;; 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; It need wmask == 0x7fff;     (assembly code is faster with a fixed wmask);; For Visual C++ 4.2 and ML 6.11c (version in directory \MASM611C of Win95 DDK);   I compile with : "ml /coff /Zi /c gvmat32.asm";;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 +4 offsets are due to the addition of pending_buf_size (in zlib;  in the deflate_state structure since the asm code was first written;  (if you compile with zlib 1.0.4 or older, remove the +4).;  Note : these value are good with a 8 bytes boundary pack structure    dep_chain_length    equ     70h+4    dep_window          equ     2ch+4    dep_strstart        equ     60h+4    dep_prev_length     equ     6ch+4    dep_nice_match      equ     84h+4    dep_w_size          equ     20h+4    dep_prev            equ     34h+4    dep_w_mask          equ     28h+4    dep_good_match      equ     80h+4    dep_match_start     equ     64h+4    dep_lookahead       equ     68h+4_TEXT                   segmentIFDEF NOUNDERLINE			public  longest_match_7fff			public  longest_match_686;                        public  match_initELSE			public  _longest_match_7fff			public  _longest_match_686;                        public  _match_initENDIF    MAX_MATCH           equ     258    MIN_MATCH           equ     3    MIN_LOOKAHEAD       equ     (MAX_MATCH+MIN_MATCH+1)IFDEF NOUNDERLINE;match_init      proc near;                ret;match_init      endpELSE;_match_init     proc near;                ret;_match_init     endpENDIFIFDEF NOUNDERLINElongest_match_7fff   proc nearELSE_longest_match_7fff  proc nearENDIF	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,2noshr:; 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,eaxnolookaheadnicematch:; 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,ecxnodist:	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 <=16normalbeg0add16:	add     chain_length,16	jz      exitloopnormalbeg0:	cmp     word ptr[edi+eax],bx	je      normalbeg2norollrcontlabnoroll:; 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     exitloopnormalbeg2noroll:; if (scan_start==*(cur_match+window)) goto normalbeg2	cmp     bp,word ptr[edx+eax]	jne     rcontlabnoroll	jmp     normalbeg2contloop3:	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,eaxjnbexitloopshort1:	jnb     exitloop; if --chain_length != 0, go to exitloop; begin the main loopbeginloop2:	sub     chain_length,16+1; if chain_length <=16, don't use the unrolled loop	jna     normalbeg0add16do16:	cmp     word ptr[edi+eax],bx	je      normalbeg2dc0maccn   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	ENDMrcontloop0:	maccn   normalbeg2dc1rcontloop1:	maccn   normalbeg2dc2rcontloop2:	maccn   normalbeg2dc3rcontloop3:	maccn   normalbeg2dc4rcontloop4:	maccn   normalbeg2dc5rcontloop5:	maccn   normalbeg2dc6rcontloop6:	maccn   normalbeg2dc7rcontloop7:	maccn   normalbeg2dc8rcontloop8:	maccn   normalbeg2dc9rcontloop9:	maccn   normalbeg2dc10rcontloop10:	maccn   short normalbeg2dc11rcontloop11:	maccn   short normalbeg2dc12rcontloop12:	maccn   short normalbeg2dc13rcontloop13:	maccn   short normalbeg2dc14rcontloop14:	maccn   short normalbeg2dc15rcontloop15:	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	ENDMnormalbeg2dc11:	normbeg rcontloop11,11normalbeg2dc12:	normbeg short rcontloop12,12normalbeg2dc13:	normbeg short rcontloop13,13normalbeg2dc14:	normbeg short rcontloop14,14normalbeg2dc15:	normbeg short rcontloop15,15normalbeg2dc10:	normbeg rcontloop10,10normalbeg2dc9:	normbeg rcontloop9,9normalbeg2dc8:	normbeg rcontloop8,8normalbeg2dc7:	normbeg rcontloop7,7normalbeg2dc6:	normbeg rcontloop6,6normalbeg2dc5:	normbeg rcontloop5,5normalbeg2dc4:	normbeg rcontloop4,4normalbeg2dc3:	normbeg rcontloop3,3normalbeg2dc2:	normbeg rcontloop2,2normalbeg2dc1:	normbeg rcontloop1,1normalbeg2dc0:	normbeg rcontloop0,0; we go in normalbeg2 because *(ushf*)(match+best_len-1) == scan_endnormalbeg2:	mov     edi,window	cmp     bp,word ptr[edi+eax]	jne     contloop3                   ; if *(ushf*)match != scan_start, continueiseq:; 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     trfinvaleq1rr:	or      dx,dx	je      eq1	mov     esi,4	jmp     trfinvaleq1:	and     edx,0ffffffh	jz      eq11	mov     esi,5	jmp     trfinvaleq11:	mov     esi,6	jmp     trfinvalbegincompare:	; 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     esitrfin:	sub     esi,scan          ; esi = lentrfinval:; 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     contloop3newbestlen:	mov     best_len,esi        ; len become best_len