2025-04-28 08:47:28 +08:00

132 lines
4.3 KiB
ArmAsm

/*****************************************************************************
* cabac-a.S: aarch64 cabac
*****************************************************************************
* Copyright (C) 2014-2025 x264 project
*
* Authors: Janne Grunau <janne-x264@jannau.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111, USA.
*
* This program is also available under a commercial proprietary license.
* For more information, contact us at licensing@x264.com.
*****************************************************************************/
#include "asm.S"
#include "asm-offsets.h"
// w11 holds x264_cabac_t.i_low
// w12 holds x264_cabac_t.i_range
function cabac_encode_decision_asm, export=1
add w10, w1, #CABAC_STATE
ldrb w3, [x0, w10, uxtw] // i_state
ldr w12, [x0, #CABAC_I_RANGE]
movrel x8, X264(cabac_range_lps), -4
movrel x9, X264(cabac_transition)
ubfx x4, x3, #1, #7
asr w5, w12, #6
add x8, x8, x4, lsl #2
orr w14, w2, w3, lsl #1
ldrb w4, [x8, w5, uxtw] // i_range_lps
ldr w11, [x0, #CABAC_I_LOW]
eor w6, w2, w3 // b ^ i_state
ldrb w9, [x9, w14, uxtw]
sub w12, w12, w4
add w7, w11, w12
tst w6, #1 // (b ^ i_state) & 1
csel w12, w4, w12, ne
csel w11, w7, w11, ne
strb w9, [x0, w10, uxtw] // i_state
cabac_encode_renorm:
ldr w2, [x0, #CABAC_I_QUEUE]
clz w5, w12
sub w5, w5, #23
lsl w11, w11, w5
lsl w12, w12, w5
adds w2, w2, w5
b.ge cabac_putbyte
stp w11, w12, [x0, #CABAC_I_LOW] // store i_low, i_range
str w2, [x0, #CABAC_I_QUEUE]
ret
.align 5
cabac_putbyte:
ldr w6, [x0, #CABAC_I_BYTES_OUTSTANDING]
add w14, w2, #10
mov w13, #-1
sub w2, w2, #8
asr w4, w11, w14 // out
lsl w13, w13, w14
subs w5, w4, #0xff
bic w11, w11, w13
cinc w6, w6, eq
b.eq 0f
1:
ldr x7, [x0, #CABAC_P]
asr w5, w4, #8 // carry
ldurb w8, [x7, #-1]
add w8, w8, w5
sub w5, w5, #1
sturb w8, [x7, #-1]
cbz w6, 3f
2:
subs w6, w6, #1
strb w5, [x7], #1
b.gt 2b
3:
strb w4, [x7], #1
str x7, [x0, #CABAC_P]
0:
stp w11, w12, [x0, #CABAC_I_LOW] // store i_low, i_range
stp w2, w6, [x0, #CABAC_I_QUEUE] // store i_queue, i_bytes_outstanding
ret
endfunc
function cabac_encode_bypass_asm, export=1, align=5
ldr w12, [x0, #CABAC_I_RANGE]
ldr w11, [x0, #CABAC_I_LOW]
ldr w2, [x0, #CABAC_I_QUEUE]
and w1, w1, w12
add w11, w1, w11, lsl #1
adds w2, w2, #1
b.ge cabac_putbyte
str w11, [x0, #CABAC_I_LOW]
str w2, [x0, #CABAC_I_QUEUE]
ret
endfunc
function cabac_encode_terminal_asm, export=1, align=5
ldr w12, [x0, #CABAC_I_RANGE]
sub w12, w12, #2
tbz w12, #8, 1f
str w12, [x0, #CABAC_I_RANGE]
ret
1:
ldr w2, [x0, #CABAC_I_QUEUE]
ldr w11, [x0, #CABAC_I_LOW]
lsl w12, w12, #1
adds w2, w2, #1
lsl w11, w11, #1
b.ge cabac_putbyte
stp w11, w12, [x0, #CABAC_I_LOW] // store i_low, i_range
str w2, [x0, #CABAC_I_QUEUE]
ret
endfunc