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Diffstat (limited to 'Build/source/libs/zlib/contrib/masmx86/gvmat32.asm')
-rw-r--r-- | Build/source/libs/zlib/contrib/masmx86/gvmat32.asm | 972 |
1 files changed, 0 insertions, 972 deletions
diff --git a/Build/source/libs/zlib/contrib/masmx86/gvmat32.asm b/Build/source/libs/zlib/contrib/masmx86/gvmat32.asm deleted file mode 100644 index bb4f854e408..00000000000 --- a/Build/source/libs/zlib/contrib/masmx86/gvmat32.asm +++ /dev/null @@ -1,972 +0,0 @@ -; gvmat32.asm -- Asm portion of the optimized longest_match for 32 bits x86 -; Copyright (C) 1995-1996 Jean-loup Gailly and Gilles Vollant. -; File written by Gilles Vollant, by modifiying the longest_match -; from Jean-loup Gailly in deflate.c -; -; http://www.zlib.net -; http://www.winimage.com/zLibDll -; http://www.muppetlabs.com/~breadbox/software/assembly.html -; -; For Visual C++ 4.x and higher and ML 6.x and higher -; ml.exe is in directory \MASM611C of Win95 DDK -; ml.exe is also distributed in http://www.masm32.com/masmdl.htm -; and in VC++2003 toolkit at http://msdn.microsoft.com/visualc/vctoolkit2003/ -; -; this file contain two implementation of longest_match -; -; longest_match_7fff : written 1996 by Gilles Vollant optimized for -; first Pentium. Assume s->w_mask == 0x7fff -; longest_match_686 : written by Brian raiter (1998), optimized for Pentium Pro -; -; for using an seembly version of longest_match, you need define ASMV in project -; There is two way in using gvmat32.asm -; -; A) Suggested method -; if you want include both longest_match_7fff and longest_match_686 -; compile the asm file running -; ml /coff /Zi /Flgvmat32.lst /c gvmat32.asm -; and include gvmat32c.c in your project -; if you have an old cpu (386,486 or first Pentium) and s->w_mask==0x7fff, -; longest_match_7fff will be used -; if you have a more modern CPU (Pentium Pro, II and higher) -; longest_match_686 will be used -; on old cpu with s->w_mask!=0x7fff, longest_match_686 will be used, -; but this is not a sitation you'll find often -; -; B) Alternative -; if you are not interresed in old cpu performance and want the smaller -; binaries possible -; -; compile the asm file running -; ml /coff /Zi /c /Flgvmat32.lst /DNOOLDPENTIUMCODE gvmat32.asm -; and do not include gvmat32c.c in your project (ou define also -; NOOLDPENTIUMCODE) -; -; note : as I known, longest_match_686 is very faster than longest_match_7fff -; on pentium Pro/II/III, faster (but less) in P4, but it seem -; longest_match_7fff can be faster (very very litte) on AMD Athlon64/K8 -; -; see below : zlib1222add must be adjuster if you use a zlib version < 1.2.2.2 - -;uInt longest_match_7fff(s, cur_match) -; deflate_state *s; -; IPos cur_match; /* current match */ - - NbStack equ 76 - cur_match equ dword ptr[esp+NbStack-0] - str_s equ dword ptr[esp+NbStack-4] -; 5 dword on top (ret,ebp,esi,edi,ebx) - adrret equ dword ptr[esp+NbStack-8] - pushebp equ dword ptr[esp+NbStack-12] - pushedi equ dword ptr[esp+NbStack-16] - pushesi equ dword ptr[esp+NbStack-20] - pushebx equ dword ptr[esp+NbStack-24] - - chain_length equ dword ptr [esp+NbStack-28] - limit equ dword ptr [esp+NbStack-32] - best_len equ dword ptr [esp+NbStack-36] - window equ dword ptr [esp+NbStack-40] - prev equ dword ptr [esp+NbStack-44] - scan_start equ word ptr [esp+NbStack-48] - wmask equ dword ptr [esp+NbStack-52] - match_start_ptr equ dword ptr [esp+NbStack-56] - nice_match equ dword ptr [esp+NbStack-60] - scan equ dword ptr [esp+NbStack-64] - - windowlen equ dword ptr [esp+NbStack-68] - match_start equ dword ptr [esp+NbStack-72] - strend equ dword ptr [esp+NbStack-76] - NbStackAdd equ (NbStack-24) - - .386p - - name gvmatch - .MODEL FLAT - - - -; all the +zlib1222add offsets are due to the addition of fields -; in zlib in the deflate_state structure since the asm code was first written -; (if you compile with zlib 1.0.4 or older, use "zlib1222add equ (-4)"). -; (if you compile with zlib between 1.0.5 and 1.2.2.1, use "zlib1222add equ 0"). -; if you compile with zlib 1.2.2.2 or later , use "zlib1222add equ 8"). - - zlib1222add equ 8 - -; Note : these value are good with a 8 bytes boundary pack structure - dep_chain_length equ 74h+zlib1222add - dep_window equ 30h+zlib1222add - dep_strstart equ 64h+zlib1222add - dep_prev_length equ 70h+zlib1222add - dep_nice_match equ 88h+zlib1222add - dep_w_size equ 24h+zlib1222add - dep_prev equ 38h+zlib1222add - dep_w_mask equ 2ch+zlib1222add - dep_good_match equ 84h+zlib1222add - dep_match_start equ 68h+zlib1222add - dep_lookahead equ 6ch+zlib1222add - - -_TEXT segment - -IFDEF NOUNDERLINE - IFDEF NOOLDPENTIUMCODE - public longest_match - public match_init - ELSE - public longest_match_7fff - public cpudetect32 - public longest_match_686 - ENDIF -ELSE - IFDEF NOOLDPENTIUMCODE - public _longest_match - public _match_init - ELSE - public _longest_match_7fff - public _cpudetect32 - public _longest_match_686 - ENDIF -ENDIF - - MAX_MATCH equ 258 - MIN_MATCH equ 3 - MIN_LOOKAHEAD equ (MAX_MATCH+MIN_MATCH+1) - - - -IFNDEF NOOLDPENTIUMCODE -IFDEF NOUNDERLINE -longest_match_7fff proc near -ELSE -_longest_match_7fff proc near -ENDIF - - mov edx,[esp+4] - - - - push ebp - push edi - push esi - push ebx - - sub esp,NbStackAdd - -; initialize or check the variables used in match.asm. - mov ebp,edx - -; chain_length = s->max_chain_length -; if (prev_length>=good_match) chain_length >>= 2 - mov edx,[ebp+dep_chain_length] - mov ebx,[ebp+dep_prev_length] - cmp [ebp+dep_good_match],ebx - ja noshr - shr edx,2 -noshr: -; we increment chain_length because in the asm, the --chain_lenght is in the beginning of the loop - inc edx - mov edi,[ebp+dep_nice_match] - mov chain_length,edx - mov eax,[ebp+dep_lookahead] - cmp eax,edi -; if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead; - jae nolookaheadnicematch - mov edi,eax -nolookaheadnicematch: -; best_len = s->prev_length - mov best_len,ebx - -; window = s->window - mov esi,[ebp+dep_window] - mov ecx,[ebp+dep_strstart] - mov window,esi - - mov nice_match,edi -; scan = window + strstart - add esi,ecx - mov scan,esi -; dx = *window - mov dx,word ptr [esi] -; bx = *(window+best_len-1) - mov bx,word ptr [esi+ebx-1] - add esi,MAX_MATCH-1 -; scan_start = *scan - mov scan_start,dx -; strend = scan + MAX_MATCH-1 - mov strend,esi -; bx = scan_end = *(window+best_len-1) - -; IPos limit = s->strstart > (IPos)MAX_DIST(s) ? -; s->strstart - (IPos)MAX_DIST(s) : NIL; - - mov esi,[ebp+dep_w_size] - sub esi,MIN_LOOKAHEAD -; here esi = MAX_DIST(s) - sub ecx,esi - ja nodist - xor ecx,ecx -nodist: - mov limit,ecx - -; prev = s->prev - mov edx,[ebp+dep_prev] - mov prev,edx - -; - mov edx,dword ptr [ebp+dep_match_start] - mov bp,scan_start - mov eax,cur_match - mov match_start,edx - - mov edx,window - mov edi,edx - add edi,best_len - mov esi,prev - dec edi -; windowlen = window + best_len -1 - mov windowlen,edi - - jmp beginloop2 - align 4 - -; here, in the loop -; eax = ax = cur_match -; ecx = limit -; bx = scan_end -; bp = scan_start -; edi = windowlen (window + best_len -1) -; esi = prev - - -;// here; chain_length <=16 -normalbeg0add16: - add chain_length,16 - jz exitloop -normalbeg0: - cmp word ptr[edi+eax],bx - je normalbeg2noroll -rcontlabnoroll: -; cur_match = prev[cur_match & wmask] - and eax,7fffh - mov ax,word ptr[esi+eax*2] -; if cur_match > limit, go to exitloop - cmp ecx,eax - jnb exitloop -; if --chain_length != 0, go to exitloop - dec chain_length - jnz normalbeg0 - jmp exitloop - -normalbeg2noroll: -; if (scan_start==*(cur_match+window)) goto normalbeg2 - cmp bp,word ptr[edx+eax] - jne rcontlabnoroll - jmp normalbeg2 - -contloop3: - mov edi,windowlen - -; cur_match = prev[cur_match & wmask] - and eax,7fffh - mov ax,word ptr[esi+eax*2] -; if cur_match > limit, go to exitloop - cmp ecx,eax -jnbexitloopshort1: - jnb exitloop -; if --chain_length != 0, go to exitloop - - -; begin the main loop -beginloop2: - sub chain_length,16+1 -; if chain_length <=16, don't use the unrolled loop - jna normalbeg0add16 - -do16: - cmp word ptr[edi+eax],bx - je normalbeg2dc0 - -maccn MACRO lab - and eax,7fffh - mov ax,word ptr[esi+eax*2] - cmp ecx,eax - jnb exitloop - cmp word ptr[edi+eax],bx - je lab - ENDM - -rcontloop0: - maccn normalbeg2dc1 - -rcontloop1: - maccn normalbeg2dc2 - -rcontloop2: - maccn normalbeg2dc3 - -rcontloop3: - maccn normalbeg2dc4 - -rcontloop4: - maccn normalbeg2dc5 - -rcontloop5: - maccn normalbeg2dc6 - -rcontloop6: - maccn normalbeg2dc7 - -rcontloop7: - maccn normalbeg2dc8 - -rcontloop8: - maccn normalbeg2dc9 - -rcontloop9: - maccn normalbeg2dc10 - -rcontloop10: - maccn short normalbeg2dc11 - -rcontloop11: - maccn short normalbeg2dc12 - -rcontloop12: - maccn short normalbeg2dc13 - -rcontloop13: - maccn short normalbeg2dc14 - -rcontloop14: - maccn short normalbeg2dc15 - -rcontloop15: - and eax,7fffh - mov ax,word ptr[esi+eax*2] - cmp ecx,eax - jnb exitloop - - sub chain_length,16 - ja do16 - jmp normalbeg0add16 - -;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; - -normbeg MACRO rcontlab,valsub -; if we are here, we know that *(match+best_len-1) == scan_end - cmp bp,word ptr[edx+eax] -; if (match != scan_start) goto rcontlab - jne rcontlab -; calculate the good chain_length, and we'll compare scan and match string - add chain_length,16-valsub - jmp iseq - ENDM - - -normalbeg2dc11: - normbeg rcontloop11,11 - -normalbeg2dc12: - normbeg short rcontloop12,12 - -normalbeg2dc13: - normbeg short rcontloop13,13 - -normalbeg2dc14: - normbeg short rcontloop14,14 - -normalbeg2dc15: - normbeg short rcontloop15,15 - -normalbeg2dc10: - normbeg rcontloop10,10 - -normalbeg2dc9: - normbeg rcontloop9,9 - -normalbeg2dc8: - normbeg rcontloop8,8 - -normalbeg2dc7: - normbeg rcontloop7,7 - -normalbeg2dc6: - normbeg rcontloop6,6 - -normalbeg2dc5: - normbeg rcontloop5,5 - -normalbeg2dc4: - normbeg rcontloop4,4 - -normalbeg2dc3: - normbeg rcontloop3,3 - -normalbeg2dc2: - normbeg rcontloop2,2 - -normalbeg2dc1: - normbeg rcontloop1,1 - -normalbeg2dc0: - normbeg rcontloop0,0 - - -; we go in normalbeg2 because *(ushf*)(match+best_len-1) == scan_end - -normalbeg2: - mov edi,window - - cmp bp,word ptr[edi+eax] - jne contloop3 ; if *(ushf*)match != scan_start, continue - -iseq: -; if we are here, we know that *(match+best_len-1) == scan_end -; and (match == scan_start) - - mov edi,edx - mov esi,scan ; esi = scan - add edi,eax ; edi = window + cur_match = match - - mov edx,[esi+3] ; compare manually dword at match+3 - xor edx,[edi+3] ; and scan +3 - - jz begincompare ; if equal, go to long compare - -; we will determine the unmatch byte and calculate len (in esi) - or dl,dl - je eq1rr - mov esi,3 - jmp trfinval -eq1rr: - or dx,dx - je eq1 - - mov esi,4 - jmp trfinval -eq1: - and edx,0ffffffh - jz eq11 - mov esi,5 - jmp trfinval -eq11: - mov esi,6 - jmp trfinval - -begincompare: - ; here we now scan and match begin same - add edi,6 - add esi,6 - mov ecx,(MAX_MATCH-(2+4))/4 ; scan for at most MAX_MATCH bytes - repe cmpsd ; loop until mismatch - - je trfin ; go to trfin if not unmatch -; we determine the unmatch byte - sub esi,4 - mov edx,[edi-4] - xor edx,[esi] - - or dl,dl - jnz trfin - inc esi - - or dx,dx - jnz trfin - inc esi - - and edx,0ffffffh - jnz trfin - inc esi - -trfin: - sub esi,scan ; esi = len -trfinval: -; here we have finised compare, and esi contain len of equal string - cmp esi,best_len ; if len > best_len, go newbestlen - ja short newbestlen -; now we restore edx, ecx and esi, for the big loop - mov esi,prev - mov ecx,limit - mov edx,window - jmp contloop3 - -newbestlen: - mov best_len,esi ; len become best_len - - mov match_start,eax ; save new position as match_start - cmp esi,nice_match ; if best_len >= nice_match, exit - jae exitloop - mov ecx,scan - mov edx,window ; restore edx=window - add ecx,esi - add esi,edx - - dec esi - mov windowlen,esi ; windowlen = window + best_len-1 - mov bx,[ecx-1] ; bx = *(scan+best_len-1) = scan_end - -; now we restore ecx and esi, for the big loop : - mov esi,prev - mov ecx,limit - jmp contloop3 - -exitloop: -; exit : s->match_start=match_start - mov ebx,match_start - mov ebp,str_s - mov ecx,best_len - mov dword ptr [ebp+dep_match_start],ebx - mov eax,dword ptr [ebp+dep_lookahead] - cmp ecx,eax - ja minexlo - mov eax,ecx -minexlo: -; return min(best_len,s->lookahead) - -; restore stack and register ebx,esi,edi,ebp - add esp,NbStackAdd - - pop ebx - pop esi - pop edi - pop ebp - ret -InfoAuthor: -; please don't remove this string ! -; Your are free use gvmat32 in any fre or commercial apps if you don't remove the string in the binary! - db 0dh,0ah,"GVMat32 optimised assembly code written 1996-98 by Gilles Vollant",0dh,0ah - - - -IFDEF NOUNDERLINE -longest_match_7fff endp -ELSE -_longest_match_7fff endp -ENDIF - - -IFDEF NOUNDERLINE -cpudetect32 proc near -ELSE -_cpudetect32 proc near -ENDIF - - push ebx - - pushfd ; push original EFLAGS - pop eax ; get original EFLAGS - mov ecx, eax ; save original EFLAGS - xor eax, 40000h ; flip AC bit in EFLAGS - push eax ; save new EFLAGS value on stack - popfd ; replace current EFLAGS value - pushfd ; get new EFLAGS - pop eax ; store new EFLAGS in EAX - xor eax, ecx ; can’t toggle AC bit, processor=80386 - jz end_cpu_is_386 ; jump if 80386 processor - push ecx - popfd ; restore AC bit in EFLAGS first - - pushfd - pushfd - pop ecx - - mov eax, ecx ; get original EFLAGS - xor eax, 200000h ; flip ID bit in EFLAGS - push eax ; save new EFLAGS value on stack - popfd ; replace current EFLAGS value - pushfd ; get new EFLAGS - pop eax ; store new EFLAGS in EAX - popfd ; restore original EFLAGS - xor eax, ecx ; can’t toggle ID bit, - je is_old_486 ; processor=old - - mov eax,1 - db 0fh,0a2h ;CPUID - -exitcpudetect: - pop ebx - ret - -end_cpu_is_386: - mov eax,0300h - jmp exitcpudetect - -is_old_486: - mov eax,0400h - jmp exitcpudetect - -IFDEF NOUNDERLINE -cpudetect32 endp -ELSE -_cpudetect32 endp -ENDIF -ENDIF - -MAX_MATCH equ 258 -MIN_MATCH equ 3 -MIN_LOOKAHEAD equ (MAX_MATCH + MIN_MATCH + 1) -MAX_MATCH_8_ equ ((MAX_MATCH + 7) AND 0FFF0h) - - -;;; stack frame offsets - -chainlenwmask equ esp + 0 ; high word: current chain len - ; low word: s->wmask -window equ esp + 4 ; local copy of s->window -windowbestlen equ esp + 8 ; s->window + bestlen -scanstart equ esp + 16 ; first two bytes of string -scanend equ esp + 12 ; last two bytes of string -scanalign equ esp + 20 ; dword-misalignment of string -nicematch equ esp + 24 ; a good enough match size -bestlen equ esp + 28 ; size of best match so far -scan equ esp + 32 ; ptr to string wanting match - -LocalVarsSize equ 36 -; saved ebx byte esp + 36 -; saved edi byte esp + 40 -; saved esi byte esp + 44 -; saved ebp byte esp + 48 -; return address byte esp + 52 -deflatestate equ esp + 56 ; the function arguments -curmatch equ esp + 60 - -;;; Offsets for fields in the deflate_state structure. These numbers -;;; are calculated from the definition of deflate_state, with the -;;; assumption that the compiler will dword-align the fields. (Thus, -;;; changing the definition of deflate_state could easily cause this -;;; program to crash horribly, without so much as a warning at -;;; compile time. Sigh.) - -dsWSize equ 36+zlib1222add -dsWMask equ 44+zlib1222add -dsWindow equ 48+zlib1222add -dsPrev equ 56+zlib1222add -dsMatchLen equ 88+zlib1222add -dsPrevMatch equ 92+zlib1222add -dsStrStart equ 100+zlib1222add -dsMatchStart equ 104+zlib1222add -dsLookahead equ 108+zlib1222add -dsPrevLen equ 112+zlib1222add -dsMaxChainLen equ 116+zlib1222add -dsGoodMatch equ 132+zlib1222add -dsNiceMatch equ 136+zlib1222add - - -;;; match.asm -- Pentium-Pro-optimized version of longest_match() -;;; Written for zlib 1.1.2 -;;; Copyright (C) 1998 Brian Raiter <breadbox@muppetlabs.com> -;;; You can look at http://www.muppetlabs.com/~breadbox/software/assembly.html -;;; -;;; This is free software; you can redistribute it and/or modify it -;;; under the terms of the GNU General Public License. - -;GLOBAL _longest_match, _match_init - - -;SECTION .text - -;;; uInt longest_match(deflate_state *deflatestate, IPos curmatch) - -;_longest_match: -IFDEF NOOLDPENTIUMCODE - IFDEF NOUNDERLINE - longest_match proc near - ELSE - _longest_match proc near - ENDIF -ELSE - IFDEF NOUNDERLINE - longest_match_686 proc near - ELSE - _longest_match_686 proc near - ENDIF -ENDIF - -;;; Save registers that the compiler may be using, and adjust esp to -;;; make room for our stack frame. - - push ebp - push edi - push esi - push ebx - sub esp, LocalVarsSize - -;;; Retrieve the function arguments. ecx will hold cur_match -;;; throughout the entire function. edx will hold the pointer to the -;;; deflate_state structure during the function's setup (before -;;; entering the main loop. - - mov edx, [deflatestate] - mov ecx, [curmatch] - -;;; uInt wmask = s->w_mask; -;;; unsigned chain_length = s->max_chain_length; -;;; if (s->prev_length >= s->good_match) { -;;; chain_length >>= 2; -;;; } - - mov eax, [edx + dsPrevLen] - mov ebx, [edx + dsGoodMatch] - cmp eax, ebx - mov eax, [edx + dsWMask] - mov ebx, [edx + dsMaxChainLen] - jl LastMatchGood - shr ebx, 2 -LastMatchGood: - -;;; chainlen is decremented once beforehand so that the function can -;;; use the sign flag instead of the zero flag for the exit test. -;;; It is then shifted into the high word, to make room for the wmask -;;; value, which it will always accompany. - - dec ebx - shl ebx, 16 - or ebx, eax - mov [chainlenwmask], ebx - -;;; if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead; - - mov eax, [edx + dsNiceMatch] - mov ebx, [edx + dsLookahead] - cmp ebx, eax - jl LookaheadLess - mov ebx, eax -LookaheadLess: mov [nicematch], ebx - -;;; register Bytef *scan = s->window + s->strstart; - - mov esi, [edx + dsWindow] - mov [window], esi - mov ebp, [edx + dsStrStart] - lea edi, [esi + ebp] - mov [scan], edi - -;;; Determine how many bytes the scan ptr is off from being -;;; dword-aligned. - - mov eax, edi - neg eax - and eax, 3 - mov [scanalign], eax - -;;; IPos limit = s->strstart > (IPos)MAX_DIST(s) ? -;;; s->strstart - (IPos)MAX_DIST(s) : NIL; - - mov eax, [edx + dsWSize] - sub eax, MIN_LOOKAHEAD - sub ebp, eax - jg LimitPositive - xor ebp, ebp -LimitPositive: - -;;; int best_len = s->prev_length; - - mov eax, [edx + dsPrevLen] - mov [bestlen], eax - -;;; Store the sum of s->window + best_len in esi locally, and in esi. - - add esi, eax - mov [windowbestlen], esi - -;;; register ush scan_start = *(ushf*)scan; -;;; register ush scan_end = *(ushf*)(scan+best_len-1); -;;; Posf *prev = s->prev; - - movzx ebx, word ptr [edi] - mov [scanstart], ebx - movzx ebx, word ptr [edi + eax - 1] - mov [scanend], ebx - mov edi, [edx + dsPrev] - -;;; Jump into the main loop. - - mov edx, [chainlenwmask] - jmp short LoopEntry - -align 4 - -;;; do { -;;; match = s->window + cur_match; -;;; if (*(ushf*)(match+best_len-1) != scan_end || -;;; *(ushf*)match != scan_start) continue; -;;; [...] -;;; } while ((cur_match = prev[cur_match & wmask]) > limit -;;; && --chain_length != 0); -;;; -;;; Here is the inner loop of the function. The function will spend the -;;; majority of its time in this loop, and majority of that time will -;;; be spent in the first ten instructions. -;;; -;;; Within this loop: -;;; ebx = scanend -;;; ecx = curmatch -;;; edx = chainlenwmask - i.e., ((chainlen << 16) | wmask) -;;; esi = windowbestlen - i.e., (window + bestlen) -;;; edi = prev -;;; ebp = limit - -LookupLoop: - and ecx, edx - movzx ecx, word ptr [edi + ecx*2] - cmp ecx, ebp - jbe LeaveNow - sub edx, 00010000h - js LeaveNow -LoopEntry: movzx eax, word ptr [esi + ecx - 1] - cmp eax, ebx - jnz LookupLoop - mov eax, [window] - movzx eax, word ptr [eax + ecx] - cmp eax, [scanstart] - jnz LookupLoop - -;;; Store the current value of chainlen. - - mov [chainlenwmask], edx - -;;; Point edi to the string under scrutiny, and esi to the string we -;;; are hoping to match it up with. In actuality, esi and edi are -;;; both pointed (MAX_MATCH_8 - scanalign) bytes ahead, and edx is -;;; initialized to -(MAX_MATCH_8 - scanalign). - - mov esi, [window] - mov edi, [scan] - add esi, ecx - mov eax, [scanalign] - mov edx, 0fffffef8h; -(MAX_MATCH_8) - lea edi, [edi + eax + 0108h] ;MAX_MATCH_8] - lea esi, [esi + eax + 0108h] ;MAX_MATCH_8] - -;;; Test the strings for equality, 8 bytes at a time. At the end, -;;; adjust edx so that it is offset to the exact byte that mismatched. -;;; -;;; We already know at this point that the first three bytes of the -;;; strings match each other, and they can be safely passed over before -;;; starting the compare loop. So what this code does is skip over 0-3 -;;; bytes, as much as necessary in order to dword-align the edi -;;; pointer. (esi will still be misaligned three times out of four.) -;;; -;;; It should be confessed that this loop usually does not represent -;;; much of the total running time. Replacing it with a more -;;; straightforward "rep cmpsb" would not drastically degrade -;;; performance. - -LoopCmps: - mov eax, [esi + edx] - xor eax, [edi + edx] - jnz LeaveLoopCmps - mov eax, [esi + edx + 4] - xor eax, [edi + edx + 4] - jnz LeaveLoopCmps4 - add edx, 8 - jnz LoopCmps - jmp short LenMaximum -LeaveLoopCmps4: add edx, 4 -LeaveLoopCmps: test eax, 0000FFFFh - jnz LenLower - add edx, 2 - shr eax, 16 -LenLower: sub al, 1 - adc edx, 0 - -;;; Calculate the length of the match. If it is longer than MAX_MATCH, -;;; then automatically accept it as the best possible match and leave. - - lea eax, [edi + edx] - mov edi, [scan] - sub eax, edi - cmp eax, MAX_MATCH - jge LenMaximum - -;;; If the length of the match is not longer than the best match we -;;; have so far, then forget it and return to the lookup loop. - - mov edx, [deflatestate] - mov ebx, [bestlen] - cmp eax, ebx - jg LongerMatch - mov esi, [windowbestlen] - mov edi, [edx + dsPrev] - mov ebx, [scanend] - mov edx, [chainlenwmask] - jmp LookupLoop - -;;; s->match_start = cur_match; -;;; best_len = len; -;;; if (len >= nice_match) break; -;;; scan_end = *(ushf*)(scan+best_len-1); - -LongerMatch: mov ebx, [nicematch] - mov [bestlen], eax - mov [edx + dsMatchStart], ecx - cmp eax, ebx - jge LeaveNow - mov esi, [window] - add esi, eax - mov [windowbestlen], esi - movzx ebx, word ptr [edi + eax - 1] - mov edi, [edx + dsPrev] - mov [scanend], ebx - mov edx, [chainlenwmask] - jmp LookupLoop - -;;; Accept the current string, with the maximum possible length. - -LenMaximum: mov edx, [deflatestate] - mov dword ptr [bestlen], MAX_MATCH - mov [edx + dsMatchStart], ecx - -;;; if ((uInt)best_len <= s->lookahead) return (uInt)best_len; -;;; return s->lookahead; - -LeaveNow: - mov edx, [deflatestate] - mov ebx, [bestlen] - mov eax, [edx + dsLookahead] - cmp ebx, eax - jg LookaheadRet - mov eax, ebx -LookaheadRet: - -;;; Restore the stack and return from whence we came. - - add esp, LocalVarsSize - pop ebx - pop esi - pop edi - pop ebp - - ret -; please don't remove this string ! -; Your can freely use gvmat32 in any free or commercial app if you don't remove the string in the binary! - db 0dh,0ah,"asm686 with masm, optimised assembly code from Brian Raiter, written 1998",0dh,0ah - - -IFDEF NOOLDPENTIUMCODE - IFDEF NOUNDERLINE - longest_match endp - ELSE - _longest_match endp - ENDIF - - IFDEF NOUNDERLINE - match_init proc near - ret - match_init endp - ELSE - _match_init proc near - ret - _match_init endp - ENDIF -ELSE - IFDEF NOUNDERLINE - longest_match_686 endp - ELSE - _longest_match_686 endp - ENDIF -ENDIF - -_TEXT ends -end |