]> git.sesse.net Git - ffmpeg/blobdiff - libavcodec/cabac.h
Add FFMPEG_ prefix to all multiple inclusion guards.
[ffmpeg] / libavcodec / cabac.h
index 3de719f4e0d14a1d862145617d91361c247fa677..d7f58d72848f7ef1ae5e254d19c637d4f5f8555c 100644 (file)
@@ -17,7 +17,6 @@
  * 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
- *
  */
 
 /**
  * Context Adaptive Binary Arithmetic Coder.
  */
 
+#ifndef FFMPEG_CABAC_H
+#define FFMPEG_CABAC_H
+
+#include "bitstream.h"
 
 //#undef NDEBUG
 #include <assert.h>
+#ifdef ARCH_X86
+#include "x86_cpu.h"
+#endif
 
 #define CABAC_BITS 16
 #define CABAC_MASK ((1<<CABAC_BITS)-1)
+#define BRANCHLESS_CABAC_DECODER 1
+//#define ARCH_X86_DISABLED 1
 
 typedef struct CABACContext{
     int low;
@@ -39,25 +47,22 @@ typedef struct CABACContext{
 #ifdef STRICT_LIMITS
     int symCount;
 #endif
-    uint8_t lps_range[2*66][4];   ///< rangeTabLPS
-    uint8_t lps_state[2*65];      ///< transIdxLPS
-    uint8_t mps_state[2*65];      ///< transIdxMPS
     const uint8_t *bytestream_start;
     const uint8_t *bytestream;
     const uint8_t *bytestream_end;
     PutBitContext pb;
 }CABACContext;
 
-extern const uint8_t ff_h264_lps_range[64][4];
-extern const uint8_t ff_h264_mps_state[64];
-extern const uint8_t ff_h264_lps_state[64];
-extern const uint8_t ff_h264_norm_shift[128];
+extern uint8_t ff_h264_mlps_state[4*64];
+extern uint8_t ff_h264_lps_range[4*2*64];  ///< rangeTabLPS
+extern uint8_t ff_h264_mps_state[2*64];     ///< transIdxMPS
+extern uint8_t ff_h264_lps_state[2*64];     ///< transIdxLPS
+extern const uint8_t ff_h264_norm_shift[512];
 
 
 void ff_init_cabac_encoder(CABACContext *c, uint8_t *buf, int buf_size);
 void ff_init_cabac_decoder(CABACContext *c, const uint8_t *buf, int buf_size);
-void ff_init_cabac_states(CABACContext *c, uint8_t const (*lps_range)[4],
-                          uint8_t const *mps_state, uint8_t const *lps_state, int state_count);
+void ff_init_cabac_states(CABACContext *c);
 
 
 static inline void put_cabac_bit(CABACContext *c, int b){
@@ -85,16 +90,17 @@ static inline void renorm_cabac_encoder(CABACContext *c){
     }
 }
 
+#if 0
 static void put_cabac(CABACContext *c, uint8_t * const state, int bit){
-    int RangeLPS= c->lps_range[*state][c->range>>6];
+    int RangeLPS= ff_h264_lps_range[2*(c->range&0xC0) + *state];
 
     if(bit == ((*state)&1)){
         c->range -= RangeLPS;
-        *state= c->mps_state[*state];
+        *state= ff_h264_mps_state[*state];
     }else{
         c->low += c->range - RangeLPS;
         c->range = RangeLPS;
-        *state= c->lps_state[*state];
+        *state= ff_h264_lps_state[*state];
     }
 
     renorm_cabac_encoder(c);
@@ -221,7 +227,7 @@ static void put_cabac_ueg(CABACContext *c, uint8_t * state, int v, int max, int
     else{
         const int sign= v < 0;
 
-        if(is_signed) v= ABS(v);
+        if(is_signed) v= FFABS(v);
 
         if(v<max){
             for(i=0; i<v; i++){
@@ -254,6 +260,7 @@ static void put_cabac_ueg(CABACContext *c, uint8_t * state, int v, int max, int
             put_cabac_bypass(c, sign);
     }
 }
+#endif /* 0 */
 
 static void refill(CABACContext *c){
 #if CABAC_BITS == 16
@@ -265,11 +272,12 @@ static void refill(CABACContext *c){
     c->bytestream+= CABAC_BITS/8;
 }
 
+#if ! ( defined(ARCH_X86) && defined(HAVE_7REGS) && defined(HAVE_EBX_AVAILABLE) && !defined(BROKEN_RELOCATIONS) )
 static void refill2(CABACContext *c){
     int i, x;
 
     x= c->low ^ (c->low-1);
-    i= 7 - ff_h264_norm_shift[x>>(CABAC_BITS+1)];
+    i= 7 - ff_h264_norm_shift[x>>(CABAC_BITS-1)];
 
     x= -CABAC_MASK;
 
@@ -282,9 +290,10 @@ static void refill2(CABACContext *c){
     c->low += x<<i;
     c->bytestream+= CABAC_BITS/8;
 }
+#endif
 
 static inline void renorm_cabac_decoder(CABACContext *c){
-    while(c->range < (0x200 << CABAC_BITS)){
+    while(c->range < 0x100){
         c->range+= c->range;
         c->low+= c->low;
         if(!(c->low & CABAC_MASK))
@@ -298,7 +307,7 @@ static inline void renorm_cabac_decoder_once(CABACContext *c){
 #if 0
     //P3:683    athlon:475
     asm(
-        "lea -0x2000000(%0), %2     \n\t"
+        "lea -0x100(%0), %2         \n\t"
         "shr $31, %2                \n\t"  //FIXME 31->63 for x86-64
         "shl %%cl, %0               \n\t"
         "shl %%cl, %1               \n\t"
@@ -307,7 +316,7 @@ static inline void renorm_cabac_decoder_once(CABACContext *c){
 #elif 0
     //P3:680    athlon:474
     asm(
-        "cmp $0x2000000, %0         \n\t"
+        "cmp $0x100, %0             \n\t"
         "setb %%cl                  \n\t"  //FIXME 31->63 for x86-64
         "shl %%cl, %0               \n\t"
         "shl %%cl, %1               \n\t"
@@ -317,7 +326,7 @@ static inline void renorm_cabac_decoder_once(CABACContext *c){
     int temp2;
     //P3:665    athlon:517
     asm(
-        "lea -0x2000000(%0), %%eax  \n\t"
+        "lea -0x100(%0), %%eax      \n\t"
         "cdq                        \n\t"
         "mov %0, %%eax              \n\t"
         "and %%edx, %0              \n\t"
@@ -330,7 +339,7 @@ static inline void renorm_cabac_decoder_once(CABACContext *c){
     int temp2;
     //P3:673    athlon:509
     asm(
-        "cmp $0x2000000, %0         \n\t"
+        "cmp $0x100, %0             \n\t"
         "sbb %%edx, %%edx           \n\t"
         "mov %0, %%eax              \n\t"
         "and %%edx, %0              \n\t"
@@ -343,7 +352,7 @@ static inline void renorm_cabac_decoder_once(CABACContext *c){
     int temp2;
     //P3:677    athlon:511
     asm(
-        "cmp $0x2000000, %0         \n\t"
+        "cmp $0x100, %0             \n\t"
         "lea (%0, %0), %%eax        \n\t"
         "lea (%1, %1), %%edx        \n\t"
         "cmovb %%eax, %0            \n\t"
@@ -353,7 +362,7 @@ static inline void renorm_cabac_decoder_once(CABACContext *c){
 #endif
 #else
     //P3:675    athlon:476
-    int shift= (uint32_t)(c->range - (0x200 << CABAC_BITS))>>31;
+    int shift= (uint32_t)(c->range - 0x100)>>31;
     c->range<<= shift;
     c->low  <<= shift;
 #endif
@@ -361,172 +370,438 @@ static inline void renorm_cabac_decoder_once(CABACContext *c){
         refill(c);
 }
 
-static int get_cabac(CABACContext *c, uint8_t * const state){
+static av_always_inline int get_cabac_inline(CABACContext *c, uint8_t * const state){
     //FIXME gcc generates duplicate load/stores for c->low and c->range
-//START_TIMER
-#ifdef ARCH_X86
-    int bit;
-
 #define LOW          "0"
 #define RANGE        "4"
-#define LPS_RANGE   "12"
-#define LPS_STATE   "12+2*66*4"
-#define MPS_STATE   "12+2*66*4+2*65"
-#define BYTESTART   "12+2*66*4+4*65"
-#define BYTE        "16+2*66*4+4*65"
-#define BYTEEND     "20+2*66*4+4*65"
+#ifdef ARCH_X86_64
+#define BYTESTART   "16"
+#define BYTE        "24"
+#define BYTEEND     "32"
+#else
+#define BYTESTART   "12"
+#define BYTE        "16"
+#define BYTEEND     "20"
+#endif
+#if defined(ARCH_X86) && defined(HAVE_7REGS) && defined(HAVE_EBX_AVAILABLE) && !defined(BROKEN_RELOCATIONS)
+    int bit;
 
+#ifndef BRANCHLESS_CABAC_DECODER
     asm volatile(
-        "movzbl (%1), %%eax                     \n\t"
+        "movzbl (%1), %0                        \n\t"
         "movl "RANGE    "(%2), %%ebx            \n\t"
         "movl "RANGE    "(%2), %%edx            \n\t"
-        "shrl $23, %%ebx                        \n\t"
-        "leal "LPS_RANGE"(%2, %%eax, 4), %%esi  \n\t"
-        "movzbl (%%ebx, %%esi), %%esi           \n\t"
-        "shll $17, %%esi                        \n\t"
+        "andl $0xC0, %%ebx                      \n\t"
+        "movzbl "MANGLE(ff_h264_lps_range)"(%0, %%ebx, 2), %%esi\n\t"
         "movl "LOW      "(%2), %%ebx            \n\t"
 //eax:state ebx:low, edx:range, esi:RangeLPS
         "subl %%esi, %%edx                      \n\t"
-        "cmpl %%edx, %%ebx                      \n\t"
+        "movl %%edx, %%ecx                      \n\t"
+        "shll $17, %%ecx                        \n\t"
+        "cmpl %%ecx, %%ebx                      \n\t"
         " ja 1f                                 \n\t"
-        "cmp $0x2000000, %%edx                  \n\t" //FIXME avoidable
+
+#if 1
+        //athlon:4067 P3:4110
+        "lea -0x100(%%edx), %%ecx               \n\t"
+        "shr $31, %%ecx                         \n\t"
+        "shl %%cl, %%edx                        \n\t"
+        "shl %%cl, %%ebx                        \n\t"
+#else
+        //athlon:4057 P3:4130
+        "cmp $0x100, %%edx                      \n\t" //FIXME avoidable
         "setb %%cl                              \n\t"
         "shl %%cl, %%edx                        \n\t"
         "shl %%cl, %%ebx                        \n\t"
-        "movb "MPS_STATE"(%2, %%eax), %%cl      \n\t"
+#endif
+        "movzbl "MANGLE(ff_h264_mps_state)"(%0), %%ecx   \n\t"
         "movb %%cl, (%1)                        \n\t"
 //eax:state ebx:low, edx:range, esi:RangeLPS
         "test %%bx, %%bx                        \n\t"
         " jnz 2f                                \n\t"
-        "movl "BYTE     "(%2), %%esi            \n\t"
+        "mov  "BYTE     "(%2), %%"REG_S"        \n\t"
         "subl $0xFFFF, %%ebx                    \n\t"
-        "movzwl (%%esi), %%ecx                  \n\t"
+        "movzwl (%%"REG_S"), %%ecx              \n\t"
         "bswap %%ecx                            \n\t"
         "shrl $15, %%ecx                        \n\t"
-        "addl $2, %%esi                         \n\t"
+        "add  $2, %%"REG_S"                     \n\t"
         "addl %%ecx, %%ebx                      \n\t"
-        "movl %%esi, "BYTE    "(%2)             \n\t"
+        "mov  %%"REG_S", "BYTE    "(%2)         \n\t"
         "jmp 2f                                 \n\t"
         "1:                                     \n\t"
 //eax:state ebx:low, edx:range, esi:RangeLPS
-        "subl %%edx, %%ebx                      \n\t"
+        "subl %%ecx, %%ebx                      \n\t"
         "movl %%esi, %%edx                      \n\t"
-        "shr $19, %%esi                         \n\t"
-        "movb " MANGLE(ff_h264_norm_shift) "(%%esi), %%cl   \n\t"
+        "movzbl " MANGLE(ff_h264_norm_shift) "(%%esi), %%ecx   \n\t"
         "shll %%cl, %%ebx                       \n\t"
         "shll %%cl, %%edx                       \n\t"
-        "movb "LPS_STATE"(%2, %%eax), %%cl      \n\t"
+        "movzbl "MANGLE(ff_h264_lps_state)"(%0), %%ecx   \n\t"
         "movb %%cl, (%1)                        \n\t"
-        "incl %%eax                             \n\t"
+        "add  $1, %0                            \n\t"
         "test %%bx, %%bx                        \n\t"
         " jnz 2f                                \n\t"
 
-        "movl "BYTE     "(%2), %%ecx            \n\t"
-        "movzwl (%%ecx), %%esi                  \n\t"
+        "mov  "BYTE     "(%2), %%"REG_c"        \n\t"
+        "movzwl (%%"REG_c"), %%esi              \n\t"
         "bswap %%esi                            \n\t"
         "shrl $15, %%esi                        \n\t"
         "subl $0xFFFF, %%esi                    \n\t"
-        "addl $2, %%ecx                         \n\t"
-        "movl %%ecx, "BYTE    "(%2)             \n\t"
+        "add  $2, %%"REG_c"                     \n\t"
+        "mov  %%"REG_c", "BYTE    "(%2)         \n\t"
 
         "leal -1(%%ebx), %%ecx                  \n\t"
         "xorl %%ebx, %%ecx                      \n\t"
-        "shrl $17, %%ecx                        \n\t"
-        "movb " MANGLE(ff_h264_norm_shift) "(%%ecx), %%cl   \n\t"
-        "neg %%cl                               \n\t"
-        "add $7, %%cl                           \n\t"
+        "shrl $15, %%ecx                        \n\t"
+        "movzbl " MANGLE(ff_h264_norm_shift) "(%%ecx), %%ecx   \n\t"
+        "neg %%ecx                              \n\t"
+        "add $7, %%ecx                          \n\t"
 
         "shll %%cl , %%esi                      \n\t"
         "addl %%esi, %%ebx                      \n\t"
         "2:                                     \n\t"
         "movl %%edx, "RANGE    "(%2)            \n\t"
         "movl %%ebx, "LOW      "(%2)            \n\t"
-        "andl $1, %%eax                         \n\t"
+        :"=&a"(bit) //FIXME this is fragile gcc either runs out of registers or miscompiles it (for example if "+a"(bit) or "+m"(*state) is used
+        :"r"(state), "r"(c)
+        : "%"REG_c, "%ebx", "%edx", "%"REG_S, "memory"
+    );
+    bit&=1;
+#else /* BRANCHLESS_CABAC_DECODER */
+
+
+#if defined HAVE_FAST_CMOV
+#define BRANCHLESS_GET_CABAC_UPDATE(ret, cabac, statep, low, lowword, range, tmp, tmpbyte)\
+        "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"\
+        "sub    "tmp"       , "low"                                     \n\t"\
+        "xor    %%ecx       , "ret"                                     \n\t"
+#else /* HAVE_FAST_CMOV */
+#define BRANCHLESS_GET_CABAC_UPDATE(ret, cabac, statep, low, lowword, range, tmp, tmpbyte)\
+        "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, cabac, statep, low, lowword, range, tmp, tmpbyte)\
+        "movzbl "statep"    , "ret"                                     \n\t"\
+        "mov    "range"     , "tmp"                                     \n\t"\
+        "and    $0xC0       , "range"                                   \n\t"\
+        "movzbl "MANGLE(ff_h264_lps_range)"("ret", "range", 2), "range" \n\t"\
+        "sub    "range"     , "tmp"                                     \n\t"\
+        BRANCHLESS_GET_CABAC_UPDATE(ret, cabac, statep, low, lowword, range, tmp, tmpbyte)\
+        "movzbl " MANGLE(ff_h264_norm_shift) "("range"), %%ecx          \n\t"\
+        "shl    %%cl        , "range"                                   \n\t"\
+        "movzbl "MANGLE(ff_h264_mlps_state)"+128("ret"), "tmp"          \n\t"\
+        "mov    "tmpbyte"   , "statep"                                  \n\t"\
+        "shl    %%cl        , "low"                                     \n\t"\
+        "test   "lowword"   , "lowword"                                 \n\t"\
+        " jnz   1f                                                      \n\t"\
+        "mov "BYTE"("cabac"), %%"REG_c"                                 \n\t"\
+        "movzwl (%%"REG_c")     , "tmp"                                 \n\t"\
+        "bswap  "tmp"                                                   \n\t"\
+        "shr    $15         , "tmp"                                     \n\t"\
+        "sub    $0xFFFF     , "tmp"                                     \n\t"\
+        "add    $2          , %%"REG_c"                                 \n\t"\
+        "mov    %%"REG_c"   , "BYTE    "("cabac")                       \n\t"\
+        "lea    -1("low")   , %%ecx                                     \n\t"\
+        "xor    "low"       , %%ecx                                     \n\t"\
+        "shr    $15         , %%ecx                                     \n\t"\
+        "movzbl " MANGLE(ff_h264_norm_shift) "(%%ecx), %%ecx            \n\t"\
+        "neg    %%ecx                                                   \n\t"\
+        "add    $7          , %%ecx                                     \n\t"\
+        "shl    %%cl        , "tmp"                                     \n\t"\
+        "add    "tmp"       , "low"                                     \n\t"\
+        "1:                                                             \n\t"
 
-        :"=&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
+    asm volatile(
+        "movl "RANGE    "(%2), %%esi            \n\t"
+        "movl "LOW      "(%2), %%ebx            \n\t"
+        BRANCHLESS_GET_CABAC("%0", "%2", "(%1)", "%%ebx", "%%bx", "%%esi", "%%edx", "%%dl")
+        "movl %%esi, "RANGE    "(%2)            \n\t"
+        "movl %%ebx, "LOW      "(%2)            \n\t"
+
+        :"=&a"(bit)
         :"r"(state), "r"(c)
-        : "%ecx", "%ebx", "%edx", "%esi"
+        : "%"REG_c, "%ebx", "%edx", "%esi", "memory"
     );
-#else
+    bit&=1;
+#endif /* BRANCHLESS_CABAC_DECODER */
+#else /* defined(ARCH_X86) && defined(HAVE_7REGS) && defined(HAVE_EBX_AVAILABLE) && !defined(BROKEN_RELOCATIONS) */
     int s = *state;
-    int RangeLPS= c->lps_range[s][c->range>>(CABAC_BITS+7)]<<(CABAC_BITS+1);
-    int bit, lps_mask attribute_unused;
+    int RangeLPS= ff_h264_lps_range[2*(c->range&0xC0) + s];
+    int bit, lps_mask av_unused;
 
     c->range -= RangeLPS;
-#if 1
-    if(c->low < c->range){
+#ifndef BRANCHLESS_CABAC_DECODER
+    if(c->low < (c->range<<(CABAC_BITS+1))){
         bit= s&1;
-#ifdef ARCH_X86
-    //P3:627
-asm(
-        "addb $2, %b0       \n\t"
-        " js 1f             \n\t"
-        "movb %b0, %1       \n\t"
-        "1:                 \n\t"
-        : "+q"(s), "=m"(*state)
-);
-#else
-        *state= c->mps_state[s]; //P3:655
-/*        if(s<126) //P3:657
-            *state= s+2;*/
-        s+=2; //P3:631
-        if(s<128)
-            *state= s;
-#endif
+        *state= ff_h264_mps_state[s];
         renorm_cabac_decoder_once(c);
     }else{
-        bit= ff_h264_norm_shift[RangeLPS>>19];
-        c->low -= c->range;
-        *state= c->lps_state[s];
+        bit= ff_h264_norm_shift[RangeLPS];
+        c->low -= (c->range<<(CABAC_BITS+1));
+        *state= ff_h264_lps_state[s];
         c->range = RangeLPS<<bit;
         c->low <<= bit;
         bit= (s&1)^1;
 
-        if(!(c->low & 0xFFFF)){
+        if(!(c->low & CABAC_MASK)){
             refill2(c);
         }
     }
-#else
-    lps_mask= (c->range - c->low)>>31;
+#else /* BRANCHLESS_CABAC_DECODER */
+    lps_mask= ((c->range<<(CABAC_BITS+1)) - c->low)>>31;
 
-    c->low -= c->range & lps_mask;
+    c->low -= (c->range<<(CABAC_BITS+1)) & lps_mask;
     c->range += (RangeLPS - c->range) & lps_mask;
 
-    bit= (s^lps_mask)&1;
-    *state= c->mps_state[s - (128&lps_mask)];
+    s^=lps_mask;
+    *state= (ff_h264_mlps_state+128)[s];
+    bit= s&1;
 
-    lps_mask= ff_h264_norm_shift[c->range>>(CABAC_BITS+2)];
+    lps_mask= ff_h264_norm_shift[c->range];
     c->range<<= lps_mask;
     c->low  <<= lps_mask;
     if(!(c->low & CABAC_MASK))
         refill2(c);
-#endif
-#endif
-//STOP_TIMER("get_cabac")
+#endif /* BRANCHLESS_CABAC_DECODER */
+#endif /* defined(ARCH_X86) && defined(HAVE_7REGS) && defined(HAVE_EBX_AVAILABLE) && !defined(BROKEN_RELOCATIONS) */
     return bit;
 }
 
+static int av_noinline get_cabac_noinline(CABACContext *c, uint8_t * const state){
+    return get_cabac_inline(c,state);
+}
+
+static int get_cabac(CABACContext *c, uint8_t * const state){
+    return get_cabac_inline(c,state);
+}
+
 static int get_cabac_bypass(CABACContext *c){
+#if 0 //not faster
+    int bit;
+    asm volatile(
+        "movl "RANGE    "(%1), %%ebx            \n\t"
+        "movl "LOW      "(%1), %%eax            \n\t"
+        "shl $17, %%ebx                         \n\t"
+        "add %%eax, %%eax                       \n\t"
+        "sub %%ebx, %%eax                       \n\t"
+        "cdq                                    \n\t"
+        "and %%edx, %%ebx                       \n\t"
+        "add %%ebx, %%eax                       \n\t"
+        "test %%ax, %%ax                        \n\t"
+        " jnz 1f                                \n\t"
+        "movl "BYTE     "(%1), %%"REG_b"        \n\t"
+        "subl $0xFFFF, %%eax                    \n\t"
+        "movzwl (%%"REG_b"), %%ecx              \n\t"
+        "bswap %%ecx                            \n\t"
+        "shrl $15, %%ecx                        \n\t"
+        "addl $2, %%"REG_b"                     \n\t"
+        "addl %%ecx, %%eax                      \n\t"
+        "movl %%"REG_b", "BYTE     "(%1)        \n\t"
+        "1:                                     \n\t"
+        "movl %%eax, "LOW      "(%1)            \n\t"
+
+        :"=&d"(bit)
+        :"r"(c)
+        : "%eax", "%"REG_b, "%ecx", "memory"
+    );
+    return bit+1;
+#else
+    int range;
     c->low += c->low;
 
     if(!(c->low & CABAC_MASK))
         refill(c);
 
-    if(c->low < c->range){
+    range= c->range<<(CABAC_BITS+1);
+    if(c->low < range){
         return 0;
     }else{
-        c->low -= c->range;
+        c->low -= range;
         return 1;
     }
+#endif
 }
 
+
+static av_always_inline int get_cabac_bypass_sign(CABACContext *c, int val){
+#if defined(ARCH_X86) && !(defined(PIC) && defined(__GNUC__))
+    asm volatile(
+        "movl "RANGE    "(%1), %%ebx            \n\t"
+        "movl "LOW      "(%1), %%eax            \n\t"
+        "shl $17, %%ebx                         \n\t"
+        "add %%eax, %%eax                       \n\t"
+        "sub %%ebx, %%eax                       \n\t"
+        "cdq                                    \n\t"
+        "and %%edx, %%ebx                       \n\t"
+        "add %%ebx, %%eax                       \n\t"
+        "xor %%edx, %%ecx                       \n\t"
+        "sub %%edx, %%ecx                       \n\t"
+        "test %%ax, %%ax                        \n\t"
+        " jnz 1f                                \n\t"
+        "mov  "BYTE     "(%1), %%"REG_b"        \n\t"
+        "subl $0xFFFF, %%eax                    \n\t"
+        "movzwl (%%"REG_b"), %%edx              \n\t"
+        "bswap %%edx                            \n\t"
+        "shrl $15, %%edx                        \n\t"
+        "add  $2, %%"REG_b"                     \n\t"
+        "addl %%edx, %%eax                      \n\t"
+        "mov  %%"REG_b", "BYTE     "(%1)        \n\t"
+        "1:                                     \n\t"
+        "movl %%eax, "LOW      "(%1)            \n\t"
+
+        :"+c"(val)
+        :"r"(c)
+        : "%eax", "%"REG_b, "%edx", "memory"
+    );
+    return val;
+#else
+    int range, mask;
+    c->low += c->low;
+
+    if(!(c->low & CABAC_MASK))
+        refill(c);
+
+    range= c->range<<(CABAC_BITS+1);
+    c->low -= range;
+    mask= c->low >> 31;
+    range &= mask;
+    c->low += range;
+    return (val^mask)-mask;
+#endif
+}
+
+//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!)
+//FIXME use some macros to avoid duplicatin get_cabac (cannot be done yet as that would make optimization work hard)
+#if defined(ARCH_X86) && defined(HAVE_7REGS) && defined(HAVE_EBX_AVAILABLE) && !defined(BROKEN_RELOCATIONS)
+static int decode_significance_x86(CABACContext *c, int max_coeff, uint8_t *significant_coeff_ctx_base, int *index){
+    void *end= significant_coeff_ctx_base + max_coeff - 1;
+    int minusstart= -(int)significant_coeff_ctx_base;
+    int minusindex= 4-(int)index;
+    int coeff_count;
+    asm volatile(
+        "movl "RANGE    "(%3), %%esi            \n\t"
+        "movl "LOW      "(%3), %%ebx            \n\t"
+
+        "2:                                     \n\t"
+
+        BRANCHLESS_GET_CABAC("%%edx", "%3", "(%1)", "%%ebx", "%%bx", "%%esi", "%%eax", "%%al")
+
+        "test $1, %%edx                         \n\t"
+        " jz 3f                                 \n\t"
+
+        BRANCHLESS_GET_CABAC("%%edx", "%3", "61(%1)", "%%ebx", "%%bx", "%%esi", "%%eax", "%%al")
+
+        "mov  %2, %%"REG_a"                     \n\t"
+        "movl %4, %%ecx                         \n\t"
+        "add  %1, %%"REG_c"                     \n\t"
+        "movl %%ecx, (%%"REG_a")                \n\t"
+
+        "test $1, %%edx                         \n\t"
+        " jnz 4f                                \n\t"
+
+        "add  $4, %%"REG_a"                     \n\t"
+        "mov  %%"REG_a", %2                     \n\t"
+
+        "3:                                     \n\t"
+        "add  $1, %1                            \n\t"
+        "cmp  %5, %1                            \n\t"
+        " jb 2b                                 \n\t"
+        "mov  %2, %%"REG_a"                     \n\t"
+        "movl %4, %%ecx                         \n\t"
+        "add  %1, %%"REG_c"                     \n\t"
+        "movl %%ecx, (%%"REG_a")                \n\t"
+        "4:                                     \n\t"
+        "add  %6, %%eax                         \n\t"
+        "shr $2, %%eax                          \n\t"
+
+        "movl %%esi, "RANGE    "(%3)            \n\t"
+        "movl %%ebx, "LOW      "(%3)            \n\t"
+        :"=&a"(coeff_count), "+r"(significant_coeff_ctx_base), "+m"(index)\
+        :"r"(c), "m"(minusstart), "m"(end), "m"(minusindex)\
+        : "%"REG_c, "%ebx", "%edx", "%esi", "memory"\
+    );
+    return coeff_count;
+}
+
+static int decode_significance_8x8_x86(CABACContext *c, uint8_t *significant_coeff_ctx_base, int *index, uint8_t *sig_off){
+    int minusindex= 4-(int)index;
+    int coeff_count;
+    long last=0;
+    asm volatile(
+        "movl "RANGE    "(%3), %%esi            \n\t"
+        "movl "LOW      "(%3), %%ebx            \n\t"
+
+        "mov %1, %%"REG_D"                      \n\t"
+        "2:                                     \n\t"
+
+        "mov %6, %%"REG_a"                      \n\t"
+        "movzbl (%%"REG_a", %%"REG_D"), %%edi   \n\t"
+        "add %5, %%"REG_D"                      \n\t"
+
+        BRANCHLESS_GET_CABAC("%%edx", "%3", "(%%"REG_D")", "%%ebx", "%%bx", "%%esi", "%%eax", "%%al")
+
+        "mov %1, %%edi                          \n\t"
+        "test $1, %%edx                         \n\t"
+        " jz 3f                                 \n\t"
+
+        "movzbl "MANGLE(last_coeff_flag_offset_8x8)"(%%edi), %%edi\n\t"
+        "add %5, %%"REG_D"                      \n\t"
+
+        BRANCHLESS_GET_CABAC("%%edx", "%3", "15(%%"REG_D")", "%%ebx", "%%bx", "%%esi", "%%eax", "%%al")
+
+        "mov %2, %%"REG_a"                      \n\t"
+        "mov %1, %%edi                          \n\t"
+        "movl %%edi, (%%"REG_a")                \n\t"
+
+        "test $1, %%edx                         \n\t"
+        " jnz 4f                                \n\t"
+
+        "add $4, %%"REG_a"                      \n\t"
+        "mov %%"REG_a", %2                      \n\t"
+
+        "3:                                     \n\t"
+        "addl $1, %%edi                         \n\t"
+        "mov %%edi, %1                          \n\t"
+        "cmpl $63, %%edi                        \n\t"
+        " jb 2b                                 \n\t"
+        "mov %2, %%"REG_a"                      \n\t"
+        "movl %%edi, (%%"REG_a")                \n\t"
+        "4:                                     \n\t"
+        "addl %4, %%eax                         \n\t"
+        "shr $2, %%eax                          \n\t"
+
+        "movl %%esi, "RANGE    "(%3)            \n\t"
+        "movl %%ebx, "LOW      "(%3)            \n\t"
+        :"=&a"(coeff_count),"+m"(last), "+m"(index)\
+        :"r"(c), "m"(minusindex), "m"(significant_coeff_ctx_base), "m"(sig_off)\
+        : "%"REG_c, "%ebx", "%edx", "%esi", "%"REG_D, "memory"\
+    );
+    return coeff_count;
+}
+#endif /* defined(ARCH_X86) && && defined(HAVE_7REGS) && defined(HAVE_EBX_AVAILABLE) && !defined(BROKEN_RELOCATIONS) */
+
 /**
  *
  * @return the number of bytes read or 0 if no end
  */
 static int get_cabac_terminate(CABACContext *c){
-    c->range -= 4<<CABAC_BITS;
-    if(c->low < c->range){
+    c->range -= 2;
+    if(c->low < c->range<<(CABAC_BITS+1)){
         renorm_cabac_decoder_once(c);
         return 0;
     }else{
@@ -534,8 +809,9 @@ static int get_cabac_terminate(CABACContext *c){
     }
 }
 
+#if 0
 /**
- * get (truncated) unnary binarization.
+ * Get (truncated) unary binarization.
  */
 static int get_cabac_u(CABACContext *c, uint8_t * state, int max, int max_index, int truncated){
     int i;
@@ -589,3 +865,6 @@ static int get_cabac_ueg(CABACContext *c, uint8_t * state, int max, int is_signe
     }else
         return i;
 }
+#endif /* 0 */
+
+#endif /* FFMPEG_CABAC_H */