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cabac: remove BRANCHLESS_CABAC_DECODER switch

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The code does not compile without this set.

Signed-off-by: Mans Rullgard <mans@mansr.com>
pull/2/head
Mans Rullgard 14 years ago
parent eaa2d5a90a
commit 8fcc0e7978
2 changed files with 1 additions and 113 deletions
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  1. 8
      libavcodec/cabac.c
  2. 106
      libavcodec/cabac.h

8
libavcodec/cabac.c
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@ -161,19 +161,11 @@ void ff_init_cabac_states(CABACContext *c){
ff_h264_mps_state[2*i+1]= 2*mps_state[i]+1;
if( i ){
#ifdef BRANCHLESS_CABAC_DECODER
ff_h264_mlps_state[128-2*i-1]= 2*lps_state[i]+0;
ff_h264_mlps_state[128-2*i-2]= 2*lps_state[i]+1;
}else{
ff_h264_mlps_state[128-2*i-1]= 1;
ff_h264_mlps_state[128-2*i-2]= 0;
#else
ff_h264_lps_state[2*i+0]= 2*lps_state[i]+0;
ff_h264_lps_state[2*i+1]= 2*lps_state[i]+1;
}else{
ff_h264_lps_state[2*i+0]= 1;
ff_h264_lps_state[2*i+1]= 0;
#endif
}
}
}

106
libavcodec/cabac.h
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@ -35,7 +35,6 @@
#define CABAC_BITS 16
#define CABAC_MASK ((1<<CABAC_BITS)-1)
#define BRANCHLESS_CABAC_DECODER 1
typedef struct CABACContext{
int low;
@ -322,89 +321,6 @@ static av_always_inline int get_cabac_inline(CABACContext *c, uint8_t * const st
#if ARCH_X86 && HAVE_7REGS && HAVE_EBX_AVAILABLE && !defined(BROKEN_RELOCATIONS)
int bit;
#ifndef BRANCHLESS_CABAC_DECODER
__asm__ volatile(
"movzbl (%1), %0 \n\t"
"movl "RANGE "(%2), %%ebx \n\t"
"movl "RANGE "(%2), %%edx \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"
"movl %%edx, %%ecx \n\t"
"shll $17, %%ecx \n\t"
"cmpl %%ecx, %%ebx \n\t"
" ja 1f \n\t"
#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"
#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"
"mov "BYTE "(%2), %%"REG_S" \n\t"
"subl $0xFFFF, %%ebx \n\t"
"movzwl (%%"REG_S"), %%ecx \n\t"
"bswap %%ecx \n\t"
"shrl $15, %%ecx \n\t"
"add $2, %%"REG_S" \n\t"
"addl %%ecx, %%ebx \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 %%ecx, %%ebx \n\t"
"movl %%esi, %%edx \n\t"
"movzbl " MANGLE(ff_h264_norm_shift) "(%%esi), %%ecx \n\t"
"shll %%cl, %%ebx \n\t"
"shll %%cl, %%edx \n\t"
"movzbl "MANGLE(ff_h264_lps_state)"(%0), %%ecx \n\t"
"movb %%cl, (%1) \n\t"
"add $1, %0 \n\t"
"test %%bx, %%bx \n\t"
" jnz 2f \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"
"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 $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"
:"=&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 HAVE_FAST_CMOV
#define BRANCHLESS_GET_CABAC_UPDATE(ret, cabac, statep, low, lowword, range, tmp, tmpbyte)\
"mov "tmp" , %%ecx \n\t"\
@ -474,31 +390,12 @@ static av_always_inline int get_cabac_inline(CABACContext *c, uint8_t * const st
: "%"REG_c, "%ebx", "%edx", "%esi", "memory"
);
bit&=1;
#endif /* BRANCHLESS_CABAC_DECODER */
#else /* ARCH_X86 && HAVE_7REGS && HAVE_EBX_AVAILABLE && !defined(BROKEN_RELOCATIONS) */
int s = *state;
int RangeLPS= ff_h264_lps_range[2*(c->range&0xC0) + s];
int bit, lps_mask av_unused;
int bit, lps_mask;
c->range -= RangeLPS;
#ifndef BRANCHLESS_CABAC_DECODER
if(c->low < (c->range<<(CABAC_BITS+1))){
bit= s&1;
*state= ff_h264_mps_state[s];
renorm_cabac_decoder_once(c);
}else{
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 & CABAC_MASK)){
refill2(c);
}
}
#else /* BRANCHLESS_CABAC_DECODER */
lps_mask= ((c->range<<(CABAC_BITS+1)) - c->low)>>31;
c->low -= (c->range<<(CABAC_BITS+1)) & lps_mask;
@ -513,7 +410,6 @@ static av_always_inline int get_cabac_inline(CABACContext *c, uint8_t * const st
c->low <<= lps_mask;
if(!(c->low & CABAC_MASK))
refill2(c);
#endif /* BRANCHLESS_CABAC_DECODER */
#endif /* ARCH_X86 && HAVE_7REGS && HAVE_EBX_AVAILABLE && !defined(BROKEN_RELOCATIONS) */
return bit;
}

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