From 4e9108ef508b481f65406538ad8a748066bd1f0c Mon Sep 17 00:00:00 2001
From: Salome Thirot <[EMAIL REDACTED]>
Date: Wed, 8 May 2024 16:04:32 +0100
Subject: [PATCH] Add 4-tap path for av1_convolve_2d_horiz_sr_neon_i8mm
Add 4-tap specialization for the horizontal pass of
av1_convolve_2d_sr_neon_i8mm. This gives up to 10% uplift over using the
8-tap path.
Change-Id: I6d67190d424a51e077f9cfe8edf8c89b446780a3
---
av1/common/arm/convolve_neon_i8mm.c | 201 +++++++++++++++++++---------
1 file changed, 140 insertions(+), 61 deletions(-)
diff --git a/av1/common/arm/convolve_neon_i8mm.c b/av1/common/arm/convolve_neon_i8mm.c
index f8b11eb35..b6a2a41ba 100644
--- a/av1/common/arm/convolve_neon_i8mm.c
+++ b/av1/common/arm/convolve_neon_i8mm.c
@@ -1060,21 +1060,6 @@ static INLINE void convolve_2d_sr_horiz_12tap_neon_i8mm(
}
}
-static INLINE int16x4_t convolve4_4_2d_h(uint8x16_t samples,
- const int8x8_t filters,
- const uint8x16_t permute_tbl,
- const int32x4_t horiz_const) {
- // Permute samples ready for dot product.
- // { 0, 1, 2, 3, 1, 2, 3, 4, 2, 3, 4, 5, 3, 4, 5, 6 }
- uint8x16_t permuted_samples = vqtbl1q_u8(samples, permute_tbl);
-
- // First 4 output values.
- int32x4_t sum = vusdotq_lane_s32(horiz_const, permuted_samples, filters, 0);
-
- // We halved the convolution filter values so -1 from the right shift.
- return vshrn_n_s32(sum, ROUND0_BITS - 1);
-}
-
static INLINE int16x8_t convolve8_8_2d_h(uint8x16_t samples,
const int8x8_t filters,
const uint8x16x3_t permute_tbl,
@@ -1103,7 +1088,7 @@ static INLINE int16x8_t convolve8_8_2d_h(uint8x16_t samples,
vshrn_n_s32(sum[1], ROUND0_BITS - 1));
}
-static INLINE void convolve_2d_sr_horiz_neon_i8mm(
+static INLINE void convolve_2d_sr_horiz_8tap_neon_i8mm(
const uint8_t *src, int src_stride, int16_t *im_block, int im_stride, int w,
int im_h, const int16_t *x_filter_ptr) {
const int bd = 8;
@@ -1118,85 +1103,173 @@ static INLINE void convolve_2d_sr_horiz_neon_i8mm(
int dst_stride = im_stride;
int height = im_h;
- if (w <= 4) {
- const uint8x16_t permute_tbl = vld1q_u8(kDotProdPermuteTbl);
- // 4-tap filters are used for blocks having width <= 4.
- // Filter values are even, so halve to reduce intermediate precision reqs.
- const int8x8_t x_filter =
- vshrn_n_s16(vcombine_s16(vld1_s16(x_filter_ptr + 2), vdup_n_s16(0)), 1);
+ const uint8x16x3_t permute_tbl = vld1q_u8_x3(kDotProdPermuteTbl);
+ // Filter values are even, so halve to reduce intermediate precision reqs.
+ const int8x8_t x_filter = vshrn_n_s16(vld1q_s16(x_filter_ptr), 1);
- src_ptr += 2;
+ do {
+ const uint8_t *s = src_ptr;
+ int16_t *d = dst_ptr;
+ int width = w;
do {
uint8x16_t s0, s1, s2, s3;
- load_u8_16x4(src_ptr, src_stride, &s0, &s1, &s2, &s3);
+ load_u8_16x4(s, src_stride, &s0, &s1, &s2, &s3);
+
+ int16x8_t d0 = convolve8_8_2d_h(s0, x_filter, permute_tbl, horiz_const);
+ int16x8_t d1 = convolve8_8_2d_h(s1, x_filter, permute_tbl, horiz_const);
+ int16x8_t d2 = convolve8_8_2d_h(s2, x_filter, permute_tbl, horiz_const);
+ int16x8_t d3 = convolve8_8_2d_h(s3, x_filter, permute_tbl, horiz_const);
+
+ store_s16_8x4(d, dst_stride, d0, d1, d2, d3);
+
+ s += 8;
+ d += 8;
+ width -= 8;
+ } while (width != 0);
+ src_ptr += 4 * src_stride;
+ dst_ptr += 4 * dst_stride;
+ height -= 4;
+ } while (height > 4);
+
+ do {
+ const uint8_t *s = src_ptr;
+ int16_t *d = dst_ptr;
+ int width = w;
+
+ do {
+ uint8x16_t s0 = vld1q_u8(s);
+ int16x8_t d0 = convolve8_8_2d_h(s0, x_filter, permute_tbl, horiz_const);
+ vst1q_s16(d, d0);
+
+ s += 8;
+ d += 8;
+ width -= 8;
+ } while (width != 0);
+ src_ptr += src_stride;
+ dst_ptr += dst_stride;
+ } while (--height != 0);
+}
+
+static INLINE int16x4_t convolve4_4_2d_h(const uint8x16_t samples,
+ const int8x8_t filters,
+ const uint8x16_t permute_tbl,
+ const int32x4_t horiz_const) {
+ // Permute samples ready for dot product.
+ // { 0, 1, 2, 3, 1, 2, 3, 4, 2, 3, 4, 5, 3, 4, 5, 6 }
+ uint8x16_t permuted_samples = vqtbl1q_u8(samples, permute_tbl);
- int16x4_t d0 = convolve4_4_2d_h(s0, x_filter, permute_tbl, horiz_const);
- int16x4_t d1 = convolve4_4_2d_h(s1, x_filter, permute_tbl, horiz_const);
- int16x4_t d2 = convolve4_4_2d_h(s2, x_filter, permute_tbl, horiz_const);
- int16x4_t d3 = convolve4_4_2d_h(s3, x_filter, permute_tbl, horiz_const);
+ int32x4_t sum = vusdotq_lane_s32(horiz_const, permuted_samples, filters, 0);
- store_s16_4x4(dst_ptr, dst_stride, d0, d1, d2, d3);
+ // We halved the convolution filter values so -1 from the right shift.
+ return vshrn_n_s32(sum, ROUND0_BITS - 1);
+}
- src_ptr += 4 * src_stride;
- dst_ptr += 4 * dst_stride;
+static INLINE int16x8_t convolve4_8_2d_h(const uint8x16_t samples,
+ const int8x8_t filters,
+ const uint8x16x2_t permute_tbl,
+ const int32x4_t horiz_const) {
+ // Permute samples ready for dot product.
+ // { 0, 1, 2, 3, 1, 2, 3, 4, 2, 3, 4, 5, 3, 4, 5, 6 }
+ // { 4, 5, 6, 7, 5, 6, 7, 8, 6, 7, 8, 9, 7, 8, 9, 10 }
+ uint8x16_t permuted_samples[2] = { vqtbl1q_u8(samples, permute_tbl.val[0]),
+ vqtbl1q_u8(samples, permute_tbl.val[1]) };
+
+ int32x4_t sum0123 =
+ vusdotq_lane_s32(horiz_const, permuted_samples[0], filters, 0);
+ int32x4_t sum4567 =
+ vusdotq_lane_s32(horiz_const, permuted_samples[1], filters, 0);
+
+ // Narrow and re-pack.
+ // We halved the filter values so -1 from right shift.
+ return vcombine_s16(vshrn_n_s32(sum0123, ROUND0_BITS - 1),
+ vshrn_n_s32(sum4567, ROUND0_BITS - 1));
+}
+
+static INLINE void convolve_2d_sr_horiz_4tap_neon_i8mm(
+ const uint8_t *src, int src_stride, int16_t *dst, int dst_stride, int width,
+ int height, const int16_t *filter_x) {
+ const int bd = 8;
+ const int16x4_t x_filter = vld1_s16(filter_x + 2);
+ // All 4-tap and bilinear filter values are even, so halve them to reduce
+ // intermediate precision requirements.
+ const int8x8_t filter = vshrn_n_s16(vcombine_s16(x_filter, vdup_n_s16(0)), 1);
+
+ // Adding a shim of 1 << (ROUND0_BITS - 1) enables us to use non-rounding
+ // shifts - which are generally faster than rounding shifts on modern CPUs.
+ // Halve the total because we will halve the filter values.
+ const int32x4_t horiz_const = vdupq_n_s32(
+ (((1 << (bd + FILTER_BITS - 1)) + (1 << (ROUND0_BITS - 1))) / 2));
+
+ if (width == 4) {
+ const uint8x16_t perm_tbl = vld1q_u8(kDotProdPermuteTbl);
+ do {
+ uint8x16_t s0, s1, s2, s3;
+ load_u8_16x4(src, src_stride, &s0, &s1, &s2, &s3);
+
+ int16x4_t d0 = convolve4_4_2d_h(s0, filter, perm_tbl, horiz_const);
+ int16x4_t d1 = convolve4_4_2d_h(s1, filter, perm_tbl, horiz_const);
+ int16x4_t d2 = convolve4_4_2d_h(s2, filter, perm_tbl, horiz_const);
+ int16x4_t d3 = convolve4_4_2d_h(s3, filter, perm_tbl, horiz_const);
+
+ store_s16_4x4(dst, dst_stride, d0, d1, d2, d3);
+
+ src += 4 * src_stride;
+ dst += 4 * dst_stride;
height -= 4;
} while (height > 4);
do {
- uint8x16_t s0 = vld1q_u8(src_ptr);
- int16x4_t d0 = convolve4_4_2d_h(s0, x_filter, permute_tbl, horiz_const);
- vst1_s16(dst_ptr, d0);
+ uint8x16_t s0 = vld1q_u8(src);
+ int16x4_t d0 = convolve4_4_2d_h(s0, filter, perm_tbl, horiz_const);
+ vst1_s16(dst, d0);
- src_ptr += src_stride;
- dst_ptr += dst_stride;
+ src += src_stride;
+ dst += dst_stride;
} while (--height != 0);
} else {
- const uint8x16x3_t permute_tbl = vld1q_u8_x3(kDotProdPermuteTbl);
- // Filter values are even, so halve to reduce intermediate precision reqs.
- const int8x8_t x_filter = vshrn_n_s16(vld1q_s16(x_filter_ptr), 1);
-
+ const uint8x16x2_t perm_tbl = vld1q_u8_x2(kDotProdPermuteTbl);
do {
- const uint8_t *s = src_ptr;
- int16_t *d = dst_ptr;
- int width = w;
+ int w = width;
+ const uint8_t *s = src;
+ int16_t *d = dst;
do {
uint8x16_t s0, s1, s2, s3;
load_u8_16x4(s, src_stride, &s0, &s1, &s2, &s3);
- int16x8_t d0 = convolve8_8_2d_h(s0, x_filter, permute_tbl, horiz_const);
- int16x8_t d1 = convolve8_8_2d_h(s1, x_filter, permute_tbl, horiz_const);
- int16x8_t d2 = convolve8_8_2d_h(s2, x_filter, permute_tbl, horiz_const);
- int16x8_t d3 = convolve8_8_2d_h(s3, x_filter, permute_tbl, horiz_const);
+ int16x8_t d0 = convolve4_8_2d_h(s0, filter, perm_tbl, horiz_const);
+ int16x8_t d1 = convolve4_8_2d_h(s1, filter, perm_tbl, horiz_const);
+ int16x8_t d2 = convolve4_8_2d_h(s2, filter, perm_tbl, horiz_const);
+ int16x8_t d3 = convolve4_8_2d_h(s3, filter, perm_tbl, horiz_const);
store_s16_8x4(d, dst_stride, d0, d1, d2, d3);
s += 8;
d += 8;
- width -= 8;
- } while (width != 0);
- src_ptr += 4 * src_stride;
- dst_ptr += 4 * dst_stride;
+ w -= 8;
+ } while (w != 0);
+ src += 4 * src_stride;
+ dst += 4 * dst_stride;
height -= 4;
} while (height > 4);
do {
- const uint8_t *s = src_ptr;
- int16_t *d = dst_ptr;
- int width = w;
+ const uint8_t *s = src;
+ int16_t *d = dst;
+ int w = width;
do {
uint8x16_t s0 = vld1q_u8(s);
- int16x8_t d0 = convolve8_8_2d_h(s0, x_filter, permute_tbl, horiz_const);
+ int16x8_t d0 = convolve4_8_2d_h(s0, filter, perm_tbl, horiz_const);
vst1q_s16(d, d0);
s += 8;
d += 8;
- width -= 8;
- } while (width != 0);
- src_ptr += src_stride;
- dst_ptr += dst_stride;
+ w -= 8;
+ } while (w != 0);
+ src += src_stride;
+ dst += dst_stride;
} while (--height != 0);
}
}
@@ -1215,6 +1288,7 @@ void av1_convolve_2d_sr_neon_i8mm(const uint8_t *src, int src_stride,
}
const int y_filter_taps = get_filter_tap(filter_params_y, subpel_y_qn);
+ const int x_filter_taps = get_filter_tap(filter_params_x, subpel_x_qn);
const int clamped_y_taps = y_filter_taps < 6 ? 6 : y_filter_taps;
const int im_h = h + clamped_y_taps - 1;
const int im_stride = MAX_SB_SIZE;
@@ -1246,8 +1320,13 @@ void av1_convolve_2d_sr_neon_i8mm(const uint8_t *src, int src_stride,
DECLARE_ALIGNED(16, int16_t,
im_block[(MAX_SB_SIZE + SUBPEL_TAPS - 1) * MAX_SB_SIZE]);
- convolve_2d_sr_horiz_neon_i8mm(src_ptr, src_stride, im_block, im_stride, w,
- im_h, x_filter_ptr);
+ if (x_filter_taps <= 4) {
+ convolve_2d_sr_horiz_4tap_neon_i8mm(src_ptr + 2, src_stride, im_block,
+ im_stride, w, im_h, x_filter_ptr);
+ } else {
+ convolve_2d_sr_horiz_8tap_neon_i8mm(src_ptr, src_stride, im_block,
+ im_stride, w, im_h, x_filter_ptr);
+ }
const int16x8_t y_filter = vld1q_s16(y_filter_ptr);