diff options
Diffstat (limited to 'newlib/libc/machine/i960/strcpy_ca.S')
| -rw-r--r-- | newlib/libc/machine/i960/strcpy_ca.S | 284 |
1 files changed, 284 insertions, 0 deletions
diff --git a/newlib/libc/machine/i960/strcpy_ca.S b/newlib/libc/machine/i960/strcpy_ca.S new file mode 100644 index 0000000..dbb9444 --- /dev/null +++ b/newlib/libc/machine/i960/strcpy_ca.S @@ -0,0 +1,284 @@ +/******************************************************************************* + * + * 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 */ + |