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cabac.h
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1/*
2 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21#ifndef AVCODEC_X86_CABAC_H
22#define AVCODEC_X86_CABAC_H
23
24#include <stddef.h>
25
26#include "libavcodec/cabac.h"
27#include "libavutil/attributes.h"
28#include "libavutil/macros.h"
29#include "libavutil/x86/asm.h"
30#include "config.h"
31
32#if (defined(__i386) && defined(__clang__) && (__clang_major__<2 || (__clang_major__==2 && __clang_minor__<10)))\
33 || ( !defined(__clang__) && defined(__llvm__) && __GNUC__==4 && __GNUC_MINOR__==2 && __GNUC_PATCHLEVEL__<=1)\
34 || (defined(__INTEL_COMPILER) && defined(_MSC_VER))
35# define BROKEN_COMPILER 1
36#else
37# define BROKEN_COMPILER 0
38#endif
39
40#if HAVE_INLINE_ASM
41
42#ifndef UNCHECKED_BITSTREAM_READER
43#define UNCHECKED_BITSTREAM_READER !CONFIG_SAFE_BITSTREAM_READER
44#endif
45
46#if UNCHECKED_BITSTREAM_READER
47#define END_CHECK(end) ""
48#else
49#define END_CHECK(end) \
50 "cmp "end" , %%"FF_REG_c" \n\t"\
51 "jge 1f \n\t"
52#endif
53
54#ifdef BROKEN_RELOCATIONS
55#define TABLES_ARG , "r"(tables)
56
57#if HAVE_FAST_CMOV
58#define BRANCHLESS_GET_CABAC_UPDATE(ret, retq, low, range, tmp) \
59 "cmp "low" , "tmp" \n\t"\
60 "cmova %%ecx , "range" \n\t"\
61 "sbb %%rcx , %%rcx \n\t"\
62 "and %%ecx , "tmp" \n\t"\
63 "xor %%rcx , "retq" \n\t"\
64 "sub "tmp" , "low" \n\t"
65#else /* HAVE_FAST_CMOV */
66#define BRANCHLESS_GET_CABAC_UPDATE(ret, retq, low, range, tmp) \
67/* P4 Prescott has crappy cmov,sbb,64-bit shift so avoid them */ \
68 "sub "low" , "tmp" \n\t"\
69 "sar $31 , "tmp" \n\t"\
70 "sub %%ecx , "range" \n\t"\
71 "and "tmp" , "range" \n\t"\
72 "add %%ecx , "range" \n\t"\
73 "shl $17 , %%ecx \n\t"\
74 "and "tmp" , %%ecx \n\t"\
75 "sub %%ecx , "low" \n\t"\
76 "xor "tmp" , "ret" \n\t"\
77 "movslq "ret" , "retq" \n\t"
78#endif /* HAVE_FAST_CMOV */
79
80#ifdef __LZCNT__
81/* renormalisation shift = lzcnt(range) - 23, refill shift = tzcnt(low) - 16 */
82#define BRANCHLESS_GET_CABAC_RENORM(range, rangeq, norm_off, tables) \
83 "lzcnt "range" , %%ecx \n\t"\
84 "sub $23 , %%ecx \n\t"
85#define BRANCHLESS_GET_CABAC_REFILL(low, tmp, norm_off, tables) \
86 "movzwl (%%"FF_REG_c") , "tmp" \n\t"\
87 "tzcnt "low" , %%ecx \n\t"\
88 "bswap "tmp" \n\t"\
89 "shr $15 , "tmp" \n\t"\
90 "sub $16 , %%ecx \n\t"\
91 "sub $0xFFFF , "tmp" \n\t"\
92 "shl %%cl , "tmp" \n\t"\
93 "add "tmp" , "low" \n\t"
94#else /* __LZCNT__ */
95#define BRANCHLESS_GET_CABAC_RENORM(range, rangeq, norm_off, tables) \
96 "movzbl "norm_off"("tables", "rangeq"), %%ecx \n\t"
97#define BRANCHLESS_GET_CABAC_REFILL(low, tmp, norm_off, tables) \
98 "movzwl (%%"FF_REG_c") , "tmp" \n\t"\
99 "lea -1("low") , %%ecx \n\t"\
100 "xor "low" , %%ecx \n\t"\
101 "shr $15 , %%ecx \n\t"\
102 "bswap "tmp" \n\t"\
103 "shr $15 , "tmp" \n\t"\
104 "movzbl "norm_off"("tables", %%rcx), %%ecx \n\t"\
105 "sub $0xFFFF , "tmp" \n\t"\
106 "neg %%ecx \n\t"\
107 "add $7 , %%ecx \n\t"\
108 "shl %%cl , "tmp" \n\t"\
109 "add "tmp" , "low" \n\t"
110#endif /* __LZCNT__ */
111
112#define BRANCHLESS_GET_CABAC(ret, retq, statep, low, lowword, range, rangeq, tmp, tmpbyte, byte, end, norm_off, lps_off, mlps_off, tables) \
113 "movzbl "statep" , "ret" \n\t"\
114 "mov "range" , "tmp" \n\t"\
115 "and $0xC0 , "range" \n\t"\
116 "lea ("ret", "range", 2), %%ecx \n\t"\
117 "movzbl "lps_off"("tables", %%rcx), "range" \n\t"\
118 "sub "range" , "tmp" \n\t"\
119 "mov "tmp" , %%ecx \n\t"\
120 "shl $17 , "tmp" \n\t"\
121 BRANCHLESS_GET_CABAC_UPDATE(ret, retq, low, range, tmp) \
122 BRANCHLESS_GET_CABAC_RENORM(range, rangeq, norm_off, tables) \
123 "shl %%cl , "range" \n\t"\
124 "movzbl "mlps_off"+128("tables", "retq"), "tmp" \n\t"\
125 "shl %%cl , "low" \n\t"\
126 "mov "tmpbyte" , "statep" \n\t"\
127 "test "lowword" , "lowword" \n\t"\
128 "jnz 2f \n\t"\
129 "mov "byte" , %%"FF_REG_c" \n\t"\
130 END_CHECK(end)\
131 "add"FF_OPSIZE" $2 , "byte" \n\t"\
132 "1: \n\t"\
133 BRANCHLESS_GET_CABAC_REFILL(low, tmp, norm_off, tables) \
134 "2: \n\t"
135
136#else /* BROKEN_RELOCATIONS */
137#define TABLES_ARG NAMED_CONSTRAINTS_ARRAY_ADD(ff_h264_cabac_tables)
138#define RIP_ARG
139
140#if HAVE_FAST_CMOV
141#define BRANCHLESS_GET_CABAC_UPDATE(ret, low, range, tmp)\
142 "mov "tmp" , %%ecx \n\t"\
143 "shl $17 , "tmp" \n\t"\
144 "cmp "low" , "tmp" \n\t"\
145 "cmova %%ecx , "range" \n\t"\
146 "sbb %%ecx , %%ecx \n\t"\
147 "and %%ecx , "tmp" \n\t"\
148 "xor %%ecx , "ret" \n\t"\
149 "sub "tmp" , "low" \n\t"
150#else /* HAVE_FAST_CMOV */
151#define BRANCHLESS_GET_CABAC_UPDATE(ret, low, range, tmp)\
152 "mov "tmp" , %%ecx \n\t"\
153 "shl $17 , "tmp" \n\t"\
154 "sub "low" , "tmp" \n\t"\
155 "sar $31 , "tmp" \n\t" /*lps_mask*/\
156 "sub %%ecx , "range" \n\t" /*RangeLPS - range*/\
157 "and "tmp" , "range" \n\t" /*(RangeLPS - range)&lps_mask*/\
158 "add %%ecx , "range" \n\t" /*new range*/\
159 "shl $17 , %%ecx \n\t"\
160 "and "tmp" , %%ecx \n\t"\
161 "sub %%ecx , "low" \n\t"\
162 "xor "tmp" , "ret" \n\t"
163#endif /* HAVE_FAST_CMOV */
164
165#ifdef __LZCNT__
166#define BRANCHLESS_GET_CABAC_RENORM(range, rangeq, norm_off, tables) \
167 "lzcnt "range" , %%ecx \n\t"\
168 "sub $23 , %%ecx \n\t"
169#define BRANCHLESS_GET_CABAC_REFILL(low, tmp, norm_off, tables) \
170 "movzwl (%%"FF_REG_c") , "tmp" \n\t"\
171 "tzcnt "low" , %%ecx \n\t"\
172 "bswap "tmp" \n\t"\
173 "shr $15 , "tmp" \n\t"\
174 "sub $16 , %%ecx \n\t"\
175 "sub $0xFFFF , "tmp" \n\t"\
176 "shl %%cl , "tmp" \n\t"\
177 "add "tmp" , "low" \n\t"
178#else /* __LZCNT__ */
179#define BRANCHLESS_GET_CABAC_RENORM(range, rangeq, norm_off, tables) \
180 "movzbl "MANGLE(ff_h264_cabac_tables)"+"norm_off"("range"), %%ecx \n\t"
181#define BRANCHLESS_GET_CABAC_REFILL(low, tmp, norm_off, tables) \
182 "movzwl (%%"FF_REG_c") , "tmp" \n\t"\
183 "lea -1("low") , %%ecx \n\t"\
184 "xor "low" , %%ecx \n\t"\
185 "shr $15 , %%ecx \n\t"\
186 "bswap "tmp" \n\t"\
187 "shr $15 , "tmp" \n\t"\
188 "movzbl "MANGLE(ff_h264_cabac_tables)"+"norm_off"(%%ecx), %%ecx \n\t"\
189 "sub $0xFFFF , "tmp" \n\t"\
190 "neg %%ecx \n\t"\
191 "add $7 , %%ecx \n\t"\
192 "shl %%cl , "tmp" \n\t"\
193 "add "tmp" , "low" \n\t"
194#endif /* __LZCNT__ */
195
196#define BRANCHLESS_GET_CABAC(ret, retq, statep, low, lowword, range, rangeq, tmp, tmpbyte, byte, end, norm_off, lps_off, mlps_off, tables) \
197 "movzbl "statep" , "ret" \n\t"\
198 "mov "range" , "tmp" \n\t"\
199 "and $0xC0 , "range" \n\t"\
200 "movzbl "MANGLE(ff_h264_cabac_tables)"+"lps_off"("ret", "range", 2), "range" \n\t"\
201 "sub "range" , "tmp" \n\t"\
202 BRANCHLESS_GET_CABAC_UPDATE(ret, low, range, tmp) \
203 BRANCHLESS_GET_CABAC_RENORM(range, rangeq, norm_off, tables) \
204 "shl %%cl , "range" \n\t"\
205 "movzbl "MANGLE(ff_h264_cabac_tables)"+"mlps_off"+128("ret"), "tmp" \n\t"\
206 "shl %%cl , "low" \n\t"\
207 "mov "tmpbyte" , "statep" \n\t"\
208 "test "lowword" , "lowword" \n\t"\
209 " jnz 2f \n\t"\
210 "mov "byte" , %%"FF_REG_c" \n\t"\
211 END_CHECK(end)\
212 "add"FF_OPSIZE" $2 , "byte" \n\t"\
213 "1: \n\t"\
214 BRANCHLESS_GET_CABAC_REFILL(low, tmp, norm_off, tables) \
215 "2: \n\t"
216
217#endif /* BROKEN_RELOCATIONS */
218
219#if HAVE_X86_7REGS && !BROKEN_COMPILER
220#define get_cabac_inline get_cabac_inline_x86
221static
222#if ARCH_X86_32
223av_noinline
224#else
225av_always_inline
226#endif
227int get_cabac_inline_x86(CABACContext *c, uint8_t *const state)
228{
229 int bit, tmp;
230#ifdef BROKEN_RELOCATIONS
231 void *tables;
232
233 __asm__ volatile(
234 "lea "MANGLE(ff_h264_cabac_tables)", %0 \n\t"
235 : "=&r"(tables)
236 : NAMED_CONSTRAINTS_ARRAY(ff_h264_cabac_tables)
237 );
238#endif
239
240 __asm__ volatile(
241 BRANCHLESS_GET_CABAC("%0", "%q0", "(%4)", "%1", "%w1",
242 "%2", "%q2", "%3", "%b3",
243 "%c6(%5)", "%c7(%5)",
244 AV_STRINGIFY(H264_NORM_SHIFT_OFFSET),
245 AV_STRINGIFY(H264_LPS_RANGE_OFFSET),
246 AV_STRINGIFY(H264_MLPS_STATE_OFFSET),
247 "%8")
248 : "=&r"(bit), "=&r"(c->low), "=&r"(c->range), "=&q"(tmp)
249 : "r"(state), "r"(c),
250 "i"(offsetof(CABACContext, bytestream)),
251 "i"(offsetof(CABACContext, bytestream_end))
252 TABLES_ARG
253 ,"1"(c->low), "2"(c->range)
254 : "%"FF_REG_c, "memory"
255 );
256 return bit & 1;
257}
258#endif /* HAVE_X86_7REGS && !BROKEN_COMPILER */
259
260#if !BROKEN_COMPILER
261#define get_cabac_bypass_sign get_cabac_bypass_sign_x86
262static av_always_inline int get_cabac_bypass_sign_x86(CABACContext *c, int val)
263{
264 x86_reg tmp;
265 __asm__ volatile(
266 "movl %c6(%2), %k1 \n\t"
267 "movl %c3(%2), %%eax \n\t"
268 "shl $17, %k1 \n\t"
269 "add %%eax, %%eax \n\t"
270 "sub %k1, %%eax \n\t"
271 "cdq \n\t"
272 "and %%edx, %k1 \n\t"
273 "add %k1, %%eax \n\t"
274 "xor %%edx, %%ecx \n\t"
275 "sub %%edx, %%ecx \n\t"
276 "test %%ax, %%ax \n\t"
277 "jnz 1f \n\t"
278 "mov %c4(%2), %1 \n\t"
279 "subl $0xFFFF, %%eax \n\t"
280 "movzwl (%1), %%edx \n\t"
281 "bswap %%edx \n\t"
282 "shrl $15, %%edx \n\t"
283#if UNCHECKED_BITSTREAM_READER
284 "add $2, %1 \n\t"
285 "addl %%edx, %%eax \n\t"
286 "mov %1, %c4(%2) \n\t"
287#else
288 "addl %%edx, %%eax \n\t"
289 "cmp %c5(%2), %1 \n\t"
290 "jge 1f \n\t"
291 "add"FF_OPSIZE" $2, %c4(%2) \n\t"
292#endif
293 "1: \n\t"
294 "movl %%eax, %c3(%2) \n\t"
295
296 : "+c"(val), "=&r"(tmp)
297 : "r"(c),
298 "i"(offsetof(CABACContext, low)),
299 "i"(offsetof(CABACContext, bytestream)),
300 "i"(offsetof(CABACContext, bytestream_end)),
301 "i"(offsetof(CABACContext, range))
302 : "%eax", "%edx", "memory"
303 );
304 return val;
305}
306
307#define get_cabac_bypass get_cabac_bypass_x86
308static av_always_inline int get_cabac_bypass_x86(CABACContext *c)
309{
310 x86_reg tmp;
311 int res;
312 __asm__ volatile(
313 "movl %c6(%2), %k1 \n\t"
314 "movl %c3(%2), %%eax \n\t"
315 "shl $17, %k1 \n\t"
316 "add %%eax, %%eax \n\t"
317 "sub %k1, %%eax \n\t"
318 "cdq \n\t"
319 "and %%edx, %k1 \n\t"
320 "add %k1, %%eax \n\t"
321 "inc %%edx \n\t"
322 "test %%ax, %%ax \n\t"
323 "jnz 1f \n\t"
324 "mov %c4(%2), %1 \n\t"
325 "subl $0xFFFF, %%eax \n\t"
326 "movzwl (%1), %%ecx \n\t"
327 "bswap %%ecx \n\t"
328 "shrl $15, %%ecx \n\t"
329 "addl %%ecx, %%eax \n\t"
330 "cmp %c5(%2), %1 \n\t"
331 "jge 1f \n\t"
332 "add"FF_OPSIZE" $2, %c4(%2) \n\t"
333 "1: \n\t"
334 "movl %%eax, %c3(%2) \n\t"
335
336 : "=&d"(res), "=&r"(tmp)
337 : "r"(c),
338 "i"(offsetof(CABACContext, low)),
339 "i"(offsetof(CABACContext, bytestream)),
340 "i"(offsetof(CABACContext, bytestream_end)),
341 "i"(offsetof(CABACContext, range))
342 : "%eax", "%ecx", "memory"
343 );
344 return res;
345}
346#endif /* !BROKEN_COMPILER */
347
348#endif /* HAVE_INLINE_ASM */
349#endif /* AVCODEC_X86_CABAC_H */
val
static double val(void *priv, double ch)
Definition aeval.c:77
NAMED_CONSTRAINTS_ARRAY
#define NAMED_CONSTRAINTS_ARRAY(...)
Definition asm.h:147
MANGLE
#define MANGLE(a)
Definition asm.h:123
x86_reg
int x86_reg
Definition asm.h:71
__asm__
__asm__(".macro parse_r var r\n\t" "\\var = -1\n\t" _IFC_REG(0) _IFC_REG(1) _IFC_REG(2) _IFC_REG(3) _IFC_REG(4) _IFC_REG(5) _IFC_REG(6) _IFC_REG(7) _IFC_REG(8) _IFC_REG(9) _IFC_REG(10) _IFC_REG(11) _IFC_REG(12) _IFC_REG(13) _IFC_REG(14) _IFC_REG(15) _IFC_REG(16) _IFC_REG(17) _IFC_REG(18) _IFC_REG(19) _IFC_REG(20) _IFC_REG(21) _IFC_REG(22) _IFC_REG(23) _IFC_REG(24) _IFC_REG(25) _IFC_REG(26) _IFC_REG(27) _IFC_REG(28) _IFC_REG(29) _IFC_REG(30) _IFC_REG(31) ".iflt \\var\n\t" ".error \"Unable to parse register name \\r\"\n\t" ".endif\n\t" ".endm")
cabac.h
Context Adaptive Binary Arithmetic Coder.
H264_LPS_RANGE_OFFSET
#define H264_LPS_RANGE_OFFSET
Definition cabac.h:34
H264_MLPS_STATE_OFFSET
#define H264_MLPS_STATE_OFFSET
Definition cabac.h:35
H264_NORM_SHIFT_OFFSET
#define H264_NORM_SHIFT_OFFSET
Definition cabac.h:33
ff_h264_cabac_tables
const uint8_t ff_h264_cabac_tables[512+4 *2 *64+4 *64+63]
bit
#define bit(string, value)
Definition cbs_mpeg2.c:56
state
static struct @346255127015250356166251341105367306144006377143 state
AV_STRINGIFY
#define AV_STRINGIFY(s)
Definition macros.h:66
attributes.h
Macro definitions for various function/variable attributes.
av_always_inline
#define av_always_inline
Definition attributes.h:72
av_noinline
#define av_noinline
Definition attributes.h:97
macros.h
Utility Preprocessor macros.
range
enum AVColorRange range
Definition mediacodec_wrapper.c:2594
tmp
static uint8_t tmp[40]
Definition aes_ctr.c:52
tables
static const uint8_t *const tables[]
Definition truemotion1data.h:830
c
static double c[64]
Definition vsrc_mptestsrc.c:89
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