ref: 3a77c57b0ca06c613fea96afe63d2870f513e97f
dir: /src/arm/64/msac.S/
/*
* Copyright © 2019, VideoLAN and dav1d authors
* Copyright © 2019, Martin Storsjo
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "src/arm/asm.S"
#include "util.S"
#define BUF_POS 0
#define BUF_END 8
#define DIF 16
#define RNG 24
#define CNT 28
#define ALLOW_UPDATE_CDF 32
const coeffs
.short 60, 56, 52, 48, 44, 40, 36, 32, 28, 24, 20, 16, 12, 8, 4, 0
.short 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
endconst
const bits
.short 0x1, 0x2, 0x4, 0x8, 0x10, 0x20, 0x40, 0x80
.short 0x100, 0x200, 0x400, 0x800, 0x1000, 0x2000, 0x4000, 0x8000
endconst
.macro ld1_n d0, d1, src, sz, n
.if \n <= 8
ld1 {\d0\sz}, [\src]
.else
ld1 {\d0\sz, \d1\sz}, [\src]
.endif
.endm
.macro st1_n s0, s1, dst, sz, n
.if \n <= 8
st1 {\s0\sz}, [\dst]
.else
st1 {\s0\sz, \s1\sz}, [\dst]
.endif
.endm
.macro ushr_n d0, d1, s0, s1, shift, sz, n
ushr \d0\sz, \s0\sz, \shift
.if \n == 16
ushr \d1\sz, \s1\sz, \shift
.endif
.endm
.macro add_n d0, d1, s0, s1, s2, s3, sz, n
add \d0\sz, \s0\sz, \s2\sz
.if \n == 16
add \d1\sz, \s1\sz, \s3\sz
.endif
.endm
.macro sub_n d0, d1, s0, s1, s2, s3, sz, n
sub \d0\sz, \s0\sz, \s2\sz
.if \n == 16
sub \d1\sz, \s1\sz, \s3\sz
.endif
.endm
.macro and_n d0, d1, s0, s1, s2, s3, sz, n
and \d0\sz, \s0\sz, \s2\sz
.if \n == 16
and \d1\sz, \s1\sz, \s3\sz
.endif
.endm
.macro cmhs_n d0, d1, s0, s1, s2, s3, sz, n
cmhs \d0\sz, \s0\sz, \s2\sz
.if \n == 16
cmhs \d1\sz, \s1\sz, \s3\sz
.endif
.endm
.macro urhadd_n d0, d1, s0, s1, s2, s3, sz, n
urhadd \d0\sz, \s0\sz, \s2\sz
.if \n == 16
urhadd \d1\sz, \s1\sz, \s3\sz
.endif
.endm
.macro sshl_n d0, d1, s0, s1, s2, s3, sz, n
sshl \d0\sz, \s0\sz, \s2\sz
.if \n == 16
sshl \d1\sz, \s1\sz, \s3\sz
.endif
.endm
.macro umull_n d0, d1, d2, d3, s0, s1, s2, s3, n
umull \d0\().4s, \s0\().4h, \s2\().4h
.if \n >= 8
umull2 \d1\().4s, \s0\().8h, \s2\().8h
.endif
.if \n == 16
umull \d2\().4s, \s1\().4h, \s3\().4h
umull2 \d3\().4s, \s1\().8h, \s3\().8h
.endif
.endm
.macro shrn_n d0, d1, s0, s1, s2, s3, shift, n
shrn \d0\().4h, \s0\().4s, \shift
.if \n >= 8
shrn2 \d0\().8h, \s1\().4s, \shift
.endif
.if \n == 16
shrn \d1\().4h, \s2\().4s, \shift
shrn2 \d1\().8h, \s3\().4s, \shift
.endif
.endm
.macro str_n idx0, idx1, dstreg, dstoff, n
str q\idx0, [\dstreg, \dstoff]
.if \n == 16
str q\idx1, [\dstreg, \dstoff + 16]
.endif
.endm
// unsigned dav1d_msac_decode_symbol_adapt4_neon(MsacContext *s, uint16_t *cdf,
// size_t n_symbols);
function msac_decode_symbol_adapt4_neon, export=1
.macro decode_update sz, szb, n
sub sp, sp, #48
add x8, x0, #RNG
ld1_n v0, v1, x1, \sz, \n // cdf
ld1r {v4\sz}, [x8] // rng
movrel x9, coeffs, 32
sub x9, x9, x2, lsl #1
ushr_n v2, v3, v0, v1, #6, \sz, \n // cdf >> EC_PROB_SHIFT
str h4, [sp, #14] // store original u = s->rng
ushr v4\sz, v4\sz, #8 // r = rng >> 8
umull_n v16, v17, v18, v19, v4, v4, v2, v3, \n // r * (cdf >> EC_PROB_SHIFT)
ld1_n v4, v5, x9, \sz, \n // EC_MIN_PROB * (n_symbols - ret)
shrn_n v2, v3, v16, v17, v18, v19, #1, \n // v >>= 7 - EC_PROB_SHIFT
add x8, x0, #DIF + 6
add_n v4, v5, v2, v3, v4, v5, \sz, \n // v += EC_MIN_PROB * (n_symbols - ret)
ld1r {v6.8h}, [x8] // dif >> (EC_WIN_SIZE - 16)
movrel x8, bits
str_n 4, 5, sp, #16, \n // store v values to allow indexed access
ld1_n v16, v17, x8, .8h, \n
cmhs_n v2, v3, v6, v6, v4, v5, .8h, \n // c >= v
and_n v6, v7, v2, v3, v16, v17, .16b, \n // One bit per halfword set in the mask
.if \n == 16
add v6.8h, v6.8h, v7.8h
.endif
addv h6, v6.8h // Aggregate mask bits
ldr w4, [x0, #ALLOW_UPDATE_CDF]
umov w3, v6.h[0]
rbit w3, w3
clz w15, w3 // ret
cbz w4, L(renorm)
// update_cdf
ldrh w3, [x1, x2, lsl #1] // count = cdf[n_symbols]
movi v5\szb, #0xff
cmp x2, #4 // set C if n_symbols >= 4 (n_symbols > 3)
mov w14, #4
lsr w4, w3, #4 // count >> 4
urhadd_n v4, v5, v5, v5, v2, v3, \sz, \n // i >= val ? -1 : 32768
adc w4, w4, w14 // (count >> 4) + (n_symbols > 3) + 4
neg w4, w4 // -rate
sub_n v4, v5, v4, v5, v0, v1, \sz, \n // (32768 - cdf[i]) or (-1 - cdf[i])
dup v6.8h, w4 // -rate
sub w3, w3, w3, lsr #5 // count - (count >= 32)
sub_n v0, v1, v0, v1, v2, v3, \sz, \n // cdf + (i >= val ? 1 : 0)
sshl_n v4, v5, v4, v5, v6, v6, \sz, \n // ({32768,-1} - cdf[i]) >> rate
add w3, w3, #1 // count + (count < 32)
add_n v0, v1, v0, v1, v4, v5, \sz, \n // cdf + (32768 - cdf[i]) >> rate
st1_n v0, v1, x1, \sz, \n
strh w3, [x1, x2, lsl #1]
.endm
decode_update .4h, .8b, 4
L(renorm):
add x8, sp, #16
add x8, x8, w15, uxtw #1
ldrh w3, [x8] // v
ldurh w4, [x8, #-2] // u
ldr w6, [x0, #CNT]
ldr x7, [x0, #DIF]
sub w4, w4, w3 // rng = u - v
clz w5, w4 // clz(rng)
eor w5, w5, #16 // d = clz(rng) ^ 16
mvn x7, x7 // ~dif
add x7, x7, x3, lsl #48 // ~dif + (v << 48)
L(renorm2):
lsl w4, w4, w5 // rng << d
subs w6, w6, w5 // cnt -= d
lsl x7, x7, x5 // (~dif + (v << 48)) << d
str w4, [x0, #RNG]
mvn x7, x7 // ~dif
b.ge 9f
// refill
ldr x3, [x0, #BUF_POS]
ldr x4, [x0, #BUF_END]
add x5, x3, #8
cmp x5, x4
b.gt 2f
ldr x3, [x3] // next_bits
add w8, w6, #23 // shift_bits = cnt + 23
add w6, w6, #16 // cnt += 16
rev x3, x3 // next_bits = bswap(next_bits)
sub x5, x5, x8, lsr #3 // buf_pos -= shift_bits >> 3
and w8, w8, #24 // shift_bits &= 24
lsr x3, x3, x8 // next_bits >>= shift_bits
sub w8, w8, w6 // shift_bits -= 16 + cnt
str x5, [x0, #BUF_POS]
lsl x3, x3, x8 // next_bits <<= shift_bits
mov w4, #48
sub w6, w4, w8 // cnt = cnt + 64 - shift_bits
eor x7, x7, x3 // dif ^= next_bits
b 9f
2: // refill_eob
mov w14, #40
sub w5, w14, w6 // c = 40 - cnt
3:
cmp x3, x4
b.ge 4f
ldrb w8, [x3], #1
lsl x8, x8, x5
eor x7, x7, x8
subs w5, w5, #8
b.ge 3b
4: // refill_eob_end
str x3, [x0, #BUF_POS]
sub w6, w14, w5 // cnt = 40 - c
9:
str w6, [x0, #CNT]
str x7, [x0, #DIF]
mov w0, w15
add sp, sp, #48
ret
endfunc
function msac_decode_symbol_adapt8_neon, export=1
decode_update .8h, .16b, 8
b L(renorm)
endfunc
function msac_decode_symbol_adapt16_neon, export=1
decode_update .8h, .16b, 16
b L(renorm)
endfunc
function msac_decode_bool_equi_neon, export=1
ldp w5, w6, [x0, #RNG] // + CNT
sub sp, sp, #48
ldr x7, [x0, #DIF]
bic w4, w5, #0xff // r &= 0xff00
add w4, w4, #8
subs x8, x7, x4, lsl #47 // dif - vw
lsr w4, w4, #1 // v
sub w5, w5, w4 // r - v
cset w15, lo
csel w4, w5, w4, hs // if (ret) v = r - v;
csel x7, x8, x7, hs // if (ret) dif = dif - vw;
clz w5, w4 // clz(rng)
mvn x7, x7 // ~dif
eor w5, w5, #16 // d = clz(rng) ^ 16
b L(renorm2)
endfunc
function msac_decode_bool_neon, export=1
ldp w5, w6, [x0, #RNG] // + CNT
sub sp, sp, #48
ldr x7, [x0, #DIF]
lsr w4, w5, #8 // r >> 8
bic w1, w1, #0x3f // f &= ~63
mul w4, w4, w1
lsr w4, w4, #7
add w4, w4, #4 // v
subs x8, x7, x4, lsl #48 // dif - vw
sub w5, w5, w4 // r - v
cset w15, lo
csel w4, w5, w4, hs // if (ret) v = r - v;
csel x7, x8, x7, hs // if (ret) dif = dif - vw;
clz w5, w4 // clz(rng)
mvn x7, x7 // ~dif
eor w5, w5, #16 // d = clz(rng) ^ 16
b L(renorm2)
endfunc
function msac_decode_bool_adapt_neon, export=1
ldr w9, [x1] // cdf[0-1]
ldp w5, w6, [x0, #RNG] // + CNT
sub sp, sp, #48
ldr x7, [x0, #DIF]
lsr w4, w5, #8 // r >> 8
and w2, w9, #0xffc0 // f &= ~63
mul w4, w4, w2
lsr w4, w4, #7
add w4, w4, #4 // v
subs x8, x7, x4, lsl #48 // dif - vw
sub w5, w5, w4 // r - v
cset w15, lo
csel w4, w5, w4, hs // if (ret) v = r - v;
csel x7, x8, x7, hs // if (ret) dif = dif - vw;
ldr w10, [x0, #ALLOW_UPDATE_CDF]
clz w5, w4 // clz(rng)
mvn x7, x7 // ~dif
eor w5, w5, #16 // d = clz(rng) ^ 16
cbz w10, L(renorm2)
lsr w2, w9, #16 // count = cdf[1]
and w9, w9, #0xffff // cdf[0]
sub w3, w2, w2, lsr #5 // count - (count >= 32)
lsr w2, w2, #4 // count >> 4
add w10, w3, #1 // count + (count < 32)
add w2, w2, #4 // rate = (count >> 4) | 4
sub w9, w9, w15 // cdf[0] -= bit
sub w11, w9, w15, lsl #15 // {cdf[0], cdf[0] - 32769}
asr w11, w11, w2 // {cdf[0], cdf[0] - 32769} >> rate
sub w9, w9, w11 // cdf[0]
strh w9, [x1]
strh w10, [x1, #2]
b L(renorm2)
endfunc