diff options
Diffstat (limited to 'third_party/zlib/contrib/masmx86/match686.asm')
-rw-r--r-- | third_party/zlib/contrib/masmx86/match686.asm | 958 |
1 files changed, 479 insertions, 479 deletions
diff --git a/third_party/zlib/contrib/masmx86/match686.asm b/third_party/zlib/contrib/masmx86/match686.asm index 3b09212f8a..69e0eed01d 100644 --- a/third_party/zlib/contrib/masmx86/match686.asm +++ b/third_party/zlib/contrib/masmx86/match686.asm @@ -1,479 +1,479 @@ -; match686.asm -- Asm portion of the optimized longest_match for 32 bits x86
-; Copyright (C) 1995-1996 Jean-loup Gailly, Brian Raiter and Gilles Vollant.
-; File written by Gilles Vollant, by converting match686.S from Brian Raiter
-; for MASM. This is as assembly version of 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 distributed in
-; http://www.microsoft.com/downloads/details.aspx?FamilyID=7a1c9da0-0510-44a2-b042-7ef370530c64
-;
-; this file contain two implementation of longest_match
-;
-; this longest_match was written by Brian raiter (1998), optimized for Pentium Pro
-; (and the faster known version of match_init on modern Core 2 Duo and AMD Phenom)
-;
-; for using an assembly version of longest_match, you need define ASMV in project
-;
-; compile the asm file running
-; ml /coff /Zi /c /Flmatch686.lst match686.asm
-; and do not include match686.obj in your project
-;
-; note: contrib of zLib 1.2.3 and earlier contained both a deprecated version for
-; Pentium (prior Pentium Pro) and this version for Pentium Pro and modern processor
-; with autoselect (with cpu detection code)
-; if you want support the old pentium optimization, you can still use these version
-;
-; this file is not optimized for old pentium, but it compatible with all x86 32 bits
-; processor (starting 80386)
-;
-;
-; see below : zlib1222add must be adjuster if you use a zlib version < 1.2.2.2
-
-;uInt longest_match(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
- public longest_match
- public match_init
-ELSE
- public _longest_match
- public _match_init
-ENDIF
-
- MAX_MATCH equ 258
- MIN_MATCH equ 3
- MIN_LOOKAHEAD equ (MAX_MATCH+MIN_MATCH+1)
-
-
-
-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
-
-
-;;; match686.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 software is provided 'as-is', without any express or implied
-;; warranty. In no event will the authors be held liable for any damages
-;; arising from the use of this software.
-;;
-;; Permission is granted to anyone to use this software for any purpose,
-;; including commercial applications, and to alter it and redistribute it
-;; freely, subject to the following restrictions:
-;;
-;; 1. The origin of this software must not be misrepresented; you must not
-;; claim that you wrote the original software. If you use this software
-;; in a product, an acknowledgment in the product documentation would be
-;; appreciated but is not required.
-;; 2. Altered source versions must be plainly marked as such, and must not be
-;; misrepresented as being the original software
-;; 3. This notice may not be removed or altered from any source distribution.
-;;
-
-;GLOBAL _longest_match, _match_init
-
-
-;SECTION .text
-
-;;; uInt longest_match(deflate_state *deflatestate, IPos curmatch)
-
-;_longest_match:
- IFDEF NOUNDERLINE
- longest_match proc near
- ELSE
- _longest_match proc near
- ENDIF
-.FPO (9, 4, 0, 0, 1, 0)
-
-;;; 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 match686 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 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
-
-
-_TEXT ends
-end
+; match686.asm -- Asm portion of the optimized longest_match for 32 bits x86 +; Copyright (C) 1995-1996 Jean-loup Gailly, Brian Raiter and Gilles Vollant. +; File written by Gilles Vollant, by converting match686.S from Brian Raiter +; for MASM. This is as assembly version of 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 distributed in +; http://www.microsoft.com/downloads/details.aspx?FamilyID=7a1c9da0-0510-44a2-b042-7ef370530c64 +; +; this file contain two implementation of longest_match +; +; this longest_match was written by Brian raiter (1998), optimized for Pentium Pro +; (and the faster known version of match_init on modern Core 2 Duo and AMD Phenom) +; +; for using an assembly version of longest_match, you need define ASMV in project +; +; compile the asm file running +; ml /coff /Zi /c /Flmatch686.lst match686.asm +; and do not include match686.obj in your project +; +; note: contrib of zLib 1.2.3 and earlier contained both a deprecated version for +; Pentium (prior Pentium Pro) and this version for Pentium Pro and modern processor +; with autoselect (with cpu detection code) +; if you want support the old pentium optimization, you can still use these version +; +; this file is not optimized for old pentium, but it compatible with all x86 32 bits +; processor (starting 80386) +; +; +; see below : zlib1222add must be adjuster if you use a zlib version < 1.2.2.2 + +;uInt longest_match(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 + public longest_match + public match_init +ELSE + public _longest_match + public _match_init +ENDIF + + MAX_MATCH equ 258 + MIN_MATCH equ 3 + MIN_LOOKAHEAD equ (MAX_MATCH+MIN_MATCH+1) + + + +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 + + +;;; match686.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 software is provided 'as-is', without any express or implied +;; warranty. In no event will the authors be held liable for any damages +;; arising from the use of this software. +;; +;; Permission is granted to anyone to use this software for any purpose, +;; including commercial applications, and to alter it and redistribute it +;; freely, subject to the following restrictions: +;; +;; 1. The origin of this software must not be misrepresented; you must not +;; claim that you wrote the original software. If you use this software +;; in a product, an acknowledgment in the product documentation would be +;; appreciated but is not required. +;; 2. Altered source versions must be plainly marked as such, and must not be +;; misrepresented as being the original software +;; 3. This notice may not be removed or altered from any source distribution. +;; + +;GLOBAL _longest_match, _match_init + + +;SECTION .text + +;;; uInt longest_match(deflate_state *deflatestate, IPos curmatch) + +;_longest_match: + IFDEF NOUNDERLINE + longest_match proc near + ELSE + _longest_match proc near + ENDIF +.FPO (9, 4, 0, 0, 1, 0) + +;;; 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 match686 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 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 + + +_TEXT ends +end |