aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec/x86/cabac.h
blob: 4795f5bb0794f308a5f7bdb57afe2cec3f2498de (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
/*
 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#ifndef AVCODEC_X86_CABAC_H
#define AVCODEC_X86_CABAC_H

#include "libavcodec/cabac.h"
#include "libavutil/attributes.h"
#include "libavutil/macros.h"
#include "libavutil/x86/asm.h"
#include "config.h"

#if   (defined(__i386) && defined(__clang__) && (__clang_major__<2 || (__clang_major__==2 && __clang_minor__<10)))\
   || (                  !defined(__clang__) && defined(__llvm__) && __GNUC__==4 && __GNUC_MINOR__==2 && __GNUC_PATCHLEVEL__<=1)\
   || (defined(__INTEL_COMPILER) && defined(_MSC_VER))
#       define BROKEN_COMPILER 1
#else
#       define BROKEN_COMPILER 0
#endif

#if HAVE_INLINE_ASM

#ifndef UNCHECKED_BITSTREAM_READER
#define UNCHECKED_BITSTREAM_READER !CONFIG_SAFE_BITSTREAM_READER
#endif

#if UNCHECKED_BITSTREAM_READER
#define END_CHECK(end) ""
#else
#define END_CHECK(end) \
        "cmp    "end"       , %%"REG_c"                                 \n\t"\
        "jge    1f                                                      \n\t"
#endif

#ifdef BROKEN_RELOCATIONS
#define TABLES_ARG , "r"(tables)

#if HAVE_FAST_CMOV
#define BRANCHLESS_GET_CABAC_UPDATE(ret, retq, low, range, tmp) \
        "cmp    "low"       , "tmp"                        \n\t"\
        "cmova  %%ecx       , "range"                      \n\t"\
        "sbb    %%rcx       , %%rcx                        \n\t"\
        "and    %%ecx       , "tmp"                        \n\t"\
        "xor    %%rcx       , "retq"                       \n\t"\
        "sub    "tmp"       , "low"                        \n\t"
#else /* HAVE_FAST_CMOV */
#define BRANCHLESS_GET_CABAC_UPDATE(ret, retq, low, range, tmp) \
/* P4 Prescott has crappy cmov,sbb,64-bit shift so avoid them */ \
        "sub    "low"       , "tmp"                        \n\t"\
        "sar    $31         , "tmp"                        \n\t"\
        "sub    %%ecx       , "range"                      \n\t"\
        "and    "tmp"       , "range"                      \n\t"\
        "add    %%ecx       , "range"                      \n\t"\
        "shl    $17         , %%ecx                        \n\t"\
        "and    "tmp"       , %%ecx                        \n\t"\
        "sub    %%ecx       , "low"                        \n\t"\
        "xor    "tmp"       , "ret"                        \n\t"\
        "movslq "ret"       , "retq"                       \n\t"
#endif /* HAVE_FAST_CMOV */

#define BRANCHLESS_GET_CABAC(ret, retq, statep, low, lowword, range, rangeq, tmp, tmpbyte, byte, end, norm_off, lps_off, mlps_off, tables) \
        "movzbl "statep"    , "ret"                                     \n\t"\
        "mov    "range"     , "tmp"                                     \n\t"\
        "and    $0xC0       , "range"                                   \n\t"\
        "lea    ("ret", "range", 2), %%ecx                              \n\t"\
        "movzbl "lps_off"("tables", %%rcx), "range"                     \n\t"\
        "sub    "range"     , "tmp"                                     \n\t"\
        "mov    "tmp"       , %%ecx                                     \n\t"\
        "shl    $17         , "tmp"                                     \n\t"\
        BRANCHLESS_GET_CABAC_UPDATE(ret, retq, low, range, tmp)              \
        "movzbl "norm_off"("tables", "rangeq"), %%ecx                   \n\t"\
        "shl    %%cl        , "range"                                   \n\t"\
        "movzbl "mlps_off"+128("tables", "retq"), "tmp"                 \n\t"\
        "shl    %%cl        , "low"                                     \n\t"\
        "mov    "tmpbyte"   , "statep"                                  \n\t"\
        "test   "lowword"   , "lowword"                                 \n\t"\
        "jnz    2f                                                      \n\t"\
        "mov    "byte"      , %%"REG_c"                                 \n\t"\
        END_CHECK(end)\
        "add"OPSIZE" $2     , "byte"                                    \n\t"\
        "1:                                                             \n\t"\
        "movzwl (%%"REG_c") , "tmp"                                     \n\t"\
        "lea    -1("low")   , %%ecx                                     \n\t"\
        "xor    "low"       , %%ecx                                     \n\t"\
        "shr    $15         , %%ecx                                     \n\t"\
        "bswap  "tmp"                                                   \n\t"\
        "shr    $15         , "tmp"                                     \n\t"\
        "movzbl "norm_off"("tables", %%rcx), %%ecx                      \n\t"\
        "sub    $0xFFFF     , "tmp"                                     \n\t"\
        "neg    %%ecx                                                   \n\t"\
        "add    $7          , %%ecx                                     \n\t"\
        "shl    %%cl        , "tmp"                                     \n\t"\
        "add    "tmp"       , "low"                                     \n\t"\
        "2:                                                             \n\t"

#else /* BROKEN_RELOCATIONS */
#define TABLES_ARG NAMED_CONSTRAINTS_ARRAY_ADD(ff_h264_cabac_tables)
#define RIP_ARG

#if HAVE_FAST_CMOV
#define BRANCHLESS_GET_CABAC_UPDATE(ret, low, range, tmp)\
        "mov    "tmp"       , %%ecx     \n\t"\
        "shl    $17         , "tmp"     \n\t"\
        "cmp    "low"       , "tmp"     \n\t"\
        "cmova  %%ecx       , "range"   \n\t"\
        "sbb    %%ecx       , %%ecx     \n\t"\
        "and    %%ecx       , "tmp"     \n\t"\
        "xor    %%ecx       , "ret"     \n\t"\
        "sub    "tmp"       , "low"     \n\t"
#else /* HAVE_FAST_CMOV */
#define BRANCHLESS_GET_CABAC_UPDATE(ret, low, range, tmp)\
        "mov    "tmp"       , %%ecx     \n\t"\
        "shl    $17         , "tmp"     \n\t"\
        "sub    "low"       , "tmp"     \n\t"\
        "sar    $31         , "tmp"     \n\t" /*lps_mask*/\
        "sub    %%ecx       , "range"   \n\t" /*RangeLPS - range*/\
        "and    "tmp"       , "range"   \n\t" /*(RangeLPS - range)&lps_mask*/\
        "add    %%ecx       , "range"   \n\t" /*new range*/\
        "shl    $17         , %%ecx     \n\t"\
        "and    "tmp"       , %%ecx     \n\t"\
        "sub    %%ecx       , "low"     \n\t"\
        "xor    "tmp"       , "ret"     \n\t"
#endif /* HAVE_FAST_CMOV */

#define BRANCHLESS_GET_CABAC(ret, retq, statep, low, lowword, range, rangeq, tmp, tmpbyte, byte, end, norm_off, lps_off, mlps_off, tables) \
        "movzbl "statep"    , "ret"                                     \n\t"\
        "mov    "range"     , "tmp"                                     \n\t"\
        "and    $0xC0       , "range"                                   \n\t"\
        "movzbl "MANGLE(ff_h264_cabac_tables)"+"lps_off"("ret", "range", 2), "range" \n\t"\
        "sub    "range"     , "tmp"                                     \n\t"\
        BRANCHLESS_GET_CABAC_UPDATE(ret, low, range, tmp)                    \
        "movzbl "MANGLE(ff_h264_cabac_tables)"+"norm_off"("range"), %%ecx    \n\t"\
        "shl    %%cl        , "range"                                   \n\t"\
        "movzbl "MANGLE(ff_h264_cabac_tables)"+"mlps_off"+128("ret"), "tmp"  \n\t"\
        "shl    %%cl        , "low"                                     \n\t"\
        "mov    "tmpbyte"   , "statep"                                  \n\t"\
        "test   "lowword"   , "lowword"                                 \n\t"\
        " jnz   2f                                                      \n\t"\
        "mov    "byte"      , %%"REG_c"                                 \n\t"\
        END_CHECK(end)\
        "add"OPSIZE" $2     , "byte"                                    \n\t"\
        "1:                                                             \n\t"\
        "movzwl (%%"REG_c")     , "tmp"                                 \n\t"\
        "lea    -1("low")   , %%ecx                                     \n\t"\
        "xor    "low"       , %%ecx                                     \n\t"\
        "shr    $15         , %%ecx                                     \n\t"\
        "bswap  "tmp"                                                   \n\t"\
        "shr    $15         , "tmp"                                     \n\t"\
        "movzbl "MANGLE(ff_h264_cabac_tables)"+"norm_off"(%%ecx), %%ecx \n\t"\
        "sub    $0xFFFF     , "tmp"                                     \n\t"\
        "neg    %%ecx                                                   \n\t"\
        "add    $7          , %%ecx                                     \n\t"\
        "shl    %%cl        , "tmp"                                     \n\t"\
        "add    "tmp"       , "low"                                     \n\t"\
        "2:                                                             \n\t"

#endif /* BROKEN_RELOCATIONS */

#if HAVE_7REGS && !BROKEN_COMPILER
#define get_cabac_inline get_cabac_inline_x86
static av_always_inline int get_cabac_inline_x86(CABACContext *c,
                                                 uint8_t *const state)
{
    int bit, tmp;
#ifdef BROKEN_RELOCATIONS
    void *tables;

    __asm__ volatile(
        "lea    "MANGLE(ff_h264_cabac_tables)", %0      \n\t"
        : "=&r"(tables)
        : NAMED_CONSTRAINTS_ARRAY(ff_h264_cabac_tables)
    );
#endif

    __asm__ volatile(
        BRANCHLESS_GET_CABAC("%0", "%q0", "(%4)", "%1", "%w1",
                             "%2", "%q2", "%3", "%b3",
                             "%c6(%5)", "%c7(%5)",
                             AV_STRINGIFY(H264_NORM_SHIFT_OFFSET),
                             AV_STRINGIFY(H264_LPS_RANGE_OFFSET),
                             AV_STRINGIFY(H264_MLPS_STATE_OFFSET),
                             "%8")
        : "=&r"(bit), "=&r"(c->low), "=&r"(c->range), "=&q"(tmp)
        : "r"(state), "r"(c),
          "i"(offsetof(CABACContext, bytestream)),
          "i"(offsetof(CABACContext, bytestream_end))
          TABLES_ARG
          ,"1"(c->low), "2"(c->range)
        : "%"REG_c, "memory"
    );
    return bit & 1;
}
#endif /* HAVE_7REGS && !BROKEN_COMPILER */

#if !BROKEN_COMPILER
#define get_cabac_bypass_sign get_cabac_bypass_sign_x86
static av_always_inline int get_cabac_bypass_sign_x86(CABACContext *c, int val)
{
    x86_reg tmp;
    __asm__ volatile(
        "movl        %c6(%2), %k1       \n\t"
        "movl        %c3(%2), %%eax     \n\t"
        "shl             $17, %k1       \n\t"
        "add           %%eax, %%eax     \n\t"
        "sub             %k1, %%eax     \n\t"
        "cdq                            \n\t"
        "and           %%edx, %k1       \n\t"
        "add             %k1, %%eax     \n\t"
        "xor           %%edx, %%ecx     \n\t"
        "sub           %%edx, %%ecx     \n\t"
        "test           %%ax, %%ax      \n\t"
        "jnz              1f            \n\t"
        "mov         %c4(%2), %1        \n\t"
        "subl        $0xFFFF, %%eax     \n\t"
        "movzwl         (%1), %%edx     \n\t"
        "bswap         %%edx            \n\t"
        "shrl            $15, %%edx     \n\t"
#if UNCHECKED_BITSTREAM_READER
        "add              $2, %1        \n\t"
        "addl          %%edx, %%eax     \n\t"
        "mov              %1, %c4(%2)   \n\t"
#else
        "addl          %%edx, %%eax     \n\t"
        "cmp         %c5(%2), %1        \n\t"
        "jge              1f            \n\t"
        "add"OPSIZE"      $2, %c4(%2)   \n\t"
#endif
        "1:                             \n\t"
        "movl          %%eax, %c3(%2)   \n\t"

        : "+c"(val), "=&r"(tmp)
        : "r"(c),
          "i"(offsetof(CABACContext, low)),
          "i"(offsetof(CABACContext, bytestream)),
          "i"(offsetof(CABACContext, bytestream_end)),
          "i"(offsetof(CABACContext, range))
        : "%eax", "%edx", "memory"
    );
    return val;
}

#define get_cabac_bypass get_cabac_bypass_x86
static av_always_inline int get_cabac_bypass_x86(CABACContext *c)
{
    x86_reg tmp;
    int res;
    __asm__ volatile(
        "movl        %c6(%2), %k1       \n\t"
        "movl        %c3(%2), %%eax     \n\t"
        "shl             $17, %k1       \n\t"
        "add           %%eax, %%eax     \n\t"
        "sub             %k1, %%eax     \n\t"
        "cdq                            \n\t"
        "and           %%edx, %k1       \n\t"
        "add             %k1, %%eax     \n\t"
        "inc           %%edx            \n\t"
        "test           %%ax, %%ax      \n\t"
        "jnz              1f            \n\t"
        "mov         %c4(%2), %1        \n\t"
        "subl        $0xFFFF, %%eax     \n\t"
        "movzwl         (%1), %%ecx     \n\t"
        "bswap         %%ecx            \n\t"
        "shrl            $15, %%ecx     \n\t"
        "addl          %%ecx, %%eax     \n\t"
        "cmp         %c5(%2), %1        \n\t"
        "jge              1f            \n\t"
        "add"OPSIZE"      $2, %c4(%2)   \n\t"
        "1:                             \n\t"
        "movl          %%eax, %c3(%2)   \n\t"

        : "=&d"(res), "=&r"(tmp)
        : "r"(c),
          "i"(offsetof(CABACContext, low)),
          "i"(offsetof(CABACContext, bytestream)),
          "i"(offsetof(CABACContext, bytestream_end)),
          "i"(offsetof(CABACContext, range))
        : "%eax", "%ecx", "memory"
    );
    return res;
}
#endif /* !BROKEN_COMPILER */

#endif /* HAVE_INLINE_ASM */
#endif /* AVCODEC_X86_CABAC_H */