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