diff options
Diffstat (limited to 'newlib/libc/machine/i960/memcpy_ca.S')
| -rw-r--r-- | newlib/libc/machine/i960/memcpy_ca.S | 353 |
1 files changed, 353 insertions, 0 deletions
diff --git a/newlib/libc/machine/i960/memcpy_ca.S b/newlib/libc/machine/i960/memcpy_ca.S new file mode 100644 index 0000000..eebfa88 --- /dev/null +++ b/newlib/libc/machine/i960/memcpy_ca.S @@ -0,0 +1,353 @@ +/******************************************************************************* + * + * 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 "memcp_ca.s" +#ifdef __PIC + .pic +#endif +#ifdef __PID + .pid +#endif +/* + * (c) copyright 1988,1992,1993 Intel Corp., all rights reserved + */ + +/* + procedure memmove (optimized assembler version for the CA) + procedure memcpy (optimized assembler version for the CA) + + dest_addr = memmove (dest_addr, src_addr, len) + dest_addr = memcpy (dest_addr, src_addr, len) + + copy len bytes pointed to by src_addr to the space pointed to by + dest_addr. Return the original dest_addr. + + Memcpy will fail if the source and destination string overlap + (in particular, if the end of the source is overlapped by the + beginning of the destination). The behavior is undefined. + This is acceptable according to the draft C standard. + Memmove will not fail if overlap exists. + + Undefined behavior will also occur if the end of the source string + (i.e. the terminating null byte) is in the last word of the program's + allocated memory space. This is so because, in several cases, the + routine will fetch ahead one word. Disallowing the fetch ahead would + impose a severe performance penalty. + + 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. The registers are used as follows: + + g0 dest ptr; not modified, so that it may be returned + g1 src ptr; shift count + g2 len + g3 src ptr (word aligned) + g4 dest ptr (word aligned) + g5 -4 for Lbackwards move + Little endian + g6 lsw of double word for extraction of 4 bytes + g7 msw of double word for extraction of 4 bytes + Big endian + g6 msw of double word for extraction of 4 bytes + g7 lsw of double word for extraction of 4 bytes + g13 return address + g14 byte extracted. +*/ + +#if __i960_BIG_ENDIAN__ +#define MSW g6 +#define LSW g7 +#else +#define LSW g6 +#define MSW g7 +#endif + + .globl _memmove, _memcpy + .globl __memmove, __memcpy + .leafproc _memmove, __memmove + .leafproc _memcpy, __memcpy + .align 2 +_memcpy: +_memmove: +#ifndef __PIC + lda Lrett,g14 +#else + lda Lrett-(.+8)(ip),g14 +#endif +__memcpy: +__memmove: + cmpibge.f 0,g2,Lquick_exit # Lexit if number of bytes to move is <= zero. + cmpo g0,g1 # if dest starts earlier than src ... + lda (g14),g13 # preserve return address + addo g2,g1,g5 # compute addr of byte after last byte of src + be.f Lexit_code # no move necessary if src and dest are same + concmpo g5,g0 # ... or if dest starts after end of src ... + notand g1,3,g3 # extract word addr of start of src + bg.f Lbackwards # ... then drop thru, else do move backwards + cmpo g3,g1 # check alignment of src + ld (g3),LSW # fetch word containing at least first byte + notand g0,3,g4 # extract word addr of start of dest + lda 4(g3),g3 # advance src word addr + bne.f Lcase_245 # branch if src is NOT word aligned + +Lcase_13: + cmpo g0,g4 # check alignment of dest + subo 4,g4,g4 # store is pre-incrementing; back up dest addr + be.t Lcase_1 # branch if dest word aligned + +Lcase_3: # src is word aligned; dest is not + addo 8,g4,g4 # move dest word ptr to first word boundary + lda (g0),g1 # copy dest byte ptr + mov LSW,MSW # make copy of first word of src + lda 32,g14 # initialize shift count to zero (mod 32) + +Lcase_25: +Lcase_3_cloop_at_start: # character copying loop for start of dest str + cmpdeci 0,g2,g2 # is max_bytes exhausted? + be.f Lexit_code # Lexit if max_bytes is exhausted +#if __i960_BIG_ENDIAN__ + rotate 8,MSW,MSW # move next byte into position for extraction + subo 8,g14,g14 # augment the shift counter + stob MSW,(g1) # store the byte in dest +#else + addo 8,g14,g14 # augment the shift counter + stob MSW,(g1) # store the byte in dest + shro 8,MSW,MSW # move next byte into position for extraction +#endif + lda 1(g1),g1 # post-increment dest ptr + cmpobne.t g1,g4,Lcase_3_cloop_at_start # branch if reached word boundary + + ld (g3),MSW # fetch msw of operand for double shift + +Lcase_4: +Lcase_3_wloop: + cmpi g2,4 # less than four bytes to move? + lda 4(g3),g3 # post-increment src word addr + eshro g14,g6,g1 # extract 4 bytes of src + bl.f Lcase_3_cloop # branch if < four bytes left to move + mov MSW,LSW # move msw to lsw + ld (g3),MSW # pre-fetch msw of operand for double shift + subi 4,g2,g2 # decrease max_byte count by the 4 bytes moved + st g1,(g4) # store 4 bytes to dest + addo 4,g4,g4 # post-increment dest ptr + b Lcase_3_wloop + +Lcase_1_wloop: # word copying loop + subi 4,g2,g2 # decrease max_byte count by the 4 bytes moved + ld (g3),LSW # pre-fetch next word of src + addo 4,g3,g3 # post-increment src addr + st g1,(g4) # store word in dest string +Lcase_1: # src and dest are word aligned + cmpi g2,4 # check for fewer than four bytes to move + addo 4,g4,g4 # pre-increment dest addr + lda (LSW),g1 # keep a copy of the src word + bge.t Lcase_1_wloop # branch if at least four bytes to copy +Lcase_3_cloop: + cmpibe.f 0,g2,Lexit_code # 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 + subi 1,g2,g2 + stob g1,(g4) # store the byte in dest + cmpi 0,g2 + lda 1(g4),g4 # post-increment dest byte addr +#if ! __i960_BIG_ENDIAN__ + shro 8,g1,g1 # move next byte into position for extraction +#endif + bne.t Lcase_1_cloop # Lexit if max_bytes is exhausted + +Lexit_code: + mov 0,g14 # conform to register conventions + bx (g13) # g0 = addr of dest; g14 = 0 +Lrett: + ret + + +Lcase_245: + cmpo g0,g4 # check alignment of dest + ld (g3),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 + lda 4(g4),g4 # move dest word addr to first word boundary + eshro g14,g6,g5 # extract four bytes + lda (g0),g1 +#if __i960_BIG_ENDIAN__ + bge.f 1f +#else + bg.f 1f +#endif + mov MSW,LSW + lda 4(g3),g3 # move src word addr to second word boundary +1: + mov g5,MSW + b Lcase_25 + + +Lbackwards: + notand g5,3,MSW # extract word addr of byte after end of src + cmpo MSW,g5 # check alignment of end of src + subo 4,MSW,g3 # retreat src word addr + addo g2,g0,g1 # compute addr of byte after end of dest + notand g1,3,g4 # extract word addr of start of dest + bne.f Lcase.245 # branch if src is NOT word aligned + +Lcase.13: + cmpo g1,g4 # check alignment of dest + ld (g3),MSW # fetch last word of src + subo 4,g3,g3 # retreat src word addr + be.t Lcase.1 # branch if dest word aligned + +Lcase.3: # src is word aligned; dest is not + mov MSW,LSW # make copy of first word of src + lda 32,g14 # initialize shift count to zero (mod 32) + +Lcase.25: +Lcase.3_cloop_at_start: # character copying loop for start of dest str + cmpdeci 0,g2,g2 # is max.bytes exhausted? + be.f Lexit_code # Lexit if max_bytes is exhausted +#if ! __i960_BIG_ENDIAN__ + rotate 8,LSW,LSW # move next byte into position for storing +#endif + lda -1(g1),g1 # pre-decrement dest ptr + cmpo g1,g4 # have we reached word boundary in dest yet? + stob LSW,(g1) # store the byte in dest +#if __i960_BIG_ENDIAN__ + shro 8,LSW,LSW # move next byte into position for storing + addo 8,g14,g14 # augment the shift counter +#else + subo 8,g14,g14 # augment the shift counter +#endif + bne.t Lcase.3_cloop_at_start # branch if reached word boundary? + + ld (g3),LSW # fetch lsw of operand for double shift + +#if __i960_BIG_ENDIAN__ + cmpobne 0,g14,Lcase.3_wloop +Lcase.3_wloop2: + cmpi g2,4 # less than four bytes to move? + lda -4(g3),g3 # post-decrement src word addr + mov MSW,g1 # extract 4 bytes of src + lda (LSW),MSW # move lsw to msw + subo 4,g4,g4 # pre-decrement dest ptr + bl.f Lcase.3_cloop # branch if < four bytes left to move + ld (g3),LSW # pre-fetch lsw of operand for double shift + subi 4,g2,g2 # decrease max.byte count by the 4 bytes moved + st g1,(g4) # store 4 bytes to dest + b Lcase.3_wloop2 +#endif + +Lcase.4: +Lcase.3_wloop: + cmpi g2,4 # less than four bytes to move? + lda -4(g3),g3 # post-decrement src word addr + eshro g14,g6,g1 # extract 4 bytes of src + lda (LSW),MSW # move lsw to msw + subo 4,g4,g4 # pre-decrement dest ptr + bl.f Lcase.3_cloop # branch if < four bytes left to move + ld (g3),LSW # pre-fetch lsw of operand for double shift + subi 4,g2,g2 # decrease max.byte count by the 4 bytes moved + st g1,(g4) # store 4 bytes to dest + b Lcase.3_wloop + +Lcase.1_wloop: # word copying loop + subi 4,g2,g2 # decrease max.byte count by the 4 bytes moved + ld (g3),MSW # pre-fetch next word of src + subo 4,g3,g3 # post-decrement src addr + st g1,(g4) # store word in dest string +Lcase.1: # src and dest are word aligned + cmpi g2,4 # check for fewer than four bytes to move + subo 4,g4,g4 # pre-decrement dest addr + lda (MSW),g1 # keep a copy of the src word + bge.t Lcase.1_wloop # branch if at least four bytes to copy +Lcase.3_cloop: + cmpibe.f 0,g2,Lexit_code # Lexit if max_bytes is exhausted +#if ! __i960_BIG_ENDIAN__ + rotate 8,g1,g1 # move next byte into position for storing +#endif + lda 4(g4),g4 # pre-decremented dest addr 4 too much + +Lcase.1_cloop: + subi 1,g4,g4 # pre-decrement dest byte addr + cmpi g4,g0 # has dest ptr reached beginning of dest? + stob g1,(g4) # store the byte in dest +#if __i960_BIG_ENDIAN__ + shro 8,g1,g1 # move next byte into position for storing +#else + rotate 8,g1,g1 # move next byte into position for storing +#endif + bne.t Lcase.1_cloop # Lexit if move is completed + b Lexit_code + +Lcase.245: + cmpo g1,g4 # check alignment of dest + ld (MSW),MSW # pre-fetch word with at least last byte + and 3,g5,g5 # compute shift count + ld (g3),LSW # pre-fetch second to last word + shlo 3,g5,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,g5,g5 # is src earlier in word, later, or sync w/ dst + cmpo g1,g5 # < indicates last word of dest has less bytes + eshro g14,g6,g5 # extract four bytes + bl.t 1f + mov LSW,MSW +#if ! __i960_BIG_ENDIAN__ + be.t 1f +#endif + subo 4,g3,g3 # move src word addr to second word boundary +1: + mov g5,LSW + b Lcase.25 + + +Lquick_exit: + mov g14,g13 + b Lexit_code + +/* end of memmove */ |