ref: 6d082201f1dba88af20f9c050aaf2166c92dc6b5
dir: /vpx_dsp/arm/variance_neon.c/
/*
* Copyright (c) 2014 The WebM project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include <arm_neon.h>
#include <assert.h>
#include "./vpx_dsp_rtcd.h"
#include "./vpx_config.h"
#include "vpx/vpx_integer.h"
#include "vpx_dsp/arm/mem_neon.h"
#include "vpx_dsp/arm/sum_neon.h"
#include "vpx_ports/mem.h"
// The variance helper functions use int16_t for sum. 8 values are accumulated
// and then added (at which point they expand up to int32_t). To avoid overflow,
// there can be no more than 32767 / 255 ~= 128 values accumulated in each
// column. For a 32x32 buffer, this results in 32 / 8 = 4 values per row * 32
// rows = 128. Asserts have been added to each function to warn against reaching
// this limit.
// Process a block of width 4 four rows at a time.
static void variance_neon_w4x4(const uint8_t *a, int a_stride, const uint8_t *b,
int b_stride, int h, uint32_t *sse, int *sum) {
int i;
int16x8_t sum_s16 = vdupq_n_s16(0);
int32x4_t sse_lo_s32 = vdupq_n_s32(0);
int32x4_t sse_hi_s32 = vdupq_n_s32(0);
// Since width is only 4, sum_s16 only loads a half row per loop.
assert(h <= 256);
for (i = 0; i < h; i += 4) {
const uint8x16_t a_u8 = load_unaligned_u8q(a, a_stride);
const uint8x16_t b_u8 = load_unaligned_u8q(b, b_stride);
const uint16x8_t diff_lo_u16 =
vsubl_u8(vget_low_u8(a_u8), vget_low_u8(b_u8));
const uint16x8_t diff_hi_u16 =
vsubl_u8(vget_high_u8(a_u8), vget_high_u8(b_u8));
const int16x8_t diff_lo_s16 = vreinterpretq_s16_u16(diff_lo_u16);
const int16x8_t diff_hi_s16 = vreinterpretq_s16_u16(diff_hi_u16);
sum_s16 = vaddq_s16(sum_s16, diff_lo_s16);
sum_s16 = vaddq_s16(sum_s16, diff_hi_s16);
sse_lo_s32 = vmlal_s16(sse_lo_s32, vget_low_s16(diff_lo_s16),
vget_low_s16(diff_lo_s16));
sse_lo_s32 = vmlal_s16(sse_lo_s32, vget_high_s16(diff_lo_s16),
vget_high_s16(diff_lo_s16));
sse_hi_s32 = vmlal_s16(sse_hi_s32, vget_low_s16(diff_hi_s16),
vget_low_s16(diff_hi_s16));
sse_hi_s32 = vmlal_s16(sse_hi_s32, vget_high_s16(diff_hi_s16),
vget_high_s16(diff_hi_s16));
a += 4 * a_stride;
b += 4 * b_stride;
}
*sum = vget_lane_s32(horizontal_add_int16x8(sum_s16), 0);
*sse = vget_lane_u32(horizontal_add_uint32x4(vreinterpretq_u32_s32(
vaddq_s32(sse_lo_s32, sse_hi_s32))),
0);
}
// Process a block of any size where the width is divisible by 16.
static void variance_neon_w16(const uint8_t *a, int a_stride, const uint8_t *b,
int b_stride, int w, int h, uint32_t *sse,
int *sum) {
int i, j;
int16x8_t sum_s16 = vdupq_n_s16(0);
int32x4_t sse_lo_s32 = vdupq_n_s32(0);
int32x4_t sse_hi_s32 = vdupq_n_s32(0);
// The loop loads 16 values at a time but doubles them up when accumulating
// into sum_s16.
assert(w / 8 * h <= 128);
for (i = 0; i < h; ++i) {
for (j = 0; j < w; j += 16) {
const uint8x16_t a_u8 = vld1q_u8(a + j);
const uint8x16_t b_u8 = vld1q_u8(b + j);
const uint16x8_t diff_lo_u16 =
vsubl_u8(vget_low_u8(a_u8), vget_low_u8(b_u8));
const uint16x8_t diff_hi_u16 =
vsubl_u8(vget_high_u8(a_u8), vget_high_u8(b_u8));
const int16x8_t diff_lo_s16 = vreinterpretq_s16_u16(diff_lo_u16);
const int16x8_t diff_hi_s16 = vreinterpretq_s16_u16(diff_hi_u16);
sum_s16 = vaddq_s16(sum_s16, diff_lo_s16);
sum_s16 = vaddq_s16(sum_s16, diff_hi_s16);
sse_lo_s32 = vmlal_s16(sse_lo_s32, vget_low_s16(diff_lo_s16),
vget_low_s16(diff_lo_s16));
sse_lo_s32 = vmlal_s16(sse_lo_s32, vget_high_s16(diff_lo_s16),
vget_high_s16(diff_lo_s16));
sse_hi_s32 = vmlal_s16(sse_hi_s32, vget_low_s16(diff_hi_s16),
vget_low_s16(diff_hi_s16));
sse_hi_s32 = vmlal_s16(sse_hi_s32, vget_high_s16(diff_hi_s16),
vget_high_s16(diff_hi_s16));
}
a += a_stride;
b += b_stride;
}
*sum = vget_lane_s32(horizontal_add_int16x8(sum_s16), 0);
*sse = vget_lane_u32(horizontal_add_uint32x4(vreinterpretq_u32_s32(
vaddq_s32(sse_lo_s32, sse_hi_s32))),
0);
}
// Process a block of width 8 two rows at a time.
static void variance_neon_w8x2(const uint8_t *a, int a_stride, const uint8_t *b,
int b_stride, int h, uint32_t *sse, int *sum) {
int i = 0;
int16x8_t sum_s16 = vdupq_n_s16(0);
int32x4_t sse_lo_s32 = vdupq_n_s32(0);
int32x4_t sse_hi_s32 = vdupq_n_s32(0);
// Each column has it's own accumulator entry in sum_s16.
assert(h <= 128);
do {
const uint8x8_t a_0_u8 = vld1_u8(a);
const uint8x8_t a_1_u8 = vld1_u8(a + a_stride);
const uint8x8_t b_0_u8 = vld1_u8(b);
const uint8x8_t b_1_u8 = vld1_u8(b + b_stride);
const uint16x8_t diff_0_u16 = vsubl_u8(a_0_u8, b_0_u8);
const uint16x8_t diff_1_u16 = vsubl_u8(a_1_u8, b_1_u8);
const int16x8_t diff_0_s16 = vreinterpretq_s16_u16(diff_0_u16);
const int16x8_t diff_1_s16 = vreinterpretq_s16_u16(diff_1_u16);
sum_s16 = vaddq_s16(sum_s16, diff_0_s16);
sum_s16 = vaddq_s16(sum_s16, diff_1_s16);
sse_lo_s32 = vmlal_s16(sse_lo_s32, vget_low_s16(diff_0_s16),
vget_low_s16(diff_0_s16));
sse_lo_s32 = vmlal_s16(sse_lo_s32, vget_low_s16(diff_1_s16),
vget_low_s16(diff_1_s16));
sse_hi_s32 = vmlal_s16(sse_hi_s32, vget_high_s16(diff_0_s16),
vget_high_s16(diff_0_s16));
sse_hi_s32 = vmlal_s16(sse_hi_s32, vget_high_s16(diff_1_s16),
vget_high_s16(diff_1_s16));
a += a_stride + a_stride;
b += b_stride + b_stride;
i += 2;
} while (i < h);
*sum = vget_lane_s32(horizontal_add_int16x8(sum_s16), 0);
*sse = vget_lane_u32(horizontal_add_uint32x4(vreinterpretq_u32_s32(
vaddq_s32(sse_lo_s32, sse_hi_s32))),
0);
}
void vpx_get8x8var_neon(const uint8_t *a, int a_stride, const uint8_t *b,
int b_stride, unsigned int *sse, int *sum) {
variance_neon_w8x2(a, a_stride, b, b_stride, 8, sse, sum);
}
void vpx_get16x16var_neon(const uint8_t *a, int a_stride, const uint8_t *b,
int b_stride, unsigned int *sse, int *sum) {
variance_neon_w16(a, a_stride, b, b_stride, 16, 16, sse, sum);
}
#define varianceNxM(n, m, shift) \
unsigned int vpx_variance##n##x##m##_neon(const uint8_t *a, int a_stride, \
const uint8_t *b, int b_stride, \
unsigned int *sse) { \
int sum; \
if (n == 4) \
variance_neon_w4x4(a, a_stride, b, b_stride, m, sse, &sum); \
else if (n == 8) \
variance_neon_w8x2(a, a_stride, b, b_stride, m, sse, &sum); \
else \
variance_neon_w16(a, a_stride, b, b_stride, n, m, sse, &sum); \
if (n * m < 16 * 16) \
return *sse - ((sum * sum) >> shift); \
else \
return *sse - (uint32_t)(((int64_t)sum * sum) >> shift); \
}
varianceNxM(4, 4, 4);
varianceNxM(4, 8, 5);
varianceNxM(8, 4, 5);
varianceNxM(8, 8, 6);
varianceNxM(8, 16, 7);
varianceNxM(16, 8, 7);
varianceNxM(16, 16, 8);
varianceNxM(16, 32, 9);
varianceNxM(32, 16, 9);
varianceNxM(32, 32, 10);
unsigned int vpx_variance32x64_neon(const uint8_t *a, int a_stride,
const uint8_t *b, int b_stride,
unsigned int *sse) {
int sum1, sum2;
uint32_t sse1, sse2;
variance_neon_w16(a, a_stride, b, b_stride, 32, 32, &sse1, &sum1);
variance_neon_w16(a + (32 * a_stride), a_stride, b + (32 * b_stride),
b_stride, 32, 32, &sse2, &sum2);
*sse = sse1 + sse2;
sum1 += sum2;
return *sse - (unsigned int)(((int64_t)sum1 * sum1) >> 11);
}
unsigned int vpx_variance64x32_neon(const uint8_t *a, int a_stride,
const uint8_t *b, int b_stride,
unsigned int *sse) {
int sum1, sum2;
uint32_t sse1, sse2;
variance_neon_w16(a, a_stride, b, b_stride, 64, 16, &sse1, &sum1);
variance_neon_w16(a + (16 * a_stride), a_stride, b + (16 * b_stride),
b_stride, 64, 16, &sse2, &sum2);
*sse = sse1 + sse2;
sum1 += sum2;
return *sse - (unsigned int)(((int64_t)sum1 * sum1) >> 11);
}
unsigned int vpx_variance64x64_neon(const uint8_t *a, int a_stride,
const uint8_t *b, int b_stride,
unsigned int *sse) {
int sum1, sum2;
uint32_t sse1, sse2;
variance_neon_w16(a, a_stride, b, b_stride, 64, 16, &sse1, &sum1);
variance_neon_w16(a + (16 * a_stride), a_stride, b + (16 * b_stride),
b_stride, 64, 16, &sse2, &sum2);
sse1 += sse2;
sum1 += sum2;
variance_neon_w16(a + (16 * 2 * a_stride), a_stride, b + (16 * 2 * b_stride),
b_stride, 64, 16, &sse2, &sum2);
sse1 += sse2;
sum1 += sum2;
variance_neon_w16(a + (16 * 3 * a_stride), a_stride, b + (16 * 3 * b_stride),
b_stride, 64, 16, &sse2, &sum2);
*sse = sse1 + sse2;
sum1 += sum2;
return *sse - (unsigned int)(((int64_t)sum1 * sum1) >> 12);
}
unsigned int vpx_mse16x16_neon(const unsigned char *src_ptr, int source_stride,
const unsigned char *ref_ptr, int recon_stride,
unsigned int *sse) {
int i;
int16x4_t d22s16, d23s16, d24s16, d25s16, d26s16, d27s16, d28s16, d29s16;
int64x1_t d0s64;
uint8x16_t q0u8, q1u8, q2u8, q3u8;
int32x4_t q7s32, q8s32, q9s32, q10s32;
uint16x8_t q11u16, q12u16, q13u16, q14u16;
int64x2_t q1s64;
q7s32 = vdupq_n_s32(0);
q8s32 = vdupq_n_s32(0);
q9s32 = vdupq_n_s32(0);
q10s32 = vdupq_n_s32(0);
for (i = 0; i < 8; i++) { // mse16x16_neon_loop
q0u8 = vld1q_u8(src_ptr);
src_ptr += source_stride;
q1u8 = vld1q_u8(src_ptr);
src_ptr += source_stride;
q2u8 = vld1q_u8(ref_ptr);
ref_ptr += recon_stride;
q3u8 = vld1q_u8(ref_ptr);
ref_ptr += recon_stride;
q11u16 = vsubl_u8(vget_low_u8(q0u8), vget_low_u8(q2u8));
q12u16 = vsubl_u8(vget_high_u8(q0u8), vget_high_u8(q2u8));
q13u16 = vsubl_u8(vget_low_u8(q1u8), vget_low_u8(q3u8));
q14u16 = vsubl_u8(vget_high_u8(q1u8), vget_high_u8(q3u8));
d22s16 = vreinterpret_s16_u16(vget_low_u16(q11u16));
d23s16 = vreinterpret_s16_u16(vget_high_u16(q11u16));
q7s32 = vmlal_s16(q7s32, d22s16, d22s16);
q8s32 = vmlal_s16(q8s32, d23s16, d23s16);
d24s16 = vreinterpret_s16_u16(vget_low_u16(q12u16));
d25s16 = vreinterpret_s16_u16(vget_high_u16(q12u16));
q9s32 = vmlal_s16(q9s32, d24s16, d24s16);
q10s32 = vmlal_s16(q10s32, d25s16, d25s16);
d26s16 = vreinterpret_s16_u16(vget_low_u16(q13u16));
d27s16 = vreinterpret_s16_u16(vget_high_u16(q13u16));
q7s32 = vmlal_s16(q7s32, d26s16, d26s16);
q8s32 = vmlal_s16(q8s32, d27s16, d27s16);
d28s16 = vreinterpret_s16_u16(vget_low_u16(q14u16));
d29s16 = vreinterpret_s16_u16(vget_high_u16(q14u16));
q9s32 = vmlal_s16(q9s32, d28s16, d28s16);
q10s32 = vmlal_s16(q10s32, d29s16, d29s16);
}
q7s32 = vaddq_s32(q7s32, q8s32);
q9s32 = vaddq_s32(q9s32, q10s32);
q10s32 = vaddq_s32(q7s32, q9s32);
q1s64 = vpaddlq_s32(q10s32);
d0s64 = vadd_s64(vget_low_s64(q1s64), vget_high_s64(q1s64));
vst1_lane_u32((uint32_t *)sse, vreinterpret_u32_s64(d0s64), 0);
return vget_lane_u32(vreinterpret_u32_s64(d0s64), 0);
}
unsigned int vpx_get4x4sse_cs_neon(const unsigned char *src_ptr,
int source_stride,
const unsigned char *ref_ptr,
int recon_stride) {
int16x4_t d22s16, d24s16, d26s16, d28s16;
int64x1_t d0s64;
uint8x8_t d0u8, d1u8, d2u8, d3u8, d4u8, d5u8, d6u8, d7u8;
int32x4_t q7s32, q8s32, q9s32, q10s32;
uint16x8_t q11u16, q12u16, q13u16, q14u16;
int64x2_t q1s64;
d0u8 = vld1_u8(src_ptr);
src_ptr += source_stride;
d4u8 = vld1_u8(ref_ptr);
ref_ptr += recon_stride;
d1u8 = vld1_u8(src_ptr);
src_ptr += source_stride;
d5u8 = vld1_u8(ref_ptr);
ref_ptr += recon_stride;
d2u8 = vld1_u8(src_ptr);
src_ptr += source_stride;
d6u8 = vld1_u8(ref_ptr);
ref_ptr += recon_stride;
d3u8 = vld1_u8(src_ptr);
src_ptr += source_stride;
d7u8 = vld1_u8(ref_ptr);
ref_ptr += recon_stride;
q11u16 = vsubl_u8(d0u8, d4u8);
q12u16 = vsubl_u8(d1u8, d5u8);
q13u16 = vsubl_u8(d2u8, d6u8);
q14u16 = vsubl_u8(d3u8, d7u8);
d22s16 = vget_low_s16(vreinterpretq_s16_u16(q11u16));
d24s16 = vget_low_s16(vreinterpretq_s16_u16(q12u16));
d26s16 = vget_low_s16(vreinterpretq_s16_u16(q13u16));
d28s16 = vget_low_s16(vreinterpretq_s16_u16(q14u16));
q7s32 = vmull_s16(d22s16, d22s16);
q8s32 = vmull_s16(d24s16, d24s16);
q9s32 = vmull_s16(d26s16, d26s16);
q10s32 = vmull_s16(d28s16, d28s16);
q7s32 = vaddq_s32(q7s32, q8s32);
q9s32 = vaddq_s32(q9s32, q10s32);
q9s32 = vaddq_s32(q7s32, q9s32);
q1s64 = vpaddlq_s32(q9s32);
d0s64 = vadd_s64(vget_low_s64(q1s64), vget_high_s64(q1s64));
return vget_lane_u32(vreinterpret_u32_s64(d0s64), 0);
}