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FFmpeg/libavcodec/x86/h264_i386.h
Martin Storsjö 676a9ee1d2 x86: Fix constraints for decode_significance*_x86
Originally, prior to 8742a4ff8, the caller code was compiled
within this condition:

ARCH_X86 && HAVE_7REGS && HAVE_EBX_AVAILABLE && !defined(BROKEN_RELOCATIONS)

Since HAVE_7REGS is defined as
(ARCH_X86_64 || (HAVE_EBX_AVAILABLE && HAVE_EBP_AVAILABLE))
the subcondition HAVE_7REGS && HAVE_EBX_AVAILABLE is equal
to HAVE_7REGS (for 32 bit at least). The correct simplification
of the original condition thus is HAVE_7REGS, not
HAVE_EBX_AVAILABLE.

This fixes compilation in some cases where HAVE_EBP_AVAILABLE = 0
and HAVE_EBX_AVAILABLE = 1.

Signed-off-by: Martin Storsjö <martin@martin.st>
2011-12-27 09:05:14 +02:00

150 lines
5.8 KiB
C

/*
* H.26L/H.264/AVC/JVT/14496-10/... encoder/decoder
* Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* H.264 / AVC / MPEG4 part10 codec.
* non-MMX i386-specific optimizations for H.264
* @author Michael Niedermayer <michaelni@gmx.at>
*/
#ifndef AVCODEC_X86_H264_I386_H
#define AVCODEC_X86_H264_I386_H
#include <stddef.h>
#include "libavcodec/cabac.h"
#include "cabac.h"
//FIXME use some macros to avoid duplicating get_cabac (cannot be done yet
//as that would make optimization work hard)
#if HAVE_7REGS && !defined(BROKEN_RELOCATIONS)
static int decode_significance_x86(CABACContext *c, int max_coeff,
uint8_t *significant_coeff_ctx_base,
int *index, x86_reg last_off){
void *end= significant_coeff_ctx_base + max_coeff - 1;
int minusstart= -(intptr_t)significant_coeff_ctx_base;
int minusindex= 4-(intptr_t)index;
int bit;
x86_reg coeff_count;
__asm__ volatile(
"2: \n\t"
BRANCHLESS_GET_CABAC("%4", "(%1)", "%3",
"%w3", "%5", "%k0", "%b0", "%6")
"test $1, %4 \n\t"
" jz 3f \n\t"
"add %10, %1 \n\t"
BRANCHLESS_GET_CABAC("%4", "(%1)", "%3",
"%w3", "%5", "%k0", "%b0", "%6")
"sub %10, %1 \n\t"
"mov %2, %0 \n\t"
"movl %7, %%ecx \n\t"
"add %1, %%"REG_c" \n\t"
"movl %%ecx, (%0) \n\t"
"test $1, %4 \n\t"
" jnz 4f \n\t"
"add"OPSIZE" $4, %2 \n\t"
"3: \n\t"
"add $1, %1 \n\t"
"cmp %8, %1 \n\t"
" jb 2b \n\t"
"mov %2, %0 \n\t"
"movl %7, %%ecx \n\t"
"add %1, %%"REG_c" \n\t"
"movl %%ecx, (%0) \n\t"
"4: \n\t"
"add %9, %k0 \n\t"
"shr $2, %k0 \n\t"
:"=&q"(coeff_count), "+r"(significant_coeff_ctx_base), "+m"(index),
"+&r"(c->low), "=&r"(bit), "+&r"(c->range),
"+m"(c->bytestream)
:"m"(minusstart), "m"(end), "m"(minusindex), "m"(last_off)
: "%"REG_c, "memory"
);
return coeff_count;
}
static int decode_significance_8x8_x86(CABACContext *c,
uint8_t *significant_coeff_ctx_base,
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;
x86_reg last=0;
x86_reg state;
__asm__ volatile(
"mov %1, %6 \n\t"
"2: \n\t"
"mov %10, %0 \n\t"
"movzbl (%0, %6), %k6 \n\t"
"add %9, %6 \n\t"
BRANCHLESS_GET_CABAC("%4", "(%6)", "%3",
"%w3", "%5", "%k0", "%b0", "%7")
"mov %1, %k6 \n\t"
"test $1, %4 \n\t"
" jz 3f \n\t"
"movzbl "MANGLE(last_coeff_flag_offset_8x8)"(%k6), %k6\n\t"
"add %11, %6 \n\t"
BRANCHLESS_GET_CABAC("%4", "(%6)", "%3",
"%w3", "%5", "%k0", "%b0", "%7")
"mov %2, %0 \n\t"
"mov %1, %k6 \n\t"
"movl %k6, (%0) \n\t"
"test $1, %4 \n\t"
" jnz 4f \n\t"
"add"OPSIZE" $4, %2 \n\t"
"3: \n\t"
"addl $1, %k6 \n\t"
"mov %k6, %1 \n\t"
"cmpl $63, %k6 \n\t"
" jb 2b \n\t"
"mov %2, %0 \n\t"
"movl %k6, (%0) \n\t"
"4: \n\t"
"addl %8, %k0 \n\t"
"shr $2, %k0 \n\t"
:"=&q"(coeff_count),"+m"(last), "+m"(index), "+&r"(c->low), "=&r"(bit),
"+&r"(c->range), "=&r"(state), "+m"(c->bytestream)
:"m"(minusindex), "m"(significant_coeff_ctx_base), "m"(sig_off), "m"(last_coeff_ctx_base)
: "%"REG_c, "memory"
);
return coeff_count;
}
#endif /* HAVE_7REGS && !defined(BROKEN_RELOCATIONS) */
#endif /* AVCODEC_X86_H264_I386_H */