diff options
Diffstat (limited to 'newlib/libc/machine/i960/memccpy_ca.S')
| -rw-r--r-- | newlib/libc/machine/i960/memccpy_ca.S | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/newlib/libc/machine/i960/memccpy_ca.S b/newlib/libc/machine/i960/memccpy_ca.S new file mode 100644 index 0000000..60c197b --- /dev/null +++ b/newlib/libc/machine/i960/memccpy_ca.S @@ -0,0 +1,245 @@ +/******************************************************************************* + * + * Copyright (c) 1993 Intel Corporation + * + * Intel hereby grants you permission to copy, modify, and distribute this + * software and its documentation. Intel grants this permission provided + * that the above copyright notice appears in all copies and that both the + * copyright notice and this permission notice appear in supporting + * documentation. In addition, Intel grants this permission provided that + * you prominently mark as "not part of the original" any modifications + * made to this software or documentation, and that the name of Intel + * Corporation not be used in advertising or publicity pertaining to + * distribution of the software or the documentation without specific, + * written prior permission. + * + * Intel Corporation provides this AS IS, WITHOUT ANY WARRANTY, EXPRESS OR + * IMPLIED, INCLUDING, WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY + * OR FITNESS FOR A PARTICULAR PURPOSE. Intel makes no guarantee or + * representations regarding the use of, or the results of the use of, + * the software and documentation in terms of correctness, accuracy, + * reliability, currentness, or otherwise; and you rely on the software, + * documentation and results solely at your own risk. + * + * IN NO EVENT SHALL INTEL BE LIABLE FOR ANY LOSS OF USE, LOSS OF BUSINESS, + * LOSS OF PROFITS, INDIRECT, INCIDENTAL, SPECIAL OR CONSEQUENTIAL DAMAGES + * OF ANY KIND. IN NO EVENT SHALL INTEL'S TOTAL LIABILITY EXCEED THE SUM + * PAID TO INTEL FOR THE PRODUCT LICENSED HEREUNDER. + * + ******************************************************************************/ + + .file "mccpy_ca.s" +#ifdef __PIC + .pic +#endif +#ifdef __PID + .pid +#endif +/* + * (c) copyright 1989,1993 Intel Corp., all rights reserved + */ + +/* + procedure memccpy (optimized assembler version for the 80960CA) + + dest_addr = memccpy (dest_addr, src_addr, char, len) + + copy len bytes pointed to by src_addr to the space pointed to by + dest_addr, stopping if char is copied. If char is copied, + return address of byte after char in dest string; else null. + + Undefined behavior will occur if the end of the source array is in + the last two words of the program's allocated memory space. This + is so because the routine fetches ahead. Disallowing the fetch + ahead would impose a severe performance penalty. + + Undefined behavior will also occur if the source and destination + strings overlap. + + + This program handles five cases: + + 1) both arguments start on a word boundary + 2) neither are word aligned, but they are offset by the same amount + 3) source is word aligned, destination is not + 4) destination is word aligned, source is not + 5) neither is word aligned, and they are offset by differing amounts + + At the time of this writing, only g0 thru g7 and g13 are available + for use in this leafproc; other registers would have to be saved and + restored. These nine registers, plus tricky use of g14 are sufficient + to implement the routine. +*/ + +#if __i960_BIG_ENDIAN__ +#define MSW g6 +#define LSW g7 +#else +#define LSW g6 +#define MSW g7 +#endif + + .globl _memccpy + .leafproc _memccpy, __memccpy + .align 2 +_memccpy: +#ifndef __PIC + lda Lrett,g14 +#else + lda Lrett-(.+8)(ip),g14 +#endif +__memccpy: + notand g1,3,g5 # extract word addr of start of src + lda (g14),g13 # preserve return address + cmpibge.f 0,g3,Lexit_char_not_found # Lexit if # of bytes to move is <= 0 + cmpo g5,g1 # check alignment of src + ld (g5),LSW # fetch word containing at least first byte + notand g0,3,g4 # extract word addr of start of dest + lda 4(g5),g5 # advance src word addr + shlo 24,g2,g2 # reduce char to single byte + bne.f Lcase_245 # branch if src is NOT word aligned + +Lcase_13: + cmpobe.t g0,g4,Lcase_1_setup # branch if dest word aligned + +Lcase_3: # src is word aligned; dest is not + mov LSW,MSW # make copy of first word of src + addo 4,g4,g1 # move dest word ptr to first word boundary + lda 32,g14 # initialize shift count to zero + +Lcase_25: +Lcase_3_cloop_at_start: # character copying loop for start of dest str + cmpdeci 0,g3,g3 # is max_bytes exhausted? +#if __i960_BIG_ENDIAN__ + lda -8(g14),g14 # augment the shift counter +#else + lda 8(g14),g14 # augment the shift counter +#endif + be.f Lexit_char_not_found # Lexit if max_bytes is exhausted +#if __i960_BIG_ENDIAN__ + rotate 8,MSW,MSW # move next byte into position for extraction +#endif + shlo 24,MSW,g4 + stob MSW,(g0) # store the byte in dest + cmpo g4,g2 + lda 1(g0),g0 # post-increment dest ptr +#if ! __i960_BIG_ENDIAN__ + shro 8,MSW,MSW # move next byte into position for extraction +#endif + be.f Lexit_char_found # Lexit if char found + cmpobne.t g1,g0,Lcase_3_cloop_at_start # branch if reached word boundary + + ld (g5),MSW # fetch msw of operand for double shift + +Lcase_4: + shro 8,g2,g4 + or g4,g2,g1 + shro 16,g1,g4 + or g4,g1,g4 + +#if __i960_BIG_ENDIAN__ + cmpobne 0,g14,Lcase_3_wloop + +Lcase_3_wloop2: + cmpi g3,4 # less than four bytes to move? + lda 4(g5),g5 # post-increment src word addr + mov LSW,g1 # extract 4 bytes of src + bl.f Lcase_13_cloop_setup # branch if < four bytes left to move + scanbyte g4,g1 # branch if word has char in it + bo.f Lcase_13_cloop_setup + mov MSW,LSW # move msw to lsw + ld (g5),MSW # pre-fetch msw of operand for double shift + subi 4,g3,g3 # decrease max_byte count by the 4 bytes moved + st g1,(g0) # store 4 bytes to dest + addo 4,g0,g0 # post-increment dest ptr + b Lcase_3_wloop2 +#endif + +Lcase_3_wloop: + cmpi g3,4 # less than four bytes to move? + lda 4(g5),g5 # post-increment src word addr + eshro g14,g6,g1 # extract 4 bytes of src + bl.f Lcase_13_cloop_setup # branch if < four bytes left to move + scanbyte g4,g1 # branch if word has char in it + bo.f Lcase_13_cloop_setup + mov MSW,LSW # move msw to lsw + ld (g5),MSW # pre-fetch msw of operand for double shift + subi 4,g3,g3 # decrease max_byte count by the 4 bytes moved + st g1,(g0) # store 4 bytes to dest + addo 4,g0,g0 # post-increment dest ptr + b Lcase_3_wloop + +Lcase_1_setup: + subo 4,g0,g0 # store is pre-incrementing; back up dest addr + shro 8,g2,g4 + or g4,g2,MSW + shro 16,MSW,g4 + or g4,MSW,g4 + b Lcase_1 +Lcase_1_wloop: # word copying loop + subi 4,g3,g3 # decrease max_byte count by the 4 bytes moved + ld (g5),LSW # pre-fetch next word of src + addo 4,g5,g5 # post-increment src addr + st g1,(g0) # store word in dest string +Lcase_1: # src and dest are word aligned + cmpi g3,4 # check for fewer than four bytes to move + addo 4,g0,g0 # pre-increment dest addr + lda (LSW),g1 # keep a copy of the src word + bl.f Lcase_13_cloop_setup # branch if less than four bytes to copy + scanbyte LSW,g4 # branch if char is not in foursome + bno.t Lcase_1_wloop +Lcase_13_cloop_setup: + cmpibe.f 0,g3,Lexit_char_not_found # Lexit if max_bytes is exhausted + +Lcase_1_cloop: +#if __i960_BIG_ENDIAN__ + rotate 8,g1,g1 # move next byte into position for extraction +#endif + shlo 24,g1,g4 + stob g1,(g0) # store the byte in dest + cmpo g4,g2 + lda 1(g0),g0 # post-increment dest byte addr + subi 1,g3,g3 + be.f Lexit_char_found # Lexit if char reached + cmpi 0,g3 +#if ! __i960_BIG_ENDIAN__ + shro 8,g1,g1 # move next byte into position for extraction +#endif + bne.t Lcase_1_cloop # continue if len not exhausted + +Lexit_char_not_found: + mov 0,g0 +Lexit_char_found: + lda 0,g14 + bx (g13) # g0 = dest array address; g14 = 0 +Lrett: + ret + + +Lcase_245: + cmpo g0,g4 # check alignment of dest + ld (g5),MSW # pre-fetch second half + and 3,g1,g1 # compute shift count + shlo 3,g1,g14 +#if __i960_BIG_ENDIAN__ + subo g14,0,g14 # adjust shift count for big endian +#endif + be.t Lcase_4 # branch if dest is word aligned + or g4,g1,g1 # is src earlier in word, later, or sync w/ dst + cmpo g0,g1 # < indicates first word of dest has more bytes + /* than first word of source. */ + eshro g14,g6,g4 # extract four bytes + lda 4(g0),g1 # move dest word addr to first word boundary +#if __i960_BIG_ENDIAN__ + bge.f 1f +#else + bg.f 1f +#endif + mov MSW,LSW + lda 4(g5),g5 # move src word addr to second word boundary +1: + notand g1,3,g1 + mov g4,MSW + b Lcase_25 + +/* end of memccpy */ |