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FFmpeg/libswscale/aarch64/hscale.S
Hubert Mazur 1e9cfa5bb0 sw_scale: Add specializations for hscale 8 to 19
Add arm64 neon implementations for hscale 8 to 19 with filter
sizes 4, 4X and 8. Both implementations are based on very similar ones
dedicated to hscale 8 to 15. The major changes refer to saving
the data - instead of writing the result as int16_t it is done
with int32_t.

These functions are heavily inspired on patches provided by J. Swinney
and M. Storsjö for hscale8to15 which were slightly adapted for
hscale8to19.

The tests and benchmarks run on AWS Graviton 2 instances. The results
from a checkasm tool shown below.

hscale_8_to_19__fs_4_dstW_512_c: 5663.2
hscale_8_to_19__fs_4_dstW_512_neon: 1259.7
hscale_8_to_19__fs_8_dstW_512_c: 9306.0
hscale_8_to_19__fs_8_dstW_512_neon: 2020.2
hscale_8_to_19__fs_12_dstW_512_c: 12932.7
hscale_8_to_19__fs_12_dstW_512_neon: 2462.5
hscale_8_to_19__fs_16_dstW_512_c: 16844.2
hscale_8_to_19__fs_16_dstW_512_neon: 4671.2
hscale_8_to_19__fs_32_dstW_512_c: 32803.7
hscale_8_to_19__fs_32_dstW_512_neon: 5474.2
hscale_8_to_19__fs_40_dstW_512_c: 40948.0
hscale_8_to_19__fs_40_dstW_512_neon: 6669.7

Signed-off-by: Hubert Mazur <hum@semihalf.com>
Signed-off-by: Martin Storsjö <martin@martin.st>
2022-11-01 15:24:43 +02:00

641 lines
39 KiB
ArmAsm

/*
* Copyright (c) 2016 Clément Bœsch <clement stupeflix.com>
* Copyright (c) 2019-2021 Sebastian Pop <spop@amazon.com>
* Copyright (c) 2022 Jonathan Swinney <jswinney@amazon.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"
/*
;-----------------------------------------------------------------------------
; horizontal line scaling
;
; void hscale<source_width>to<intermediate_nbits>_<filterSize>_<opt>
; (SwsContext *c, int{16,32}_t *dst,
; int dstW, const uint{8,16}_t *src,
; const int16_t *filter,
; const int32_t *filterPos, int filterSize);
;
; Scale one horizontal line. Input is either 8-bit width or 16-bit width
; ($source_width can be either 8, 9, 10 or 16, difference is whether we have to
; downscale before multiplying). Filter is 14 bits. Output is either 15 bits
; (in int16_t) or 19 bits (in int32_t), as given in $intermediate_nbits. Each
; output pixel is generated from $filterSize input pixels, the position of
; the first pixel is given in filterPos[nOutputPixel].
;----------------------------------------------------------------------------- */
function ff_hscale8to15_X8_neon, export=1
sbfiz x7, x6, #1, #32 // filterSize*2 (*2 because int16)
1: ldr w8, [x5], #4 // filterPos[idx]
ldr w0, [x5], #4 // filterPos[idx + 1]
ldr w11, [x5], #4 // filterPos[idx + 2]
ldr w9, [x5], #4 // filterPos[idx + 3]
mov x16, x4 // filter0 = filter
add x12, x16, x7 // filter1 = filter0 + filterSize*2
add x13, x12, x7 // filter2 = filter1 + filterSize*2
add x4, x13, x7 // filter3 = filter2 + filterSize*2
movi v0.2D, #0 // val sum part 1 (for dst[0])
movi v1.2D, #0 // val sum part 2 (for dst[1])
movi v2.2D, #0 // val sum part 3 (for dst[2])
movi v3.2D, #0 // val sum part 4 (for dst[3])
add x17, x3, w8, UXTW // srcp + filterPos[0]
add x8, x3, w0, UXTW // srcp + filterPos[1]
add x0, x3, w11, UXTW // srcp + filterPos[2]
add x11, x3, w9, UXTW // srcp + filterPos[3]
mov w15, w6 // filterSize counter
2: ld1 {v4.8B}, [x17], #8 // srcp[filterPos[0] + {0..7}]
ld1 {v5.8H}, [x16], #16 // load 8x16-bit filter values, part 1
ld1 {v6.8B}, [x8], #8 // srcp[filterPos[1] + {0..7}]
ld1 {v7.8H}, [x12], #16 // load 8x16-bit at filter+filterSize
uxtl v4.8H, v4.8B // unpack part 1 to 16-bit
smlal v0.4S, v4.4H, v5.4H // v0 accumulates srcp[filterPos[0] + {0..3}] * filter[{0..3}]
smlal2 v0.4S, v4.8H, v5.8H // v0 accumulates srcp[filterPos[0] + {4..7}] * filter[{4..7}]
ld1 {v16.8B}, [x0], #8 // srcp[filterPos[2] + {0..7}]
ld1 {v17.8H}, [x13], #16 // load 8x16-bit at filter+2*filterSize
uxtl v6.8H, v6.8B // unpack part 2 to 16-bit
smlal v1.4S, v6.4H, v7.4H // v1 accumulates srcp[filterPos[1] + {0..3}] * filter[{0..3}]
uxtl v16.8H, v16.8B // unpack part 3 to 16-bit
smlal v2.4S, v16.4H, v17.4H // v2 accumulates srcp[filterPos[2] + {0..3}] * filter[{0..3}]
smlal2 v2.4S, v16.8H, v17.8H // v2 accumulates srcp[filterPos[2] + {4..7}] * filter[{4..7}]
ld1 {v18.8B}, [x11], #8 // srcp[filterPos[3] + {0..7}]
smlal2 v1.4S, v6.8H, v7.8H // v1 accumulates srcp[filterPos[1] + {4..7}] * filter[{4..7}]
ld1 {v19.8H}, [x4], #16 // load 8x16-bit at filter+3*filterSize
subs w15, w15, #8 // j -= 8: processed 8/filterSize
uxtl v18.8H, v18.8B // unpack part 4 to 16-bit
smlal v3.4S, v18.4H, v19.4H // v3 accumulates srcp[filterPos[3] + {0..3}] * filter[{0..3}]
smlal2 v3.4S, v18.8H, v19.8H // v3 accumulates srcp[filterPos[3] + {4..7}] * filter[{4..7}]
b.gt 2b // inner loop if filterSize not consumed completely
addp v0.4S, v0.4S, v1.4S // part01 horizontal pair adding
addp v2.4S, v2.4S, v3.4S // part23 horizontal pair adding
addp v0.4S, v0.4S, v2.4S // part0123 horizontal pair adding
subs w2, w2, #4 // dstW -= 4
sqshrn v0.4H, v0.4S, #7 // shift and clip the 2x16-bit final values
st1 {v0.4H}, [x1], #8 // write to destination part0123
b.gt 1b // loop until end of line
ret
endfunc
function ff_hscale8to15_X4_neon, export=1
// x0 SwsContext *c (not used)
// x1 int16_t *dst
// w2 int dstW
// x3 const uint8_t *src
// x4 const int16_t *filter
// x5 const int32_t *filterPos
// w6 int filterSize
// This function for filter sizes that are 4 mod 8. In other words, anything that's 0 mod 4 but not
// 0 mod 8. It also assumes that dstW is 0 mod 4.
lsl w7, w6, #1 // w7 = filterSize * 2
1:
ldp w8, w9, [x5] // filterPos[idx + 0], [idx + 1]
ldp w10, w11, [x5, #8] // filterPos[idx + 2], [idx + 3]
movi v16.2d, #0 // initialize accumulator for idx + 0
movi v17.2d, #0 // initialize accumulator for idx + 1
movi v18.2d, #0 // initialize accumulator for idx + 2
movi v19.2d, #0 // initialize accumulator for idx + 3
mov x12, x4 // filter pointer for idx + 0
add x13, x4, x7 // filter pointer for idx + 1
add x8, x3, w8, uxtw // srcp + filterPos[idx + 0]
add x9, x3, w9, uxtw // srcp + filterPos[idx + 1]
add x14, x13, x7 // filter pointer for idx + 2
add x10, x3, w10, uxtw // srcp + filterPos[idx + 2]
add x11, x3, w11, uxtw // srcp + filterPos[idx + 3]
mov w0, w6 // copy filterSize to a temp register, w0
add x5, x5, #16 // advance the filterPos pointer
add x15, x14, x7 // filter pointer for idx + 3
mov x16, xzr // temp register for offsetting filter pointers
2:
// This section loops over 8-wide chunks of filter size
ldr d4, [x8], #8 // load 8 bytes from srcp for idx + 0
ldr q0, [x12, x16] // load 8 values, 16 bytes from filter for idx + 0
ldr d5, [x9], #8 // load 8 bytes from srcp for idx + 1
ldr q1, [x13, x16] // load 8 values, 16 bytes from filter for idx + 1
uxtl v4.8h, v4.8b // unsigned extend long for idx + 0
uxtl v5.8h, v5.8b // unsigned extend long for idx + 1
ldr d6, [x10], #8 // load 8 bytes from srcp for idx + 2
ldr q2, [x14, x16] // load 8 values, 16 bytes from filter for idx + 2
smlal v16.4s, v0.4h, v4.4h // val += src[srcPos + j + 0..3] * filter[fs * i + j + 0..3], idx + 0
smlal v17.4s, v1.4h, v5.4h // val += src[srcPos + j + 0..3] * filter[fs * i + j + 0..3], idx + 1
ldr d7, [x11], #8 // load 8 bytes from srcp for idx + 3
ldr q3, [x15, x16] // load 8 values, 16 bytes from filter for idx + 3
sub w0, w0, #8 // decrement the remaining filterSize counter
smlal2 v16.4s, v0.8h, v4.8h // val += src[srcPos + j + 4..7] * filter[fs * i + j + 4..7], idx + 0
smlal2 v17.4s, v1.8h, v5.8h // val += src[srcPos + j + 4..7] * filter[fs * i + j + 4..7], idx + 1
uxtl v6.8h, v6.8b // unsigned extend long for idx + 2
uxtl v7.8h, v7.8b // unsigned extend long for idx + 3
smlal v18.4s, v2.4h, v6.4h // val += src[srcPos + j + 0..3] * filter[fs * i + j + 0..3], idx + 2
smlal v19.4s, v3.4h, v7.4h // val += src[srcPos + j + 0..3] * filter[fs * i + j + 0..3], idx + 3
cmp w0, #8 // are there at least 8 more elements in filter to consume?
add x16, x16, #16 // advance the offsetting register for filter values
smlal2 v18.4s, v2.8h, v6.8h // val += src[srcPos + j + 4..7] * filter[fs * i + j + 4..7], idx + 2
smlal2 v19.4s, v3.8h, v7.8h // val += src[srcPos + j + 4..7] * filter[fs * i + j + 4..7], idx + 3
b.ge 2b // branch back to inner loop
// complete the remaining 4 filter elements
sub x17, x7, #8 // calculate the offset of the filter pointer for the remaining 4 elements
ldr s4, [x8] // load 4 bytes from srcp for idx + 0
ldr d0, [x12, x17] // load 4 values, 8 bytes from filter for idx + 0
ldr s5, [x9] // load 4 bytes from srcp for idx + 1
ldr d1, [x13, x17] // load 4 values, 8 bytes from filter for idx + 1
uxtl v4.8h, v4.8b // unsigned extend long for idx + 0
uxtl v5.8h, v5.8b // unsigned extend long for idx + 1
ldr s6, [x10] // load 4 bytes from srcp for idx + 2
ldr d2, [x14, x17] // load 4 values, 8 bytes from filter for idx + 2
smlal v16.4s, v0.4h, v4.4h // val += src[srcPos + j + 0..3] * filter[fs * i + j + 0..3], idx + 0
smlal v17.4s, v1.4h, v5.4h // val += src[srcPos + j + 0..3] * filter[fs * i + j + 0..3], idx + 1
ldr s7, [x11] // load 4 bytes from srcp for idx + 3
ldr d3, [x15, x17] // load 4 values, 8 bytes from filter for idx + 3
uxtl v6.8h, v6.8b // unsigned extend long for idx + 2
uxtl v7.8h, v7.8b // unsigned extend long for idx + 3
addp v16.4s, v16.4s, v17.4s // horizontal pair adding for idx 0,1
smlal v18.4s, v2.4h, v6.4h // val += src[srcPos + j + 0..3] * filter[fs * i + j + 0..3], idx + 2
smlal v19.4s, v3.4h, v7.4h // val += src[srcPos + j + 0..3] * filter[fs * i + j + 0..3], idx + 3
addp v18.4s, v18.4s, v19.4s // horizontal pair adding for idx 2,3
addp v16.4s, v16.4s, v18.4s // final horizontal pair adding producing one vector with results for idx = 0..3
subs w2, w2, #4 // dstW -= 4
sqshrn v0.4h, v16.4s, #7 // shift and clip the 2x16-bit final values
st1 {v0.4h}, [x1], #8 // write to destination idx 0..3
add x4, x4, x7, lsl #2 // filter += (filterSize*2) * 4
b.gt 1b // loop until end of line
ret
endfunc
function ff_hscale8to15_4_neon, export=1
// x0 SwsContext *c (not used)
// x1 int16_t *dst
// x2 int dstW
// x3 const uint8_t *src
// x4 const int16_t *filter
// x5 const int32_t *filterPos
// x6 int filterSize
// x8-x15 registers for gathering src data
// v0 madd accumulator 4S
// v1-v4 filter values (16 bit) 8H
// v5 madd accumulator 4S
// v16-v19 src values (8 bit) 8B
// This implementation has 4 sections:
// 1. Prefetch src data
// 2. Interleaved prefetching src data and madd
// 3. Complete madd
// 4. Complete remaining iterations when dstW % 8 != 0
sub sp, sp, #32 // allocate 32 bytes on the stack
cmp w2, #16 // if dstW <16, skip to the last block used for wrapping up
b.lt 2f
// load 8 values from filterPos to be used as offsets into src
ldp w8, w9, [x5] // filterPos[idx + 0], [idx + 1]
ldp w10, w11, [x5, #8] // filterPos[idx + 2], [idx + 3]
ldp w12, w13, [x5, #16] // filterPos[idx + 4], [idx + 5]
ldp w14, w15, [x5, #24] // filterPos[idx + 6], [idx + 7]
add x5, x5, #32 // advance filterPos
// gather random access data from src into contiguous memory
ldr w8, [x3, w8, UXTW] // src[filterPos[idx + 0]][0..3]
ldr w9, [x3, w9, UXTW] // src[filterPos[idx + 1]][0..3]
ldr w10, [x3, w10, UXTW] // src[filterPos[idx + 2]][0..3]
ldr w11, [x3, w11, UXTW] // src[filterPos[idx + 3]][0..3]
ldr w12, [x3, w12, UXTW] // src[filterPos[idx + 4]][0..3]
ldr w13, [x3, w13, UXTW] // src[filterPos[idx + 5]][0..3]
ldr w14, [x3, w14, UXTW] // src[filterPos[idx + 6]][0..3]
ldr w15, [x3, w15, UXTW] // src[filterPos[idx + 7]][0..3]
stp w8, w9, [sp] // *scratch_mem = { src[filterPos[idx + 0]][0..3], src[filterPos[idx + 1]][0..3] }
stp w10, w11, [sp, #8] // *scratch_mem = { src[filterPos[idx + 2]][0..3], src[filterPos[idx + 3]][0..3] }
stp w12, w13, [sp, #16] // *scratch_mem = { src[filterPos[idx + 4]][0..3], src[filterPos[idx + 5]][0..3] }
stp w14, w15, [sp, #24] // *scratch_mem = { src[filterPos[idx + 6]][0..3], src[filterPos[idx + 7]][0..3] }
1:
ld4 {v16.8B, v17.8B, v18.8B, v19.8B}, [sp] // transpose 8 bytes each from src into 4 registers
// load 8 values from filterPos to be used as offsets into src
ldp w8, w9, [x5] // filterPos[idx + 0][0..3], [idx + 1][0..3], next iteration
ldp w10, w11, [x5, #8] // filterPos[idx + 2][0..3], [idx + 3][0..3], next iteration
ldp w12, w13, [x5, #16] // filterPos[idx + 4][0..3], [idx + 5][0..3], next iteration
ldp w14, w15, [x5, #24] // filterPos[idx + 6][0..3], [idx + 7][0..3], next iteration
movi v0.2D, #0 // Clear madd accumulator for idx 0..3
movi v5.2D, #0 // Clear madd accumulator for idx 4..7
ld4 {v1.8H, v2.8H, v3.8H, v4.8H}, [x4], #64 // load filter idx + 0..7
add x5, x5, #32 // advance filterPos
// interleaved SIMD and prefetching intended to keep ld/st and vector pipelines busy
uxtl v16.8H, v16.8B // unsigned extend long, covert src data to 16-bit
uxtl v17.8H, v17.8B // unsigned extend long, covert src data to 16-bit
ldr w8, [x3, w8, UXTW] // src[filterPos[idx + 0]], next iteration
ldr w9, [x3, w9, UXTW] // src[filterPos[idx + 1]], next iteration
uxtl v18.8H, v18.8B // unsigned extend long, covert src data to 16-bit
uxtl v19.8H, v19.8B // unsigned extend long, covert src data to 16-bit
ldr w10, [x3, w10, UXTW] // src[filterPos[idx + 2]], next iteration
ldr w11, [x3, w11, UXTW] // src[filterPos[idx + 3]], next iteration
smlal v0.4S, v1.4H, v16.4H // multiply accumulate inner loop j = 0, idx = 0..3
smlal v0.4S, v2.4H, v17.4H // multiply accumulate inner loop j = 1, idx = 0..3
ldr w12, [x3, w12, UXTW] // src[filterPos[idx + 4]], next iteration
ldr w13, [x3, w13, UXTW] // src[filterPos[idx + 5]], next iteration
smlal v0.4S, v3.4H, v18.4H // multiply accumulate inner loop j = 2, idx = 0..3
smlal v0.4S, v4.4H, v19.4H // multiply accumulate inner loop j = 3, idx = 0..3
ldr w14, [x3, w14, UXTW] // src[filterPos[idx + 6]], next iteration
ldr w15, [x3, w15, UXTW] // src[filterPos[idx + 7]], next iteration
smlal2 v5.4S, v1.8H, v16.8H // multiply accumulate inner loop j = 0, idx = 4..7
smlal2 v5.4S, v2.8H, v17.8H // multiply accumulate inner loop j = 1, idx = 4..7
stp w8, w9, [sp] // *scratch_mem = { src[filterPos[idx + 0]][0..3], src[filterPos[idx + 1]][0..3] }
stp w10, w11, [sp, #8] // *scratch_mem = { src[filterPos[idx + 2]][0..3], src[filterPos[idx + 3]][0..3] }
smlal2 v5.4S, v3.8H, v18.8H // multiply accumulate inner loop j = 2, idx = 4..7
smlal2 v5.4S, v4.8H, v19.8H // multiply accumulate inner loop j = 3, idx = 4..7
stp w12, w13, [sp, #16] // *scratch_mem = { src[filterPos[idx + 4]][0..3], src[filterPos[idx + 5]][0..3] }
stp w14, w15, [sp, #24] // *scratch_mem = { src[filterPos[idx + 6]][0..3], src[filterPos[idx + 7]][0..3] }
sub w2, w2, #8 // dstW -= 8
sqshrn v0.4H, v0.4S, #7 // shift and clip the 2x16-bit final values
sqshrn v1.4H, v5.4S, #7 // shift and clip the 2x16-bit final values
st1 {v0.4H, v1.4H}, [x1], #16 // write to dst[idx + 0..7]
cmp w2, #16 // continue on main loop if there are at least 16 iterations left
b.ge 1b
// last full iteration
ld4 {v16.8B, v17.8B, v18.8B, v19.8B}, [sp]
ld4 {v1.8H, v2.8H, v3.8H, v4.8H}, [x4], #64 // load filter idx + 0..7
movi v0.2D, #0 // Clear madd accumulator for idx 0..3
movi v5.2D, #0 // Clear madd accumulator for idx 4..7
uxtl v16.8H, v16.8B // unsigned extend long, covert src data to 16-bit
uxtl v17.8H, v17.8B // unsigned extend long, covert src data to 16-bit
uxtl v18.8H, v18.8B // unsigned extend long, covert src data to 16-bit
uxtl v19.8H, v19.8B // unsigned extend long, covert src data to 16-bit
smlal v0.4S, v1.4H, v16.4H // multiply accumulate inner loop j = 0, idx = 0..3
smlal v0.4S, v2.4H, v17.4H // multiply accumulate inner loop j = 1, idx = 0..3
smlal v0.4S, v3.4H, v18.4H // multiply accumulate inner loop j = 2, idx = 0..3
smlal v0.4S, v4.4H, v19.4H // multiply accumulate inner loop j = 3, idx = 0..3
smlal2 v5.4S, v1.8H, v16.8H // multiply accumulate inner loop j = 0, idx = 4..7
smlal2 v5.4S, v2.8H, v17.8H // multiply accumulate inner loop j = 1, idx = 4..7
smlal2 v5.4S, v3.8H, v18.8H // multiply accumulate inner loop j = 2, idx = 4..7
smlal2 v5.4S, v4.8H, v19.8H // multiply accumulate inner loop j = 3, idx = 4..7
subs w2, w2, #8 // dstW -= 8
sqshrn v0.4H, v0.4S, #7 // shift and clip the 2x16-bit final values
sqshrn v1.4H, v5.4S, #7 // shift and clip the 2x16-bit final values
st1 {v0.4H, v1.4H}, [x1], #16 // write to dst[idx + 0..7]
cbnz w2, 2f // if >0 iterations remain, jump to the wrap up section
add sp, sp, #32 // clean up stack
ret
// finish up when dstW % 8 != 0 or dstW < 16
2:
// load src
ldr w8, [x5], #4 // filterPos[i]
add x9, x3, w8, UXTW // calculate the address for src load
ld1 {v5.S}[0], [x9] // src[filterPos[i] + 0..3]
// load filter
ld1 {v6.4H}, [x4], #8 // filter[filterSize * i + 0..3]
uxtl v5.8H, v5.8B // unsigned exten long, convert src data to 16-bit
smull v0.4S, v5.4H, v6.4H // 4 iterations of src[...] * filter[...]
addv s0, v0.4S // add up products of src and filter values
sqshrn h0, s0, #7 // shift and clip the 2x16-bit final value
st1 {v0.H}[0], [x1], #2 // dst[i] = ...
sub w2, w2, #1 // dstW--
cbnz w2, 2b
add sp, sp, #32 // clean up stack
ret
endfunc
function ff_hscale8to19_4_neon, export=1
// x0 SwsContext *c (unused)
// x1 int32_t *dst
// w2 int dstW
// x3 const uint8_t *src // treat it as uint16_t *src
// x4 const uint16_t *filter
// x5 const int32_t *filterPos
// w6 int filterSize
movi v18.4s, #1
movi v17.4s, #1
shl v18.4s, v18.4s, #19
sub v18.4s, v18.4s, v17.4s // max allowed value
cmp w2, #16
b.lt 2f // move to last block
ldp w8, w9, [x5] // filterPos[0], filterPos[1]
ldp w10, w11, [x5, #8] // filterPos[2], filterPos[3]
ldp w12, w13, [x5, #16] // filterPos[4], filterPos[5]
ldp w14, w15, [x5, #24] // filterPos[6], filterPos[7]
add x5, x5, #32
// load data from
ldr w8, [x3, w8, UXTW]
ldr w9, [x3, w9, UXTW]
ldr w10, [x3, w10, UXTW]
ldr w11, [x3, w11, UXTW]
ldr w12, [x3, w12, UXTW]
ldr w13, [x3, w13, UXTW]
ldr w14, [x3, w14, UXTW]
ldr w15, [x3, w15, UXTW]
sub sp, sp, #32
stp w8, w9, [sp]
stp w10, w11, [sp, #8]
stp w12, w13, [sp, #16]
stp w14, w15, [sp, #24]
1:
ld4 {v0.8b, v1.8b, v2.8b, v3.8b}, [sp]
ld4 {v28.8h, v29.8h, v30.8h, v31.8h}, [x4], #64 // filter[0..7]
// load filterPositions into registers for next iteration
ldp w8, w9, [x5] // filterPos[0], filterPos[1]
ldp w10, w11, [x5, #8] // filterPos[2], filterPos[3]
ldp w12, w13, [x5, #16] // filterPos[4], filterPos[5]
ldp w14, w15, [x5, #24] // filterPos[6], filterPos[7]
add x5, x5, #32
uxtl v0.8h, v0.8b
ldr w8, [x3, w8, UXTW]
smull v5.4s, v0.4h, v28.4h // multiply first column of src
ldr w9, [x3, w9, UXTW]
smull2 v6.4s, v0.8h, v28.8h
stp w8, w9, [sp]
uxtl v1.8h, v1.8b
ldr w10, [x3, w10, UXTW]
smlal v5.4s, v1.4h, v29.4h // multiply second column of src
ldr w11, [x3, w11, UXTW]
smlal2 v6.4s, v1.8h, v29.8h
stp w10, w11, [sp, #8]
uxtl v2.8h, v2.8b
ldr w12, [x3, w12, UXTW]
smlal v5.4s, v2.4h, v30.4h // multiply third column of src
ldr w13, [x3, w13, UXTW]
smlal2 v6.4s, v2.8h, v30.8h
stp w12, w13, [sp, #16]
uxtl v3.8h, v3.8b
ldr w14, [x3, w14, UXTW]
smlal v5.4s, v3.4h, v31.4h // multiply fourth column of src
ldr w15, [x3, w15, UXTW]
smlal2 v6.4s, v3.8h, v31.8h
stp w14, w15, [sp, #24]
sub w2, w2, #8
sshr v5.4s, v5.4s, #3
sshr v6.4s, v6.4s, #3
smin v5.4s, v5.4s, v18.4s
smin v6.4s, v6.4s, v18.4s
st1 {v5.4s, v6.4s}, [x1], #32
cmp w2, #16
b.ge 1b
// here we make last iteration, without updating the registers
ld4 {v0.8b, v1.8b, v2.8b, v3.8b}, [sp]
ld4 {v28.8h, v29.8h, v30.8h, v31.8h}, [x4], #64 // filter[0..7]
uxtl v0.8h, v0.8b
uxtl v1.8h, v1.8b
smull v5.4s, v0.4h, v28.4h
smull2 v6.4s, v0.8h, v28.8h
uxtl v2.8h, v2.8b
smlal v5.4s, v1.4h, v29.4H
smlal2 v6.4s, v1.8h, v29.8H
uxtl v3.8h, v3.8b
smlal v5.4s, v2.4h, v30.4H
smlal2 v6.4s, v2.8h, v30.8H
smlal v5.4s, v3.4h, v31.4H
smlal2 v6.4s, v3.8h, v31.8h
sshr v5.4s, v5.4s, #3
sshr v6.4s, v6.4s, #3
smin v5.4s, v5.4s, v18.4s
smin v6.4s, v6.4s, v18.4s
sub w2, w2, #8
st1 {v5.4s, v6.4s}, [x1], #32
add sp, sp, #32 // restore stack
cbnz w2, 2f
ret
2:
ldr w8, [x5], #4 // load filterPos
add x9, x3, w8, UXTW // src + filterPos
ld1 {v0.s}[0], [x9] // load 4 * uint8_t* into one single
ld1 {v31.4h}, [x4], #8
uxtl v0.8h, v0.8b
smull v5.4s, v0.4h, v31.4H
saddlv d0, v5.4S
sqshrn s0, d0, #3
smin v0.4s, v0.4s, v18.4s
st1 {v0.s}[0], [x1], #4
sub w2, w2, #1
cbnz w2, 2b // if iterations remain jump to beginning
ret
endfunc
function ff_hscale8to19_X8_neon, export=1
movi v20.4s, #1
movi v17.4s, #1
shl v20.4s, v20.4s, #19
sub v20.4s, v20.4s, v17.4s
sbfiz x7, x6, #1, #32 // filterSize*2 (*2 because int16)
1:
mov x16, x4 // filter0 = filter
ldr w8, [x5], #4 // filterPos[idx]
add x12, x16, x7 // filter1 = filter0 + filterSize*2
ldr w0, [x5], #4 // filterPos[idx + 1]
add x13, x12, x7 // filter2 = filter1 + filterSize*2
ldr w11, [x5], #4 // filterPos[idx + 2]
add x4, x13, x7 // filter3 = filter2 + filterSize*2
ldr w9, [x5], #4 // filterPos[idx + 3]
movi v0.2D, #0 // val sum part 1 (for dst[0])
movi v1.2D, #0 // val sum part 2 (for dst[1])
movi v2.2D, #0 // val sum part 3 (for dst[2])
movi v3.2D, #0 // val sum part 4 (for dst[3])
add x17, x3, w8, UXTW // srcp + filterPos[0]
add x8, x3, w0, UXTW // srcp + filterPos[1]
add x0, x3, w11, UXTW // srcp + filterPos[2]
add x11, x3, w9, UXTW // srcp + filterPos[3]
mov w15, w6 // filterSize counter
2: ld1 {v4.8B}, [x17], #8 // srcp[filterPos[0] + {0..7}]
ld1 {v5.8H}, [x16], #16 // load 8x16-bit filter values, part 1
uxtl v4.8H, v4.8B // unpack part 1 to 16-bit
smlal v0.4S, v4.4H, v5.4H // v0 accumulates srcp[filterPos[0] + {0..3}] * filter[{0..3}]
ld1 {v6.8B}, [x8], #8 // srcp[filterPos[1] + {0..7}]
smlal2 v0.4S, v4.8H, v5.8H // v0 accumulates srcp[filterPos[0] + {4..7}] * filter[{4..7}]
ld1 {v7.8H}, [x12], #16 // load 8x16-bit at filter+filterSize
ld1 {v16.8B}, [x0], #8 // srcp[filterPos[2] + {0..7}]
uxtl v6.8H, v6.8B // unpack part 2 to 16-bit
ld1 {v17.8H}, [x13], #16 // load 8x16-bit at filter+2*filterSize
uxtl v16.8H, v16.8B // unpack part 3 to 16-bit
smlal v1.4S, v6.4H, v7.4H // v1 accumulates srcp[filterPos[1] + {0..3}] * filter[{0..3}]
ld1 {v18.8B}, [x11], #8 // srcp[filterPos[3] + {0..7}]
smlal v2.4S, v16.4H, v17.4H // v2 accumulates srcp[filterPos[2] + {0..3}] * filter[{0..3}]
ld1 {v19.8H}, [x4], #16 // load 8x16-bit at filter+3*filterSize
smlal2 v2.4S, v16.8H, v17.8H // v2 accumulates srcp[filterPos[2] + {4..7}] * filter[{4..7}]
uxtl v18.8H, v18.8B // unpack part 4 to 16-bit
smlal2 v1.4S, v6.8H, v7.8H // v1 accumulates srcp[filterPos[1] + {4..7}] * filter[{4..7}]
smlal v3.4S, v18.4H, v19.4H // v3 accumulates srcp[filterPos[3] + {0..3}] * filter[{0..3}]
subs w15, w15, #8 // j -= 8: processed 8/filterSize
smlal2 v3.4S, v18.8H, v19.8H // v3 accumulates srcp[filterPos[3] + {4..7}] * filter[{4..7}]
b.gt 2b // inner loop if filterSize not consumed completely
addp v0.4S, v0.4S, v1.4S // part01 horizontal pair adding
addp v2.4S, v2.4S, v3.4S // part23 horizontal pair adding
addp v0.4S, v0.4S, v2.4S // part0123 horizontal pair adding
subs w2, w2, #4 // dstW -= 4
sshr v0.4s, v0.4S, #3 // shift and clip the 2x16-bit final values
smin v0.4s, v0.4s, v20.4s
st1 {v0.4s}, [x1], #16 // write to destination part0123
b.gt 1b // loop until end of line
ret
endfunc
function ff_hscale8to19_X4_neon, export=1
// x0 SwsContext *c (not used)
// x1 int16_t *dst
// w2 int dstW
// x3 const uint8_t *src
// x4 const int16_t *filter
// x5 const int32_t *filterPos
// w6 int filterSize
movi v20.4s, #1
movi v17.4s, #1
shl v20.4s, v20.4s, #19
sub v20.4s, v20.4s, v17.4s
lsl w7, w6, #1
1:
ldp w8, w9, [x5]
ldp w10, w11, [x5, #8]
movi v16.2d, #0 // initialize accumulator for idx + 0
movi v17.2d, #0 // initialize accumulator for idx + 1
movi v18.2d, #0 // initialize accumulator for idx + 2
movi v19.2d, #0 // initialize accumulator for idx + 3
mov x12, x4 // filter + 0
add x13, x4, x7 // filter + 1
add x8, x3, w8, UXTW // srcp + filterPos 0
add x14, x13, x7 // filter + 2
add x9, x3, w9, UXTW // srcp + filterPos 1
add x15, x14, x7 // filter + 3
add x10, x3, w10, UXTW // srcp + filterPos 2
mov w0, w6 // save the filterSize to temporary variable
add x11, x3, w11, UXTW // srcp + filterPos 3
add x5, x5, #16 // advance filter position
mov x16, xzr // clear the register x16 used for offsetting the filter values
2:
ldr d4, [x8], #8 // load src values for idx 0
ldr q31, [x12, x16] // load filter values for idx 0
uxtl v4.8h, v4.8b // extend type to match the filter' size
ldr d5, [x9], #8 // load src values for idx 1
smlal v16.4s, v4.4h, v31.4h // multiplication of lower half for idx 0
uxtl v5.8h, v5.8b // extend type to match the filter' size
ldr q30, [x13, x16] // load filter values for idx 1
smlal2 v16.4s, v4.8h, v31.8h // multiplication of upper half for idx 0
ldr d6, [x10], #8 // load src values for idx 2
ldr q29, [x14, x16] // load filter values for idx 2
smlal v17.4s, v5.4h, v30.4H // multiplication of lower half for idx 1
ldr d7, [x11], #8 // load src values for idx 3
smlal2 v17.4s, v5.8h, v30.8H // multiplication of upper half for idx 1
uxtl v6.8h, v6.8B // extend tpye to matchi the filter's size
ldr q28, [x15, x16] // load filter values for idx 3
smlal v18.4s, v6.4h, v29.4h // multiplication of lower half for idx 2
uxtl v7.8h, v7.8B
smlal2 v18.4s, v6.8h, v29.8H // multiplication of upper half for idx 2
sub w0, w0, #8
smlal v19.4s, v7.4h, v28.4H // multiplication of lower half for idx 3
cmp w0, #8
smlal2 v19.4s, v7.8h, v28.8h // multiplication of upper half for idx 3
add x16, x16, #16 // advance filter values indexing
b.ge 2b
// 4 iterations left
sub x17, x7, #8 // step back to wrap up the filter pos for last 4 elements
ldr s4, [x8] // load src values for idx 0
ldr d31, [x12, x17] // load filter values for idx 0
uxtl v4.8h, v4.8b // extend type to match the filter' size
ldr s5, [x9] // load src values for idx 1
smlal v16.4s, v4.4h, v31.4h
ldr d30, [x13, x17] // load filter values for idx 1
uxtl v5.8h, v5.8b // extend type to match the filter' size
ldr s6, [x10] // load src values for idx 2
smlal v17.4s, v5.4h, v30.4h
uxtl v6.8h, v6.8B // extend type to match the filter's size
ldr d29, [x14, x17] // load filter values for idx 2
ldr s7, [x11] // load src values for idx 3
addp v16.4s, v16.4s, v17.4s
uxtl v7.8h, v7.8B
ldr d28, [x15, x17] // load filter values for idx 3
smlal v18.4s, v6.4h, v29.4h
smlal v19.4s, v7.4h, v28.4h
subs w2, w2, #4
addp v18.4s, v18.4s, v19.4s
addp v16.4s, v16.4s, v18.4s
sshr v16.4s, v16.4s, #3
smin v16.4s, v16.4s, v20.4s
st1 {v16.4s}, [x1], #16
add x4, x4, x7, lsl #2
b.gt 1b
ret
endfunc