| /******************************************************************************* |
| * |
| * 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 "strcp_ca.s" |
| #ifdef __PIC |
| .pic |
| #endif |
| #ifdef __PID |
| .pid |
| #endif |
| /* |
| * (c) copyright 1988,1993 Intel Corp., all rights reserved |
| */ |
| |
| /* |
| procedure strcpy (optimized assembler version for the CA) |
| |
| dest_addr = strcpy (dest_addr, src_addr) |
| |
| copy the null terminated string pointed to by src_addr to |
| the string space pointed to by dest_addr. Return the original |
| dest_addr. |
| |
| This routine 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. |
| |
| 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, strcpy |
| 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 original dest ptr; not modified, so that it may be returned. |
| g1 src ptr; shift count |
| g2 dest ptr; 4 bytes of src |
| g3 src ptr (word aligned) |
| g4 dest ptr (word aligned) |
| g5 0xff -- byte extraction mask |
| g6 lsw of double word for extraction of 4 bytes (little endian) |
| msw of double word for extraction of 4 bytes (big endian) |
| g7 msw of double word for extraction of 4 bytes (little endian) |
| lsw of double word for extraction of 4 bytes (big endian) |
| g13 return address |
| g14 byte extracted. When reaches null byte, which is zero, we will |
| be in conformance with register conventions, and can return to |
| the caller with a clear conscience. |
| |
| procedure strcat |
| |
| dest_addr = strcat (dest_addr, src_addr) |
| |
| Appends the string pointed to by src_addr to the string pointed |
| to by dest_addr. The first character of the source string is |
| copied to the location initially occupied by the trailing null |
| byte of the destination string. Thereafter, characters are copied |
| from the source to the destination up thru the null byte that |
| trails the source string. |
| */ |
| |
| #if __i960_BIG_ENDIAN__ |
| #define MSW g6 |
| #define LSW g7 |
| #else |
| #define LSW g6 |
| #define MSW g7 |
| #endif |
| |
| .globl _strcpy, _strcat |
| .globl __strcpy, __strcat |
| .leafproc _strcpy, __strcpy |
| .leafproc _strcat, __strcat |
| .align 2 |
| _strcat: |
| #ifndef __PIC |
| lda Lrett,g14 |
| #else |
| lda Lrett-(.+8)(ip),g14 |
| #endif |
| __strcat: |
| notand g0,3,g4 # extract word addr of start of dest |
| lda (g14),g13 # preserve return address |
| and g0,3,LSW # extract byte offset of dest |
| ld (g4),MSW # fetch word containing at least first byte |
| shlo 3,LSW,g14 # get shift count for making mask for first word |
| subi 1,0,LSW # mask initially all ones |
| #if __i960_BIG_ENDIAN__ |
| shro g14,LSW,LSW # get mask for bytes needed from first word |
| lda 0xff000000,g5 # byte extraction mask |
| #else |
| shlo g14,LSW,LSW # get mask for bytes needed from first word |
| lda 0xff,g5 # byte extraction mask |
| #endif |
| notor MSW,LSW,MSW # set unneeded bytes to all ones |
| Lsearch_for_word_with_null: |
| scanbyte 0,MSW # check for null byte |
| lda 4(g4),g4 # post-increment dest word pointer |
| mov MSW,LSW # keep a copy of current word |
| ld (g4),MSW # fetch next word of dest |
| bno.t Lsearch_for_word_with_null # branch if null not found yet |
| and g5,LSW,g14 # extract byte |
| cmpo 0,g14 # branch if null is first byte of word |
| subo 4,g4,g4 # move dest word ptr back to word with null |
| notand g1,3,g3 # extract word addr of start of src |
| lda (g4),g2 # set dest byte ptr to 1st byte of word w/ null |
| be.f Lcase_14 |
| Lsearch_for_null: |
| #if __i960_BIG_ENDIAN__ |
| shro 8,g5,g5 # move mask down to next byte |
| #else |
| shlo 8,g5,g5 # move mask up to next byte |
| #endif |
| lda 1(g2),g2 # move dest byte ptr to next byte |
| and g5,LSW,g14 # extract byte |
| cmpobne.t 0,g14,Lsearch_for_null # branch if null is not yet found |
| lda 0xff,g5 # byte extraction mask |
| b Lcase_235.a |
| |
| |
| _strcpy: |
| #ifndef __PIC |
| lda Lrett,g14 |
| #else |
| lda Lrett-(.+8)(ip),g14 |
| #endif |
| __strcpy: |
| notand g0,3,g4 # extract word addr of start of dest |
| lda (g14),g13 # preserve return address |
| cmpo g0,g4 # check alignment of dest |
| lda 0xff,g5 # load mask for byte extraction |
| notand g1,3,g3 # extract word addr of start of src |
| bne.f Lcase_235 # branch if dest is NOT word aligned |
| |
| Lcase_14: |
| cmpo g3,g1 # check alignment of src |
| ld (g3),LSW # fetch word containing at least first byte |
| shlo 3,g1,g1 # compute shift count |
| lda 4(g3),g3 # advance src word addr |
| #if __i960_BIG_ENDIAN__ |
| lda 0xff,g5 # byte extraction mask |
| #endif |
| bne.f Lcase_4 # branch if src is NOT word aligned |
| |
| Lcase_1: # src and dest are word aligned |
| subo 4,g4,g4 # store is pre-incrementing; back up dest addr |
| Lcase_1_wloop: # word copying loop |
| scanbyte 0,LSW # check for null byte in src word |
| lda (LSW),g2 # keep a copy of the src word |
| addo 4,g4,g4 # pre-increment dest addr |
| ld (g3),LSW # pre-fetch next word of src |
| addo 4,g3,g3 # post-increment src addr |
| bo.f Lcase_1_cloop # branch if word contains null byte |
| st g2,(g4) # store word in dest string |
| b Lcase_1_wloop |
| |
| Lcase_3_cloop: |
| Lcase_1_cloop: # character copying loop |
| #if __i960_BIG_ENDIAN__ |
| rotate 8,g2,g2 # move next byte into position for extraction |
| and g5,g2,g14 # extract next char |
| #else |
| and g5,g2,g14 # extract next char |
| shro 8,g2,g2 # move next byte into position for extraction |
| #endif |
| cmpo 0,g14 # check for null byte |
| stob g14,(g4) # store the byte in dest |
| lda 1(g4),g4 # post-increment dest byte addr |
| bne.t Lcase_1_cloop # branch if null not reached |
| |
| Lexit_code: |
| bx (g13) # g0 = addr of dest; g14 = 0 |
| Lrett: |
| ret |
| |
| Lcase_3: # src is word aligned; dest is not |
| addo 4,g4,g4 # move dest word ptr to first word boundary |
| mov LSW,MSW # make copy of first word of src |
| lda 0,g1 # initialize shift count to zero |
| |
| Lcase_25: |
| Lcase_3_cloop_at_start: # character copying loop for start of dest str |
| #if __i960_BIG_ENDIAN__ |
| rotate 8,MSW,MSW # move next byte into position for extraction |
| and g5,MSW,g14 # extract next char |
| #else |
| and g5,MSW,g14 # extract next char |
| shro 8,MSW,MSW # move next byte into position for extraction |
| #endif |
| cmpo 0,g14 # check for null byte |
| stob g14,(g2) # store the byte in dest |
| lda 1(g2),g2 # post-increment dest ptr |
| be.f Lexit_code # branch if null byte reached |
| cmpo g2,g4 # have we reached word boundary in dest? |
| lda 8(g1),g1 # augment the shift counter |
| bne.t Lcase_3_cloop_at_start |
| |
| Lcase_4: |
| ld (g3),MSW # fetch msw of operand for double shift |
| #if __i960_BIG_ENDIAN__ |
| subo g1,0,g1 # Adjust shift count for big endian. |
| #endif |
| |
| Lcase_3_wloop: |
| eshro g1,g6,g2 # extract 4 bytes of src |
| lda 4(g3),g3 # post-increment src word addr |
| scanbyte 0,g2 # check for null byte |
| lda (MSW),LSW # move msw to lsw |
| ld (g3),MSW # pre-fetch msw of operand for double shift |
| bo.f Lcase_3_cloop # branch if word contains null byte |
| st g2,(g4) # store 4 bytes to dest |
| addo 4,g4,g4 # post-increment dest ptr |
| b Lcase_3_wloop |
| |
| Lcase_235: |
| lda (g0),g2 # copy dest ptr |
| Lcase_235.a: |
| cmpo g3,g1 # check alignment of src |
| ld (g3),LSW # fetch word containing at least first byte |
| and 3,g1,g14 # compute shift count |
| lda 4(g3),g3 # advance src word addr |
| shlo 3,g14,g1 |
| be.t Lcase_3 # branch if dest is word aligned |
| or g4,g14,g14 # is src earlier in word, later, or sync w/ dst |
| ld (g3),MSW # pre-fetch second half |
| cmpo g2,g14 # < indicates first word of dest has more bytes |
| lda 4(g4),g4 # move dest word addr to first word boundary |
| /* than first word of source. */ |
| #if __i960_BIG_ENDIAN__ |
| subo g1,0,g14 # Adjust shift count for big endian. |
| eshro g14,g6,g14 # extract four bytes |
| bge.f 1f |
| #else |
| eshro g1,g6,g14 # extract four bytes |
| bg.f 1f |
| #endif |
| mov MSW,LSW |
| lda 4(g3),g3 # move src word addr to second word boundary |
| 1: |
| mov g14,MSW |
| b Lcase_25 |
| |
| /* end of strcpy */ |
| |