ffmpeg/libswscale/aarch64/output.S
Swinney, Jonathan 3e708722a2 swscale/aarch64: vscale optimization
Use scalar times vector multiply accumlate instructions instead of
vector times vector to remove the need for replicating load instructions
which are slightly slower.

On AWS c7g (Graviton 3, Neoverse V1) instances:
yuv2yuvX_8_0_512_accurate_neon:  1144.8  987.4
yuv2yuvX_16_0_512_accurate_neon: 2080.5 1869.4

Signed-off-by: Jonathan Swinney <jswinney@amazon.com>
Signed-off-by: Martin Storsjö <martin@martin.st>
2022-08-16 13:40:42 +03:00

58 lines
3.7 KiB
ArmAsm

/*
* Copyright (c) 2016 Clément Bœsch <clement stupeflix.com>
*
* 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
*/
#include "libavutil/aarch64/asm.S"
function ff_yuv2planeX_8_neon, export=1
ld1 {v0.8B}, [x5] // load 8x8-bit dither
cbz w6, 1f // check if offsetting present
ext v0.8B, v0.8B, v0.8B, #3 // honor offsetting which can be 0 or 3 only
1: uxtl v0.8H, v0.8B // extend dither to 16-bit
ushll v1.4S, v0.4H, #12 // extend dither to 32-bit with left shift by 12 (part 1)
ushll2 v2.4S, v0.8H, #12 // extend dither to 32-bit with left shift by 12 (part 2)
mov x7, #0 // i = 0
2: mov v3.16B, v1.16B // initialize accumulator part 1 with dithering value
mov v4.16B, v2.16B // initialize accumulator part 2 with dithering value
mov w8, w1 // tmpfilterSize = filterSize
mov x9, x2 // srcp = src
mov x10, x0 // filterp = filter
3: ldp x11, x12, [x9], #16 // get 2 pointers: src[j] and src[j+1]
ldr s7, [x10], #4 // read 2x16-bit coeff X and Y at filter[j] and filter[j+1]
add x11, x11, x7, lsl #1 // &src[j ][i]
add x12, x12, x7, lsl #1 // &src[j+1][i]
ld1 {v5.8H}, [x11] // read 8x16-bit @ src[j ][i + {0..7}]: A,B,C,D,E,F,G,H
ld1 {v6.8H}, [x12] // read 8x16-bit @ src[j+1][i + {0..7}]: I,J,K,L,M,N,O,P
smlal v3.4S, v5.4H, v7.H[0] // val0 += {A,B,C,D} * X
smlal2 v4.4S, v5.8H, v7.H[0] // val1 += {E,F,G,H} * X
smlal v3.4S, v6.4H, v7.H[1] // val0 += {I,J,K,L} * Y
smlal2 v4.4S, v6.8H, v7.H[1] // val1 += {M,N,O,P} * Y
subs w8, w8, #2 // tmpfilterSize -= 2
b.gt 3b // loop until filterSize consumed
sqshrun v3.4h, v3.4s, #16 // clip16(val0>>16)
sqshrun2 v3.8h, v4.4s, #16 // clip16(val1>>16)
uqshrn v3.8b, v3.8h, #3 // clip8(val>>19)
st1 {v3.8b}, [x3], #8 // write to destination
subs w4, w4, #8 // dstW -= 8
add x7, x7, #8 // i += 8
b.gt 2b // loop until width consumed
ret
endfunc