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Diffstat (limited to 'win32/lm32_lcc.asm')
| -rw-r--r-- | win32/lm32_lcc.asm | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/win32/lm32_lcc.asm b/win32/lm32_lcc.asm new file mode 100644 index 0000000..0450fe3 --- /dev/null +++ b/win32/lm32_lcc.asm @@ -0,0 +1,174 @@ +;=========================================================================== +; Copyright (c) 1990-1999 Info-ZIP. All rights reserved. +; +; See the accompanying file LICENSE, version 1999-Oct-05 or later +; (the contents of which are also included in zip.h) for terms of use. +; If, for some reason, both of these files are missing, the Info-ZIP license +; also may be found at: ftp://ftp.cdrom.com/pub/infozip/license.html +;=========================================================================== +; match32.asm by Jean-loup Gailly. + +; match32.asm, optimized version of longest_match() in deflate.c +; To be used only with 32 bit flat model. To simplify the code, the option +; -DDYN_ALLOC is not supported. +; This file is only optional. If you don't have an assembler, use the +; C version (add -DNO_ASM to CFLAGS in makefile and remove match.o +; from OBJI). If you have reduced WSIZE in zip.h, then make sure this is +; assembled with an equivalent -DWSIZE=<whatever>. +; +; Win32 (Windows NT) version - 1994/04/13 by Steve Salisbury +; * works with Microsoft MASM 6.1X and Microsoft Visual C++ / 32-bit edition +; +; The code in this file has been copied verbatim from match32.{asm|S}; +; only the assembler syntax and metacommands have been adapted to +; the habits of the free LCC-Win32 C compiler package. +; IMPORTANT NOTE to the Info-ZIP editors: +; The TAB characters in this source file are required by the parser of +; the LCC-Win32 assembler program and MUST NOT be removed!! +; +;============================================================================== +; +; Do NOT assemble this source if external crc32 routine from zlib gets used. +; + + +;/* This version is for 386 Unix or OS/2 in 32 bit mode. +; * Warning: it uses the AT&T syntax: mov source,dest +; * This file is only optional. If you want to force the C version, +; * add -DNO_ASM to CFLAGS in Makefile and set OBJA to an empty string. +; * If you have reduced WSIZE in (g)zip.h, then make sure this is +; * assembled with an equivalent -DWSIZE=<whatever>. +; * This version assumes static allocation of the arrays (-DDYN_ALLOC not used). +; */ + + .text + .file "match.S" + + + .text + .type _match_init,function + +_match_init: + ret +_$98: + .size _match_init,_$98-_match_init + .globl _match_init + +;/*----------------------------------------------------------------------- +; * Set match_start to the longest match starting at the given string and +; * return its length. Matches shorter or equal to prev_length are discarded, +; * in which case the result is equal to prev_length and match_start is +; * garbage. +; * IN assertions: cur_match is the head of the hash chain for the current +; * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1 +; */ + + .align 4 + .type _longest_match,function + +_longest_match: ;/* int longest_match(cur_match) */ + +; cur_match equ 20(%esp) +; /* return address */ /* esp+16 */ + push %ebp + push %edi +;/* esp+8 */ + push %esi +;/* esp+4 */ + push %ebx +;/* esp */ + +;/* +; * match equ esi +; * scan equ edi +; * chain_length equ ebp +; * best_len equ ebx +; * limit equ edx +; */ + mov 20(%esp),%esi + mov _strstart,%edx + mov _max_chain_length,%ebp + mov %edx,%edi + sub $(32768-262),%edx + cld + jae limit_ok + sub %edx,%edx +limit_ok: + add $2+_window,%edi + mov _prev_length,%ebx + movw -2(%edi),%cx + movw -3(%ebx,%edi),%ax + cmp _good_match,%ebx + jb do_scan + shr $2,%ebp + jmp do_scan + + .align 4 +long_loop: +;/* at this point, edi == scan+2, esi == cur_match */ + movw -3(%ebx,%edi),%ax + movw -2(%edi),%cx +short_loop: +;/* +; * at this point, di == scan+2, si == cur_match, +; * ax = scan[best_len-1..best_len] and cx = scan[0..1] +; */ + and $(32768-1), %esi + dec %ebp + movw _prev(,%esi,2),%si + jz the_end + cmp %edx,%esi + jbe the_end +do_scan: + cmpw _window-1(%ebx,%esi),%ax + jne short_loop + cmpw _window(%esi),%cx + jne short_loop + + add $2+_window,%esi + mov $((258>>1)-1),%ecx + mov %edi,%eax + repe; cmpsw +;/* loop until mismatch */ + je maxmatch +;/* match of length MAX_MATCH? */ +mismatch: + movb -2(%edi),%cl + xchg %edi,%eax + subb -2(%esi),%cl + sub %edi,%eax + sub $2+_window,%esi + sub %eax,%esi + subb $1,%cl + adc $0,%eax + cmp %ebx,%eax + jle long_loop + mov %esi,_match_start + mov %eax,%ebx + cmp _nice_match,%eax +; /* len >= nice_match ? */ + jl long_loop +the_end: + mov %ebx,%eax + pop %ebx + pop %esi + pop %edi + pop %ebp + ret + .align 4 +maxmatch: + cmpsb + jmp mismatch +_$99: + + .size _longest_match,_$99-_longest_match + .globl _longest_match + + .extern _nice_match + .extern _good_match + .extern _max_chain_length + .extern _match_start + .extern _strstart + .extern _prev_length + .extern _prev + .extern _window |