write cabac low and range variables as early as possible to prevent stalls...

write cabac low and range variables as early as possible to prevent stalls from reading them before they where written, the P4 is said to disslike that alot, on P3 its 2% faster (START/STOP_TIMER over decode_residual)

Originally committed as revision 6657 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/cabac.h

@@ -478,8 +478,10 @@ static int get_cabac(CABACContext *c, uint8_t * const state){
 
         "shr $19, %%esi                         \n\t"
         "movzbl " MANGLE(ff_h264_norm_shift) "(%%esi), %%ecx   \n\t"
-        "shll %%cl, %%ebx                       \n\t"
         "shll %%cl, %%edx                       \n\t"
+        "movl %%edx, "RANGE    "(%2)            \n\t"
+        "shll %%cl, %%ebx                       \n\t"
+        "movl %%ebx, "LOW      "(%2)            \n\t"
         "test %%bx, %%bx                        \n\t"
         " jnz 1f                                \n\t"
 
@@ -500,9 +502,8 @@ static int get_cabac(CABACContext *c, uint8_t * const state){
 
         "shll %%cl , %%esi                      \n\t"
         "addl %%esi, %%ebx                      \n\t"
-        "1:                                     \n\t"
-        "movl %%edx, "RANGE    "(%2)            \n\t"
         "movl %%ebx, "LOW      "(%2)            \n\t"
+        "1:                                     \n\t"
         :"=&a"(bit)
         :"r"(state), "r"(c)
         : "%ecx", "%ebx", "%edx", "%esi"