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 0 573 574 575
