diff options
Diffstat (limited to 'cpukit/zlib/contrib/masmx86/gvmat32.asm')
| -rw-r--r-- | cpukit/zlib/contrib/masmx86/gvmat32.asm | 972 |
1 files changed, 0 insertions, 972 deletions
diff --git a/cpukit/zlib/contrib/masmx86/gvmat32.asm b/cpukit/zlib/contrib/masmx86/gvmat32.asm deleted file mode 100644 index 874bb2d482..0000000000 --- a/cpukit/zlib/contrib/masmx86/gvmat32.asm +++ /dev/null @@ -1,972 +0,0 @@ -; gvmat32.asm -- Asm portion of the optimized longest_match for 32 bits x86
-; Copyright (C) 1995-1996 Jean-loup Gailly and Gilles Vollant.
-; File written by Gilles Vollant, by modifiying the longest_match
-; from Jean-loup Gailly in deflate.c
-;
-; http://www.zlib.net
-; http://www.winimage.com/zLibDll
-; http://www.muppetlabs.com/~breadbox/software/assembly.html
-;
-; For Visual C++ 4.x and higher and ML 6.x and higher
-; ml.exe is in directory \MASM611C of Win95 DDK
-; ml.exe is also distributed in http://www.masm32.com/masmdl.htm
-; and in VC++2003 toolkit at http://msdn.microsoft.com/visualc/vctoolkit2003/
-;
-; this file contain two implementation of longest_match
-;
-; longest_match_7fff : written 1996 by Gilles Vollant optimized for
-; first Pentium. Assume s->w_mask == 0x7fff
-; longest_match_686 : written by Brian raiter (1998), optimized for Pentium Pro
-;
-; for using an seembly version of longest_match, you need define ASMV in project
-; There is two way in using gvmat32.asm
-;
-; A) Suggested method
-; if you want include both longest_match_7fff and longest_match_686
-; compile the asm file running
-; ml /coff /Zi /Flgvmat32.lst /c gvmat32.asm
-; and include gvmat32c.c in your project
-; if you have an old cpu (386,486 or first Pentium) and s->w_mask==0x7fff,
-; longest_match_7fff will be used
-; if you have a more modern CPU (Pentium Pro, II and higher)
-; longest_match_686 will be used
-; on old cpu with s->w_mask!=0x7fff, longest_match_686 will be used,
-; but this is not a sitation you'll find often
-;
-; B) Alternative
-; if you are not interresed in old cpu performance and want the smaller
-; binaries possible
-;
-; compile the asm file running
-; ml /coff /Zi /c /Flgvmat32.lst /DNOOLDPENTIUMCODE gvmat32.asm
-; and do not include gvmat32c.c in your project (ou define also
-; NOOLDPENTIUMCODE)
-;
-; note : as I known, longest_match_686 is very faster than longest_match_7fff
-; on pentium Pro/II/III, faster (but less) in P4, but it seem
-; longest_match_7fff can be faster (very very litte) on AMD Athlon64/K8
-;
-; see below : zlib1222add must be adjuster if you use a zlib version < 1.2.2.2
-
-;uInt longest_match_7fff(s, cur_match)
-; deflate_state *s;
-; IPos cur_match; /* current match */
-
- NbStack equ 76
- cur_match equ dword ptr[esp+NbStack-0]
- str_s equ dword ptr[esp+NbStack-4]
-; 5 dword on top (ret,ebp,esi,edi,ebx)
- adrret equ dword ptr[esp+NbStack-8]
- pushebp equ dword ptr[esp+NbStack-12]
- pushedi equ dword ptr[esp+NbStack-16]
- pushesi equ dword ptr[esp+NbStack-20]
- pushebx equ dword ptr[esp+NbStack-24]
-
- chain_length equ dword ptr [esp+NbStack-28]
- limit equ dword ptr [esp+NbStack-32]
- best_len equ dword ptr [esp+NbStack-36]
- window equ dword ptr [esp+NbStack-40]
- prev equ dword ptr [esp+NbStack-44]
- scan_start equ word ptr [esp+NbStack-48]
- wmask equ dword ptr [esp+NbStack-52]
- match_start_ptr equ dword ptr [esp+NbStack-56]
- nice_match equ dword ptr [esp+NbStack-60]
- scan equ dword ptr [esp+NbStack-64]
-
- windowlen equ dword ptr [esp+NbStack-68]
- match_start equ dword ptr [esp+NbStack-72]
- strend equ dword ptr [esp+NbStack-76]
- NbStackAdd equ (NbStack-24)
-
- .386p
-
- name gvmatch
- .MODEL FLAT
-
-
-
-; all the +zlib1222add offsets are due to the addition of fields
-; in zlib in the deflate_state structure since the asm code was first written
-; (if you compile with zlib 1.0.4 or older, use "zlib1222add equ (-4)").
-; (if you compile with zlib between 1.0.5 and 1.2.2.1, use "zlib1222add equ 0").
-; if you compile with zlib 1.2.2.2 or later , use "zlib1222add equ 8").
-
- zlib1222add equ 8
-
-; Note : these value are good with a 8 bytes boundary pack structure
- dep_chain_length equ 74h+zlib1222add
- dep_window equ 30h+zlib1222add
- dep_strstart equ 64h+zlib1222add
- dep_prev_length equ 70h+zlib1222add
- dep_nice_match equ 88h+zlib1222add
- dep_w_size equ 24h+zlib1222add
- dep_prev equ 38h+zlib1222add
- dep_w_mask equ 2ch+zlib1222add
- dep_good_match equ 84h+zlib1222add
- dep_match_start equ 68h+zlib1222add
- dep_lookahead equ 6ch+zlib1222add
-
-
-_TEXT segment
-
-IFDEF NOUNDERLINE
- IFDEF NOOLDPENTIUMCODE
- public longest_match
- public match_init
- ELSE
- public longest_match_7fff
- public cpudetect32
- public longest_match_686
- ENDIF
-ELSE
- IFDEF NOOLDPENTIUMCODE
- public _longest_match
- public _match_init
- ELSE
- public _longest_match_7fff
- public _cpudetect32
- public _longest_match_686
- ENDIF
-ENDIF
-
- MAX_MATCH equ 258
- MIN_MATCH equ 3
- MIN_LOOKAHEAD equ (MAX_MATCH+MIN_MATCH+1)
-
-
-
-IFNDEF NOOLDPENTIUMCODE
-IFDEF NOUNDERLINE
-longest_match_7fff proc near
-ELSE
-_longest_match_7fff proc near
-ENDIF
-
- mov edx,[esp+4]
-
-
-
- push ebp
- push edi
- push esi
- push ebx
-
- sub esp,NbStackAdd
-
-; initialize or check the variables used in match.asm.
- mov ebp,edx
-
-; chain_length = s->max_chain_length
-; if (prev_length>=good_match) chain_length >>= 2
- mov edx,[ebp+dep_chain_length]
- mov ebx,[ebp+dep_prev_length]
- cmp [ebp+dep_good_match],ebx
- ja noshr
- shr edx,2
-noshr:
-; we increment chain_length because in the asm, the --chain_lenght is in the beginning of the loop
- inc edx
- mov edi,[ebp+dep_nice_match]
- mov chain_length,edx
- mov eax,[ebp+dep_lookahead]
- cmp eax,edi
-; if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
- jae nolookaheadnicematch
- mov edi,eax
-nolookaheadnicematch:
-; best_len = s->prev_length
- mov best_len,ebx
-
-; window = s->window
- mov esi,[ebp+dep_window]
- mov ecx,[ebp+dep_strstart]
- mov window,esi
-
- mov nice_match,edi
-; scan = window + strstart
- add esi,ecx
- mov scan,esi
-; dx = *window
- mov dx,word ptr [esi]
-; bx = *(window+best_len-1)
- mov bx,word ptr [esi+ebx-1]
- add esi,MAX_MATCH-1
-; scan_start = *scan
- mov scan_start,dx
-; strend = scan + MAX_MATCH-1
- mov strend,esi
-; bx = scan_end = *(window+best_len-1)
-
-; IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
-; s->strstart - (IPos)MAX_DIST(s) : NIL;
-
- mov esi,[ebp+dep_w_size]
- sub esi,MIN_LOOKAHEAD
-; here esi = MAX_DIST(s)
- sub ecx,esi
- ja nodist
- xor ecx,ecx
-nodist:
- mov limit,ecx
-
-; prev = s->prev
- mov edx,[ebp+dep_prev]
- mov prev,edx
-
-;
- mov edx,dword ptr [ebp+dep_match_start]
- mov bp,scan_start
- mov eax,cur_match
- mov match_start,edx
-
- mov edx,window
- mov edi,edx
- add edi,best_len
- mov esi,prev
- dec edi
-; windowlen = window + best_len -1
- mov windowlen,edi
-
- jmp beginloop2
- align 4
-
-; here, in the loop
-; eax = ax = cur_match
-; ecx = limit
-; bx = scan_end
-; bp = scan_start
-; edi = windowlen (window + best_len -1)
-; esi = prev
-
-
-;// here; chain_length <=16
-normalbeg0add16:
- add chain_length,16
- jz exitloop
-normalbeg0:
- cmp word ptr[edi+eax],bx
- je normalbeg2noroll
-rcontlabnoroll:
-; cur_match = prev[cur_match & wmask]
- and eax,7fffh
- mov ax,word ptr[esi+eax*2]
-; if cur_match > limit, go to exitloop
- cmp ecx,eax
- jnb exitloop
-; if --chain_length != 0, go to exitloop
- dec chain_length
- jnz normalbeg0
- jmp exitloop
-
-normalbeg2noroll:
-; if (scan_start==*(cur_match+window)) goto normalbeg2
- cmp bp,word ptr[edx+eax]
- jne rcontlabnoroll
- jmp normalbeg2
-
-contloop3:
- mov edi,windowlen
-
-; cur_match = prev[cur_match & wmask]
- and eax,7fffh
- mov ax,word ptr[esi+eax*2]
-; if cur_match > limit, go to exitloop
- cmp ecx,eax
-jnbexitloopshort1:
- jnb exitloop
-; if --chain_length != 0, go to exitloop
-
-
-; begin the main loop
-beginloop2:
- sub chain_length,16+1
-; if chain_length <=16, don't use the unrolled loop
- jna normalbeg0add16
-
-do16:
- cmp word ptr[edi+eax],bx
- je normalbeg2dc0
-
-maccn MACRO lab
- and eax,7fffh
- mov ax,word ptr[esi+eax*2]
- cmp ecx,eax
- jnb exitloop
- cmp word ptr[edi+eax],bx
- je lab
- ENDM
-
-rcontloop0:
- maccn normalbeg2dc1
-
-rcontloop1:
- maccn normalbeg2dc2
-
-rcontloop2:
- maccn normalbeg2dc3
-
-rcontloop3:
- maccn normalbeg2dc4
-
-rcontloop4:
- maccn normalbeg2dc5
-
-rcontloop5:
- maccn normalbeg2dc6
-
-rcontloop6:
- maccn normalbeg2dc7
-
-rcontloop7:
- maccn normalbeg2dc8
-
-rcontloop8:
- maccn normalbeg2dc9
-
-rcontloop9:
- maccn normalbeg2dc10
-
-rcontloop10:
- maccn short normalbeg2dc11
-
-rcontloop11:
- maccn short normalbeg2dc12
-
-rcontloop12:
- maccn short normalbeg2dc13
-
-rcontloop13:
- maccn short normalbeg2dc14
-
-rcontloop14:
- maccn short normalbeg2dc15
-
-rcontloop15:
- and eax,7fffh
- mov ax,word ptr[esi+eax*2]
- cmp ecx,eax
- jnb exitloop
-
- sub chain_length,16
- ja do16
- jmp normalbeg0add16
-
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-
-normbeg MACRO rcontlab,valsub
-; if we are here, we know that *(match+best_len-1) == scan_end
- cmp bp,word ptr[edx+eax]
-; if (match != scan_start) goto rcontlab
- jne rcontlab
-; calculate the good chain_length, and we'll compare scan and match string
- add chain_length,16-valsub
- jmp iseq
- ENDM
-
-
-normalbeg2dc11:
- normbeg rcontloop11,11
-
-normalbeg2dc12:
- normbeg short rcontloop12,12
-
-normalbeg2dc13:
- normbeg short rcontloop13,13
-
-normalbeg2dc14:
- normbeg short rcontloop14,14
-
-normalbeg2dc15:
- normbeg short rcontloop15,15
-
-normalbeg2dc10:
- normbeg rcontloop10,10
-
-normalbeg2dc9:
- normbeg rcontloop9,9
-
-normalbeg2dc8:
- normbeg rcontloop8,8
-
-normalbeg2dc7:
- normbeg rcontloop7,7
-
-normalbeg2dc6:
- normbeg rcontloop6,6
-
-normalbeg2dc5:
- normbeg rcontloop5,5
-
-normalbeg2dc4:
- normbeg rcontloop4,4
-
-normalbeg2dc3:
- normbeg rcontloop3,3
-
-normalbeg2dc2:
- normbeg rcontloop2,2
-
-normalbeg2dc1:
- normbeg rcontloop1,1
-
-normalbeg2dc0:
- normbeg rcontloop0,0
-
-
-; we go in normalbeg2 because *(ushf*)(match+best_len-1) == scan_end
-
-normalbeg2:
- mov edi,window
-
- cmp bp,word ptr[edi+eax]
- jne contloop3 ; if *(ushf*)match != scan_start, continue
-
-iseq:
-; if we are here, we know that *(match+best_len-1) == scan_end
-; and (match == scan_start)
-
- mov edi,edx
- mov esi,scan ; esi = scan
- add edi,eax ; edi = window + cur_match = match
-
- mov edx,[esi+3] ; compare manually dword at match+3
- xor edx,[edi+3] ; and scan +3
-
- jz begincompare ; if equal, go to long compare
-
-; we will determine the unmatch byte and calculate len (in esi)
- or dl,dl
- je eq1rr
- mov esi,3
- jmp trfinval
-eq1rr:
- or dx,dx
- je eq1
-
- mov esi,4
- jmp trfinval
-eq1:
- and edx,0ffffffh
- jz eq11
- mov esi,5
- jmp trfinval
-eq11:
- mov esi,6
- jmp trfinval
-
-begincompare:
- ; here we now scan and match begin same
- add edi,6
- add esi,6
- mov ecx,(MAX_MATCH-(2+4))/4 ; scan for at most MAX_MATCH bytes
- repe cmpsd ; loop until mismatch
-
- je trfin ; go to trfin if not unmatch
-; we determine the unmatch byte
- sub esi,4
- mov edx,[edi-4]
- xor edx,[esi]
-
- or dl,dl
- jnz trfin
- inc esi
-
- or dx,dx
- jnz trfin
- inc esi
-
- and edx,0ffffffh
- jnz trfin
- inc esi
-
-trfin:
- sub esi,scan ; esi = len
-trfinval:
-; here we have finised compare, and esi contain len of equal string
- cmp esi,best_len ; if len > best_len, go newbestlen
- ja short newbestlen
-; now we restore edx, ecx and esi, for the big loop
- mov esi,prev
- mov ecx,limit
- mov edx,window
- jmp contloop3
-
-newbestlen:
- mov best_len,esi ; len become best_len
-
- mov match_start,eax ; save new position as match_start
- cmp esi,nice_match ; if best_len >= nice_match, exit
- jae exitloop
- mov ecx,scan
- mov edx,window ; restore edx=window
- add ecx,esi
- add esi,edx
-
- dec esi
- mov windowlen,esi ; windowlen = window + best_len-1
- mov bx,[ecx-1] ; bx = *(scan+best_len-1) = scan_end
-
-; now we restore ecx and esi, for the big loop :
- mov esi,prev
- mov ecx,limit
- jmp contloop3
-
-exitloop:
-; exit : s->match_start=match_start
- mov ebx,match_start
- mov ebp,str_s
- mov ecx,best_len
- mov dword ptr [ebp+dep_match_start],ebx
- mov eax,dword ptr [ebp+dep_lookahead]
- cmp ecx,eax
- ja minexlo
- mov eax,ecx
-minexlo:
-; return min(best_len,s->lookahead)
-
-; restore stack and register ebx,esi,edi,ebp
- add esp,NbStackAdd
-
- pop ebx
- pop esi
- pop edi
- pop ebp
- ret
-InfoAuthor:
-; please don't remove this string !
-; Your are free use gvmat32 in any fre or commercial apps if you don't remove the string in the binary!
- db 0dh,0ah,"GVMat32 optimised assembly code written 1996-98 by Gilles Vollant",0dh,0ah
-
-
-
-IFDEF NOUNDERLINE
-longest_match_7fff endp
-ELSE
-_longest_match_7fff endp
-ENDIF
-
-
-IFDEF NOUNDERLINE
-cpudetect32 proc near
-ELSE
-_cpudetect32 proc near
-ENDIF
-
- push ebx
-
- pushfd ; push original EFLAGS
- pop eax ; get original EFLAGS
- mov ecx, eax ; save original EFLAGS
- xor eax, 40000h ; flip AC bit in EFLAGS
- push eax ; save new EFLAGS value on stack
- popfd ; replace current EFLAGS value
- pushfd ; get new EFLAGS
- pop eax ; store new EFLAGS in EAX
- xor eax, ecx ; can’t toggle AC bit, processor=80386
- jz end_cpu_is_386 ; jump if 80386 processor
- push ecx
- popfd ; restore AC bit in EFLAGS first
-
- pushfd
- pushfd
- pop ecx
-
- mov eax, ecx ; get original EFLAGS
- xor eax, 200000h ; flip ID bit in EFLAGS
- push eax ; save new EFLAGS value on stack
- popfd ; replace current EFLAGS value
- pushfd ; get new EFLAGS
- pop eax ; store new EFLAGS in EAX
- popfd ; restore original EFLAGS
- xor eax, ecx ; can’t toggle ID bit,
- je is_old_486 ; processor=old
-
- mov eax,1
- db 0fh,0a2h ;CPUID
-
-exitcpudetect:
- pop ebx
- ret
-
-end_cpu_is_386:
- mov eax,0300h
- jmp exitcpudetect
-
-is_old_486:
- mov eax,0400h
- jmp exitcpudetect
-
-IFDEF NOUNDERLINE
-cpudetect32 endp
-ELSE
-_cpudetect32 endp
-ENDIF
-ENDIF
-
-MAX_MATCH equ 258
-MIN_MATCH equ 3
-MIN_LOOKAHEAD equ (MAX_MATCH + MIN_MATCH + 1)
-MAX_MATCH_8_ equ ((MAX_MATCH + 7) AND 0FFF0h)
-
-
-;;; stack frame offsets
-
-chainlenwmask equ esp + 0 ; high word: current chain len
- ; low word: s->wmask
-window equ esp + 4 ; local copy of s->window
-windowbestlen equ esp + 8 ; s->window + bestlen
-scanstart equ esp + 16 ; first two bytes of string
-scanend equ esp + 12 ; last two bytes of string
-scanalign equ esp + 20 ; dword-misalignment of string
-nicematch equ esp + 24 ; a good enough match size
-bestlen equ esp + 28 ; size of best match so far
-scan equ esp + 32 ; ptr to string wanting match
-
-LocalVarsSize equ 36
-; saved ebx byte esp + 36
-; saved edi byte esp + 40
-; saved esi byte esp + 44
-; saved ebp byte esp + 48
-; return address byte esp + 52
-deflatestate equ esp + 56 ; the function arguments
-curmatch equ esp + 60
-
-;;; Offsets for fields in the deflate_state structure. These numbers
-;;; are calculated from the definition of deflate_state, with the
-;;; assumption that the compiler will dword-align the fields. (Thus,
-;;; changing the definition of deflate_state could easily cause this
-;;; program to crash horribly, without so much as a warning at
-;;; compile time. Sigh.)
-
-dsWSize equ 36+zlib1222add
-dsWMask equ 44+zlib1222add
-dsWindow equ 48+zlib1222add
-dsPrev equ 56+zlib1222add
-dsMatchLen equ 88+zlib1222add
-dsPrevMatch equ 92+zlib1222add
-dsStrStart equ 100+zlib1222add
-dsMatchStart equ 104+zlib1222add
-dsLookahead equ 108+zlib1222add
-dsPrevLen equ 112+zlib1222add
-dsMaxChainLen equ 116+zlib1222add
-dsGoodMatch equ 132+zlib1222add
-dsNiceMatch equ 136+zlib1222add
-
-
-;;; match.asm -- Pentium-Pro-optimized version of longest_match()
-;;; Written for zlib 1.1.2
-;;; Copyright (C) 1998 Brian Raiter <breadbox@muppetlabs.com>
-;;; You can look at http://www.muppetlabs.com/~breadbox/software/assembly.html
-;;;
-;;; This is free software; you can redistribute it and/or modify it
-;;; under the terms of the GNU General Public License.
-
-;GLOBAL _longest_match, _match_init
-
-
-;SECTION .text
-
-;;; uInt longest_match(deflate_state *deflatestate, IPos curmatch)
-
-;_longest_match:
-IFDEF NOOLDPENTIUMCODE
- IFDEF NOUNDERLINE
- longest_match proc near
- ELSE
- _longest_match proc near
- ENDIF
-ELSE
- IFDEF NOUNDERLINE
- longest_match_686 proc near
- ELSE
- _longest_match_686 proc near
- ENDIF
-ENDIF
-
-;;; Save registers that the compiler may be using, and adjust esp to
-;;; make room for our stack frame.
-
- push ebp
- push edi
- push esi
- push ebx
- sub esp, LocalVarsSize
-
-;;; Retrieve the function arguments. ecx will hold cur_match
-;;; throughout the entire function. edx will hold the pointer to the
-;;; deflate_state structure during the function's setup (before
-;;; entering the main loop.
-
- mov edx, [deflatestate]
- mov ecx, [curmatch]
-
-;;; uInt wmask = s->w_mask;
-;;; unsigned chain_length = s->max_chain_length;
-;;; if (s->prev_length >= s->good_match) {
-;;; chain_length >>= 2;
-;;; }
-
- mov eax, [edx + dsPrevLen]
- mov ebx, [edx + dsGoodMatch]
- cmp eax, ebx
- mov eax, [edx + dsWMask]
- mov ebx, [edx + dsMaxChainLen]
- jl LastMatchGood
- shr ebx, 2
-LastMatchGood:
-
-;;; chainlen is decremented once beforehand so that the function can
-;;; use the sign flag instead of the zero flag for the exit test.
-;;; It is then shifted into the high word, to make room for the wmask
-;;; value, which it will always accompany.
-
- dec ebx
- shl ebx, 16
- or ebx, eax
- mov [chainlenwmask], ebx
-
-;;; if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
-
- mov eax, [edx + dsNiceMatch]
- mov ebx, [edx + dsLookahead]
- cmp ebx, eax
- jl LookaheadLess
- mov ebx, eax
-LookaheadLess: mov [nicematch], ebx
-
-;;; register Bytef *scan = s->window + s->strstart;
-
- mov esi, [edx + dsWindow]
- mov [window], esi
- mov ebp, [edx + dsStrStart]
- lea edi, [esi + ebp]
- mov [scan], edi
-
-;;; Determine how many bytes the scan ptr is off from being
-;;; dword-aligned.
-
- mov eax, edi
- neg eax
- and eax, 3
- mov [scanalign], eax
-
-;;; IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
-;;; s->strstart - (IPos)MAX_DIST(s) : NIL;
-
- mov eax, [edx + dsWSize]
- sub eax, MIN_LOOKAHEAD
- sub ebp, eax
- jg LimitPositive
- xor ebp, ebp
-LimitPositive:
-
-;;; int best_len = s->prev_length;
-
- mov eax, [edx + dsPrevLen]
- mov [bestlen], eax
-
-;;; Store the sum of s->window + best_len in esi locally, and in esi.
-
- add esi, eax
- mov [windowbestlen], esi
-
-;;; register ush scan_start = *(ushf*)scan;
-;;; register ush scan_end = *(ushf*)(scan+best_len-1);
-;;; Posf *prev = s->prev;
-
- movzx ebx, word ptr [edi]
- mov [scanstart], ebx
- movzx ebx, word ptr [edi + eax - 1]
- mov [scanend], ebx
- mov edi, [edx + dsPrev]
-
-;;; Jump into the main loop.
-
- mov edx, [chainlenwmask]
- jmp short LoopEntry
-
-align 4
-
-;;; do {
-;;; match = s->window + cur_match;
-;;; if (*(ushf*)(match+best_len-1) != scan_end ||
-;;; *(ushf*)match != scan_start) continue;
-;;; [...]
-;;; } while ((cur_match = prev[cur_match & wmask]) > limit
-;;; && --chain_length != 0);
-;;;
-;;; Here is the inner loop of the function. The function will spend the
-;;; majority of its time in this loop, and majority of that time will
-;;; be spent in the first ten instructions.
-;;;
-;;; Within this loop:
-;;; ebx = scanend
-;;; ecx = curmatch
-;;; edx = chainlenwmask - i.e., ((chainlen << 16) | wmask)
-;;; esi = windowbestlen - i.e., (window + bestlen)
-;;; edi = prev
-;;; ebp = limit
-
-LookupLoop:
- and ecx, edx
- movzx ecx, word ptr [edi + ecx*2]
- cmp ecx, ebp
- jbe LeaveNow
- sub edx, 00010000h
- js LeaveNow
-LoopEntry: movzx eax, word ptr [esi + ecx - 1]
- cmp eax, ebx
- jnz LookupLoop
- mov eax, [window]
- movzx eax, word ptr [eax + ecx]
- cmp eax, [scanstart]
- jnz LookupLoop
-
-;;; Store the current value of chainlen.
-
- mov [chainlenwmask], edx
-
-;;; Point edi to the string under scrutiny, and esi to the string we
-;;; are hoping to match it up with. In actuality, esi and edi are
-;;; both pointed (MAX_MATCH_8 - scanalign) bytes ahead, and edx is
-;;; initialized to -(MAX_MATCH_8 - scanalign).
-
- mov esi, [window]
- mov edi, [scan]
- add esi, ecx
- mov eax, [scanalign]
- mov edx, 0fffffef8h; -(MAX_MATCH_8)
- lea edi, [edi + eax + 0108h] ;MAX_MATCH_8]
- lea esi, [esi + eax + 0108h] ;MAX_MATCH_8]
-
-;;; Test the strings for equality, 8 bytes at a time. At the end,
-;;; adjust edx so that it is offset to the exact byte that mismatched.
-;;;
-;;; We already know at this point that the first three bytes of the
-;;; strings match each other, and they can be safely passed over before
-;;; starting the compare loop. So what this code does is skip over 0-3
-;;; bytes, as much as necessary in order to dword-align the edi
-;;; pointer. (esi will still be misaligned three times out of four.)
-;;;
-;;; It should be confessed that this loop usually does not represent
-;;; much of the total running time. Replacing it with a more
-;;; straightforward "rep cmpsb" would not drastically degrade
-;;; performance.
-
-LoopCmps:
- mov eax, [esi + edx]
- xor eax, [edi + edx]
- jnz LeaveLoopCmps
- mov eax, [esi + edx + 4]
- xor eax, [edi + edx + 4]
- jnz LeaveLoopCmps4
- add edx, 8
- jnz LoopCmps
- jmp short LenMaximum
-LeaveLoopCmps4: add edx, 4
-LeaveLoopCmps: test eax, 0000FFFFh
- jnz LenLower
- add edx, 2
- shr eax, 16
-LenLower: sub al, 1
- adc edx, 0
-
-;;; Calculate the length of the match. If it is longer than MAX_MATCH,
-;;; then automatically accept it as the best possible match and leave.
-
- lea eax, [edi + edx]
- mov edi, [scan]
- sub eax, edi
- cmp eax, MAX_MATCH
- jge LenMaximum
-
-;;; If the length of the match is not longer than the best match we
-;;; have so far, then forget it and return to the lookup loop.
-
- mov edx, [deflatestate]
- mov ebx, [bestlen]
- cmp eax, ebx
- jg LongerMatch
- mov esi, [windowbestlen]
- mov edi, [edx + dsPrev]
- mov ebx, [scanend]
- mov edx, [chainlenwmask]
- jmp LookupLoop
-
-;;; s->match_start = cur_match;
-;;; best_len = len;
-;;; if (len >= nice_match) break;
-;;; scan_end = *(ushf*)(scan+best_len-1);
-
-LongerMatch: mov ebx, [nicematch]
- mov [bestlen], eax
- mov [edx + dsMatchStart], ecx
- cmp eax, ebx
- jge LeaveNow
- mov esi, [window]
- add esi, eax
- mov [windowbestlen], esi
- movzx ebx, word ptr [edi + eax - 1]
- mov edi, [edx + dsPrev]
- mov [scanend], ebx
- mov edx, [chainlenwmask]
- jmp LookupLoop
-
-;;; Accept the current string, with the maximum possible length.
-
-LenMaximum: mov edx, [deflatestate]
- mov dword ptr [bestlen], MAX_MATCH
- mov [edx + dsMatchStart], ecx
-
-;;; if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
-;;; return s->lookahead;
-
-LeaveNow:
- mov edx, [deflatestate]
- mov ebx, [bestlen]
- mov eax, [edx + dsLookahead]
- cmp ebx, eax
- jg LookaheadRet
- mov eax, ebx
-LookaheadRet:
-
-;;; Restore the stack and return from whence we came.
-
- add esp, LocalVarsSize
- pop ebx
- pop esi
- pop edi
- pop ebp
-
- ret
-; please don't remove this string !
-; Your can freely use gvmat32 in any free or commercial app if you don't remove the string in the binary!
- db 0dh,0ah,"asm686 with masm, optimised assembly code from Brian Raiter, written 1998",0dh,0ah
-
-
-IFDEF NOOLDPENTIUMCODE
- IFDEF NOUNDERLINE
- longest_match endp
- ELSE
- _longest_match endp
- ENDIF
-
- IFDEF NOUNDERLINE
- match_init proc near
- ret
- match_init endp
- ELSE
- _match_init proc near
- ret
- _match_init endp
- ENDIF
-ELSE
- IFDEF NOUNDERLINE
- longest_match_686 endp
- ELSE
- _longest_match_686 endp
- ENDIF
-ENDIF
-
-_TEXT ends
-end
|