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/*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVCODEC_AARCH64_CABAC_H
#define AVCODEC_AARCH64_CABAC_H
#include "config.h"
#if HAVE_INLINE_ASM
#include "libavutil/attributes.h"
#include "libavutil/internal.h"
#include "libavcodec/cabac.h"
#define get_cabac_inline get_cabac_inline_aarch64
static av_always_inline int get_cabac_inline_aarch64(CABACContext *c,
uint8_t *const state)
{
int bit;
void *reg_a, *reg_b, *reg_c, *tmp;
__asm__ volatile(
"ldrb %w[bit] , [%[state]] \n\t"
"add %[r_b] , %[tables] , %[lps_off] \n\t"
"mov %w[tmp] , %w[range] \n\t"
"and %w[range] , %w[range] , #0xC0 \n\t"
"lsl %w[r_c] , %w[range] , #1 \n\t"
"add %[r_b] , %[r_b] , %w[bit], UXTW \n\t"
"ldrb %w[range] , [%[r_b], %w[r_c], SXTW] \n\t"
"sub %w[r_c] , %w[tmp] , %w[range] \n\t"
"lsl %w[tmp] , %w[r_c] , #17 \n\t"
"cmp %w[tmp] , %w[low] \n\t"
"csel %w[tmp] , %w[tmp] , wzr , cc \n\t"
"csel %w[range] , %w[r_c] , %w[range], gt \n\t"
"cinv %w[bit] , %w[bit] , cc \n\t"
"sub %w[low] , %w[low] , %w[tmp] \n\t"
"add %[r_b] , %[tables] , %[norm_off] \n\t"
"add %[r_a] , %[tables] , %[mlps_off] \n\t"
"ldrb %w[tmp] , [%[r_b], %w[range], SXTW] \n\t"
"ldrb %w[r_a] , [%[r_a], %w[bit], SXTW] \n\t"
"lsl %w[low] , %w[low] , %w[tmp] \n\t"
"lsl %w[range] , %w[range] , %w[tmp] \n\t"
"uxth %w[r_c] , %w[low] \n\t"
"strb %w[r_a] , [%[state]] \n\t"
"cbnz %w[r_c] , 2f \n\t"
"ldr %[r_c] , [%[c], %[byte]] \n\t"
"ldr %[r_a] , [%[c], %[end]] \n\t"
"ldrh %w[tmp] , [%[r_c]] \n\t"
"cmp %[r_c] , %[r_a] \n\t"
"b.ge 1f \n\t"
"add %[r_a] , %[r_c] , #2 \n\t"
"str %[r_a] , [%[c], %[byte]] \n\t"
"1: \n\t"
"sub %w[r_c] , %w[low] , #1 \n\t"
"eor %w[r_c] , %w[r_c] , %w[low] \n\t"
"rev %w[tmp] , %w[tmp] \n\t"
"lsr %w[r_c] , %w[r_c] , #15 \n\t"
"lsr %w[tmp] , %w[tmp] , #15 \n\t"
"ldrb %w[r_c] , [%[r_b], %w[r_c], SXTW] \n\t"
"mov %w[r_b] , #0xFFFF \n\t"
"mov %w[r_a] , #7 \n\t"
"sub %w[tmp] , %w[tmp] , %w[r_b] \n\t"
"sub %w[r_c] , %w[r_a] , %w[r_c] \n\t"
"lsl %w[tmp] , %w[tmp] , %w[r_c] \n\t"
"add %w[low] , %w[low] , %w[tmp] \n\t"
"2: \n\t"
: [bit]"=&r"(bit),
[low]"+&r"(c->low),
[range]"+&r"(c->range),
[r_a]"=&r"(reg_a),
[r_b]"=&r"(reg_b),
[r_c]"=&r"(reg_c),
[tmp]"=&r"(tmp)
: [c]"r"(c),
[state]"r"(state),
[tables]"r"(ff_h264_cabac_tables),
[byte]"i"(offsetof(CABACContext, bytestream)),
[end]"i"(offsetof(CABACContext, bytestream_end)),
[norm_off]"I"(H264_NORM_SHIFT_OFFSET),
[lps_off]"I"(H264_LPS_RANGE_OFFSET),
[mlps_off]"I"(H264_MLPS_STATE_OFFSET + 128)
: "memory", "cc"
);
return bit & 1;
}
#endif /* HAVE_INLINE_ASM */
#endif /* AVCODEC_AARCH64_CABAC_H */
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