text: /*
   * 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,64bit 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 */
  