ref: ca9cd4976b283e7053c0abc8b9224582502ceffd
dir: /src/arm/32/msac.S/
/*
* Copyright © 2019, VideoLAN and dav1d authors
* Copyright © 2020, 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 4
#define DIF 8
#define RNG 12
#define CNT 16
#define ALLOW_UPDATE_CDF 20
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, align=4
.short 0x1, 0x2, 0x4, 0x8, 0x10, 0x20, 0x40, 0x80
.short 0x100, 0x200, 0x400, 0x800, 0x1000, 0x2000, 0x4000, 0x8000
endconst
.macro vld1_align_n d0, q0, q1, src, n
.if \n == 4
vld1.16 {\d0}, [\src, :64]
.elseif \n == 8
vld1.16 {\q0}, [\src, :128]
.else
vld1.16 {\q0, \q1}, [\src, :128]
.endif
.endm
.macro vld1_n d0, q0, q1, src, n
.if \n == 4
vld1.16 {\d0}, [\src]
.elseif \n == 8
vld1.16 {\q0}, [\src]
.else
vld1.16 {\q0, \q1}, [\src]
.endif
.endm
.macro vst1_align_n d0, q0, q1, src, n
.if \n == 4
vst1.16 {\d0}, [\src, :64]
.elseif \n == 8
vst1.16 {\q0}, [\src, :128]
.else
vst1.16 {\q0, \q1}, [\src, :128]
.endif
.endm
.macro vst1_n d0, q0, q1, src, n
.if \n == 4
vst1.16 {\d0}, [\src]
.elseif \n == 8
vst1.16 {\q0}, [\src]
.else
vst1.16 {\q0, \q1}, [\src]
.endif
.endm
.macro vshr_n d0, d1, d2, s0, s1, s2, s3, s4, s5, n
.if \n == 4
vshr.u16 \d0, \s0, \s3
.else
vshr.u16 \d1, \s1, \s4
.if \n == 16
vshr.u16 \d2, \s2, \s5
.endif
.endif
.endm
.macro vadd_n d0, d1, d2, s0, s1, s2, s3, s4, s5, n
.if \n == 4
vadd.i16 \d0, \s0, \s3
.else
vadd.i16 \d1, \s1, \s4
.if \n == 16
vadd.i16 \d2, \s2, \s5
.endif
.endif
.endm
.macro vsub_n d0, d1, d2, s0, s1, s2, s3, s4, s5, n
.if \n == 4
vsub.i16 \d0, \s0, \s3
.else
vsub.i16 \d1, \s1, \s4
.if \n == 16
vsub.i16 \d2, \s2, \s5
.endif
.endif
.endm
.macro vand_n d0, d1, d2, s0, s1, s2, s3, s4, s5, n
.if \n == 4
vand \d0, \s0, \s3
.else
vand \d1, \s1, \s4
.if \n == 16
vand \d2, \s2, \s5
.endif
.endif
.endm
.macro vcge_n d0, d1, d2, s0, s1, s2, s3, s4, s5, n
.if \n == 4
vcge.u16 \d0, \s0, \s3
.else
vcge.u16 \d1, \s1, \s4
.if \n == 16
vcge.u16 \d2, \s2, \s5
.endif
.endif
.endm
.macro vrhadd_n d0, d1, d2, s0, s1, s2, s3, s4, s5, n
.if \n == 4
vrhadd.u16 \d0, \s0, \s3
.else
vrhadd.u16 \d1, \s1, \s4
.if \n == 16
vrhadd.u16 \d2, \s2, \s5
.endif
.endif
.endm
.macro vshl_n d0, d1, d2, s0, s1, s2, s3, s4, s5, n
.if \n == 4
vshl.s16 \d0, \s0, \s3
.else
vshl.s16 \d1, \s1, \s4
.if \n == 16
vshl.s16 \d2, \s2, \s5
.endif
.endif
.endm
.macro vqdmulh_n d0, d1, d2, s0, s1, s2, s3, s4, s5, n
.if \n == 4
vqdmulh.s16 \d0, \s0, \s3
.else
vqdmulh.s16 \d1, \s1, \s4
.if \n == 16
vqdmulh.s16 \d2, \s2, \s5
.endif
.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 n
push {r4-r10,lr}
sub sp, sp, #48
add r8, r0, #RNG
vld1_align_n d0, q0, q1, r1, \n // cdf
vld1.16 {d16[]}, [r8, :16] // rng
movrel_local r9, coeffs, 30
vmov.i16 d30, #0x7f00 // 0x7f00
sub r9, r9, r2, lsl #1
vmvn.i16 q14, #0x3f // 0xffc0
add r8, sp, #14
vand d22, d16, d30 // rng & 0x7f00
vst1.16 {d16[0]}, [r8, :16] // store original u = s->rng
vand_n d4, q2, q3, d0, q0, q1, d28, q14, q14, \n // cdf & 0xffc0
.if \n > 4
vmov d23, d22
.endif
vld1_n d16, q8, q9, r9, \n // EC_MIN_PROB * (n_symbols - ret)
vqdmulh_n d20, q10, q11, d4, q2, q3, d22, q11, q11, \n // ((cdf >> EC_PROB_SHIFT) * (r - 128)) >> 1
add r8, r0, #DIF + 2
vadd_n d16, q8, q9, d4, q2, q3, d16, q8, q9, \n // v = cdf + EC_MIN_PROB * (n_symbols - ret)
.if \n == 4
vmov.i16 d17, #0
.endif
vadd_n d16, q8, q9, d20, q10, q11, d16, q8, q9, \n // v = ((cdf >> EC_PROB_SHIFT) * r) >> 1 + EC_MIN_PROB * (n_symbols - ret)
add r9, sp, #16
vld1.16 {d20[]}, [r8, :16] // dif >> (EC_WIN_SIZE - 16)
movrel_local r8, bits
vst1_n q8, q8, q9, r9, \n // store v values to allow indexed access
vmov d21, d20
vld1_align_n q12, q12, q13, r8, \n
.if \n == 16
vmov q11, q10
.endif
vcge_n q2, q2, q3, q10, q10, q11, q8, q8, q9, \n // c >= v
vand_n q10, q10, q11, q2, q2, q3, q12, q12, q13, \n // One bit per halfword set in the mask
.if \n == 16
vadd.i16 q10, q10, q11
.endif
vadd.i16 d20, d20, d21 // Aggregate mask bits
ldr r4, [r0, #ALLOW_UPDATE_CDF]
vpadd.i16 d20, d20, d20
lsl r10, r2, #1
vpadd.i16 d20, d20, d20
vmov.u16 r3, d20[0]
cmp r4, #0
rbit r3, r3
clz lr, r3 // ret
beq L(renorm)
// update_cdf
ldrh r3, [r1, r10] // count = cdf[n_symbols]
vmov.i8 q10, #0xff
.if \n == 16
mov r4, #-5
.else
mvn r12, r2
mov r4, #-4
cmn r12, #3 // set C if n_symbols <= 2
.endif
vrhadd_n d16, q8, q9, d20, q10, q10, d4, q2, q3, \n // i >= val ? -1 : 32768
.if \n == 16
sub r4, r4, r3, lsr #4 // -((count >> 4) + 5)
.else
lsr r12, r3, #4 // count >> 4
sbc r4, r4, r12 // -((count >> 4) + (n_symbols > 2) + 4)
.endif
vsub_n d16, q8, q9, d16, q8, q9, d0, q0, q1, \n // (32768 - cdf[i]) or (-1 - cdf[i])
.if \n == 4
vdup.16 d20, r4 // -rate
.else
vdup.16 q10, r4 // -rate
.endif
sub r3, r3, r3, lsr #5 // count - (count == 32)
vsub_n d0, q0, q1, d0, q0, q1, d4, q2, q3, \n // cdf + (i >= val ? 1 : 0)
vshl_n d16, q8, q9, d16, q8, q9, d20, q10, q10, \n // ({32768,-1} - cdf[i]) >> rate
add r3, r3, #1 // count + (count < 32)
vadd_n d0, q0, q1, d0, q0, q1, d16, q8, q9, \n // cdf + (32768 - cdf[i]) >> rate
vst1_align_n d0, q0, q1, r1, \n
strh r3, [r1, r10]
.endm
decode_update 4
L(renorm):
add r8, sp, #16
add r8, r8, lr, lsl #1
ldrh r3, [r8] // v
ldrh r4, [r8, #-2] // u
ldr r6, [r0, #CNT]
ldr r7, [r0, #DIF]
sub r4, r4, r3 // rng = u - v
clz r5, r4 // clz(rng)
eor r5, r5, #16 // d = clz(rng) ^ 16
mvn r7, r7 // ~dif
add r7, r7, r3, lsl #16 // ~dif + (v << 16)
L(renorm2):
lsl r4, r4, r5 // rng << d
subs r6, r6, r5 // cnt -= d
lsl r7, r7, r5 // (~dif + (v << 16)) << d
str r4, [r0, #RNG]
mvn r7, r7 // ~dif
bhs 9f
// refill
ldr r3, [r0, #BUF_POS] // BUF_POS
ldr r4, [r0, #BUF_END] // BUF_END
add r5, r3, #4
cmp r5, r4
bgt 2f
ldr r3, [r3] // next_bits
add r8, r6, #23 // shift_bits = cnt + 23
add r6, r6, #16 // cnt += 16
rev r3, r3 // next_bits = bswap(next_bits)
sub r5, r5, r8, lsr #3 // buf_pos -= shift_bits >> 3
and r8, r8, #24 // shift_bits &= 24
lsr r3, r3, r8 // next_bits >>= shift_bits
sub r8, r8, r6 // shift_bits -= 16 + cnt
str r5, [r0, #BUF_POS]
lsl r3, r3, r8 // next_bits <<= shift_bits
rsb r6, r8, #16 // cnt = cnt + 32 - shift_bits
eor r7, r7, r3 // dif ^= next_bits
b 9f
2: // refill_eob
rsb r5, r6, #8 // c = 8 - cnt
3:
cmp r3, r4
bge 4f
ldrb r8, [r3], #1
lsl r8, r8, r5
eor r7, r7, r8
subs r5, r5, #8
bge 3b
4: // refill_eob_end
str r3, [r0, #BUF_POS]
rsb r6, r5, #8 // cnt = 8 - c
9:
str r6, [r0, #CNT]
str r7, [r0, #DIF]
mov r0, lr
add sp, sp, #48
pop {r4-r10,pc}
endfunc
function msac_decode_symbol_adapt8_neon, export=1
decode_update 8
b L(renorm)
endfunc
function msac_decode_symbol_adapt16_neon, export=1
decode_update 16
b L(renorm)
endfunc
function msac_decode_hi_tok_neon, export=1
push {r4-r10,lr}
vld1.16 {d0}, [r1, :64] // cdf
add r4, r0, #RNG
vmov.i16 d31, #0x7f00 // 0x7f00
movrel_local r5, coeffs, 30-2*3
vmvn.i16 d30, #0x3f // 0xffc0
ldrh r9, [r1, #6] // count = cdf[n_symbols]
vld1.16 {d1[]}, [r4, :16] // rng
movrel_local r4, bits
vld1.16 {d29}, [r5] // EC_MIN_PROB * (n_symbols - ret)
add r5, r0, #DIF + 2
vld1.16 {q8}, [r4, :128]
mov r2, #-24
vand d20, d0, d30 // cdf & 0xffc0
ldr r10, [r0, #ALLOW_UPDATE_CDF]
vld1.16 {d2[]}, [r5, :16] // dif >> (EC_WIN_SIZE - 16)
sub sp, sp, #48
ldr r6, [r0, #CNT]
ldr r7, [r0, #DIF]
vmov d3, d2
1:
vand d23, d1, d31 // rng & 0x7f00
vqdmulh.s16 d18, d20, d23 // ((cdf >> EC_PROB_SHIFT) * (r - 128)) >> 1
add r12, sp, #14
vadd.i16 d6, d20, d29 // v = cdf + EC_MIN_PROB * (n_symbols - ret)
vadd.i16 d6, d18, d6 // v = ((cdf >> EC_PROB_SHIFT) * r) >> 1 + EC_MIN_PROB * (n_symbols - ret)
vmov.i16 d7, #0
vst1.16 {d1[0]}, [r12, :16] // store original u = s->rng
add r12, sp, #16
vcge.u16 q2, q1, q3 // c >= v
vst1.16 {q3}, [r12] // store v values to allow indexed access
vand q9, q2, q8 // One bit per halfword set in the mask
vadd.i16 d18, d18, d19 // Aggregate mask bits
vpadd.i16 d18, d18, d18
vpadd.i16 d18, d18, d18
vmov.u16 r3, d18[0]
cmp r10, #0
add r2, r2, #5
rbit r3, r3
add r8, sp, #16
clz lr, r3 // ret
beq 2f
// update_cdf
vmov.i8 d22, #0xff
mov r4, #-5
vrhadd.u16 d6, d22, d4 // i >= val ? -1 : 32768
sub r4, r4, r9, lsr #4 // -((count >> 4) + 5)
vsub.i16 d6, d6, d0 // (32768 - cdf[i]) or (-1 - cdf[i])
vdup.16 d18, r4 // -rate
sub r9, r9, r9, lsr #5 // count - (count == 32)
vsub.i16 d0, d0, d4 // cdf + (i >= val ? 1 : 0)
vshl.s16 d6, d6, d18 // ({32768,-1} - cdf[i]) >> rate
add r9, r9, #1 // count + (count < 32)
vadd.i16 d0, d0, d6 // cdf + (32768 - cdf[i]) >> rate
vst1.16 {d0}, [r1, :64]
vand d20, d0, d30 // cdf & 0xffc0
strh r9, [r1, #6]
2:
add r8, r8, lr, lsl #1
ldrh r3, [r8] // v
ldrh r4, [r8, #-2] // u
sub r4, r4, r3 // rng = u - v
clz r5, r4 // clz(rng)
eor r5, r5, #16 // d = clz(rng) ^ 16
mvn r7, r7 // ~dif
add r7, r7, r3, lsl #16 // ~dif + (v << 16)
lsl r4, r4, r5 // rng << d
subs r6, r6, r5 // cnt -= d
lsl r7, r7, r5 // (~dif + (v << 16)) << d
str r4, [r0, #RNG]
vdup.16 d1, r4
mvn r7, r7 // ~dif
bhs 9f
// refill
ldr r3, [r0, #BUF_POS] // BUF_POS
ldr r4, [r0, #BUF_END] // BUF_END
add r5, r3, #4
cmp r5, r4
bgt 2f
ldr r3, [r3] // next_bits
add r8, r6, #23 // shift_bits = cnt + 23
add r6, r6, #16 // cnt += 16
rev r3, r3 // next_bits = bswap(next_bits)
sub r5, r5, r8, lsr #3 // buf_pos -= shift_bits >> 3
and r8, r8, #24 // shift_bits &= 24
lsr r3, r3, r8 // next_bits >>= shift_bits
sub r8, r8, r6 // shift_bits -= 16 + cnt
str r5, [r0, #BUF_POS]
lsl r3, r3, r8 // next_bits <<= shift_bits
rsb r6, r8, #16 // cnt = cnt + 32 - shift_bits
eor r7, r7, r3 // dif ^= next_bits
b 9f
2: // refill_eob
rsb r5, r6, #8 // c = 40 - cnt
3:
cmp r3, r4
bge 4f
ldrb r8, [r3], #1
lsl r8, r8, r5
eor r7, r7, r8
subs r5, r5, #8
bge 3b
4: // refill_eob_end
str r3, [r0, #BUF_POS]
rsb r6, r5, #8 // cnt = 40 - c
9:
lsl lr, lr, #1
sub lr, lr, #5
lsr r12, r7, #16
adds r2, r2, lr // carry = tok_br < 3 || tok == 15
vdup.16 q1, r12
bcc 1b // loop if !carry
add r2, r2, #30
str r6, [r0, #CNT]
add sp, sp, #48
str r7, [r0, #DIF]
lsr r0, r2, #1
pop {r4-r10,pc}
endfunc
function msac_decode_bool_equi_neon, export=1
push {r4-r10,lr}
ldr r5, [r0, #RNG]
ldr r6, [r0, #CNT]
sub sp, sp, #48
ldr r7, [r0, #DIF]
bic r4, r5, #0xff // r &= 0xff00
add r4, r4, #8
mov r2, #0
subs r8, r7, r4, lsl #15 // dif - vw
lsr r4, r4, #1 // v
sub r5, r5, r4 // r - v
itee lo
movlo r2, #1
movhs r4, r5 // if (ret) v = r - v;
movhs r7, r8 // if (ret) dif = dif - vw;
clz r5, r4 // clz(rng)
mvn r7, r7 // ~dif
eor r5, r5, #16 // d = clz(rng) ^ 16
mov lr, r2
b L(renorm2)
endfunc
function msac_decode_bool_neon, export=1
push {r4-r10,lr}
ldr r5, [r0, #RNG]
ldr r6, [r0, #CNT]
sub sp, sp, #48
ldr r7, [r0, #DIF]
lsr r4, r5, #8 // r >> 8
bic r1, r1, #0x3f // f &= ~63
mul r4, r4, r1
mov r2, #0
lsr r4, r4, #7
add r4, r4, #4 // v
subs r8, r7, r4, lsl #16 // dif - vw
sub r5, r5, r4 // r - v
itee lo
movlo r2, #1
movhs r4, r5 // if (ret) v = r - v;
movhs r7, r8 // if (ret) dif = dif - vw;
clz r5, r4 // clz(rng)
mvn r7, r7 // ~dif
eor r5, r5, #16 // d = clz(rng) ^ 16
mov lr, r2
b L(renorm2)
endfunc
function msac_decode_bool_adapt_neon, export=1
push {r4-r10,lr}
ldr r9, [r1] // cdf[0-1]
ldr r5, [r0, #RNG]
movw lr, #0xffc0
ldr r6, [r0, #CNT]
sub sp, sp, #48
ldr r7, [r0, #DIF]
lsr r4, r5, #8 // r >> 8
and r2, r9, lr // f &= ~63
mul r4, r4, r2
mov r2, #0
lsr r4, r4, #7
add r4, r4, #4 // v
subs r8, r7, r4, lsl #16 // dif - vw
sub r5, r5, r4 // r - v
ldr r10, [r0, #ALLOW_UPDATE_CDF]
itee lo
movlo r2, #1
movhs r4, r5 // if (ret) v = r - v;
movhs r7, r8 // if (ret) dif = dif - vw;
cmp r10, #0
clz r5, r4 // clz(rng)
mvn r7, r7 // ~dif
eor r5, r5, #16 // d = clz(rng) ^ 16
mov lr, r2
beq L(renorm2)
lsr r2, r9, #16 // count = cdf[1]
uxth r9, r9 // cdf[0]
sub r3, r2, r2, lsr #5 // count - (count >= 32)
lsr r2, r2, #4 // count >> 4
add r10, r3, #1 // count + (count < 32)
add r2, r2, #4 // rate = (count >> 4) | 4
sub r9, r9, lr // cdf[0] -= bit
sub r3, r9, lr, lsl #15 // {cdf[0], cdf[0] - 32769}
asr r3, r3, r2 // {cdf[0], cdf[0] - 32769} >> rate
sub r9, r9, r3 // cdf[0]
strh r9, [r1]
strh r10, [r1, #2]
b L(renorm2)
endfunc