FFmpeg/libavcodec/x86/cabac.h
Mans Rullgard c5ee740745 x86: cabac: fix register constraints for 32-bit mode
Some operands need to be accessed in byte mode, which restricts the
available registers in 32-bit mode.  Using the 'q' constraint selects
a suitable register.

Signed-off-by: Mans Rullgard <mans@mansr.com>
2011-06-20 23:36:40 +01:00

149 lines
7.1 KiB
C

/*
* 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
*/
#ifndef AVCODEC_X86_CABAC_H
#define AVCODEC_X86_CABAC_H
#include "libavcodec/cabac.h"
#include "libavutil/attributes.h"
#include "libavutil/x86_cpu.h"
#include "config.h"
#if HAVE_FAST_CMOV
#define BRANCHLESS_GET_CABAC_UPDATE(ret, cabac, statep, low, lowword, range, tmp)\
"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)\
"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, byte) \
"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) \
"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"
#if ARCH_X86 && HAVE_7REGS && !defined(BROKEN_RELOCATIONS)
#define get_cabac_inline get_cabac_inline_x86
static av_always_inline int get_cabac_inline_x86(CABACContext *c,
uint8_t *const state)
{
int bit, low, range, tmp;
__asm__ volatile(
"movl %a6(%5), %2 \n\t"
"movl %a7(%5), %1 \n\t"
BRANCHLESS_GET_CABAC("%0", "%5", "(%4)", "%1", "%w1", "%2",
"%3", "%b3", "%a8")
"movl %2, %a6(%5) \n\t"
"movl %1, %a7(%5) \n\t"
:"=&r"(bit), "=&r"(low), "=&r"(range), "=&q"(tmp)
:"r"(state), "r"(c),
"i"(offsetof(CABACContext, range)), "i"(offsetof(CABACContext, low)),
"i"(offsetof(CABACContext, bytestream))
: "%"REG_c, "memory"
);
return bit & 1;
}
#endif /* ARCH_X86 && HAVE_7REGS && !defined(BROKEN_RELOCATIONS) */
#define get_cabac_bypass_sign get_cabac_bypass_sign_x86
static av_always_inline int get_cabac_bypass_sign_x86(CABACContext *c, int val)
{
x86_reg tmp;
__asm__ volatile(
"movl %a3(%2), %k1 \n\t"
"movl %a4(%2), %%eax \n\t"
"shl $17, %k1 \n\t"
"add %%eax, %%eax \n\t"
"sub %k1, %%eax \n\t"
"cltd \n\t"
"and %%edx, %k1 \n\t"
"add %k1, %%eax \n\t"
"xor %%edx, %%ecx \n\t"
"sub %%edx, %%ecx \n\t"
"test %%ax, %%ax \n\t"
" jnz 1f \n\t"
"mov %a5(%2), %1 \n\t"
"subl $0xFFFF, %%eax \n\t"
"movzwl (%1), %%edx \n\t"
"bswap %%edx \n\t"
"shrl $15, %%edx \n\t"
"add $2, %1 \n\t"
"addl %%edx, %%eax \n\t"
"mov %1, %a5(%2) \n\t"
"1: \n\t"
"movl %%eax, %a4(%2) \n\t"
:"+c"(val), "=&r"(tmp)
:"r"(c),
"i"(offsetof(CABACContext, range)), "i"(offsetof(CABACContext, low)),
"i"(offsetof(CABACContext, bytestream))
: "%eax", "%edx", "memory"
);
return val;
}
#endif /* AVCODEC_X86_CABAC_H */