git.sesse.net Git - ffmpeg/blob - libavcodec/x86/cabac.h

   1 /*
   2  * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
   3  *
   4  * This file is part of Libav.
   5  *
   6  * Libav 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  * Libav 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 Libav; 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 "libavcodec/cabac.h"
  25 #include "libavutil/attributes.h"
  26 #include "libavutil/x86/asm.h"
  27 #include "libavutil/internal.h"
  28 #include "config.h"
  29
  30 #if HAVE_INLINE_ASM
  31
  32 #ifdef BROKEN_RELOCATIONS
  33 #define TABLES_ARG , "r"(tables)
  34
  35 #if HAVE_FAST_CMOV
  36 #define BRANCHLESS_GET_CABAC_UPDATE(ret, retq, low, range, tmp) \
  37         "cmp    "low"       , "tmp"                        \n\t"\
  38         "cmova  %%ecx       , "range"                      \n\t"\
  39         "sbb    %%rcx       , %%rcx                        \n\t"\
  40         "and    %%ecx       , "tmp"                        \n\t"\
  41         "xor    %%rcx       , "retq"                       \n\t"\
  42         "sub    "tmp"       , "low"                        \n\t"
  43 #else /* HAVE_FAST_CMOV */
  44 #define BRANCHLESS_GET_CABAC_UPDATE(ret, retq, low, range, tmp) \
  45 /* P4 Prescott has crappy cmov,sbb,64bit shift so avoid them */ \
  46         "sub    "low"       , "tmp"                        \n\t"\
  47         "sar    $31         , "tmp"                        \n\t"\
  48         "sub    %%ecx       , "range"                      \n\t"\
  49         "and    "tmp"       , "range"                      \n\t"\
  50         "add    %%ecx       , "range"                      \n\t"\
  51         "shl    $17         , %%ecx                        \n\t"\
  52         "and    "tmp"       , %%ecx                        \n\t"\
  53         "sub    %%ecx       , "low"                        \n\t"\
  54         "xor    "tmp"       , "ret"                        \n\t"\
  55         "movslq "ret"       , "retq"                       \n\t"
  56 #endif /* HAVE_FAST_CMOV */
  57
  58 #define BRANCHLESS_GET_CABAC(ret, retq, statep, low, lowword, range, rangeq, tmp, tmpbyte, byte, end, norm_off, lps_off, mlps_off, tables) \
  59         "movzbl "statep"    , "ret"                                     \n\t"\
  60         "mov    "range"     , "tmp"                                     \n\t"\
  61         "and    $0xC0       , "range"                                   \n\t"\
  62         "lea    ("ret", "range", 2), %%ecx                              \n\t"\
  63         "movzbl "lps_off"("tables", %%rcx), "range"                     \n\t"\
  64         "sub    "range"     , "tmp"                                     \n\t"\
  65         "mov    "tmp"       , %%ecx                                     \n\t"\
  66         "shl    $17         , "tmp"                                     \n\t"\
  67         BRANCHLESS_GET_CABAC_UPDATE(ret, retq, low, range, tmp)              \
  68         "movzbl "norm_off"("tables", "rangeq"), %%ecx                   \n\t"\
  69         "shl    %%cl        , "range"                                   \n\t"\
  70         "movzbl "mlps_off"+128("tables", "retq"), "tmp"                 \n\t"\
  71         "shl    %%cl        , "low"                                     \n\t"\
  72         "mov    "tmpbyte"   , "statep"                                  \n\t"\
  73         "test   "lowword"   , "lowword"                                 \n\t"\
  74         "jnz    2f                                                      \n\t"\
  75         "mov    "byte"      , %%"REG_c"                                 \n\t"\
  76         "add"OPSIZE" $2     , "byte"                                    \n\t"\
  77         "movzwl (%%"REG_c") , "tmp"                                     \n\t"\
  78         "lea    -1("low")   , %%ecx                                     \n\t"\
  79         "xor    "low"       , %%ecx                                     \n\t"\
  80         "shr    $15         , %%ecx                                     \n\t"\
  81         "bswap  "tmp"                                                   \n\t"\
  82         "shr    $15         , "tmp"                                     \n\t"\
  83         "movzbl "norm_off"("tables", %%rcx), %%ecx                      \n\t"\
  84         "sub    $0xFFFF     , "tmp"                                     \n\t"\
  85         "neg    %%ecx                                                   \n\t"\
  86         "add    $7          , %%ecx                                     \n\t"\
  87         "shl    %%cl        , "tmp"                                     \n\t"\
  88         "add    "tmp"       , "low"                                     \n\t"\
  89         "2:                                                             \n\t"
  90
  91 #else /* BROKEN_RELOCATIONS */
  92 #define TABLES_ARG
  93 #define RIP_ARG
  94
  95 #if HAVE_FAST_CMOV
  96 #define BRANCHLESS_GET_CABAC_UPDATE(ret, low, range, tmp)\
  97         "mov    "tmp"       , %%ecx     \n\t"\
  98         "shl    $17         , "tmp"     \n\t"\
  99         "cmp    "low"       , "tmp"     \n\t"\
 100         "cmova  %%ecx       , "range"   \n\t"\
 101         "sbb    %%ecx       , %%ecx     \n\t"\
 102         "and    %%ecx       , "tmp"     \n\t"\
 103         "xor    %%ecx       , "ret"     \n\t"\
 104         "sub    "tmp"       , "low"     \n\t"
 105 #else /* HAVE_FAST_CMOV */
 106 #define BRANCHLESS_GET_CABAC_UPDATE(ret, low, range, tmp)\
 107         "mov    "tmp"       , %%ecx     \n\t"\
 108         "shl    $17         , "tmp"     \n\t"\
 109         "sub    "low"       , "tmp"     \n\t"\
 110         "sar    $31         , "tmp"     \n\t" /*lps_mask*/\
 111         "sub    %%ecx       , "range"   \n\t" /*RangeLPS - range*/\
 112         "and    "tmp"       , "range"   \n\t" /*(RangeLPS - range)&lps_mask*/\
 113         "add    %%ecx       , "range"   \n\t" /*new range*/\
 114         "shl    $17         , %%ecx     \n\t"\
 115         "and    "tmp"       , %%ecx     \n\t"\
 116         "sub    %%ecx       , "low"     \n\t"\
 117         "xor    "tmp"       , "ret"     \n\t"
 118 #endif /* HAVE_FAST_CMOV */
 119
 120 #define BRANCHLESS_GET_CABAC(ret, retq, statep, low, lowword, range, rangeq, tmp, tmpbyte, byte, end, norm_off, lps_off, mlps_off, tables) \
 121         "movzbl "statep"    , "ret"                                     \n\t"\
 122         "mov    "range"     , "tmp"                                     \n\t"\
 123         "and    $0xC0       , "range"                                   \n\t"\
 124         "movzbl "MANGLE(ff_h264_cabac_tables)"+"lps_off"("ret", "range", 2), "range" \n\t"\
 125         "sub    "range"     , "tmp"                                     \n\t"\
 126         BRANCHLESS_GET_CABAC_UPDATE(ret, low, range, tmp)                    \
 127         "movzbl "MANGLE(ff_h264_cabac_tables)"+"norm_off"("range"), %%ecx    \n\t"\
 128         "shl    %%cl        , "range"                                   \n\t"\
 129         "movzbl "MANGLE(ff_h264_cabac_tables)"+"mlps_off"+128("ret"), "tmp"  \n\t"\
 130         "shl    %%cl        , "low"                                     \n\t"\
 131         "mov    "tmpbyte"   , "statep"                                  \n\t"\
 132         "test   "lowword"   , "lowword"                                 \n\t"\
 133         " jnz   2f                                                      \n\t"\
 134         "mov    "byte"      , %%"REG_c"                                 \n\t"\
 135         "add"OPSIZE" $2     , "byte"                                    \n\t"\
 136         "movzwl (%%"REG_c")     , "tmp"                                 \n\t"\
 137         "lea    -1("low")   , %%ecx                                     \n\t"\
 138         "xor    "low"       , %%ecx                                     \n\t"\
 139         "shr    $15         , %%ecx                                     \n\t"\
 140         "bswap  "tmp"                                                   \n\t"\
 141         "shr    $15         , "tmp"                                     \n\t"\
 142         "movzbl "MANGLE(ff_h264_cabac_tables)"+"norm_off"(%%ecx), %%ecx \n\t"\
 143         "sub    $0xFFFF     , "tmp"                                     \n\t"\
 144         "neg    %%ecx                                                   \n\t"\
 145         "add    $7          , %%ecx                                     \n\t"\
 146         "shl    %%cl        , "tmp"                                     \n\t"\
 147         "add    "tmp"       , "low"                                     \n\t"\
 148         "2:                                                             \n\t"
 149
 150 #endif /* BROKEN_RELOCATIONS */
 151
 152
 153 #if HAVE_7REGS && !(defined(__i386) && defined(__clang__) && (__clang_major__<2 || (__clang_major__==2 && __clang_minor__<10)))\
 154                && !(                  !defined(__clang__) && defined(__llvm__) && __GNUC__==4 && __GNUC_MINOR__==2 && __GNUC_PATCHLEVEL__<=1)
 155 #define get_cabac_inline get_cabac_inline_x86
 156 static av_always_inline int get_cabac_inline_x86(CABACContext *c,
 157                                                  uint8_t *const state)
 158 {
 159     int bit, tmp;
 160 #ifdef BROKEN_RELOCATIONS
 161     void *tables;
 162
 163     __asm__ volatile(
 164         "lea    "MANGLE(ff_h264_cabac_tables)", %0      \n\t"
 165         : "=&r"(tables)
 166     );
 167 #endif
 168
 169     __asm__ volatile(
 170         BRANCHLESS_GET_CABAC("%0", "%q0", "(%4)", "%1", "%w1",
 171                              "%2", "%q2", "%3", "%b3",
 172                              "%c6(%5)", "%c7(%5)",
 173                              AV_STRINGIFY(H264_NORM_SHIFT_OFFSET),
 174                              AV_STRINGIFY(H264_LPS_RANGE_OFFSET),
 175                              AV_STRINGIFY(H264_MLPS_STATE_OFFSET),
 176                              "%8")
 177         : "=&r"(bit), "=&r"(c->low), "=&r"(c->range), "=&q"(tmp)
 178         : "r"(state), "r"(c),
 179           "i"(offsetof(CABACContext, bytestream)),
 180           "i"(offsetof(CABACContext, bytestream_end))
 181           TABLES_ARG
 182           ,"1"(c->low), "2"(c->range)
 183         : "%"REG_c, "memory"
 184     );
 185     return bit & 1;
 186 }
 187 #endif /* HAVE_7REGS */
 188
 189 #define get_cabac_bypass_sign get_cabac_bypass_sign_x86
 190 static av_always_inline int get_cabac_bypass_sign_x86(CABACContext *c, int val)
 191 {
 192     x86_reg tmp;
 193     __asm__ volatile(
 194         "movl        %c6(%2), %k1       \n\t"
 195         "movl        %c3(%2), %%eax     \n\t"
 196         "shl             $17, %k1       \n\t"
 197         "add           %%eax, %%eax     \n\t"
 198         "sub             %k1, %%eax     \n\t"
 199         "cltd                           \n\t"
 200         "and           %%edx, %k1       \n\t"
 201         "add             %k1, %%eax     \n\t"
 202         "xor           %%edx, %%ecx     \n\t"
 203         "sub           %%edx, %%ecx     \n\t"
 204         "test           %%ax, %%ax      \n\t"
 205         "jnz              1f            \n\t"
 206         "mov         %c4(%2), %1        \n\t"
 207         "subl        $0xFFFF, %%eax     \n\t"
 208         "movzwl         (%1), %%edx     \n\t"
 209         "bswap         %%edx            \n\t"
 210         "shrl            $15, %%edx     \n\t"
 211         "add              $2, %1        \n\t"
 212         "addl          %%edx, %%eax     \n\t"
 213         "mov              %1, %c4(%2)   \n\t"
 214         "1:                             \n\t"
 215         "movl          %%eax, %c3(%2)   \n\t"
 216
 217         : "+c"(val), "=&r"(tmp)
 218         : "r"(c),
 219           "i"(offsetof(CABACContext, low)),
 220           "i"(offsetof(CABACContext, bytestream)),
 221           "i"(offsetof(CABACContext, bytestream_end)),
 222           "i"(offsetof(CABACContext, range))
 223         : "%eax", "%edx", "memory"
 224     );
 225     return val;
 226 }
 227
 228 #endif /* HAVE_INLINE_ASM */
 229 #endif /* AVCODEC_X86_CABAC_H */