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; gvmat32.asm -- Asm portion of the optimized longest_match for 32 bits x86
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; Copyright (C) 1995-1996 Jean-loup Gailly and Gilles Vollant.
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; File written by Gilles Vollant, by modifiying the longest_match
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; from Jean-loup Gailly in deflate.c
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; It need wmask == 0x7fff
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; (assembly code is faster with a fixed wmask)
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; For Visual C++ 4.2 and ML 6.11c (version in directory \MASM611C of Win95 DDK)
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; I compile with : "ml /coff /Zi /c gvmat32.asm"
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;uInt longest_match_7fff(s, cur_match)
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; IPos cur_match; /* current match */
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cur_match equ dword ptr[esp+NbStack-0]
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str_s equ dword ptr[esp+NbStack-4]
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; 5 dword on top (ret,ebp,esi,edi,ebx)
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adrret equ dword ptr[esp+NbStack-8]
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pushebp equ dword ptr[esp+NbStack-12]
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pushedi equ dword ptr[esp+NbStack-16]
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pushesi equ dword ptr[esp+NbStack-20]
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pushebx equ dword ptr[esp+NbStack-24]
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chain_length equ dword ptr [esp+NbStack-28]
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limit equ dword ptr [esp+NbStack-32]
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best_len equ dword ptr [esp+NbStack-36]
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window equ dword ptr [esp+NbStack-40]
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prev equ dword ptr [esp+NbStack-44]
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scan_start equ word ptr [esp+NbStack-48]
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wmask equ dword ptr [esp+NbStack-52]
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match_start_ptr equ dword ptr [esp+NbStack-56]
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nice_match equ dword ptr [esp+NbStack-60]
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scan equ dword ptr [esp+NbStack-64]
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windowlen equ dword ptr [esp+NbStack-68]
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match_start equ dword ptr [esp+NbStack-72]
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strend equ dword ptr [esp+NbStack-76]
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NbStackAdd equ (NbStack-24)
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; all the +4 offsets are due to the addition of pending_buf_size (in zlib
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; in the deflate_state structure since the asm code was first written
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; (if you compile with zlib 1.0.4 or older, remove the +4).
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; Note : these value are good with a 8 bytes boundary pack structure
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dep_chain_length equ 70h+4
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dep_strstart equ 60h+4
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dep_prev_length equ 6ch+4
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dep_nice_match equ 84h+4
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dep_good_match equ 80h+4
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dep_match_start equ 64h+4
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dep_lookahead equ 68h+4
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public longest_match_7fff
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public _longest_match_7fff
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MIN_LOOKAHEAD equ (MAX_MATCH+MIN_MATCH+1)
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;_match_init proc near
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longest_match_7fff proc near
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_longest_match_7fff proc near
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; initialize or check the variables used in match.asm.
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; chain_length = s->max_chain_length
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; if (prev_length>=good_match) chain_length >>= 2
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mov edx,[ebp+dep_chain_length]
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mov ebx,[ebp+dep_prev_length]
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cmp [ebp+dep_good_match],ebx
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; we increment chain_length because in the asm, the --chain_lenght is in the beginning of the loop
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mov edi,[ebp+dep_nice_match]
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mov eax,[ebp+dep_lookahead]
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; if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
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jae nolookaheadnicematch
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nolookaheadnicematch:
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; best_len = s->prev_length
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mov esi,[ebp+dep_window]
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mov ecx,[ebp+dep_strstart]
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; scan = window + strstart
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mov dx,word ptr [esi]
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; bx = *(window+best_len-1)
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mov bx,word ptr [esi+ebx-1]
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; strend = scan + MAX_MATCH-1
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; bx = scan_end = *(window+best_len-1)
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; IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
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; s->strstart - (IPos)MAX_DIST(s) : NIL;
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mov esi,[ebp+dep_w_size]
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sub esi,MIN_LOOKAHEAD
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; here esi = MAX_DIST(s)
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mov edx,[ebp+dep_prev]
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mov edx,dword ptr [ebp+dep_match_start]
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; windowlen = window + best_len -1
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; eax = ax = cur_match
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; edi = windowlen (window + best_len -1)
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;// here; chain_length <=16
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cmp word ptr[edi+eax],bx
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; cur_match = prev[cur_match & wmask]
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mov ax,word ptr[esi+eax*2]
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; if cur_match > limit, go to exitloop
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; if --chain_length != 0, go to exitloop
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; if (scan_start==*(cur_match+window)) goto normalbeg2
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cmp bp,word ptr[edx+eax]
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; cur_match = prev[cur_match & wmask]
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mov ax,word ptr[esi+eax*2]
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; if cur_match > limit, go to exitloop
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; if --chain_length != 0, go to exitloop
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; begin the main loop
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sub chain_length,16+1
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; if chain_length <=16, don't use the unrolled loop
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cmp word ptr[edi+eax],bx
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mov ax,word ptr[esi+eax*2]
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cmp word ptr[edi+eax],bx
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maccn short normalbeg2dc11
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maccn short normalbeg2dc12
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maccn short normalbeg2dc13
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maccn short normalbeg2dc14
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maccn short normalbeg2dc15
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mov ax,word ptr[esi+eax*2]
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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normbeg MACRO rcontlab,valsub
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; if we are here, we know that *(match+best_len-1) == scan_end
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cmp bp,word ptr[edx+eax]
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; if (match != scan_start) goto rcontlab
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; calculate the good chain_length, and we'll compare scan and match string
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add chain_length,16-valsub
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normbeg rcontloop11,11
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normbeg short rcontloop12,12
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normbeg short rcontloop13,13
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normbeg short rcontloop14,14
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normbeg short rcontloop15,15
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normbeg rcontloop10,10
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; we go in normalbeg2 because *(ushf*)(match+best_len-1) == scan_end
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cmp bp,word ptr[edi+eax]
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jne contloop3 ; if *(ushf*)match != scan_start, continue
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; if we are here, we know that *(match+best_len-1) == scan_end
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; and (match == scan_start)
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mov esi,scan ; esi = scan
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add edi,eax ; edi = window + cur_match = match
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mov edx,[esi+3] ; compare manually dword at match+3
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xor edx,[edi+3] ; and scan +3
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jz begincompare ; if equal, go to long compare
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; we will determine the unmatch byte and calculate len (in esi)
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; here we now scan and match begin same
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mov ecx,(MAX_MATCH-(2+4))/4 ; scan for at most MAX_MATCH bytes
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repe cmpsd ; loop until mismatch
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je trfin ; go to trfin if not unmatch
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; we determine the unmatch byte
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sub esi,scan ; esi = len
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; here we have finised compare, and esi contain len of equal string
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cmp esi,best_len ; if len > best_len, go newbestlen
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; now we restore edx, ecx and esi, for the big loop
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mov best_len,esi ; len become best_len
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mov match_start,eax ; save new position as match_start
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cmp esi,nice_match ; if best_len >= nice_match, exit
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mov edx,window ; restore edx=window
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mov windowlen,esi ; windowlen = window + best_len-1
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mov bx,[ecx-1] ; bx = *(scan+best_len-1) = scan_end
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; now we restore ecx and esi, for the big loop :
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; exit : s->match_start=match_start
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mov dword ptr [ebp+dep_match_start],ebx
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mov eax,dword ptr [ebp+dep_lookahead]
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; return min(best_len,s->lookahead)
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; restore stack and register ebx,esi,edi,ebp
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; please don't remove this string !
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; Your are free use gvmat32 in any fre or commercial apps if you don't remove the string in the binary!
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db 0dh,0ah,"GVMat32 optimised assembly code written 1996-98 by Gilles Vollant",0dh,0ah
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longest_match_7fff endp
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_longest_match_7fff endp
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cpudetect32 proc near
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_cpudetect32 proc near
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pushfd ; push original EFLAGS
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pop eax ; get original EFLAGS
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mov ecx, eax ; save original EFLAGS
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xor eax, 40000h ; flip AC bit in EFLAGS
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push eax ; save new EFLAGS value on stack
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popfd ; replace current EFLAGS value
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pushfd ; get new EFLAGS
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pop eax ; store new EFLAGS in EAX
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xor eax, ecx ; can�t toggle AC bit, processor=80386
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jz end_cpu_is_386 ; jump if 80386 processor
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popfd ; restore AC bit in EFLAGS first
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mov eax, ecx ; get original EFLAGS
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xor eax, 200000h ; flip ID bit in EFLAGS
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push eax ; save new EFLAGS value on stack
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popfd ; replace current EFLAGS value
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pushfd ; get new EFLAGS
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pop eax ; store new EFLAGS in EAX
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popfd ; restore original EFLAGS
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xor eax, ecx ; can�t toggle ID bit,
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je is_old_486 ; processor=old
added
removed
gdchart0.94c/zlib-1.1.3/contrib/asm386/gvmat32.asm
