src/third-party/zlib/contrib/gcc_gvmat64/gvmat64.S (view raw)
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