annotate src/zlib-1.2.7/contrib/gcc_gvmat64/gvmat64.S @ 23:619f715526df sv_v2.1

Update Vamp plugin SDK to 2.5
author Chris Cannam
date Thu, 09 May 2013 10:52:46 +0100
parents e13257ea84a4
children
rev   line source
Chris@4 1 /*
Chris@4 2 ;uInt longest_match_x64(
Chris@4 3 ; deflate_state *s,
Chris@4 4 ; IPos cur_match); // current match
Chris@4 5
Chris@4 6 ; gvmat64.S -- Asm portion of the optimized longest_match for 32 bits x86_64
Chris@4 7 ; (AMD64 on Athlon 64, Opteron, Phenom
Chris@4 8 ; and Intel EM64T on Pentium 4 with EM64T, Pentium D, Core 2 Duo, Core I5/I7)
Chris@4 9 ; this file is translation from gvmat64.asm to GCC 4.x (for Linux, Mac XCode)
Chris@4 10 ; Copyright (C) 1995-2010 Jean-loup Gailly, Brian Raiter and Gilles Vollant.
Chris@4 11 ;
Chris@4 12 ; File written by Gilles Vollant, by converting to assembly the longest_match
Chris@4 13 ; from Jean-loup Gailly in deflate.c of zLib and infoZip zip.
Chris@4 14 ; and by taking inspiration on asm686 with masm, optimised assembly code
Chris@4 15 ; from Brian Raiter, written 1998
Chris@4 16 ;
Chris@4 17 ; This software is provided 'as-is', without any express or implied
Chris@4 18 ; warranty. In no event will the authors be held liable for any damages
Chris@4 19 ; arising from the use of this software.
Chris@4 20 ;
Chris@4 21 ; Permission is granted to anyone to use this software for any purpose,
Chris@4 22 ; including commercial applications, and to alter it and redistribute it
Chris@4 23 ; freely, subject to the following restrictions:
Chris@4 24 ;
Chris@4 25 ; 1. The origin of this software must not be misrepresented; you must not
Chris@4 26 ; claim that you wrote the original software. If you use this software
Chris@4 27 ; in a product, an acknowledgment in the product documentation would be
Chris@4 28 ; appreciated but is not required.
Chris@4 29 ; 2. Altered source versions must be plainly marked as such, and must not be
Chris@4 30 ; misrepresented as being the original software
Chris@4 31 ; 3. This notice may not be removed or altered from any source distribution.
Chris@4 32 ;
Chris@4 33 ; http://www.zlib.net
Chris@4 34 ; http://www.winimage.com/zLibDll
Chris@4 35 ; http://www.muppetlabs.com/~breadbox/software/assembly.html
Chris@4 36 ;
Chris@4 37 ; to compile this file for zLib, I use option:
Chris@4 38 ; gcc -c -arch x86_64 gvmat64.S
Chris@4 39
Chris@4 40
Chris@4 41 ;uInt longest_match(s, cur_match)
Chris@4 42 ; deflate_state *s;
Chris@4 43 ; IPos cur_match; // current match /
Chris@4 44 ;
Chris@4 45 ; with XCode for Mac, I had strange error with some jump on intel syntax
Chris@4 46 ; this is why BEFORE_JMP and AFTER_JMP are used
Chris@4 47 */
Chris@4 48
Chris@4 49
Chris@4 50 #define BEFORE_JMP .att_syntax
Chris@4 51 #define AFTER_JMP .intel_syntax noprefix
Chris@4 52
Chris@4 53 #ifndef NO_UNDERLINE
Chris@4 54 # define match_init _match_init
Chris@4 55 # define longest_match _longest_match
Chris@4 56 #endif
Chris@4 57
Chris@4 58 .intel_syntax noprefix
Chris@4 59
Chris@4 60 .globl match_init, longest_match
Chris@4 61 .text
Chris@4 62 longest_match:
Chris@4 63
Chris@4 64
Chris@4 65
Chris@4 66 #define LocalVarsSize 96
Chris@4 67 /*
Chris@4 68 ; register used : rax,rbx,rcx,rdx,rsi,rdi,r8,r9,r10,r11,r12
Chris@4 69 ; free register : r14,r15
Chris@4 70 ; register can be saved : rsp
Chris@4 71 */
Chris@4 72
Chris@4 73 #define chainlenwmask (rsp + 8 - LocalVarsSize)
Chris@4 74 #define nicematch (rsp + 16 - LocalVarsSize)
Chris@4 75
Chris@4 76 #define save_rdi (rsp + 24 - LocalVarsSize)
Chris@4 77 #define save_rsi (rsp + 32 - LocalVarsSize)
Chris@4 78 #define save_rbx (rsp + 40 - LocalVarsSize)
Chris@4 79 #define save_rbp (rsp + 48 - LocalVarsSize)
Chris@4 80 #define save_r12 (rsp + 56 - LocalVarsSize)
Chris@4 81 #define save_r13 (rsp + 64 - LocalVarsSize)
Chris@4 82 #define save_r14 (rsp + 72 - LocalVarsSize)
Chris@4 83 #define save_r15 (rsp + 80 - LocalVarsSize)
Chris@4 84
Chris@4 85
Chris@4 86 /*
Chris@4 87 ; all the +4 offsets are due to the addition of pending_buf_size (in zlib
Chris@4 88 ; in the deflate_state structure since the asm code was first written
Chris@4 89 ; (if you compile with zlib 1.0.4 or older, remove the +4).
Chris@4 90 ; Note : these value are good with a 8 bytes boundary pack structure
Chris@4 91 */
Chris@4 92
Chris@4 93 #define MAX_MATCH 258
Chris@4 94 #define MIN_MATCH 3
Chris@4 95 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
Chris@4 96
Chris@4 97 /*
Chris@4 98 ;;; Offsets for fields in the deflate_state structure. These numbers
Chris@4 99 ;;; are calculated from the definition of deflate_state, with the
Chris@4 100 ;;; assumption that the compiler will dword-align the fields. (Thus,
Chris@4 101 ;;; changing the definition of deflate_state could easily cause this
Chris@4 102 ;;; program to crash horribly, without so much as a warning at
Chris@4 103 ;;; compile time. Sigh.)
Chris@4 104
Chris@4 105 ; all the +zlib1222add offsets are due to the addition of fields
Chris@4 106 ; in zlib in the deflate_state structure since the asm code was first written
Chris@4 107 ; (if you compile with zlib 1.0.4 or older, use "zlib1222add equ (-4)").
Chris@4 108 ; (if you compile with zlib between 1.0.5 and 1.2.2.1, use "zlib1222add equ 0").
Chris@4 109 ; if you compile with zlib 1.2.2.2 or later , use "zlib1222add equ 8").
Chris@4 110 */
Chris@4 111
Chris@4 112
Chris@4 113
Chris@4 114 /* you can check the structure offset by running
Chris@4 115
Chris@4 116 #include <stdlib.h>
Chris@4 117 #include <stdio.h>
Chris@4 118 #include "deflate.h"
Chris@4 119
Chris@4 120 void print_depl()
Chris@4 121 {
Chris@4 122 deflate_state ds;
Chris@4 123 deflate_state *s=&ds;
Chris@4 124 printf("size pointer=%u\n",(int)sizeof(void*));
Chris@4 125
Chris@4 126 printf("#define dsWSize %u\n",(int)(((char*)&(s->w_size))-((char*)s)));
Chris@4 127 printf("#define dsWMask %u\n",(int)(((char*)&(s->w_mask))-((char*)s)));
Chris@4 128 printf("#define dsWindow %u\n",(int)(((char*)&(s->window))-((char*)s)));
Chris@4 129 printf("#define dsPrev %u\n",(int)(((char*)&(s->prev))-((char*)s)));
Chris@4 130 printf("#define dsMatchLen %u\n",(int)(((char*)&(s->match_length))-((char*)s)));
Chris@4 131 printf("#define dsPrevMatch %u\n",(int)(((char*)&(s->prev_match))-((char*)s)));
Chris@4 132 printf("#define dsStrStart %u\n",(int)(((char*)&(s->strstart))-((char*)s)));
Chris@4 133 printf("#define dsMatchStart %u\n",(int)(((char*)&(s->match_start))-((char*)s)));
Chris@4 134 printf("#define dsLookahead %u\n",(int)(((char*)&(s->lookahead))-((char*)s)));
Chris@4 135 printf("#define dsPrevLen %u\n",(int)(((char*)&(s->prev_length))-((char*)s)));
Chris@4 136 printf("#define dsMaxChainLen %u\n",(int)(((char*)&(s->max_chain_length))-((char*)s)));
Chris@4 137 printf("#define dsGoodMatch %u\n",(int)(((char*)&(s->good_match))-((char*)s)));
Chris@4 138 printf("#define dsNiceMatch %u\n",(int)(((char*)&(s->nice_match))-((char*)s)));
Chris@4 139 }
Chris@4 140 */
Chris@4 141
Chris@4 142 #define dsWSize 68
Chris@4 143 #define dsWMask 76
Chris@4 144 #define dsWindow 80
Chris@4 145 #define dsPrev 96
Chris@4 146 #define dsMatchLen 144
Chris@4 147 #define dsPrevMatch 148
Chris@4 148 #define dsStrStart 156
Chris@4 149 #define dsMatchStart 160
Chris@4 150 #define dsLookahead 164
Chris@4 151 #define dsPrevLen 168
Chris@4 152 #define dsMaxChainLen 172
Chris@4 153 #define dsGoodMatch 188
Chris@4 154 #define dsNiceMatch 192
Chris@4 155
Chris@4 156 #define window_size [ rcx + dsWSize]
Chris@4 157 #define WMask [ rcx + dsWMask]
Chris@4 158 #define window_ad [ rcx + dsWindow]
Chris@4 159 #define prev_ad [ rcx + dsPrev]
Chris@4 160 #define strstart [ rcx + dsStrStart]
Chris@4 161 #define match_start [ rcx + dsMatchStart]
Chris@4 162 #define Lookahead [ rcx + dsLookahead] //; 0ffffffffh on infozip
Chris@4 163 #define prev_length [ rcx + dsPrevLen]
Chris@4 164 #define max_chain_length [ rcx + dsMaxChainLen]
Chris@4 165 #define good_match [ rcx + dsGoodMatch]
Chris@4 166 #define nice_match [ rcx + dsNiceMatch]
Chris@4 167
Chris@4 168 /*
Chris@4 169 ; windows:
Chris@4 170 ; parameter 1 in rcx(deflate state s), param 2 in rdx (cur match)
Chris@4 171
Chris@4 172 ; see http://weblogs.asp.net/oldnewthing/archive/2004/01/14/58579.aspx and
Chris@4 173 ; http://msdn.microsoft.com/library/en-us/kmarch/hh/kmarch/64bitAMD_8e951dd2-ee77-4728-8702-55ce4b5dd24a.xml.asp
Chris@4 174 ;
Chris@4 175 ; All registers must be preserved across the call, except for
Chris@4 176 ; rax, rcx, rdx, r8, r9, r10, and r11, which are scratch.
Chris@4 177
Chris@4 178 ;
Chris@4 179 ; gcc on macosx-linux:
Chris@4 180 ; see http://www.x86-64.org/documentation/abi-0.99.pdf
Chris@4 181 ; param 1 in rdi, param 2 in rsi
Chris@4 182 ; rbx, rsp, rbp, r12 to r15 must be preserved
Chris@4 183
Chris@4 184 ;;; Save registers that the compiler may be using, and adjust esp to
Chris@4 185 ;;; make room for our stack frame.
Chris@4 186
Chris@4 187
Chris@4 188 ;;; Retrieve the function arguments. r8d will hold cur_match
Chris@4 189 ;;; throughout the entire function. edx will hold the pointer to the
Chris@4 190 ;;; deflate_state structure during the function's setup (before
Chris@4 191 ;;; entering the main loop.
Chris@4 192
Chris@4 193 ; ms: parameter 1 in rcx (deflate_state* s), param 2 in edx -> r8 (cur match)
Chris@4 194 ; mac: param 1 in rdi, param 2 rsi
Chris@4 195 ; this clear high 32 bits of r8, which can be garbage in both r8 and rdx
Chris@4 196 */
Chris@4 197 mov [save_rbx],rbx
Chris@4 198 mov [save_rbp],rbp
Chris@4 199
Chris@4 200
Chris@4 201 mov rcx,rdi
Chris@4 202
Chris@4 203 mov r8d,esi
Chris@4 204
Chris@4 205
Chris@4 206 mov [save_r12],r12
Chris@4 207 mov [save_r13],r13
Chris@4 208 mov [save_r14],r14
Chris@4 209 mov [save_r15],r15
Chris@4 210
Chris@4 211
Chris@4 212 //;;; uInt wmask = s->w_mask;
Chris@4 213 //;;; unsigned chain_length = s->max_chain_length;
Chris@4 214 //;;; if (s->prev_length >= s->good_match) {
Chris@4 215 //;;; chain_length >>= 2;
Chris@4 216 //;;; }
Chris@4 217
Chris@4 218
Chris@4 219 mov edi, prev_length
Chris@4 220 mov esi, good_match
Chris@4 221 mov eax, WMask
Chris@4 222 mov ebx, max_chain_length
Chris@4 223 cmp edi, esi
Chris@4 224 jl LastMatchGood
Chris@4 225 shr ebx, 2
Chris@4 226 LastMatchGood:
Chris@4 227
Chris@4 228 //;;; chainlen is decremented once beforehand so that the function can
Chris@4 229 //;;; use the sign flag instead of the zero flag for the exit test.
Chris@4 230 //;;; It is then shifted into the high word, to make room for the wmask
Chris@4 231 //;;; value, which it will always accompany.
Chris@4 232
Chris@4 233 dec ebx
Chris@4 234 shl ebx, 16
Chris@4 235 or ebx, eax
Chris@4 236
Chris@4 237 //;;; on zlib only
Chris@4 238 //;;; if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
Chris@4 239
Chris@4 240
Chris@4 241
Chris@4 242 mov eax, nice_match
Chris@4 243 mov [chainlenwmask], ebx
Chris@4 244 mov r10d, Lookahead
Chris@4 245 cmp r10d, eax
Chris@4 246 cmovnl r10d, eax
Chris@4 247 mov [nicematch],r10d
Chris@4 248
Chris@4 249
Chris@4 250
Chris@4 251 //;;; register Bytef *scan = s->window + s->strstart;
Chris@4 252 mov r10, window_ad
Chris@4 253 mov ebp, strstart
Chris@4 254 lea r13, [r10 + rbp]
Chris@4 255
Chris@4 256 //;;; Determine how many bytes the scan ptr is off from being
Chris@4 257 //;;; dword-aligned.
Chris@4 258
Chris@4 259 mov r9,r13
Chris@4 260 neg r13
Chris@4 261 and r13,3
Chris@4 262
Chris@4 263 //;;; IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
Chris@4 264 //;;; s->strstart - (IPos)MAX_DIST(s) : NIL;
Chris@4 265
Chris@4 266
Chris@4 267 mov eax, window_size
Chris@4 268 sub eax, MIN_LOOKAHEAD
Chris@4 269
Chris@4 270
Chris@4 271 xor edi,edi
Chris@4 272 sub ebp, eax
Chris@4 273
Chris@4 274 mov r11d, prev_length
Chris@4 275
Chris@4 276 cmovng ebp,edi
Chris@4 277
Chris@4 278 //;;; int best_len = s->prev_length;
Chris@4 279
Chris@4 280
Chris@4 281 //;;; Store the sum of s->window + best_len in esi locally, and in esi.
Chris@4 282
Chris@4 283 lea rsi,[r10+r11]
Chris@4 284
Chris@4 285 //;;; register ush scan_start = *(ushf*)scan;
Chris@4 286 //;;; register ush scan_end = *(ushf*)(scan+best_len-1);
Chris@4 287 //;;; Posf *prev = s->prev;
Chris@4 288
Chris@4 289 movzx r12d,word ptr [r9]
Chris@4 290 movzx ebx, word ptr [r9 + r11 - 1]
Chris@4 291
Chris@4 292 mov rdi, prev_ad
Chris@4 293
Chris@4 294 //;;; Jump into the main loop.
Chris@4 295
Chris@4 296 mov edx, [chainlenwmask]
Chris@4 297
Chris@4 298 cmp bx,word ptr [rsi + r8 - 1]
Chris@4 299 jz LookupLoopIsZero
Chris@4 300
Chris@4 301
Chris@4 302
Chris@4 303 LookupLoop1:
Chris@4 304 and r8d, edx
Chris@4 305
Chris@4 306 movzx r8d, word ptr [rdi + r8*2]
Chris@4 307 cmp r8d, ebp
Chris@4 308 jbe LeaveNow
Chris@4 309
Chris@4 310
Chris@4 311
Chris@4 312 sub edx, 0x00010000
Chris@4 313 BEFORE_JMP
Chris@4 314 js LeaveNow
Chris@4 315 AFTER_JMP
Chris@4 316
Chris@4 317 LoopEntry1:
Chris@4 318 cmp bx,word ptr [rsi + r8 - 1]
Chris@4 319 BEFORE_JMP
Chris@4 320 jz LookupLoopIsZero
Chris@4 321 AFTER_JMP
Chris@4 322
Chris@4 323 LookupLoop2:
Chris@4 324 and r8d, edx
Chris@4 325
Chris@4 326 movzx r8d, word ptr [rdi + r8*2]
Chris@4 327 cmp r8d, ebp
Chris@4 328 BEFORE_JMP
Chris@4 329 jbe LeaveNow
Chris@4 330 AFTER_JMP
Chris@4 331 sub edx, 0x00010000
Chris@4 332 BEFORE_JMP
Chris@4 333 js LeaveNow
Chris@4 334 AFTER_JMP
Chris@4 335
Chris@4 336 LoopEntry2:
Chris@4 337 cmp bx,word ptr [rsi + r8 - 1]
Chris@4 338 BEFORE_JMP
Chris@4 339 jz LookupLoopIsZero
Chris@4 340 AFTER_JMP
Chris@4 341
Chris@4 342 LookupLoop4:
Chris@4 343 and r8d, edx
Chris@4 344
Chris@4 345 movzx r8d, word ptr [rdi + r8*2]
Chris@4 346 cmp r8d, ebp
Chris@4 347 BEFORE_JMP
Chris@4 348 jbe LeaveNow
Chris@4 349 AFTER_JMP
Chris@4 350 sub edx, 0x00010000
Chris@4 351 BEFORE_JMP
Chris@4 352 js LeaveNow
Chris@4 353 AFTER_JMP
Chris@4 354
Chris@4 355 LoopEntry4:
Chris@4 356
Chris@4 357 cmp bx,word ptr [rsi + r8 - 1]
Chris@4 358 BEFORE_JMP
Chris@4 359 jnz LookupLoop1
Chris@4 360 jmp LookupLoopIsZero
Chris@4 361 AFTER_JMP
Chris@4 362 /*
Chris@4 363 ;;; do {
Chris@4 364 ;;; match = s->window + cur_match;
Chris@4 365 ;;; if (*(ushf*)(match+best_len-1) != scan_end ||
Chris@4 366 ;;; *(ushf*)match != scan_start) continue;
Chris@4 367 ;;; [...]
Chris@4 368 ;;; } while ((cur_match = prev[cur_match & wmask]) > limit
Chris@4 369 ;;; && --chain_length != 0);
Chris@4 370 ;;;
Chris@4 371 ;;; Here is the inner loop of the function. The function will spend the
Chris@4 372 ;;; majority of its time in this loop, and majority of that time will
Chris@4 373 ;;; be spent in the first ten instructions.
Chris@4 374 ;;;
Chris@4 375 ;;; Within this loop:
Chris@4 376 ;;; ebx = scanend
Chris@4 377 ;;; r8d = curmatch
Chris@4 378 ;;; edx = chainlenwmask - i.e., ((chainlen << 16) | wmask)
Chris@4 379 ;;; esi = windowbestlen - i.e., (window + bestlen)
Chris@4 380 ;;; edi = prev
Chris@4 381 ;;; ebp = limit
Chris@4 382 */
Chris@4 383 .balign 16
Chris@4 384 LookupLoop:
Chris@4 385 and r8d, edx
Chris@4 386
Chris@4 387 movzx r8d, word ptr [rdi + r8*2]
Chris@4 388 cmp r8d, ebp
Chris@4 389 BEFORE_JMP
Chris@4 390 jbe LeaveNow
Chris@4 391 AFTER_JMP
Chris@4 392 sub edx, 0x00010000
Chris@4 393 BEFORE_JMP
Chris@4 394 js LeaveNow
Chris@4 395 AFTER_JMP
Chris@4 396
Chris@4 397 LoopEntry:
Chris@4 398
Chris@4 399 cmp bx,word ptr [rsi + r8 - 1]
Chris@4 400 BEFORE_JMP
Chris@4 401 jnz LookupLoop1
Chris@4 402 AFTER_JMP
Chris@4 403 LookupLoopIsZero:
Chris@4 404 cmp r12w, word ptr [r10 + r8]
Chris@4 405 BEFORE_JMP
Chris@4 406 jnz LookupLoop1
Chris@4 407 AFTER_JMP
Chris@4 408
Chris@4 409
Chris@4 410 //;;; Store the current value of chainlen.
Chris@4 411 mov [chainlenwmask], edx
Chris@4 412 /*
Chris@4 413 ;;; Point edi to the string under scrutiny, and esi to the string we
Chris@4 414 ;;; are hoping to match it up with. In actuality, esi and edi are
Chris@4 415 ;;; both pointed (MAX_MATCH_8 - scanalign) bytes ahead, and edx is
Chris@4 416 ;;; initialized to -(MAX_MATCH_8 - scanalign).
Chris@4 417 */
Chris@4 418 lea rsi,[r8+r10]
Chris@4 419 mov rdx, 0xfffffffffffffef8 //; -(MAX_MATCH_8)
Chris@4 420 lea rsi, [rsi + r13 + 0x0108] //;MAX_MATCH_8]
Chris@4 421 lea rdi, [r9 + r13 + 0x0108] //;MAX_MATCH_8]
Chris@4 422
Chris@4 423 prefetcht1 [rsi+rdx]
Chris@4 424 prefetcht1 [rdi+rdx]
Chris@4 425
Chris@4 426 /*
Chris@4 427 ;;; Test the strings for equality, 8 bytes at a time. At the end,
Chris@4 428 ;;; adjust rdx so that it is offset to the exact byte that mismatched.
Chris@4 429 ;;;
Chris@4 430 ;;; We already know at this point that the first three bytes of the
Chris@4 431 ;;; strings match each other, and they can be safely passed over before
Chris@4 432 ;;; starting the compare loop. So what this code does is skip over 0-3
Chris@4 433 ;;; bytes, as much as necessary in order to dword-align the edi
Chris@4 434 ;;; pointer. (rsi will still be misaligned three times out of four.)
Chris@4 435 ;;;
Chris@4 436 ;;; It should be confessed that this loop usually does not represent
Chris@4 437 ;;; much of the total running time. Replacing it with a more
Chris@4 438 ;;; straightforward "rep cmpsb" would not drastically degrade
Chris@4 439 ;;; performance.
Chris@4 440 */
Chris@4 441
Chris@4 442 LoopCmps:
Chris@4 443 mov rax, [rsi + rdx]
Chris@4 444 xor rax, [rdi + rdx]
Chris@4 445 jnz LeaveLoopCmps
Chris@4 446
Chris@4 447 mov rax, [rsi + rdx + 8]
Chris@4 448 xor rax, [rdi + rdx + 8]
Chris@4 449 jnz LeaveLoopCmps8
Chris@4 450
Chris@4 451
Chris@4 452 mov rax, [rsi + rdx + 8+8]
Chris@4 453 xor rax, [rdi + rdx + 8+8]
Chris@4 454 jnz LeaveLoopCmps16
Chris@4 455
Chris@4 456 add rdx,8+8+8
Chris@4 457
Chris@4 458 BEFORE_JMP
Chris@4 459 jnz LoopCmps
Chris@4 460 jmp LenMaximum
Chris@4 461 AFTER_JMP
Chris@4 462
Chris@4 463 LeaveLoopCmps16: add rdx,8
Chris@4 464 LeaveLoopCmps8: add rdx,8
Chris@4 465 LeaveLoopCmps:
Chris@4 466
Chris@4 467 test eax, 0x0000FFFF
Chris@4 468 jnz LenLower
Chris@4 469
Chris@4 470 test eax,0xffffffff
Chris@4 471
Chris@4 472 jnz LenLower32
Chris@4 473
Chris@4 474 add rdx,4
Chris@4 475 shr rax,32
Chris@4 476 or ax,ax
Chris@4 477 BEFORE_JMP
Chris@4 478 jnz LenLower
Chris@4 479 AFTER_JMP
Chris@4 480
Chris@4 481 LenLower32:
Chris@4 482 shr eax,16
Chris@4 483 add rdx,2
Chris@4 484
Chris@4 485 LenLower:
Chris@4 486 sub al, 1
Chris@4 487 adc rdx, 0
Chris@4 488 //;;; Calculate the length of the match. If it is longer than MAX_MATCH,
Chris@4 489 //;;; then automatically accept it as the best possible match and leave.
Chris@4 490
Chris@4 491 lea rax, [rdi + rdx]
Chris@4 492 sub rax, r9
Chris@4 493 cmp eax, MAX_MATCH
Chris@4 494 BEFORE_JMP
Chris@4 495 jge LenMaximum
Chris@4 496 AFTER_JMP
Chris@4 497 /*
Chris@4 498 ;;; If the length of the match is not longer than the best match we
Chris@4 499 ;;; have so far, then forget it and return to the lookup loop.
Chris@4 500 ;///////////////////////////////////
Chris@4 501 */
Chris@4 502 cmp eax, r11d
Chris@4 503 jg LongerMatch
Chris@4 504
Chris@4 505 lea rsi,[r10+r11]
Chris@4 506
Chris@4 507 mov rdi, prev_ad
Chris@4 508 mov edx, [chainlenwmask]
Chris@4 509 BEFORE_JMP
Chris@4 510 jmp LookupLoop
Chris@4 511 AFTER_JMP
Chris@4 512 /*
Chris@4 513 ;;; s->match_start = cur_match;
Chris@4 514 ;;; best_len = len;
Chris@4 515 ;;; if (len >= nice_match) break;
Chris@4 516 ;;; scan_end = *(ushf*)(scan+best_len-1);
Chris@4 517 */
Chris@4 518 LongerMatch:
Chris@4 519 mov r11d, eax
Chris@4 520 mov match_start, r8d
Chris@4 521 cmp eax, [nicematch]
Chris@4 522 BEFORE_JMP
Chris@4 523 jge LeaveNow
Chris@4 524 AFTER_JMP
Chris@4 525
Chris@4 526 lea rsi,[r10+rax]
Chris@4 527
Chris@4 528 movzx ebx, word ptr [r9 + rax - 1]
Chris@4 529 mov rdi, prev_ad
Chris@4 530 mov edx, [chainlenwmask]
Chris@4 531 BEFORE_JMP
Chris@4 532 jmp LookupLoop
Chris@4 533 AFTER_JMP
Chris@4 534
Chris@4 535 //;;; Accept the current string, with the maximum possible length.
Chris@4 536
Chris@4 537 LenMaximum:
Chris@4 538 mov r11d,MAX_MATCH
Chris@4 539 mov match_start, r8d
Chris@4 540
Chris@4 541 //;;; if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
Chris@4 542 //;;; return s->lookahead;
Chris@4 543
Chris@4 544 LeaveNow:
Chris@4 545 mov eax, Lookahead
Chris@4 546 cmp r11d, eax
Chris@4 547 cmovng eax, r11d
Chris@4 548
Chris@4 549
Chris@4 550
Chris@4 551 //;;; Restore the stack and return from whence we came.
Chris@4 552
Chris@4 553
Chris@4 554 // mov rsi,[save_rsi]
Chris@4 555 // mov rdi,[save_rdi]
Chris@4 556 mov rbx,[save_rbx]
Chris@4 557 mov rbp,[save_rbp]
Chris@4 558 mov r12,[save_r12]
Chris@4 559 mov r13,[save_r13]
Chris@4 560 mov r14,[save_r14]
Chris@4 561 mov r15,[save_r15]
Chris@4 562
Chris@4 563
Chris@4 564 ret 0
Chris@4 565 //; please don't remove this string !
Chris@4 566 //; Your can freely use gvmat64 in any free or commercial app
Chris@4 567 //; but it is far better don't remove the string in the binary!
Chris@4 568 // 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@4 569
Chris@4 570
Chris@4 571 match_init:
Chris@4 572 ret 0
Chris@4 573
Chris@4 574