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Diffstat (limited to 'private/crt32/string/i386/memccpy.asm')
| -rw-r--r-- | private/crt32/string/i386/memccpy.asm | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/private/crt32/string/i386/memccpy.asm b/private/crt32/string/i386/memccpy.asm new file mode 100644 index 000000000..728f4ce23 --- /dev/null +++ b/private/crt32/string/i386/memccpy.asm @@ -0,0 +1,103 @@ + page ,132 + title memccpy - copy bytes until character found +;*** +;memccpy.asm - copy bytes until a character is found +; +; Copyright (c) 1985-1991, Microsoft Corporation. All rights reserved. +; +;Purpose: +; defines _memccpy() - copies bytes until a specifed character +; is found, or a maximum number of characters have been copied. +; +;Revision History: +; 05-16-84 RN initial version +; 05-17-88 SJM Add model-independent (large model) ifdef +; 08-04-88 SJM convert to cruntime/ add 32-bit support +; 08-23-88 JCR Minor 386 adjustments +; 10-25-88 JCR General cleanup for 386-only code +; 03-23-90 GJF Changed to _stdcall. Also, fixed the copyright. +; 01-17-91 GJF ANSI naming. +; 05-10-91 GJF Back to _cdecl, sigh... +; 10-27-92 SKS Avoid using a MASM keyword ("C") as a parameter name +; +;******************************************************************************* + + .xlist + include cruntime.inc + .list + +page +;*** +;char *_memccpy(dest, src, _c, count) - copy bytes until character found +; +;Purpose: +; Copies bytes from src to dest until count bytes have been +; copied, or up to and including the character _c, whichever +; comes first. +; +; Algorithm: +; char * +; _memccpy (dest, sorc, _c, count) +; char *dest, *sorc, _c; +; unsigned int count; +; { +; while (count && (*dest++ = *sorc++) != _c) +; count--; +; +; return(count ? dest : NULL); +; } +; +;Entry: +; char *dest - pointer to memory to receive copy +; char *src - source of bytes +; char _c - character to stop copy at +; int count - max number of bytes to copy +; +;Exit: +; returns pointer to byte immediately after _c in dest; +; returns NULL if _c was never found +; +;Uses: +; +;Exceptions: +; +;******************************************************************************* + + CODESEG + + public _memccpy +_memccpy proc \ + uses edi esi, \ + dest:ptr byte, \ + sorc:ptr byte, \ + _c:byte, \ + count:IWORD + + mov edi,dest ; di = dest + mov esi,sorc ; si = source + + mov ah,_c ; ah = byte to look for + mov ecx,count ; cx = max byte count + jecxz short retnull ; don't do loop if nothing to move + +lupe: + lodsb ; get byte into al and kick si + stosb ; store byte from al and kick di + cmp al,ah ; see if we just moved the byte + je short toend ; end of string + + loop lupe ; dec cx & jmp to lupe if nonzero + ; else drop out & return NULL +retnull: + xor edi,edi ; null pointer +toend: + mov eax,edi ; return value + +ifdef _STDCALL_ + ret 2*DPSIZE + 2*ISIZE ; _stdcall return +else + ret ; _cdecl return +endif + +_memccpy endp + end |