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H.264: optimize CABAC x86 asm for Atom

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pull/2/head
Jason Garrett-Glaser 13 years ago
parent 8dcf518430
commit 6c32576548
3 changed files with 12 additions and 16 deletions
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  1. 2
      libavcodec/h264_cabac.c
  2. 15
      libavcodec/x86/cabac.h
  3. 11
      libavcodec/x86/h264_i386.h

2
libavcodec/h264_cabac.c
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@ -1649,7 +1649,7 @@ static av_always_inline void decode_cabac_residual_internal( H264Context *h, DCT
const uint8_t *sig_off = significant_coeff_flag_offset_8x8[MB_FIELD];
#if ARCH_X86 && HAVE_7REGS && HAVE_EBX_AVAILABLE && !defined(BROKEN_RELOCATIONS)
coeff_count= decode_significance_8x8_x86(CC, significant_coeff_ctx_base, index,
last_coeff_ctx_base-significant_coeff_ctx_base, sig_off);
last_coeff_ctx_base, sig_off);
} else {
coeff_count= decode_significance_x86(CC, max_coeff, significant_coeff_ctx_base, index,
last_coeff_ctx_base-significant_coeff_ctx_base);

15
libavcodec/x86/cabac.h
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@ -34,8 +34,8 @@
"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"
"xor %%ecx , "ret" \n\t"\
"sub "tmp" , "low" \n\t"
#else /* HAVE_FAST_CMOV */
#define BRANCHLESS_GET_CABAC_UPDATE(ret, cabac, statep, low, lowword, range, tmp)\
"mov "tmp" , %%ecx \n\t"\
@ -62,21 +62,20 @@
"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"\
"mov "tmpbyte" , "statep" \n\t"\
"test "lowword" , "lowword" \n\t"\
" jnz 1f \n\t"\
"mov "byte"("cabac"), %%"REG_c" \n\t"\
"add $2 , "byte "("cabac") \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"\
"bswap "tmp" \n\t"\
"shr $15 , "tmp" \n\t"\
"movzbl " MANGLE(ff_h264_norm_shift) "(%%ecx), %%ecx \n\t"\
"sub $0xFFFF , "tmp" \n\t"\
"neg %%ecx \n\t"\
"add $7 , %%ecx \n\t"\
"shl %%cl , "tmp" \n\t"\

11
libavcodec/x86/h264_i386.h
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@ -72,8 +72,7 @@ static int decode_significance_x86(CABACContext *c, int max_coeff,
"test $1, %4 \n\t"
" jnz 4f \n\t"
"add $4, %0 \n\t"
"mov %0, %2 \n\t"
"add $4, %2 \n\t"
"3: \n\t"
"add $1, %1 \n\t"
@ -101,7 +100,7 @@ static int decode_significance_x86(CABACContext *c, int max_coeff,
static int decode_significance_8x8_x86(CABACContext *c,
uint8_t *significant_coeff_ctx_base,
int *index, x86_reg last_off, const uint8_t *sig_off){
int *index, uint8_t *last_coeff_ctx_base, const uint8_t *sig_off){
int minusindex= 4-(intptr_t)index;
int bit;
x86_reg coeff_count;
@ -128,7 +127,6 @@ static int decode_significance_8x8_x86(CABACContext *c,
" jz 3f \n\t"
"movzbl "MANGLE(last_coeff_flag_offset_8x8)"(%k6), %k6\n\t"
"add %9, %6 \n\t"
"add %11, %6 \n\t"
BRANCHLESS_GET_CABAC("%4", "%7", "(%6)", "%3",
@ -141,8 +139,7 @@ static int decode_significance_8x8_x86(CABACContext *c,
"test $1, %4 \n\t"
" jnz 4f \n\t"
"add $4, %0 \n\t"
"mov %0, %2 \n\t"
"add $4, %2 \n\t"
"3: \n\t"
"addl $1, %k6 \n\t"
@ -159,7 +156,7 @@ static int decode_significance_8x8_x86(CABACContext *c,
"movl %3, %a13(%7) \n\t"
:"=&q"(coeff_count),"+m"(last), "+m"(index), "=&r"(low), "=&r"(bit),
"=&r"(range), "=&r"(state)
:"r"(c), "m"(minusindex), "m"(significant_coeff_ctx_base), "m"(sig_off), "m"(last_off),
:"r"(c), "m"(minusindex), "m"(significant_coeff_ctx_base), "m"(sig_off), "m"(last_coeff_ctx_base),
"i"(offsetof(CABACContext, range)), "i"(offsetof(CABACContext, low)),
"i"(offsetof(CABACContext, bytestream))
: "%"REG_c, "memory"

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