Add ARCH_X86_32 as a new define for 32 bit x86 architectures and change
[libav.git] / libavcodec / cabac.h
1 /*
2 * H.26L/H.264/AVC/JVT/14496-10/... encoder/decoder
3 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 *
21 */
22
23 /**
24 * @file cabac.h
25 * Context Adaptive Binary Arithmetic Coder.
26 */
27
28
29 //#undef NDEBUG
30 #include <assert.h>
31 #ifdef ARCH_X86_64
32 #define ARCH_X86
33 #endif
34 #ifdef ARCH_X86
35 #include "x86_cpu.h"
36 #endif
37
38 #define CABAC_BITS 16
39 #define CABAC_MASK ((1<<CABAC_BITS)-1)
40 #define BRANCHLESS_CABAC_DECODER 1
41 //#define ARCH_X86_DISABLED 1
42
43 typedef struct CABACContext{
44 int low;
45 int range;
46 int outstanding_count;
47 #ifdef STRICT_LIMITS
48 int symCount;
49 #endif
50 const uint8_t *bytestream_start;
51 const uint8_t *bytestream;
52 const uint8_t *bytestream_end;
53 PutBitContext pb;
54 }CABACContext;
55
56 extern uint8_t ff_h264_mlps_state[4*64];
57 extern uint8_t ff_h264_lps_range[4*2*64]; ///< rangeTabLPS
58 extern uint8_t ff_h264_mps_state[2*64]; ///< transIdxMPS
59 extern uint8_t ff_h264_lps_state[2*64]; ///< transIdxLPS
60 extern const uint8_t ff_h264_norm_shift[512];
61
62
63 void ff_init_cabac_encoder(CABACContext *c, uint8_t *buf, int buf_size);
64 void ff_init_cabac_decoder(CABACContext *c, const uint8_t *buf, int buf_size);
65 void ff_init_cabac_states(CABACContext *c);
66
67
68 static inline void put_cabac_bit(CABACContext *c, int b){
69 put_bits(&c->pb, 1, b);
70 for(;c->outstanding_count; c->outstanding_count--){
71 put_bits(&c->pb, 1, 1-b);
72 }
73 }
74
75 static inline void renorm_cabac_encoder(CABACContext *c){
76 while(c->range < 0x100){
77 //FIXME optimize
78 if(c->low<0x100){
79 put_cabac_bit(c, 0);
80 }else if(c->low<0x200){
81 c->outstanding_count++;
82 c->low -= 0x100;
83 }else{
84 put_cabac_bit(c, 1);
85 c->low -= 0x200;
86 }
87
88 c->range+= c->range;
89 c->low += c->low;
90 }
91 }
92
93 static void put_cabac(CABACContext *c, uint8_t * const state, int bit){
94 int RangeLPS= ff_h264_lps_range[2*(c->range&0xC0) + *state];
95
96 if(bit == ((*state)&1)){
97 c->range -= RangeLPS;
98 *state= ff_h264_mps_state[*state];
99 }else{
100 c->low += c->range - RangeLPS;
101 c->range = RangeLPS;
102 *state= ff_h264_lps_state[*state];
103 }
104
105 renorm_cabac_encoder(c);
106
107 #ifdef STRICT_LIMITS
108 c->symCount++;
109 #endif
110 }
111
112 static void put_cabac_static(CABACContext *c, int RangeLPS, int bit){
113 assert(c->range > RangeLPS);
114
115 if(!bit){
116 c->range -= RangeLPS;
117 }else{
118 c->low += c->range - RangeLPS;
119 c->range = RangeLPS;
120 }
121
122 renorm_cabac_encoder(c);
123
124 #ifdef STRICT_LIMITS
125 c->symCount++;
126 #endif
127 }
128
129 /**
130 * @param bit 0 -> write zero bit, !=0 write one bit
131 */
132 static void put_cabac_bypass(CABACContext *c, int bit){
133 c->low += c->low;
134
135 if(bit){
136 c->low += c->range;
137 }
138 //FIXME optimize
139 if(c->low<0x200){
140 put_cabac_bit(c, 0);
141 }else if(c->low<0x400){
142 c->outstanding_count++;
143 c->low -= 0x200;
144 }else{
145 put_cabac_bit(c, 1);
146 c->low -= 0x400;
147 }
148
149 #ifdef STRICT_LIMITS
150 c->symCount++;
151 #endif
152 }
153
154 /**
155 *
156 * @return the number of bytes written
157 */
158 static int put_cabac_terminate(CABACContext *c, int bit){
159 c->range -= 2;
160
161 if(!bit){
162 renorm_cabac_encoder(c);
163 }else{
164 c->low += c->range;
165 c->range= 2;
166
167 renorm_cabac_encoder(c);
168
169 assert(c->low <= 0x1FF);
170 put_cabac_bit(c, c->low>>9);
171 put_bits(&c->pb, 2, ((c->low>>7)&3)|1);
172
173 flush_put_bits(&c->pb); //FIXME FIXME FIXME XXX wrong
174 }
175
176 #ifdef STRICT_LIMITS
177 c->symCount++;
178 #endif
179
180 return (put_bits_count(&c->pb)+7)>>3;
181 }
182
183 /**
184 * put (truncated) unary binarization.
185 */
186 static void put_cabac_u(CABACContext *c, uint8_t * state, int v, int max, int max_index, int truncated){
187 int i;
188
189 assert(v <= max);
190
191 #if 1
192 for(i=0; i<v; i++){
193 put_cabac(c, state, 1);
194 if(i < max_index) state++;
195 }
196 if(truncated==0 || v<max)
197 put_cabac(c, state, 0);
198 #else
199 if(v <= max_index){
200 for(i=0; i<v; i++){
201 put_cabac(c, state+i, 1);
202 }
203 if(truncated==0 || v<max)
204 put_cabac(c, state+i, 0);
205 }else{
206 for(i=0; i<=max_index; i++){
207 put_cabac(c, state+i, 1);
208 }
209 for(; i<v; i++){
210 put_cabac(c, state+max_index, 1);
211 }
212 if(truncated==0 || v<max)
213 put_cabac(c, state+max_index, 0);
214 }
215 #endif
216 }
217
218 /**
219 * put unary exp golomb k-th order binarization.
220 */
221 static void put_cabac_ueg(CABACContext *c, uint8_t * state, int v, int max, int is_signed, int k, int max_index){
222 int i;
223
224 if(v==0)
225 put_cabac(c, state, 0);
226 else{
227 const int sign= v < 0;
228
229 if(is_signed) v= FFABS(v);
230
231 if(v<max){
232 for(i=0; i<v; i++){
233 put_cabac(c, state, 1);
234 if(i < max_index) state++;
235 }
236
237 put_cabac(c, state, 0);
238 }else{
239 int m= 1<<k;
240
241 for(i=0; i<max; i++){
242 put_cabac(c, state, 1);
243 if(i < max_index) state++;
244 }
245
246 v -= max;
247 while(v >= m){ //FIXME optimize
248 put_cabac_bypass(c, 1);
249 v-= m;
250 m+= m;
251 }
252 put_cabac_bypass(c, 0);
253 while(m>>=1){
254 put_cabac_bypass(c, v&m);
255 }
256 }
257
258 if(is_signed)
259 put_cabac_bypass(c, sign);
260 }
261 }
262
263 static void refill(CABACContext *c){
264 #if CABAC_BITS == 16
265 c->low+= (c->bytestream[0]<<9) + (c->bytestream[1]<<1);
266 #else
267 c->low+= c->bytestream[0]<<1;
268 #endif
269 c->low -= CABAC_MASK;
270 c->bytestream+= CABAC_BITS/8;
271 }
272
273 static void refill2(CABACContext *c){
274 int i, x;
275
276 x= c->low ^ (c->low-1);
277 i= 7 - ff_h264_norm_shift[x>>(CABAC_BITS-1)];
278
279 x= -CABAC_MASK;
280
281 #if CABAC_BITS == 16
282 x+= (c->bytestream[0]<<9) + (c->bytestream[1]<<1);
283 #else
284 x+= c->bytestream[0]<<1;
285 #endif
286
287 c->low += x<<i;
288 c->bytestream+= CABAC_BITS/8;
289 }
290
291 static inline void renorm_cabac_decoder(CABACContext *c){
292 while(c->range < 0x100){
293 c->range+= c->range;
294 c->low+= c->low;
295 if(!(c->low & CABAC_MASK))
296 refill(c);
297 }
298 }
299
300 static inline void renorm_cabac_decoder_once(CABACContext *c){
301 #ifdef ARCH_X86_DISABLED
302 int temp;
303 #if 0
304 //P3:683 athlon:475
305 asm(
306 "lea -0x100(%0), %2 \n\t"
307 "shr $31, %2 \n\t" //FIXME 31->63 for x86-64
308 "shl %%cl, %0 \n\t"
309 "shl %%cl, %1 \n\t"
310 : "+r"(c->range), "+r"(c->low), "+c"(temp)
311 );
312 #elif 0
313 //P3:680 athlon:474
314 asm(
315 "cmp $0x100, %0 \n\t"
316 "setb %%cl \n\t" //FIXME 31->63 for x86-64
317 "shl %%cl, %0 \n\t"
318 "shl %%cl, %1 \n\t"
319 : "+r"(c->range), "+r"(c->low), "+c"(temp)
320 );
321 #elif 1
322 int temp2;
323 //P3:665 athlon:517
324 asm(
325 "lea -0x100(%0), %%eax \n\t"
326 "cdq \n\t"
327 "mov %0, %%eax \n\t"
328 "and %%edx, %0 \n\t"
329 "and %1, %%edx \n\t"
330 "add %%eax, %0 \n\t"
331 "add %%edx, %1 \n\t"
332 : "+r"(c->range), "+r"(c->low), "+a"(temp), "+d"(temp2)
333 );
334 #elif 0
335 int temp2;
336 //P3:673 athlon:509
337 asm(
338 "cmp $0x100, %0 \n\t"
339 "sbb %%edx, %%edx \n\t"
340 "mov %0, %%eax \n\t"
341 "and %%edx, %0 \n\t"
342 "and %1, %%edx \n\t"
343 "add %%eax, %0 \n\t"
344 "add %%edx, %1 \n\t"
345 : "+r"(c->range), "+r"(c->low), "+a"(temp), "+d"(temp2)
346 );
347 #else
348 int temp2;
349 //P3:677 athlon:511
350 asm(
351 "cmp $0x100, %0 \n\t"
352 "lea (%0, %0), %%eax \n\t"
353 "lea (%1, %1), %%edx \n\t"
354 "cmovb %%eax, %0 \n\t"
355 "cmovb %%edx, %1 \n\t"
356 : "+r"(c->range), "+r"(c->low), "+a"(temp), "+d"(temp2)
357 );
358 #endif
359 #else
360 //P3:675 athlon:476
361 int shift= (uint32_t)(c->range - 0x100)>>31;
362 c->range<<= shift;
363 c->low <<= shift;
364 #endif
365 if(!(c->low & CABAC_MASK))
366 refill(c);
367 }
368
369 static int always_inline get_cabac_inline(CABACContext *c, uint8_t * const state){
370 //FIXME gcc generates duplicate load/stores for c->low and c->range
371 #define LOW "0"
372 #define RANGE "4"
373 #ifdef ARCH_X86_64
374 #define BYTESTART "16"
375 #define BYTE "24"
376 #define BYTEEND "32"
377 #else
378 #define BYTESTART "12"
379 #define BYTE "16"
380 #define BYTEEND "20"
381 #endif
382 #if defined(ARCH_X86_32) && !(defined(PIC) && defined(__GNUC__))
383 int bit;
384
385 #ifndef BRANCHLESS_CABAC_DECODER
386 asm volatile(
387 "movzbl (%1), %0 \n\t"
388 "movl "RANGE "(%2), %%ebx \n\t"
389 "movl "RANGE "(%2), %%edx \n\t"
390 "andl $0xC0, %%ebx \n\t"
391 "movzbl "MANGLE(ff_h264_lps_range)"(%0, %%ebx, 2), %%esi\n\t"
392 "movl "LOW "(%2), %%ebx \n\t"
393 //eax:state ebx:low, edx:range, esi:RangeLPS
394 "subl %%esi, %%edx \n\t"
395 "movl %%edx, %%ecx \n\t"
396 "shll $17, %%ecx \n\t"
397 "cmpl %%ecx, %%ebx \n\t"
398 " ja 1f \n\t"
399
400 #if 1
401 //athlon:4067 P3:4110
402 "lea -0x100(%%edx), %%ecx \n\t"
403 "shr $31, %%ecx \n\t"
404 "shl %%cl, %%edx \n\t"
405 "shl %%cl, %%ebx \n\t"
406 #else
407 //athlon:4057 P3:4130
408 "cmp $0x100, %%edx \n\t" //FIXME avoidable
409 "setb %%cl \n\t"
410 "shl %%cl, %%edx \n\t"
411 "shl %%cl, %%ebx \n\t"
412 #endif
413 "movzbl "MANGLE(ff_h264_mps_state)"(%0), %%ecx \n\t"
414 "movb %%cl, (%1) \n\t"
415 //eax:state ebx:low, edx:range, esi:RangeLPS
416 "test %%bx, %%bx \n\t"
417 " jnz 2f \n\t"
418 "mov "BYTE "(%2), %%"REG_S" \n\t"
419 "subl $0xFFFF, %%ebx \n\t"
420 "movzwl (%%"REG_S"), %%ecx \n\t"
421 "bswap %%ecx \n\t"
422 "shrl $15, %%ecx \n\t"
423 "add $2, %%"REG_S" \n\t"
424 "addl %%ecx, %%ebx \n\t"
425 "mov %%"REG_S", "BYTE "(%2) \n\t"
426 "jmp 2f \n\t"
427 "1: \n\t"
428 //eax:state ebx:low, edx:range, esi:RangeLPS
429 "subl %%ecx, %%ebx \n\t"
430 "movl %%esi, %%edx \n\t"
431 "movzbl " MANGLE(ff_h264_norm_shift) "(%%esi), %%ecx \n\t"
432 "shll %%cl, %%ebx \n\t"
433 "shll %%cl, %%edx \n\t"
434 "movzbl "MANGLE(ff_h264_lps_state)"(%0), %%ecx \n\t"
435 "movb %%cl, (%1) \n\t"
436 "add $1, %0 \n\t"
437 "test %%bx, %%bx \n\t"
438 " jnz 2f \n\t"
439
440 "mov "BYTE "(%2), %%"REG_c" \n\t"
441 "movzwl (%%"REG_c"), %%esi \n\t"
442 "bswap %%esi \n\t"
443 "shrl $15, %%esi \n\t"
444 "subl $0xFFFF, %%esi \n\t"
445 "add $2, %%"REG_c" \n\t"
446 "mov %%"REG_c", "BYTE "(%2) \n\t"
447
448 "leal -1(%%ebx), %%ecx \n\t"
449 "xorl %%ebx, %%ecx \n\t"
450 "shrl $15, %%ecx \n\t"
451 "movzbl " MANGLE(ff_h264_norm_shift) "(%%ecx), %%ecx \n\t"
452 "neg %%ecx \n\t"
453 "add $7, %%ecx \n\t"
454
455 "shll %%cl , %%esi \n\t"
456 "addl %%esi, %%ebx \n\t"
457 "2: \n\t"
458 "movl %%edx, "RANGE "(%2) \n\t"
459 "movl %%ebx, "LOW "(%2) \n\t"
460 :"=&a"(bit) //FIXME this is fragile gcc either runs out of registers or misscompiles it (for example if "+a"(bit) or "+m"(*state) is used
461 :"r"(state), "r"(c)
462 : "%"REG_c, "%ebx", "%edx", "%"REG_S, "memory"
463 );
464 bit&=1;
465 #else /* BRANCHLESS_CABAC_DECODER */
466
467
468 #if defined CMOV_IS_FAST
469 #define BRANCHLESS_GET_CABAC_UPDATE(ret, cabac, statep, low, lowword, range, tmp, tmpbyte)\
470 "mov "tmp" , %%ecx \n\t"\
471 "shl $17 , "tmp" \n\t"\
472 "cmp "low" , "tmp" \n\t"\
473 "cmova %%ecx , "range" \n\t"\
474 "sbb %%ecx , %%ecx \n\t"\
475 "and %%ecx , "tmp" \n\t"\
476 "sub "tmp" , "low" \n\t"\
477 "xor %%ecx , "ret" \n\t"
478 #else /* CMOV_IS_FAST */
479 #define BRANCHLESS_GET_CABAC_UPDATE(ret, cabac, statep, low, lowword, range, tmp, tmpbyte)\
480 "mov "tmp" , %%ecx \n\t"\
481 "shl $17 , "tmp" \n\t"\
482 "sub "low" , "tmp" \n\t"\
483 "sar $31 , "tmp" \n\t" /*lps_mask*/\
484 "sub %%ecx , "range" \n\t" /*RangeLPS - range*/\
485 "and "tmp" , "range" \n\t" /*(RangeLPS - range)&lps_mask*/\
486 "add %%ecx , "range" \n\t" /*new range*/\
487 "shl $17 , %%ecx \n\t"\
488 "and "tmp" , %%ecx \n\t"\
489 "sub %%ecx , "low" \n\t"\
490 "xor "tmp" , "ret" \n\t"
491 #endif /* CMOV_IS_FAST */
492
493
494 #define BRANCHLESS_GET_CABAC(ret, cabac, statep, low, lowword, range, tmp, tmpbyte)\
495 "movzbl "statep" , "ret" \n\t"\
496 "mov "range" , "tmp" \n\t"\
497 "and $0xC0 , "range" \n\t"\
498 "movzbl "MANGLE(ff_h264_lps_range)"("ret", "range", 2), "range" \n\t"\
499 "sub "range" , "tmp" \n\t"\
500 BRANCHLESS_GET_CABAC_UPDATE(ret, cabac, statep, low, lowword, range, tmp, tmpbyte)\
501 "movzbl " MANGLE(ff_h264_norm_shift) "("range"), %%ecx \n\t"\
502 "shl %%cl , "range" \n\t"\
503 "movzbl "MANGLE(ff_h264_mlps_state)"+128("ret"), "tmp" \n\t"\
504 "mov "tmpbyte" , "statep" \n\t"\
505 "shl %%cl , "low" \n\t"\
506 "test "lowword" , "lowword" \n\t"\
507 " jnz 1f \n\t"\
508 "mov "BYTE"("cabac"), %%"REG_c" \n\t"\
509 "movzwl (%%"REG_c") , "tmp" \n\t"\
510 "bswap "tmp" \n\t"\
511 "shr $15 , "tmp" \n\t"\
512 "sub $0xFFFF , "tmp" \n\t"\
513 "add $2 , %%"REG_c" \n\t"\
514 "mov %%"REG_c" , "BYTE "("cabac") \n\t"\
515 "lea -1("low") , %%ecx \n\t"\
516 "xor "low" , %%ecx \n\t"\
517 "shr $15 , %%ecx \n\t"\
518 "movzbl " MANGLE(ff_h264_norm_shift) "(%%ecx), %%ecx \n\t"\
519 "neg %%ecx \n\t"\
520 "add $7 , %%ecx \n\t"\
521 "shl %%cl , "tmp" \n\t"\
522 "add "tmp" , "low" \n\t"\
523 "1: \n\t"
524
525 asm volatile(
526 "movl "RANGE "(%2), %%esi \n\t"
527 "movl "LOW "(%2), %%ebx \n\t"
528 BRANCHLESS_GET_CABAC("%0", "%2", "(%1)", "%%ebx", "%%bx", "%%esi", "%%edx", "%%dl")
529 "movl %%esi, "RANGE "(%2) \n\t"
530 "movl %%ebx, "LOW "(%2) \n\t"
531
532 :"=&a"(bit)
533 :"r"(state), "r"(c)
534 : "%"REG_c, "%ebx", "%edx", "%esi", "memory"
535 );
536 bit&=1;
537 #endif /* BRANCHLESS_CABAC_DECODER */
538 #else /* defined(ARCH_X86_32) && !(defined(PIC) && defined(__GNUC__)) */
539 int s = *state;
540 int RangeLPS= ff_h264_lps_range[2*(c->range&0xC0) + s];
541 int bit, lps_mask attribute_unused;
542
543 c->range -= RangeLPS;
544 #ifndef BRANCHLESS_CABAC_DECODER
545 if(c->low < (c->range<<17)){
546 bit= s&1;
547 *state= ff_h264_mps_state[s];
548 renorm_cabac_decoder_once(c);
549 }else{
550 bit= ff_h264_norm_shift[RangeLPS];
551 c->low -= (c->range<<17);
552 *state= ff_h264_lps_state[s];
553 c->range = RangeLPS<<bit;
554 c->low <<= bit;
555 bit= (s&1)^1;
556
557 if(!(c->low & 0xFFFF)){
558 refill2(c);
559 }
560 }
561 #else /* BRANCHLESS_CABAC_DECODER */
562 lps_mask= ((c->range<<17) - c->low)>>31;
563
564 c->low -= (c->range<<17) & lps_mask;
565 c->range += (RangeLPS - c->range) & lps_mask;
566
567 s^=lps_mask;
568 *state= (ff_h264_mlps_state+128)[s];
569 bit= s&1;
570
571 lps_mask= ff_h264_norm_shift[c->range];
572 c->range<<= lps_mask;
573 c->low <<= lps_mask;
574 if(!(c->low & CABAC_MASK))
575 refill2(c);
576 #endif /* BRANCHLESS_CABAC_DECODER */
577 #endif /* defined(ARCH_X86_32) && !(defined(PIC) && defined(__GNUC__)) */
578 return bit;
579 }
580
581 static int __attribute((noinline)) get_cabac_noinline(CABACContext *c, uint8_t * const state){
582 return get_cabac_inline(c,state);
583 }
584
585 static int get_cabac(CABACContext *c, uint8_t * const state){
586 return get_cabac_inline(c,state);
587 }
588
589 static int get_cabac_bypass(CABACContext *c){
590 #if 0 //not faster
591 int bit;
592 asm volatile(
593 "movl "RANGE "(%1), %%ebx \n\t"
594 "movl "LOW "(%1), %%eax \n\t"
595 "shl $17, %%ebx \n\t"
596 "add %%eax, %%eax \n\t"
597 "sub %%ebx, %%eax \n\t"
598 "cdq \n\t"
599 "and %%edx, %%ebx \n\t"
600 "add %%ebx, %%eax \n\t"
601 "test %%ax, %%ax \n\t"
602 " jnz 1f \n\t"
603 "movl "BYTE "(%1), %%"REG_b" \n\t"
604 "subl $0xFFFF, %%eax \n\t"
605 "movzwl (%%"REG_b"), %%ecx \n\t"
606 "bswap %%ecx \n\t"
607 "shrl $15, %%ecx \n\t"
608 "addl $2, %%"REG_b" \n\t"
609 "addl %%ecx, %%eax \n\t"
610 "movl %%"REG_b", "BYTE "(%1) \n\t"
611 "1: \n\t"
612 "movl %%eax, "LOW "(%1) \n\t"
613
614 :"=&d"(bit)
615 :"r"(c)
616 : "%eax", "%"REG_b, "%ecx", "memory"
617 );
618 return bit+1;
619 #else
620 int range;
621 c->low += c->low;
622
623 if(!(c->low & CABAC_MASK))
624 refill(c);
625
626 range= c->range<<17;
627 if(c->low < range){
628 return 0;
629 }else{
630 c->low -= range;
631 return 1;
632 }
633 #endif
634 }
635
636
637 static always_inline int get_cabac_bypass_sign(CABACContext *c, int val){
638 #ifdef ARCH_X86
639 asm volatile(
640 "movl "RANGE "(%1), %%ebx \n\t"
641 "movl "LOW "(%1), %%eax \n\t"
642 "shl $17, %%ebx \n\t"
643 "add %%eax, %%eax \n\t"
644 "sub %%ebx, %%eax \n\t"
645 "cdq \n\t"
646 "and %%edx, %%ebx \n\t"
647 "add %%ebx, %%eax \n\t"
648 "xor %%edx, %%ecx \n\t"
649 "sub %%edx, %%ecx \n\t"
650 "test %%ax, %%ax \n\t"
651 " jnz 1f \n\t"
652 "mov "BYTE "(%1), %%"REG_b" \n\t"
653 "subl $0xFFFF, %%eax \n\t"
654 "movzwl (%%"REG_b"), %%edx \n\t"
655 "bswap %%edx \n\t"
656 "shrl $15, %%edx \n\t"
657 "add $2, %%"REG_b" \n\t"
658 "addl %%edx, %%eax \n\t"
659 "mov %%"REG_b", "BYTE "(%1) \n\t"
660 "1: \n\t"
661 "movl %%eax, "LOW "(%1) \n\t"
662
663 :"+c"(val)
664 :"r"(c)
665 : "%eax", "%"REG_b, "%edx", "memory"
666 );
667 return val;
668 #else
669 int range, mask;
670 c->low += c->low;
671
672 if(!(c->low & CABAC_MASK))
673 refill(c);
674
675 range= c->range<<17;
676 c->low -= range;
677 mask= c->low >> 31;
678 range &= mask;
679 c->low += range;
680 return (val^mask)-mask;
681 #endif
682 }
683
684 //FIXME the x86 code from this file should be moved into i386/h264 or cabac something.c/h (note ill kill you if you move my code away from under my fingers before iam finished with it!)
685 //FIXME use some macros to avoid duplicatin get_cabac (cant be done yet as that would make optimization work hard)
686 #if defined(ARCH_X86_32) && !(defined(PIC) && defined(__GNUC__))
687 static int decode_significance_x86(CABACContext *c, int max_coeff, uint8_t *significant_coeff_ctx_base, int *index){
688 void *end= significant_coeff_ctx_base + max_coeff - 1;
689 int minusstart= -(int)significant_coeff_ctx_base;
690 int minusindex= 4-(int)index;
691 int coeff_count;
692 asm volatile(
693 "movl "RANGE "(%3), %%esi \n\t"
694 "movl "LOW "(%3), %%ebx \n\t"
695
696 "2: \n\t"
697
698 BRANCHLESS_GET_CABAC("%%edx", "%3", "(%1)", "%%ebx", "%%bx", "%%esi", "%%eax", "%%al")
699
700 "test $1, %%edx \n\t"
701 " jz 3f \n\t"
702
703 BRANCHLESS_GET_CABAC("%%edx", "%3", "61(%1)", "%%ebx", "%%bx", "%%esi", "%%eax", "%%al")
704
705 "mov %2, %%"REG_a" \n\t"
706 "movl %4, %%ecx \n\t"
707 "add %1, %%"REG_c" \n\t"
708 "movl %%ecx, (%%"REG_a") \n\t"
709
710 "test $1, %%edx \n\t"
711 " jnz 4f \n\t"
712
713 "add $4, %%"REG_a" \n\t"
714 "mov %%"REG_a", %2 \n\t"
715
716 "3: \n\t"
717 "add $1, %1 \n\t"
718 "cmp %5, %1 \n\t"
719 " jb 2b \n\t"
720 "mov %2, %%"REG_a" \n\t"
721 "movl %4, %%ecx \n\t"
722 "add %1, %%"REG_c" \n\t"
723 "movl %%ecx, (%%"REG_a") \n\t"
724 "4: \n\t"
725 "add %6, %%eax \n\t"
726 "shr $2, %%eax \n\t"
727
728 "movl %%esi, "RANGE "(%3) \n\t"
729 "movl %%ebx, "LOW "(%3) \n\t"
730 :"=&a"(coeff_count), "+r"(significant_coeff_ctx_base), "+m"(index)\
731 :"r"(c), "m"(minusstart), "m"(end), "m"(minusindex)\
732 : "%"REG_c, "%ebx", "%edx", "%esi", "memory"\
733 );
734 return coeff_count;
735 }
736
737 static int decode_significance_8x8_x86(CABACContext *c, uint8_t *significant_coeff_ctx_base, int *index, uint8_t *sig_off){
738 int minusindex= 4-(int)index;
739 int coeff_count;
740 long last=0;
741 asm volatile(
742 "movl "RANGE "(%3), %%esi \n\t"
743 "movl "LOW "(%3), %%ebx \n\t"
744
745 "mov %1, %%"REG_D" \n\t"
746 "2: \n\t"
747
748 "mov %6, %%"REG_a" \n\t"
749 "movzbl (%%"REG_a", %%"REG_D"), %%edi \n\t"
750 "add %5, %%"REG_D" \n\t"
751
752 BRANCHLESS_GET_CABAC("%%edx", "%3", "(%%"REG_D")", "%%ebx", "%%bx", "%%esi", "%%eax", "%%al")
753
754 "mov %1, %%edi \n\t"
755 "test $1, %%edx \n\t"
756 " jz 3f \n\t"
757
758 "movzbl "MANGLE(last_coeff_flag_offset_8x8)"(%%edi), %%edi\n\t"
759 "add %5, %%"REG_D" \n\t"
760
761 BRANCHLESS_GET_CABAC("%%edx", "%3", "15(%%"REG_D")", "%%ebx", "%%bx", "%%esi", "%%eax", "%%al")
762
763 "mov %2, %%"REG_a" \n\t"
764 "mov %1, %%edi \n\t"
765 "movl %%edi, (%%"REG_a") \n\t"
766
767 "test $1, %%edx \n\t"
768 " jnz 4f \n\t"
769
770 "add $4, %%"REG_a" \n\t"
771 "mov %%"REG_a", %2 \n\t"
772
773 "3: \n\t"
774 "addl $1, %%edi \n\t"
775 "mov %%edi, %1 \n\t"
776 "cmpl $63, %%edi \n\t"
777 " jb 2b \n\t"
778 "mov %2, %%"REG_a" \n\t"
779 "movl %%edi, (%%"REG_a") \n\t"
780 "4: \n\t"
781 "addl %4, %%eax \n\t"
782 "shr $2, %%eax \n\t"
783
784 "movl %%esi, "RANGE "(%3) \n\t"
785 "movl %%ebx, "LOW "(%3) \n\t"
786 :"=&a"(coeff_count),"+m"(last), "+m"(index)\
787 :"r"(c), "m"(minusindex), "m"(significant_coeff_ctx_base), "m"(sig_off)\
788 : "%"REG_c, "%ebx", "%edx", "%esi", "%"REG_D, "memory"\
789 );
790 return coeff_count;
791 }
792 #endif /* defined(ARCH_X86_32) && !(defined(PIC) && defined(__GNUC__)) */
793
794 /**
795 *
796 * @return the number of bytes read or 0 if no end
797 */
798 static int get_cabac_terminate(CABACContext *c){
799 c->range -= 2;
800 if(c->low < c->range<<17){
801 renorm_cabac_decoder_once(c);
802 return 0;
803 }else{
804 return c->bytestream - c->bytestream_start;
805 }
806 }
807
808 /**
809 * get (truncated) unnary binarization.
810 */
811 static int get_cabac_u(CABACContext *c, uint8_t * state, int max, int max_index, int truncated){
812 int i;
813
814 for(i=0; i<max; i++){
815 if(get_cabac(c, state)==0)
816 return i;
817
818 if(i< max_index) state++;
819 }
820
821 return truncated ? max : -1;
822 }
823
824 /**
825 * get unary exp golomb k-th order binarization.
826 */
827 static int get_cabac_ueg(CABACContext *c, uint8_t * state, int max, int is_signed, int k, int max_index){
828 int i, v;
829 int m= 1<<k;
830
831 if(get_cabac(c, state)==0)
832 return 0;
833
834 if(0 < max_index) state++;
835
836 for(i=1; i<max; i++){
837 if(get_cabac(c, state)==0){
838 if(is_signed && get_cabac_bypass(c)){
839 return -i;
840 }else
841 return i;
842 }
843
844 if(i < max_index) state++;
845 }
846
847 while(get_cabac_bypass(c)){
848 i+= m;
849 m+= m;
850 }
851
852 v=0;
853 while(m>>=1){
854 v+= v + get_cabac_bypass(c);
855 }
856 i += v;
857
858 if(is_signed && get_cabac_bypass(c)){
859 return -i;
860 }else
861 return i;
862 }