ +#ifdef STACK_GROWS_DOWNWARD + emit_move_insn (target, virtual_stack_dynamic_rtx); +#endif + } + + if (MUST_ALIGN) + { + /* CEIL_DIV_EXPR needs to worry about the addition overflowing, + but we know it can't. So add ourselves and then do + TRUNC_DIV_EXPR. */ + target = expand_binop (Pmode, add_optab, target, + GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1), + NULL_RTX, 1, OPTAB_LIB_WIDEN); + target = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, target, + GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT), + NULL_RTX, 1); + target = expand_mult (Pmode, target, + GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT), + NULL_RTX, 1); + } + + /* Some systems require a particular insn to refer to the stack + to make the pages exist. */ +#ifdef HAVE_probe + if (HAVE_probe) + emit_insn (gen_probe ()); +#endif + + /* Record the new stack level for nonlocal gotos. */ + if (nonlocal_goto_handler_slots != 0) + emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX); + + return target; +} + +/* Emit one stack probe at ADDRESS, an address within the stack. */ + +static void +emit_stack_probe (address) + rtx address; +{ + rtx memref = gen_rtx_MEM (word_mode, address); + + MEM_VOLATILE_P (memref) = 1; + + if (STACK_CHECK_PROBE_LOAD) + emit_move_insn (gen_reg_rtx (word_mode), memref); + else + emit_move_insn (memref, const0_rtx); +} + +/* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive. + FIRST is a constant and size is a Pmode RTX. These are offsets from the + current stack pointer. STACK_GROWS_DOWNWARD says whether to add or + subtract from the stack. If SIZE is constant, this is done + with a fixed number of probes. Otherwise, we must make a loop. */ + +#ifdef STACK_GROWS_DOWNWARD +#define STACK_GROW_OP MINUS +#else +#define STACK_GROW_OP PLUS +#endif + +void +probe_stack_range (first, size) + HOST_WIDE_INT first; + rtx size; +{ + /* First see if we have an insn to check the stack. Use it if so. */ +#ifdef HAVE_check_stack + if (HAVE_check_stack) + { + rtx last_addr + = force_operand (gen_rtx_STACK_GROW_OP (Pmode, + stack_pointer_rtx, + plus_constant (size, first)), + NULL_RTX); + + if (insn_operand_predicate[(int) CODE_FOR_check_stack][0] + && ! ((*insn_operand_predicate[(int) CODE_FOR_check_stack][0]) + (last_address, Pmode))) + last_address = copy_to_mode_reg (Pmode, last_address); + + emit_insn (gen_check_stack (last_address)); + return; + } +#endif + + /* If we have to generate explicit probes, see if we have a constant + small number of them to generate. If so, that's the easy case. */ + if (GET_CODE (size) == CONST_INT + && INTVAL (size) < 10 * STACK_CHECK_PROBE_INTERVAL) + { + HOST_WIDE_INT offset; + + /* Start probing at FIRST + N * STACK_CHECK_PROBE_INTERVAL + for values of N from 1 until it exceeds LAST. If only one + probe is needed, this will not generate any code. Then probe + at LAST. */ + for (offset = first + STACK_CHECK_PROBE_INTERVAL; + offset < INTVAL (size); + offset = offset + STACK_CHECK_PROBE_INTERVAL) + emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode, + stack_pointer_rtx, + GEN_INT (offset))); + + emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode, + stack_pointer_rtx, + plus_constant (size, first))); + } + + /* In the variable case, do the same as above, but in a loop. We emit loop + notes so that loop optimization can be done. */ + else + { + rtx test_addr + = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode, + stack_pointer_rtx, + GEN_INT (first + STACK_CHECK_PROBE_INTERVAL)), + NULL_RTX); + rtx last_addr + = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode, + stack_pointer_rtx, + plus_constant (size, first)), + NULL_RTX); + rtx incr = GEN_INT (STACK_CHECK_PROBE_INTERVAL); + rtx loop_lab = gen_label_rtx (); + rtx test_lab = gen_label_rtx (); + rtx end_lab = gen_label_rtx (); + rtx temp; + + if (GET_CODE (test_addr) != REG + || REGNO (test_addr) < FIRST_PSEUDO_REGISTER) + test_addr = force_reg (Pmode, test_addr); + + emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG); + emit_jump (test_lab); + + emit_label (loop_lab); + emit_stack_probe (test_addr); + + emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT); + +#ifdef STACK_GROWS_DOWNWARD +#define CMP_OPCODE GTU + temp = expand_binop (Pmode, sub_optab, test_addr, incr, test_addr, + 1, OPTAB_WIDEN); +#else +#define CMP_OPCODE LTU + temp = expand_binop (Pmode, add_optab, test_addr, incr, test_addr, + 1, OPTAB_WIDEN); +#endif + + if (temp != test_addr) + abort (); + + emit_label (test_lab); + emit_cmp_insn (test_addr, last_addr, CMP_OPCODE, NULL_RTX, Pmode, 1, 0); + emit_jump_insn ((*bcc_gen_fctn[(int) CMP_OPCODE]) (loop_lab)); + emit_jump (end_lab); + emit_note (NULL_PTR, NOTE_INSN_LOOP_END); + emit_label (end_lab); + + /* If will be doing stupid optimization, show test_addr is still live. */ + if (obey_regdecls) + emit_insn (gen_rtx_USE (VOIDmode, test_addr)); + + emit_stack_probe (last_addr); + } +} + +/* Return an rtx representing the register or memory location + in which a scalar value of data type VALTYPE + was returned by a function call to function FUNC. + FUNC is a FUNCTION_DECL node if the precise function is known, + otherwise 0. */ + +rtx +hard_function_value (valtype, func) + tree valtype; + tree func; +{ + rtx val = FUNCTION_VALUE (valtype, func); + if (GET_CODE (val) == REG + && GET_MODE (val) == BLKmode) + { + int bytes = int_size_in_bytes (valtype); + enum machine_mode tmpmode; + for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT); + tmpmode != MAX_MACHINE_MODE; + tmpmode = GET_MODE_WIDER_MODE (tmpmode)) + { + /* Have we found a large enough mode? */ + if (GET_MODE_SIZE (tmpmode) >= bytes) + break; + } + + /* No suitable mode found. */ + if (tmpmode == MAX_MACHINE_MODE) + abort (); + + PUT_MODE (val, tmpmode); + } + return val; +} + +/* Return an rtx representing the register or memory location + in which a scalar value of mode MODE was returned by a library call. */ + +rtx +hard_libcall_value (mode) + enum machine_mode mode; +{ + return LIBCALL_VALUE (mode); +} + +/* Look up the tree code for a given rtx code + to provide the arithmetic operation for REAL_ARITHMETIC. + The function returns an int because the caller may not know + what `enum tree_code' means. */ + +int +rtx_to_tree_code (code) + enum rtx_code code; +{ + enum tree_code tcode; + + switch (code) + { + case PLUS: + tcode = PLUS_EXPR; + break; + case MINUS: + tcode = MINUS_EXPR; + break; + case MULT: + tcode = MULT_EXPR; + break; + case DIV: + tcode = RDIV_EXPR; + break; + case SMIN: + tcode = MIN_EXPR; + break; + case SMAX: + tcode = MAX_EXPR; + break; + default: + tcode = LAST_AND_UNUSED_TREE_CODE; + break; + } + return ((int) tcode); +} |