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 62longest_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 120void print_depl() 121{ 122deflate_state ds; 123deflate_state *s=&ds; 124printf("size pointer=%u\n",(int)sizeof(void*)); 125 126printf("#define dsWSize %u\n",(int)(((char*)&(s->w_size))-((char*)s))); 127printf("#define dsWMask %u\n",(int)(((char*)&(s->w_mask))-((char*)s))); 128printf("#define dsWindow %u\n",(int)(((char*)&(s->window))-((char*)s))); 129printf("#define dsPrev %u\n",(int)(((char*)&(s->prev))-((char*)s))); 130printf("#define dsMatchLen %u\n",(int)(((char*)&(s->match_length))-((char*)s))); 131printf("#define dsPrevMatch %u\n",(int)(((char*)&(s->prev_match))-((char*)s))); 132printf("#define dsStrStart %u\n",(int)(((char*)&(s->strstart))-((char*)s))); 133printf("#define dsMatchStart %u\n",(int)(((char*)&(s->match_start))-((char*)s))); 134printf("#define dsLookahead %u\n",(int)(((char*)&(s->lookahead))-((char*)s))); 135printf("#define dsPrevLen %u\n",(int)(((char*)&(s->prev_length))-((char*)s))); 136printf("#define dsMaxChainLen %u\n",(int)(((char*)&(s->max_chain_length))-((char*)s))); 137printf("#define dsGoodMatch %u\n",(int)(((char*)&(s->good_match))-((char*)s))); 138printf("#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 226LastMatchGood: 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 303LookupLoop1: 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 317LoopEntry1: 318 cmp bx,word ptr [rsi + r8 - 1] 319 BEFORE_JMP 320 jz LookupLoopIsZero 321 AFTER_JMP 322 323LookupLoop2: 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 336LoopEntry2: 337 cmp bx,word ptr [rsi + r8 - 1] 338 BEFORE_JMP 339 jz LookupLoopIsZero 340 AFTER_JMP 341 342LookupLoop4: 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 355LoopEntry4: 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 384LookupLoop: 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 397LoopEntry: 398 399 cmp bx,word ptr [rsi + r8 - 1] 400 BEFORE_JMP 401 jnz LookupLoop1 402 AFTER_JMP 403LookupLoopIsZero: 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 442LoopCmps: 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 463LeaveLoopCmps16: add rdx,8 464LeaveLoopCmps8: add rdx,8 465LeaveLoopCmps: 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 481LenLower32: 482 shr eax,16 483 add rdx,2 484 485LenLower: 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*/ 518LongerMatch: 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 537LenMaximum: 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 544LeaveNow: 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 571match_init: 572 ret 0 573 574 575