ref: 67aa6c8c23bc6ca90cfde756015f0aae61fe20f7
dir: /vp9/encoder/arm/neon/vp9_error_neon.c/
/*
* Copyright (c) 2015 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 "./vp9_rtcd.h"
int64_t vp9_block_error_fp_neon(const int16_t *coeff, const int16_t *dqcoeff,
int block_size) {
int64x2_t error = vdupq_n_s64(0);
assert(block_size >= 8);
assert((block_size % 8) == 0);
do {
const int16x8_t c = vld1q_s16(coeff);
const int16x8_t d = vld1q_s16(dqcoeff);
const int16x8_t diff = vsubq_s16(c, d);
const int16x4_t diff_lo = vget_low_s16(diff);
const int16x4_t diff_hi = vget_high_s16(diff);
// diff is 15-bits, the squares 30, so we can store 2 in 31-bits before
// accumulating them in 64-bits.
const int32x4_t err0 = vmull_s16(diff_lo, diff_lo);
const int32x4_t err1 = vmlal_s16(err0, diff_hi, diff_hi);
const int64x2_t err2 = vaddl_s32(vget_low_s32(err1), vget_high_s32(err1));
error = vaddq_s64(error, err2);
coeff += 8;
dqcoeff += 8;
block_size -= 8;
} while (block_size != 0);
return vgetq_lane_s64(error, 0) + vgetq_lane_s64(error, 1);
}