zlib 1.2.2.3v1.2.2.3

1 files changed, 972 insertions, 909 deletions

diff --git a/contrib/masmx86/gvmat32.asm b/contrib/masmx86/gvmat32.asm
index e841a7f..874bb2d 100644
--- a/contrib/masmx86/gvmat32.asm
+++ b/contrib/masmx86/gvmat32.asm
@@ -1,909 +1,972 @@
-;
-; 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 +addstr offsets are due to the addition of pending_buf_size in zlib 1.04
-;  and adding gzhead and gzindex in zlib 1.2.2.1
-;  in the deflate_state structure since the asm code was first written
-;  (if you compile with zlib 1.0.4 or older, set addstr to 0).
-;  (if you compiler with zlib between 1.04 and 1.2.1, set addstr to 4)
-;  Note : these value are good with a 8 bytes boundary pack structure
-
-    addstr              equ     4+8
-    dep_chain_length    equ     70h+addstr
-    dep_window          equ     2ch+addstr
-    dep_strstart        equ     60h+addstr
-    dep_prev_length     equ     6ch+addstr
-    dep_nice_match      equ     84h+addstr
-    dep_w_size          equ     20h+addstr
-    dep_prev            equ     34h+addstr
-    dep_w_mask          equ     28h+addstr
-    dep_good_match      equ     80h+addstr
-    dep_match_start     equ     64h+addstr
-    dep_lookahead       equ     68h+addstr
-
-
-_TEXT                   segment
-
-IFDEF NOUNDERLINE
-                        public  longest_match_7fff
-                        public  longest_match_686
-;                        public  match_init
-ELSE
-                        public  _longest_match_7fff
-                        public  _longest_match_686
-;                        public  _match_init
-ENDIF
-
-    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      endp
-ELSE
-;_match_init     proc near
-;                ret
-;_match_init     endp
-ENDIF
-
-
-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
-
-
-
-
-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+addstr-4
-dsWMask         equ 44+addstr-4
-dsWindow        equ 48+addstr-4
-dsPrev          equ 56+addstr-4
-dsMatchLen      equ 88+addstr-4
-dsPrevMatch     equ 92+addstr-4
-dsStrStart      equ 100+addstr-4
-dsMatchStart    equ 104+addstr-4
-dsLookahead     equ 108+addstr-4
-dsPrevLen       equ 112+addstr-4
-dsMaxChainLen   equ 116+addstr-4
-dsGoodMatch     equ 132+addstr-4
-dsNiceMatch     equ 136+addstr-4
-
-
-;;; 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 NOUNDERLINE
-longest_match_686   proc near
-ELSE
-_longest_match_686  proc near
-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 NOUNDERLINE
-longest_match_686   endp
-ELSE
-_longest_match_686  endp
-ENDIF
-
-_TEXT   ends
-end
+; 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