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/*
* Copyright (c) 2024, Alliance for Open Media. All rights reserved
*
* This source code is subject to the terms of the BSD 2 Clause License and
* the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
* was not distributed with this source code in the LICENSE file, you can
* obtain it at www.aomedia.org/license/software. If the Alliance for Open
* Media Patent License 1.0 was not distributed with this source code in the
* PATENTS file, you can obtain it at www.aomedia.org/license/patent.
*/
#include <arm_neon.h>
#include <assert.h>
#include "aom_dsp/arm/aom_convolve8_neon.h"
#include "aom_dsp/arm/mem_neon.h"
#include "aom_dsp/arm/transpose_neon.h"
#include "config/aom_dsp_rtcd.h"
static inline uint8x8_t convolve8_4_h(uint8x8_t s0, uint8x8_t s1, uint8x8_t s2,
uint8x8_t s3, int8x8_t filter) {
int8x16_t filter_x2 = vcombine_s8(filter, filter);
uint8x16_t s01 = vcombine_u8(s0, s1);
uint8x16_t s23 = vcombine_u8(s2, s3);
// Transform sample range to [-128, 127] for 8-bit signed dot product.
int8x16_t s01_128 = vreinterpretq_s8_u8(vsubq_u8(s01, vdupq_n_u8(128)));
int8x16_t s23_128 = vreinterpretq_s8_u8(vsubq_u8(s23, vdupq_n_u8(128)));
// Accumulate into 128 << (FILTER_BITS - 1) / 2 to account for range
// transform.
const int32x4_t acc = vdupq_n_s32((128 << (FILTER_BITS - 1)) / 2);
int32x4_t sum01 = vdotq_s32(acc, s01_128, filter_x2);
int32x4_t sum23 = vdotq_s32(acc, s23_128, filter_x2);
int32x4_t sum0123 = vpaddq_s32(sum01, sum23);
int16x8_t sum = vcombine_s16(vmovn_s32(sum0123), vdup_n_s16(0));
// We halved the filter values so -1 from right shift.
return vqrshrun_n_s16(sum, FILTER_BITS - 1);
}
static inline uint8x8_t convolve8_8_h(uint8x8_t s0, uint8x8_t s1, uint8x8_t s2,
uint8x8_t s3, uint8x8_t s4, uint8x8_t s5,
uint8x8_t s6, uint8x8_t s7,
int8x8_t filter) {
int8x16_t filter_x2 = vcombine_s8(filter, filter);
uint8x16_t s01 = vcombine_u8(s0, s1);
uint8x16_t s23 = vcombine_u8(s2, s3);
uint8x16_t s45 = vcombine_u8(s4, s5);
uint8x16_t s67 = vcombine_u8(s6, s7);
// Transform sample range to [-128, 127] for 8-bit signed dot product.
int8x16_t s01_128 = vreinterpretq_s8_u8(vsubq_u8(s01, vdupq_n_u8(128)));
int8x16_t s23_128 = vreinterpretq_s8_u8(vsubq_u8(s23, vdupq_n_u8(128)));
int8x16_t s45_128 = vreinterpretq_s8_u8(vsubq_u8(s45, vdupq_n_u8(128)));
int8x16_t s67_128 = vreinterpretq_s8_u8(vsubq_u8(s67, vdupq_n_u8(128)));
// Accumulate into 128 << (FILTER_BITS - 1) / 2 to account for range
// transform.
const int32x4_t acc = vdupq_n_s32((128 << (FILTER_BITS - 1)) / 2);
int32x4_t sum01 = vdotq_s32(acc, s01_128, filter_x2);
int32x4_t sum23 = vdotq_s32(acc, s23_128, filter_x2);
int32x4_t sum45 = vdotq_s32(acc, s45_128, filter_x2);
int32x4_t sum67 = vdotq_s32(acc, s67_128, filter_x2);
int32x4_t sum0123 = vpaddq_s32(sum01, sum23);
int32x4_t sum4567 = vpaddq_s32(sum45, sum67);
int16x8_t sum = vcombine_s16(vmovn_s32(sum0123), vmovn_s32(sum4567));
// We halved the filter values so -1 from right shift.
return vqrshrun_n_s16(sum, FILTER_BITS - 1);
}
static inline void scaled_convolve_horiz_neon_dotprod(
const uint8_t *src, const ptrdiff_t src_stride, uint8_t *dst,
const ptrdiff_t dst_stride, const InterpKernel *const x_filter,
const int x0_q4, const int x_step_q4, int w, int h) {
DECLARE_ALIGNED(16, uint8_t, temp[8 * 8]);
if (w == 4) {
do {
int x_q4 = x0_q4;
// Process a 4x4 tile.
for (int r = 0; r < 4; ++r) {
// Halve filter values (all even) to avoid the need for saturating
// arithmetic in convolution kernels.
const int8x8_t filter =
vshrn_n_s16(vld1q_s16(x_filter[x_q4 & SUBPEL_MASK]), 1);
const uint8_t *s = &src[x_q4 >> SUBPEL_BITS];
uint8x8_t s0, s1, s2, s3;
load_u8_8x4(s, src_stride, &s0, &s1, &s2, &s3);
uint8x8_t d0 = convolve8_4_h(s0, s1, s2, s3, filter);
store_u8_4x1(&temp[4 * r], d0);
x_q4 += x_step_q4;
}
// Transpose the 4x4 result tile and store.
uint8x8_t d01 = vld1_u8(temp + 0);
uint8x8_t d23 = vld1_u8(temp + 8);
transpose_elems_inplace_u8_4x4(&d01, &d23);
store_u8x4_strided_x2(dst + 0 * dst_stride, 2 * dst_stride, d01);
store_u8x4_strided_x2(dst + 1 * dst_stride, 2 * dst_stride, d23);
src += 4 * src_stride;
dst += 4 * dst_stride;
h -= 4;
} while (h > 0);
return;
}
// w >= 8
do {
int x_q4 = x0_q4;
uint8_t *d = dst;
int width = w;
do {
// Process an 8x8 tile.
for (int r = 0; r < 8; ++r) {
// Halve filter values (all even) to avoid the need for saturating
// arithmetic in convolution kernels.
const int8x8_t filter =
vshrn_n_s16(vld1q_s16(x_filter[x_q4 & SUBPEL_MASK]), 1);
const uint8_t *s = &src[x_q4 >> SUBPEL_BITS];
uint8x8_t s0, s1, s2, s3, s4, s5, s6, s7;
load_u8_8x8(s, src_stride, &s0, &s1, &s2, &s3, &s4, &s5, &s6, &s7);
uint8x8_t d0 = convolve8_8_h(s0, s1, s2, s3, s4, s5, s6, s7, filter);
vst1_u8(&temp[r * 8], d0);
x_q4 += x_step_q4;
}
// Transpose the 8x8 result tile and store.
uint8x8_t d0, d1, d2, d3, d4, d5, d6, d7;
load_u8_8x8(temp, 8, &d0, &d1, &d2, &d3, &d4, &d5, &d6, &d7);
transpose_elems_inplace_u8_8x8(&d0, &d1, &d2, &d3, &d4, &d5, &d6, &d7);
store_u8_8x8(d, dst_stride, d0, d1, d2, d3, d4, d5, d6, d7);
d += 8;
width -= 8;
} while (width != 0);
src += 8 * src_stride;
dst += 8 * dst_stride;
h -= 8;
} while (h > 0);
}
static inline uint8x8_t convolve8_4_v(uint8x8_t s0, uint8x8_t s1, uint8x8_t s2,
uint8x8_t s3, uint8x8_t s4, uint8x8_t s5,
uint8x8_t s6, uint8x8_t s7,
int8x8_t filter) {
uint8x16_t s01 = vcombine_u8(vzip1_u8(s0, s1), vdup_n_u8(0));
uint8x16_t s23 = vcombine_u8(vzip1_u8(s2, s3), vdup_n_u8(0));
uint8x16_t s45 = vcombine_u8(vzip1_u8(s4, s5), vdup_n_u8(0));
uint8x16_t s67 = vcombine_u8(vzip1_u8(s6, s7), vdup_n_u8(0));
uint8x16_t s0123 = vreinterpretq_u8_u16(
vzip1q_u16(vreinterpretq_u16_u8(s01), vreinterpretq_u16_u8(s23)));
uint8x16_t s4567 = vreinterpretq_u8_u16(
vzip1q_u16(vreinterpretq_u16_u8(s45), vreinterpretq_u16_u8(s67)));
// Transform sample range to [-128, 127] for 8-bit signed dot product.
int8x16_t s0123_128 = vreinterpretq_s8_u8(vsubq_u8(s0123, vdupq_n_u8(128)));
int8x16_t s4567_128 = vreinterpretq_s8_u8(vsubq_u8(s4567, vdupq_n_u8(128)));
// Accumulate into 128 << (FILTER_BITS - 1) to account for range transform.
int32x4_t sum = vdupq_n_s32(128 << (FILTER_BITS - 1));
sum = vdotq_lane_s32(sum, s0123_128, filter, 0);
sum = vdotq_lane_s32(sum, s4567_128, filter, 1);
// We halved the filter values so -1 from right shift.
return vqrshrun_n_s16(vcombine_s16(vmovn_s32(sum), vdup_n_s16(0)),
FILTER_BITS - 1);
}
static inline uint8x8_t convolve8_8_v(uint8x8_t s0, uint8x8_t s1, uint8x8_t s2,
uint8x8_t s3, uint8x8_t s4, uint8x8_t s5,
uint8x8_t s6, uint8x8_t s7,
int8x8_t filter) {
uint8x16_t s01 =
vzip1q_u8(vcombine_u8(s0, vdup_n_u8(0)), vcombine_u8(s1, vdup_n_u8(0)));
uint8x16_t s23 =
vzip1q_u8(vcombine_u8(s2, vdup_n_u8(0)), vcombine_u8(s3, vdup_n_u8(0)));
uint8x16_t s45 =
vzip1q_u8(vcombine_u8(s4, vdup_n_u8(0)), vcombine_u8(s5, vdup_n_u8(0)));
uint8x16_t s67 =
vzip1q_u8(vcombine_u8(s6, vdup_n_u8(0)), vcombine_u8(s7, vdup_n_u8(0)));
uint8x16_t s0123[2] = {
vreinterpretq_u8_u16(
vzip1q_u16(vreinterpretq_u16_u8(s01), vreinterpretq_u16_u8(s23))),
vreinterpretq_u8_u16(
vzip2q_u16(vreinterpretq_u16_u8(s01), vreinterpretq_u16_u8(s23)))
};
uint8x16_t s4567[2] = {
vreinterpretq_u8_u16(
vzip1q_u16(vreinterpretq_u16_u8(s45), vreinterpretq_u16_u8(s67))),
vreinterpretq_u8_u16(
vzip2q_u16(vreinterpretq_u16_u8(s45), vreinterpretq_u16_u8(s67)))
};
// Transform sample range to [-128, 127] for 8-bit signed dot product.
int8x16_t s0123_128[2] = {
vreinterpretq_s8_u8(vsubq_u8(s0123[0], vdupq_n_u8(128))),
vreinterpretq_s8_u8(vsubq_u8(s0123[1], vdupq_n_u8(128)))
};
int8x16_t s4567_128[2] = {
vreinterpretq_s8_u8(vsubq_u8(s4567[0], vdupq_n_u8(128))),
vreinterpretq_s8_u8(vsubq_u8(s4567[1], vdupq_n_u8(128)))
};
// Accumulate into 128 << (FILTER_BITS - 1) to account for range transform.
const int32x4_t acc = vdupq_n_s32(128 << (FILTER_BITS - 1));
int32x4_t sum0123 = vdotq_lane_s32(acc, s0123_128[0], filter, 0);
sum0123 = vdotq_lane_s32(sum0123, s4567_128[0], filter, 1);
int32x4_t sum4567 = vdotq_lane_s32(acc, s0123_128[1], filter, 0);
sum4567 = vdotq_lane_s32(sum4567, s4567_128[1], filter, 1);
int16x8_t sum = vcombine_s16(vmovn_s32(sum0123), vmovn_s32(sum4567));
// We halved the filter values so -1 from right shift.
return vqrshrun_n_s16(sum, FILTER_BITS - 1);
}
static inline void scaled_convolve_vert_neon_dotprod(
const uint8_t *src, const ptrdiff_t src_stride, uint8_t *dst,
const ptrdiff_t dst_stride, const InterpKernel *const y_filter,
const int y0_q4, const int y_step_q4, int w, int h) {
int y_q4 = y0_q4;
if (w == 4) {
do {
const uint8_t *s = &src[(y_q4 >> SUBPEL_BITS) * src_stride];
if (y_q4 & SUBPEL_MASK) {
// Halve filter values (all even) to avoid the need for saturating
// arithmetic in convolution kernels.
const int8x8_t filter =
vshrn_n_s16(vld1q_s16(y_filter[y_q4 & SUBPEL_MASK]), 1);
uint8x8_t s0, s1, s2, s3, s4, s5, s6, s7;
load_u8_8x8(s, src_stride, &s0, &s1, &s2, &s3, &s4, &s5, &s6, &s7);
uint8x8_t d0 = convolve8_4_v(s0, s1, s2, s3, s4, s5, s6, s7, filter);
store_u8_4x1(dst, d0);
} else {
// Memcpy for non-subpel locations.
memcpy(dst, &s[(SUBPEL_TAPS / 2 - 1) * src_stride], 4);
}
y_q4 += y_step_q4;
dst += dst_stride;
} while (--h != 0);
return;
}
// w >= 8
do {
const uint8_t *s = &src[(y_q4 >> SUBPEL_BITS) * src_stride];
uint8_t *d = dst;
int width = w;
if (y_q4 & SUBPEL_MASK) {
// Halve filter values (all even) to avoid the need for saturating
// arithmetic in convolution kernels.
const int8x8_t filter =
vshrn_n_s16(vld1q_s16(y_filter[y_q4 & SUBPEL_MASK]), 1);
do {
uint8x8_t s0, s1, s2, s3, s4, s5, s6, s7;
load_u8_8x8(s, src_stride, &s0, &s1, &s2, &s3, &s4, &s5, &s6, &s7);
uint8x8_t d0 = convolve8_8_v(s0, s1, s2, s3, s4, s5, s6, s7, filter);
vst1_u8(d, d0);
s += 8;
d += 8;
width -= 8;
} while (width != 0);
} else {
// Memcpy for non-subpel locations.
s += (SUBPEL_TAPS / 2 - 1) * src_stride;
do {
uint8x8_t s0 = vld1_u8(s);
vst1_u8(d, s0);
s += 8;
d += 8;
width -= 8;
} while (width != 0);
}
y_q4 += y_step_q4;
dst += dst_stride;
} while (--h != 0);
}
void aom_scaled_2d_neon_dotprod(const uint8_t *src, ptrdiff_t src_stride,
uint8_t *dst, ptrdiff_t dst_stride,
const InterpKernel *filter, int x0_q4,
int x_step_q4, int y0_q4, int y_step_q4, int w,
int h) {
// Fixed size intermediate buffer, im_block, places limits on parameters.
// 2d filtering proceeds in 2 steps:
// (1) Interpolate horizontally into an intermediate buffer, temp.
// (2) Interpolate temp vertically to derive the sub-pixel result.
// Deriving the maximum number of rows in the im_block buffer (135):
// --Smallest scaling factor is x1/2 ==> y_step_q4 = 32 (Normative).
// --Largest block size is 64x64 pixels.
// --64 rows in the downscaled frame span a distance of (64 - 1) * 32 in the
// original frame (in 1/16th pixel units).
// --Must round-up because block may be located at sub-pixel position.
// --Require an additional SUBPEL_TAPS rows for the 8-tap filter tails.
// --((64 - 1) * 32 + 15) >> 4 + 8 = 135.
// --Require an additional 8 rows for the horiz_w8 transpose tail.
// When calling in frame scaling function, the smallest scaling factor is x1/4
// ==> y_step_q4 = 64. Since w and h are at most 16, the temp buffer is still
// big enough.
DECLARE_ALIGNED(16, uint8_t, im_block[(135 + 8) * 64]);
const int im_height =
(((h - 1) * y_step_q4 + y0_q4) >> SUBPEL_BITS) + SUBPEL_TAPS;
const ptrdiff_t im_stride = 64;
assert(w <= 64);
assert(h <= 64);
assert(y_step_q4 <= 32 || (y_step_q4 <= 64 && h <= 32));
assert(x_step_q4 <= 64);
// Account for needing SUBPEL_TAPS / 2 - 1 lines prior and SUBPEL_TAPS / 2
// lines post both horizontally and vertically.
const ptrdiff_t horiz_offset = SUBPEL_TAPS / 2 - 1;
const ptrdiff_t vert_offset = (SUBPEL_TAPS / 2 - 1) * src_stride;
scaled_convolve_horiz_neon_dotprod(src - horiz_offset - vert_offset,
src_stride, im_block, im_stride, filter,
x0_q4, x_step_q4, w, im_height);
scaled_convolve_vert_neon_dotprod(im_block, im_stride, dst, dst_stride,
filter, y0_q4, y_step_q4, w, h);
}