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libavcodec
aarch64
cabac.h
Go to the documentation of this file.
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/*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#ifndef AVCODEC_AARCH64_CABAC_H
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#define AVCODEC_AARCH64_CABAC_H
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#include "config.h"
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#if HAVE_INLINE_ASM
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#include "
libavutil/attributes.h
"
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#include "
libavutil/internal.h
"
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#include "
libavcodec/cabac.h
"
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#define get_cabac_inline get_cabac_inline_aarch64
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static
av_always_inline
int
get_cabac_inline_aarch64(
CABACContext
*
c
,
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uint8_t
*
const
state
)
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{
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int
bit;
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void
*reg_a, *reg_b, *reg_c, *tmp;
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__asm__
volatile
(
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"ldrb %w[bit] , [%[state]] \n\t"
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"add %[r_b] , %[tables] , %[lps_off] \n\t"
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"mov %w[tmp] , %w[range] \n\t"
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"and %w[range] , %w[range] , #0xC0 \n\t"
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"lsl %w[r_c] , %w[range] , #1 \n\t"
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"add %[r_b] , %[r_b] , %w[bit], UXTW \n\t"
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"ldrb %w[range] , [%[r_b], %w[r_c], SXTW] \n\t"
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"sub %w[r_c] , %w[tmp] , %w[range] \n\t"
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"lsl %w[tmp] , %w[r_c] , #17 \n\t"
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"cmp %w[tmp] , %w[low] \n\t"
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"csel %w[tmp] , %w[tmp] , wzr , cc \n\t"
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"csel %w[range] , %w[r_c] , %w[range], gt \n\t"
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"cinv %w[bit] , %w[bit] , cc \n\t"
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"sub %w[low] , %w[low] , %w[tmp] \n\t"
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"add %[r_b] , %[tables] , %[norm_off] \n\t"
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"add %[r_a] , %[tables] , %[mlps_off] \n\t"
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"ldrb %w[tmp] , [%[r_b], %w[range], SXTW] \n\t"
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"ldrb %w[r_a] , [%[r_a], %w[bit], SXTW] \n\t"
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"lsl %w[low] , %w[low] , %w[tmp] \n\t"
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"lsl %w[range] , %w[range] , %w[tmp] \n\t"
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"uxth %w[r_c] , %w[low] \n\t"
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"strb %w[r_a] , [%[state]] \n\t"
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"cbnz %w[r_c] , 2f \n\t"
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"ldr %[r_c] , [%[c], %[byte]] \n\t"
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"ldr %[r_a] , [%[c], %[end]] \n\t"
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"ldrh %w[tmp] , [%[r_c]] \n\t"
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"cmp %[r_c] , %[r_a] \n\t"
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"b.ge 1f \n\t"
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"add %[r_a] , %[r_c] , #2 \n\t"
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"str %[r_a] , [%[c], %[byte]] \n\t"
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"1: \n\t"
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"sub %w[r_c] , %w[low] , #1 \n\t"
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"eor %w[r_c] , %w[r_c] , %w[low] \n\t"
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"rev %w[tmp] , %w[tmp] \n\t"
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"lsr %w[r_c] , %w[r_c] , #15 \n\t"
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"lsr %w[tmp] , %w[tmp] , #15 \n\t"
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"ldrb %w[r_c] , [%[r_b], %w[r_c], SXTW] \n\t"
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"mov %w[r_b] , #0xFFFF \n\t"
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"mov %w[r_a] , #7 \n\t"
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"sub %w[tmp] , %w[tmp] , %w[r_b] \n\t"
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"sub %w[r_c] , %w[r_a] , %w[r_c] \n\t"
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"lsl %w[tmp] , %w[tmp] , %w[r_c] \n\t"
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"add %w[low] , %w[low] , %w[tmp] \n\t"
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"2: \n\t"
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: [bit]
"=&r"
(bit),
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[low]
"+&r"
(c->
low
),
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[range]
"+&r"
(c->
range
),
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[r_a]
"=&r"
(reg_a),
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[
r_b
]
"=&r"
(reg_b),
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[r_c]
"=&r"
(reg_c),
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[tmp]
"=&r"
(tmp)
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: [c]
"r"
(c),
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[
state
]
"r"
(
state
),
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[
tables
]
"r"
(
ff_h264_cabac_tables
),
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[
byte
]
"i"
(offsetof(
CABACContext
, bytestream)),
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[
end
]
"i"
(offsetof(
CABACContext
, bytestream_end)),
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[norm_off]
"I"
(
H264_NORM_SHIFT_OFFSET
),
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[lps_off]
"I"
(
H264_LPS_RANGE_OFFSET
),
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[mlps_off]
"I"
(
H264_MLPS_STATE_OFFSET
+ 128)
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:
"memory"
,
"cc"
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);
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return
bit & 1;
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}
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#endif
/* HAVE_INLINE_ASM */
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#endif
/* AVCODEC_AARCH64_CABAC_H */
Generated on Sun Mar 8 2015 02:34:47 for FFmpeg by
1.8.2