annotate src/zlib-1.2.8/contrib/masmx64/gvmat64.asm @ 56:af97cad61ff0

Add updated build of PortAudio for OSX
author Chris Cannam <cannam@all-day-breakfast.com>
date Tue, 03 Jan 2017 15:10:52 +0000
parents 5ea0608b923f
children
rev   line source
Chris@43 1 ;uInt longest_match_x64(
Chris@43 2 ; deflate_state *s,
Chris@43 3 ; IPos cur_match); /* current match */
Chris@43 4
Chris@43 5 ; gvmat64.asm -- Asm portion of the optimized longest_match for 32 bits x86_64
Chris@43 6 ; (AMD64 on Athlon 64, Opteron, Phenom
Chris@43 7 ; and Intel EM64T on Pentium 4 with EM64T, Pentium D, Core 2 Duo, Core I5/I7)
Chris@43 8 ; Copyright (C) 1995-2010 Jean-loup Gailly, Brian Raiter and Gilles Vollant.
Chris@43 9 ;
Chris@43 10 ; File written by Gilles Vollant, by converting to assembly the longest_match
Chris@43 11 ; from Jean-loup Gailly in deflate.c of zLib and infoZip zip.
Chris@43 12 ;
Chris@43 13 ; and by taking inspiration on asm686 with masm, optimised assembly code
Chris@43 14 ; from Brian Raiter, written 1998
Chris@43 15 ;
Chris@43 16 ; This software is provided 'as-is', without any express or implied
Chris@43 17 ; warranty. In no event will the authors be held liable for any damages
Chris@43 18 ; arising from the use of this software.
Chris@43 19 ;
Chris@43 20 ; Permission is granted to anyone to use this software for any purpose,
Chris@43 21 ; including commercial applications, and to alter it and redistribute it
Chris@43 22 ; freely, subject to the following restrictions:
Chris@43 23 ;
Chris@43 24 ; 1. The origin of this software must not be misrepresented; you must not
Chris@43 25 ; claim that you wrote the original software. If you use this software
Chris@43 26 ; in a product, an acknowledgment in the product documentation would be
Chris@43 27 ; appreciated but is not required.
Chris@43 28 ; 2. Altered source versions must be plainly marked as such, and must not be
Chris@43 29 ; misrepresented as being the original software
Chris@43 30 ; 3. This notice may not be removed or altered from any source distribution.
Chris@43 31 ;
Chris@43 32 ;
Chris@43 33 ;
Chris@43 34 ; http://www.zlib.net
Chris@43 35 ; http://www.winimage.com/zLibDll
Chris@43 36 ; http://www.muppetlabs.com/~breadbox/software/assembly.html
Chris@43 37 ;
Chris@43 38 ; to compile this file for infozip Zip, I use option:
Chris@43 39 ; ml64.exe /Flgvmat64 /c /Zi /DINFOZIP gvmat64.asm
Chris@43 40 ;
Chris@43 41 ; to compile this file for zLib, I use option:
Chris@43 42 ; ml64.exe /Flgvmat64 /c /Zi gvmat64.asm
Chris@43 43 ; Be carrefull to adapt zlib1222add below to your version of zLib
Chris@43 44 ; (if you use a version of zLib before 1.0.4 or after 1.2.2.2, change
Chris@43 45 ; value of zlib1222add later)
Chris@43 46 ;
Chris@43 47 ; This file compile with Microsoft Macro Assembler (x64) for AMD64
Chris@43 48 ;
Chris@43 49 ; ml64.exe is given with Visual Studio 2005/2008/2010 and Windows WDK
Chris@43 50 ;
Chris@43 51 ; (you can get Windows WDK with ml64 for AMD64 from
Chris@43 52 ; http://www.microsoft.com/whdc/Devtools/wdk/default.mspx for low price)
Chris@43 53 ;
Chris@43 54
Chris@43 55
Chris@43 56 ;uInt longest_match(s, cur_match)
Chris@43 57 ; deflate_state *s;
Chris@43 58 ; IPos cur_match; /* current match */
Chris@43 59 .code
Chris@43 60 longest_match PROC
Chris@43 61
Chris@43 62
Chris@43 63 ;LocalVarsSize equ 88
Chris@43 64 LocalVarsSize equ 72
Chris@43 65
Chris@43 66 ; register used : rax,rbx,rcx,rdx,rsi,rdi,r8,r9,r10,r11,r12
Chris@43 67 ; free register : r14,r15
Chris@43 68 ; register can be saved : rsp
Chris@43 69
Chris@43 70 chainlenwmask equ rsp + 8 - LocalVarsSize ; high word: current chain len
Chris@43 71 ; low word: s->wmask
Chris@43 72 ;window equ rsp + xx - LocalVarsSize ; local copy of s->window ; stored in r10
Chris@43 73 ;windowbestlen equ rsp + xx - LocalVarsSize ; s->window + bestlen , use r10+r11
Chris@43 74 ;scanstart equ rsp + xx - LocalVarsSize ; first two bytes of string ; stored in r12w
Chris@43 75 ;scanend equ rsp + xx - LocalVarsSize ; last two bytes of string use ebx
Chris@43 76 ;scanalign equ rsp + xx - LocalVarsSize ; dword-misalignment of string r13
Chris@43 77 ;bestlen equ rsp + xx - LocalVarsSize ; size of best match so far -> r11d
Chris@43 78 ;scan equ rsp + xx - LocalVarsSize ; ptr to string wanting match -> r9
Chris@43 79 IFDEF INFOZIP
Chris@43 80 ELSE
Chris@43 81 nicematch equ (rsp + 16 - LocalVarsSize) ; a good enough match size
Chris@43 82 ENDIF
Chris@43 83
Chris@43 84 save_rdi equ rsp + 24 - LocalVarsSize
Chris@43 85 save_rsi equ rsp + 32 - LocalVarsSize
Chris@43 86 save_rbx equ rsp + 40 - LocalVarsSize
Chris@43 87 save_rbp equ rsp + 48 - LocalVarsSize
Chris@43 88 save_r12 equ rsp + 56 - LocalVarsSize
Chris@43 89 save_r13 equ rsp + 64 - LocalVarsSize
Chris@43 90 ;save_r14 equ rsp + 72 - LocalVarsSize
Chris@43 91 ;save_r15 equ rsp + 80 - LocalVarsSize
Chris@43 92
Chris@43 93
Chris@43 94 ; summary of register usage
Chris@43 95 ; scanend ebx
Chris@43 96 ; scanendw bx
Chris@43 97 ; chainlenwmask edx
Chris@43 98 ; curmatch rsi
Chris@43 99 ; curmatchd esi
Chris@43 100 ; windowbestlen r8
Chris@43 101 ; scanalign r9
Chris@43 102 ; scanalignd r9d
Chris@43 103 ; window r10
Chris@43 104 ; bestlen r11
Chris@43 105 ; bestlend r11d
Chris@43 106 ; scanstart r12d
Chris@43 107 ; scanstartw r12w
Chris@43 108 ; scan r13
Chris@43 109 ; nicematch r14d
Chris@43 110 ; limit r15
Chris@43 111 ; limitd r15d
Chris@43 112 ; prev rcx
Chris@43 113
Chris@43 114 ; all the +4 offsets are due to the addition of pending_buf_size (in zlib
Chris@43 115 ; in the deflate_state structure since the asm code was first written
Chris@43 116 ; (if you compile with zlib 1.0.4 or older, remove the +4).
Chris@43 117 ; Note : these value are good with a 8 bytes boundary pack structure
Chris@43 118
Chris@43 119
Chris@43 120 MAX_MATCH equ 258
Chris@43 121 MIN_MATCH equ 3
Chris@43 122 MIN_LOOKAHEAD equ (MAX_MATCH+MIN_MATCH+1)
Chris@43 123
Chris@43 124
Chris@43 125 ;;; Offsets for fields in the deflate_state structure. These numbers
Chris@43 126 ;;; are calculated from the definition of deflate_state, with the
Chris@43 127 ;;; assumption that the compiler will dword-align the fields. (Thus,
Chris@43 128 ;;; changing the definition of deflate_state could easily cause this
Chris@43 129 ;;; program to crash horribly, without so much as a warning at
Chris@43 130 ;;; compile time. Sigh.)
Chris@43 131
Chris@43 132 ; all the +zlib1222add offsets are due to the addition of fields
Chris@43 133 ; in zlib in the deflate_state structure since the asm code was first written
Chris@43 134 ; (if you compile with zlib 1.0.4 or older, use "zlib1222add equ (-4)").
Chris@43 135 ; (if you compile with zlib between 1.0.5 and 1.2.2.1, use "zlib1222add equ 0").
Chris@43 136 ; if you compile with zlib 1.2.2.2 or later , use "zlib1222add equ 8").
Chris@43 137
Chris@43 138
Chris@43 139 IFDEF INFOZIP
Chris@43 140
Chris@43 141 _DATA SEGMENT
Chris@43 142 COMM window_size:DWORD
Chris@43 143 ; WMask ; 7fff
Chris@43 144 COMM window:BYTE:010040H
Chris@43 145 COMM prev:WORD:08000H
Chris@43 146 ; MatchLen : unused
Chris@43 147 ; PrevMatch : unused
Chris@43 148 COMM strstart:DWORD
Chris@43 149 COMM match_start:DWORD
Chris@43 150 ; Lookahead : ignore
Chris@43 151 COMM prev_length:DWORD ; PrevLen
Chris@43 152 COMM max_chain_length:DWORD
Chris@43 153 COMM good_match:DWORD
Chris@43 154 COMM nice_match:DWORD
Chris@43 155 prev_ad equ OFFSET prev
Chris@43 156 window_ad equ OFFSET window
Chris@43 157 nicematch equ nice_match
Chris@43 158 _DATA ENDS
Chris@43 159 WMask equ 07fffh
Chris@43 160
Chris@43 161 ELSE
Chris@43 162
Chris@43 163 IFNDEF zlib1222add
Chris@43 164 zlib1222add equ 8
Chris@43 165 ENDIF
Chris@43 166 dsWSize equ 56+zlib1222add+(zlib1222add/2)
Chris@43 167 dsWMask equ 64+zlib1222add+(zlib1222add/2)
Chris@43 168 dsWindow equ 72+zlib1222add
Chris@43 169 dsPrev equ 88+zlib1222add
Chris@43 170 dsMatchLen equ 128+zlib1222add
Chris@43 171 dsPrevMatch equ 132+zlib1222add
Chris@43 172 dsStrStart equ 140+zlib1222add
Chris@43 173 dsMatchStart equ 144+zlib1222add
Chris@43 174 dsLookahead equ 148+zlib1222add
Chris@43 175 dsPrevLen equ 152+zlib1222add
Chris@43 176 dsMaxChainLen equ 156+zlib1222add
Chris@43 177 dsGoodMatch equ 172+zlib1222add
Chris@43 178 dsNiceMatch equ 176+zlib1222add
Chris@43 179
Chris@43 180 window_size equ [ rcx + dsWSize]
Chris@43 181 WMask equ [ rcx + dsWMask]
Chris@43 182 window_ad equ [ rcx + dsWindow]
Chris@43 183 prev_ad equ [ rcx + dsPrev]
Chris@43 184 strstart equ [ rcx + dsStrStart]
Chris@43 185 match_start equ [ rcx + dsMatchStart]
Chris@43 186 Lookahead equ [ rcx + dsLookahead] ; 0ffffffffh on infozip
Chris@43 187 prev_length equ [ rcx + dsPrevLen]
Chris@43 188 max_chain_length equ [ rcx + dsMaxChainLen]
Chris@43 189 good_match equ [ rcx + dsGoodMatch]
Chris@43 190 nice_match equ [ rcx + dsNiceMatch]
Chris@43 191 ENDIF
Chris@43 192
Chris@43 193 ; parameter 1 in r8(deflate state s), param 2 in rdx (cur match)
Chris@43 194
Chris@43 195 ; see http://weblogs.asp.net/oldnewthing/archive/2004/01/14/58579.aspx and
Chris@43 196 ; http://msdn.microsoft.com/library/en-us/kmarch/hh/kmarch/64bitAMD_8e951dd2-ee77-4728-8702-55ce4b5dd24a.xml.asp
Chris@43 197 ;
Chris@43 198 ; All registers must be preserved across the call, except for
Chris@43 199 ; rax, rcx, rdx, r8, r9, r10, and r11, which are scratch.
Chris@43 200
Chris@43 201
Chris@43 202
Chris@43 203 ;;; Save registers that the compiler may be using, and adjust esp to
Chris@43 204 ;;; make room for our stack frame.
Chris@43 205
Chris@43 206
Chris@43 207 ;;; Retrieve the function arguments. r8d will hold cur_match
Chris@43 208 ;;; throughout the entire function. edx will hold the pointer to the
Chris@43 209 ;;; deflate_state structure during the function's setup (before
Chris@43 210 ;;; entering the main loop.
Chris@43 211
Chris@43 212 ; parameter 1 in rcx (deflate_state* s), param 2 in edx -> r8 (cur match)
Chris@43 213
Chris@43 214 ; this clear high 32 bits of r8, which can be garbage in both r8 and rdx
Chris@43 215
Chris@43 216 mov [save_rdi],rdi
Chris@43 217 mov [save_rsi],rsi
Chris@43 218 mov [save_rbx],rbx
Chris@43 219 mov [save_rbp],rbp
Chris@43 220 IFDEF INFOZIP
Chris@43 221 mov r8d,ecx
Chris@43 222 ELSE
Chris@43 223 mov r8d,edx
Chris@43 224 ENDIF
Chris@43 225 mov [save_r12],r12
Chris@43 226 mov [save_r13],r13
Chris@43 227 ; mov [save_r14],r14
Chris@43 228 ; mov [save_r15],r15
Chris@43 229
Chris@43 230
Chris@43 231 ;;; uInt wmask = s->w_mask;
Chris@43 232 ;;; unsigned chain_length = s->max_chain_length;
Chris@43 233 ;;; if (s->prev_length >= s->good_match) {
Chris@43 234 ;;; chain_length >>= 2;
Chris@43 235 ;;; }
Chris@43 236
Chris@43 237 mov edi, prev_length
Chris@43 238 mov esi, good_match
Chris@43 239 mov eax, WMask
Chris@43 240 mov ebx, max_chain_length
Chris@43 241 cmp edi, esi
Chris@43 242 jl LastMatchGood
Chris@43 243 shr ebx, 2
Chris@43 244 LastMatchGood:
Chris@43 245
Chris@43 246 ;;; chainlen is decremented once beforehand so that the function can
Chris@43 247 ;;; use the sign flag instead of the zero flag for the exit test.
Chris@43 248 ;;; It is then shifted into the high word, to make room for the wmask
Chris@43 249 ;;; value, which it will always accompany.
Chris@43 250
Chris@43 251 dec ebx
Chris@43 252 shl ebx, 16
Chris@43 253 or ebx, eax
Chris@43 254
Chris@43 255 ;;; on zlib only
Chris@43 256 ;;; if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
Chris@43 257
Chris@43 258 IFDEF INFOZIP
Chris@43 259 mov [chainlenwmask], ebx
Chris@43 260 ; on infozip nice_match = [nice_match]
Chris@43 261 ELSE
Chris@43 262 mov eax, nice_match
Chris@43 263 mov [chainlenwmask], ebx
Chris@43 264 mov r10d, Lookahead
Chris@43 265 cmp r10d, eax
Chris@43 266 cmovnl r10d, eax
Chris@43 267 mov [nicematch],r10d
Chris@43 268 ENDIF
Chris@43 269
Chris@43 270 ;;; register Bytef *scan = s->window + s->strstart;
Chris@43 271 mov r10, window_ad
Chris@43 272 mov ebp, strstart
Chris@43 273 lea r13, [r10 + rbp]
Chris@43 274
Chris@43 275 ;;; Determine how many bytes the scan ptr is off from being
Chris@43 276 ;;; dword-aligned.
Chris@43 277
Chris@43 278 mov r9,r13
Chris@43 279 neg r13
Chris@43 280 and r13,3
Chris@43 281
Chris@43 282 ;;; IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
Chris@43 283 ;;; s->strstart - (IPos)MAX_DIST(s) : NIL;
Chris@43 284 IFDEF INFOZIP
Chris@43 285 mov eax,07efah ; MAX_DIST = (WSIZE-MIN_LOOKAHEAD) (0x8000-(3+8+1))
Chris@43 286 ELSE
Chris@43 287 mov eax, window_size
Chris@43 288 sub eax, MIN_LOOKAHEAD
Chris@43 289 ENDIF
Chris@43 290 xor edi,edi
Chris@43 291 sub ebp, eax
Chris@43 292
Chris@43 293 mov r11d, prev_length
Chris@43 294
Chris@43 295 cmovng ebp,edi
Chris@43 296
Chris@43 297 ;;; int best_len = s->prev_length;
Chris@43 298
Chris@43 299
Chris@43 300 ;;; Store the sum of s->window + best_len in esi locally, and in esi.
Chris@43 301
Chris@43 302 lea rsi,[r10+r11]
Chris@43 303
Chris@43 304 ;;; register ush scan_start = *(ushf*)scan;
Chris@43 305 ;;; register ush scan_end = *(ushf*)(scan+best_len-1);
Chris@43 306 ;;; Posf *prev = s->prev;
Chris@43 307
Chris@43 308 movzx r12d,word ptr [r9]
Chris@43 309 movzx ebx, word ptr [r9 + r11 - 1]
Chris@43 310
Chris@43 311 mov rdi, prev_ad
Chris@43 312
Chris@43 313 ;;; Jump into the main loop.
Chris@43 314
Chris@43 315 mov edx, [chainlenwmask]
Chris@43 316
Chris@43 317 cmp bx,word ptr [rsi + r8 - 1]
Chris@43 318 jz LookupLoopIsZero
Chris@43 319
Chris@43 320 LookupLoop1:
Chris@43 321 and r8d, edx
Chris@43 322
Chris@43 323 movzx r8d, word ptr [rdi + r8*2]
Chris@43 324 cmp r8d, ebp
Chris@43 325 jbe LeaveNow
Chris@43 326 sub edx, 00010000h
Chris@43 327 js LeaveNow
Chris@43 328
Chris@43 329 LoopEntry1:
Chris@43 330 cmp bx,word ptr [rsi + r8 - 1]
Chris@43 331 jz LookupLoopIsZero
Chris@43 332
Chris@43 333 LookupLoop2:
Chris@43 334 and r8d, edx
Chris@43 335
Chris@43 336 movzx r8d, word ptr [rdi + r8*2]
Chris@43 337 cmp r8d, ebp
Chris@43 338 jbe LeaveNow
Chris@43 339 sub edx, 00010000h
Chris@43 340 js LeaveNow
Chris@43 341
Chris@43 342 LoopEntry2:
Chris@43 343 cmp bx,word ptr [rsi + r8 - 1]
Chris@43 344 jz LookupLoopIsZero
Chris@43 345
Chris@43 346 LookupLoop4:
Chris@43 347 and r8d, edx
Chris@43 348
Chris@43 349 movzx r8d, word ptr [rdi + r8*2]
Chris@43 350 cmp r8d, ebp
Chris@43 351 jbe LeaveNow
Chris@43 352 sub edx, 00010000h
Chris@43 353 js LeaveNow
Chris@43 354
Chris@43 355 LoopEntry4:
Chris@43 356
Chris@43 357 cmp bx,word ptr [rsi + r8 - 1]
Chris@43 358 jnz LookupLoop1
Chris@43 359 jmp LookupLoopIsZero
Chris@43 360
Chris@43 361
Chris@43 362 ;;; do {
Chris@43 363 ;;; match = s->window + cur_match;
Chris@43 364 ;;; if (*(ushf*)(match+best_len-1) != scan_end ||
Chris@43 365 ;;; *(ushf*)match != scan_start) continue;
Chris@43 366 ;;; [...]
Chris@43 367 ;;; } while ((cur_match = prev[cur_match & wmask]) > limit
Chris@43 368 ;;; && --chain_length != 0);
Chris@43 369 ;;;
Chris@43 370 ;;; Here is the inner loop of the function. The function will spend the
Chris@43 371 ;;; majority of its time in this loop, and majority of that time will
Chris@43 372 ;;; be spent in the first ten instructions.
Chris@43 373 ;;;
Chris@43 374 ;;; Within this loop:
Chris@43 375 ;;; ebx = scanend
Chris@43 376 ;;; r8d = curmatch
Chris@43 377 ;;; edx = chainlenwmask - i.e., ((chainlen << 16) | wmask)
Chris@43 378 ;;; esi = windowbestlen - i.e., (window + bestlen)
Chris@43 379 ;;; edi = prev
Chris@43 380 ;;; ebp = limit
Chris@43 381
Chris@43 382 LookupLoop:
Chris@43 383 and r8d, edx
Chris@43 384
Chris@43 385 movzx r8d, word ptr [rdi + r8*2]
Chris@43 386 cmp r8d, ebp
Chris@43 387 jbe LeaveNow
Chris@43 388 sub edx, 00010000h
Chris@43 389 js LeaveNow
Chris@43 390
Chris@43 391 LoopEntry:
Chris@43 392
Chris@43 393 cmp bx,word ptr [rsi + r8 - 1]
Chris@43 394 jnz LookupLoop1
Chris@43 395 LookupLoopIsZero:
Chris@43 396 cmp r12w, word ptr [r10 + r8]
Chris@43 397 jnz LookupLoop1
Chris@43 398
Chris@43 399
Chris@43 400 ;;; Store the current value of chainlen.
Chris@43 401 mov [chainlenwmask], edx
Chris@43 402
Chris@43 403 ;;; Point edi to the string under scrutiny, and esi to the string we
Chris@43 404 ;;; are hoping to match it up with. In actuality, esi and edi are
Chris@43 405 ;;; both pointed (MAX_MATCH_8 - scanalign) bytes ahead, and edx is
Chris@43 406 ;;; initialized to -(MAX_MATCH_8 - scanalign).
Chris@43 407
Chris@43 408 lea rsi,[r8+r10]
Chris@43 409 mov rdx, 0fffffffffffffef8h; -(MAX_MATCH_8)
Chris@43 410 lea rsi, [rsi + r13 + 0108h] ;MAX_MATCH_8]
Chris@43 411 lea rdi, [r9 + r13 + 0108h] ;MAX_MATCH_8]
Chris@43 412
Chris@43 413 prefetcht1 [rsi+rdx]
Chris@43 414 prefetcht1 [rdi+rdx]
Chris@43 415
Chris@43 416
Chris@43 417 ;;; Test the strings for equality, 8 bytes at a time. At the end,
Chris@43 418 ;;; adjust rdx so that it is offset to the exact byte that mismatched.
Chris@43 419 ;;;
Chris@43 420 ;;; We already know at this point that the first three bytes of the
Chris@43 421 ;;; strings match each other, and they can be safely passed over before
Chris@43 422 ;;; starting the compare loop. So what this code does is skip over 0-3
Chris@43 423 ;;; bytes, as much as necessary in order to dword-align the edi
Chris@43 424 ;;; pointer. (rsi will still be misaligned three times out of four.)
Chris@43 425 ;;;
Chris@43 426 ;;; It should be confessed that this loop usually does not represent
Chris@43 427 ;;; much of the total running time. Replacing it with a more
Chris@43 428 ;;; straightforward "rep cmpsb" would not drastically degrade
Chris@43 429 ;;; performance.
Chris@43 430
Chris@43 431
Chris@43 432 LoopCmps:
Chris@43 433 mov rax, [rsi + rdx]
Chris@43 434 xor rax, [rdi + rdx]
Chris@43 435 jnz LeaveLoopCmps
Chris@43 436
Chris@43 437 mov rax, [rsi + rdx + 8]
Chris@43 438 xor rax, [rdi + rdx + 8]
Chris@43 439 jnz LeaveLoopCmps8
Chris@43 440
Chris@43 441
Chris@43 442 mov rax, [rsi + rdx + 8+8]
Chris@43 443 xor rax, [rdi + rdx + 8+8]
Chris@43 444 jnz LeaveLoopCmps16
Chris@43 445
Chris@43 446 add rdx,8+8+8
Chris@43 447
Chris@43 448 jnz short LoopCmps
Chris@43 449 jmp short LenMaximum
Chris@43 450 LeaveLoopCmps16: add rdx,8
Chris@43 451 LeaveLoopCmps8: add rdx,8
Chris@43 452 LeaveLoopCmps:
Chris@43 453
Chris@43 454 test eax, 0000FFFFh
Chris@43 455 jnz LenLower
Chris@43 456
Chris@43 457 test eax,0ffffffffh
Chris@43 458
Chris@43 459 jnz LenLower32
Chris@43 460
Chris@43 461 add rdx,4
Chris@43 462 shr rax,32
Chris@43 463 or ax,ax
Chris@43 464 jnz LenLower
Chris@43 465
Chris@43 466 LenLower32:
Chris@43 467 shr eax,16
Chris@43 468 add rdx,2
Chris@43 469 LenLower: sub al, 1
Chris@43 470 adc rdx, 0
Chris@43 471 ;;; Calculate the length of the match. If it is longer than MAX_MATCH,
Chris@43 472 ;;; then automatically accept it as the best possible match and leave.
Chris@43 473
Chris@43 474 lea rax, [rdi + rdx]
Chris@43 475 sub rax, r9
Chris@43 476 cmp eax, MAX_MATCH
Chris@43 477 jge LenMaximum
Chris@43 478
Chris@43 479 ;;; If the length of the match is not longer than the best match we
Chris@43 480 ;;; have so far, then forget it and return to the lookup loop.
Chris@43 481 ;///////////////////////////////////
Chris@43 482
Chris@43 483 cmp eax, r11d
Chris@43 484 jg LongerMatch
Chris@43 485
Chris@43 486 lea rsi,[r10+r11]
Chris@43 487
Chris@43 488 mov rdi, prev_ad
Chris@43 489 mov edx, [chainlenwmask]
Chris@43 490 jmp LookupLoop
Chris@43 491
Chris@43 492 ;;; s->match_start = cur_match;
Chris@43 493 ;;; best_len = len;
Chris@43 494 ;;; if (len >= nice_match) break;
Chris@43 495 ;;; scan_end = *(ushf*)(scan+best_len-1);
Chris@43 496
Chris@43 497 LongerMatch:
Chris@43 498 mov r11d, eax
Chris@43 499 mov match_start, r8d
Chris@43 500 cmp eax, [nicematch]
Chris@43 501 jge LeaveNow
Chris@43 502
Chris@43 503 lea rsi,[r10+rax]
Chris@43 504
Chris@43 505 movzx ebx, word ptr [r9 + rax - 1]
Chris@43 506 mov rdi, prev_ad
Chris@43 507 mov edx, [chainlenwmask]
Chris@43 508 jmp LookupLoop
Chris@43 509
Chris@43 510 ;;; Accept the current string, with the maximum possible length.
Chris@43 511
Chris@43 512 LenMaximum:
Chris@43 513 mov r11d,MAX_MATCH
Chris@43 514 mov match_start, r8d
Chris@43 515
Chris@43 516 ;;; if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
Chris@43 517 ;;; return s->lookahead;
Chris@43 518
Chris@43 519 LeaveNow:
Chris@43 520 IFDEF INFOZIP
Chris@43 521 mov eax,r11d
Chris@43 522 ELSE
Chris@43 523 mov eax, Lookahead
Chris@43 524 cmp r11d, eax
Chris@43 525 cmovng eax, r11d
Chris@43 526 ENDIF
Chris@43 527
Chris@43 528 ;;; Restore the stack and return from whence we came.
Chris@43 529
Chris@43 530
Chris@43 531 mov rsi,[save_rsi]
Chris@43 532 mov rdi,[save_rdi]
Chris@43 533 mov rbx,[save_rbx]
Chris@43 534 mov rbp,[save_rbp]
Chris@43 535 mov r12,[save_r12]
Chris@43 536 mov r13,[save_r13]
Chris@43 537 ; mov r14,[save_r14]
Chris@43 538 ; mov r15,[save_r15]
Chris@43 539
Chris@43 540
Chris@43 541 ret 0
Chris@43 542 ; please don't remove this string !
Chris@43 543 ; Your can freely use gvmat64 in any free or commercial app
Chris@43 544 ; but it is far better don't remove the string in the binary!
Chris@43 545 db 0dh,0ah,"asm686 with masm, optimised assembly code from Brian Raiter, written 1998, converted to amd 64 by Gilles Vollant 2005",0dh,0ah,0
Chris@43 546 longest_match ENDP
Chris@43 547
Chris@43 548 match_init PROC
Chris@43 549 ret 0
Chris@43 550 match_init ENDP
Chris@43 551
Chris@43 552
Chris@43 553 END