ref: aaaf9215e21d9aae155738aadeeaded3662d8b16
dir: /vpx_dsp/arm/quantize_neon.c/
/*
* Copyright (c) 2017 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_config.h"
#include "./vpx_dsp_rtcd.h"
#include "vpx_dsp/arm/mem_neon.h"
void vpx_quantize_b_neon(const tran_low_t *coeff_ptr, intptr_t n_coeffs,
int skip_block, const int16_t *zbin_ptr,
const int16_t *round_ptr, const int16_t *quant_ptr,
const int16_t *quant_shift_ptr, tran_low_t *qcoeff_ptr,
tran_low_t *dqcoeff_ptr, const int16_t *dequant_ptr,
uint16_t *eob_ptr, const int16_t *scan_ptr,
const int16_t *iscan_ptr) {
const int16x8_t one = vdupq_n_s16(1);
const int16x8_t neg_one = vdupq_n_s16(-1);
uint16x8_t eob_max;
(void)scan_ptr;
(void)skip_block;
assert(!skip_block);
// Process first 8 values which include a dc component.
{
// Only the first element of each vector is DC.
const int16x8_t zbin = vld1q_s16(zbin_ptr);
const int16x8_t round = vld1q_s16(round_ptr);
const int16x8_t quant = vld1q_s16(quant_ptr);
const int16x8_t quant_shift = vld1q_s16(quant_shift_ptr);
const int16x8_t dequant = vld1q_s16(dequant_ptr);
// Add one because the eob does not index from 0.
const uint16x8_t iscan =
vreinterpretq_u16_s16(vaddq_s16(vld1q_s16(iscan_ptr), one));
const int16x8_t coeff = load_tran_low_to_s16q(coeff_ptr);
const int16x8_t coeff_sign = vshrq_n_s16(coeff, 15);
const int16x8_t coeff_abs = vabsq_s16(coeff);
const int16x8_t zbin_mask =
vreinterpretq_s16_u16(vcgeq_s16(coeff_abs, zbin));
const int16x8_t rounded = vqaddq_s16(coeff_abs, round);
// (round * quant * 2) >> 16 >> 1 == (round * quant) >> 16
int16x8_t qcoeff = vshrq_n_s16(vqdmulhq_s16(rounded, quant), 1);
qcoeff = vaddq_s16(qcoeff, rounded);
// (qcoeff * quant_shift * 2) >> 16 >> 1 == (qcoeff * quant_shift) >> 16
qcoeff = vshrq_n_s16(vqdmulhq_s16(qcoeff, quant_shift), 1);
// Restore the sign bit.
qcoeff = veorq_s16(qcoeff, coeff_sign);
qcoeff = vsubq_s16(qcoeff, coeff_sign);
qcoeff = vandq_s16(qcoeff, zbin_mask);
// Set non-zero elements to -1 and use that to extract values for eob.
eob_max = vandq_u16(vtstq_s16(qcoeff, neg_one), iscan);
coeff_ptr += 8;
iscan_ptr += 8;
store_s16q_to_tran_low(qcoeff_ptr, qcoeff);
qcoeff_ptr += 8;
qcoeff = vmulq_s16(qcoeff, dequant);
store_s16q_to_tran_low(dqcoeff_ptr, qcoeff);
dqcoeff_ptr += 8;
}
n_coeffs -= 8;
{
const int16x8_t zbin = vdupq_n_s16(zbin_ptr[1]);
const int16x8_t round = vdupq_n_s16(round_ptr[1]);
const int16x8_t quant = vdupq_n_s16(quant_ptr[1]);
const int16x8_t quant_shift = vdupq_n_s16(quant_shift_ptr[1]);
const int16x8_t dequant = vdupq_n_s16(dequant_ptr[1]);
do {
// Add one because the eob is not its index.
const uint16x8_t iscan =
vreinterpretq_u16_s16(vaddq_s16(vld1q_s16(iscan_ptr), one));
const int16x8_t coeff = load_tran_low_to_s16q(coeff_ptr);
const int16x8_t coeff_sign = vshrq_n_s16(coeff, 15);
const int16x8_t coeff_abs = vabsq_s16(coeff);
const int16x8_t zbin_mask =
vreinterpretq_s16_u16(vcgeq_s16(coeff_abs, zbin));
const int16x8_t rounded = vqaddq_s16(coeff_abs, round);
// (round * quant * 2) >> 16 >> 1 == (round * quant) >> 16
int16x8_t qcoeff = vshrq_n_s16(vqdmulhq_s16(rounded, quant), 1);
qcoeff = vaddq_s16(qcoeff, rounded);
// (qcoeff * quant_shift * 2) >> 16 >> 1 == (qcoeff * quant_shift) >> 16
qcoeff = vshrq_n_s16(vqdmulhq_s16(qcoeff, quant_shift), 1);
// Restore the sign bit.
qcoeff = veorq_s16(qcoeff, coeff_sign);
qcoeff = vsubq_s16(qcoeff, coeff_sign);
qcoeff = vandq_s16(qcoeff, zbin_mask);
// Set non-zero elements to -1 and use that to extract values for eob.
eob_max =
vmaxq_u16(eob_max, vandq_u16(vtstq_s16(qcoeff, neg_one), iscan));
coeff_ptr += 8;
iscan_ptr += 8;
store_s16q_to_tran_low(qcoeff_ptr, qcoeff);
qcoeff_ptr += 8;
qcoeff = vmulq_s16(qcoeff, dequant);
store_s16q_to_tran_low(dqcoeff_ptr, qcoeff);
dqcoeff_ptr += 8;
n_coeffs -= 8;
} while (n_coeffs > 0);
}
{
const uint16x4_t eob_max_0 =
vmax_u16(vget_low_u16(eob_max), vget_high_u16(eob_max));
const uint16x4_t eob_max_1 = vpmax_u16(eob_max_0, eob_max_0);
const uint16x4_t eob_max_2 = vpmax_u16(eob_max_1, eob_max_1);
vst1_lane_u16(eob_ptr, eob_max_2, 0);
}
}
static INLINE int32x4_t extract_sign_bit(int32x4_t a) {
return vreinterpretq_s32_u32(vshrq_n_u32(vreinterpretq_u32_s32(a), 31));
}
// Main difference is that zbin values are halved before comparison and dqcoeff
// values are divided by 2. zbin is rounded but dqcoeff is not.
void vpx_quantize_b_32x32_neon(
const tran_low_t *coeff_ptr, intptr_t n_coeffs, int skip_block,
const int16_t *zbin_ptr, const int16_t *round_ptr, const int16_t *quant_ptr,
const int16_t *quant_shift_ptr, tran_low_t *qcoeff_ptr,
tran_low_t *dqcoeff_ptr, const int16_t *dequant_ptr, uint16_t *eob_ptr,
const int16_t *scan_ptr, const int16_t *iscan_ptr) {
const int16x8_t one = vdupq_n_s16(1);
const int16x8_t neg_one = vdupq_n_s16(-1);
uint16x8_t eob_max;
int i;
(void)scan_ptr;
(void)n_coeffs; // Because we will always calculate 32*32.
(void)skip_block;
assert(!skip_block);
// Process first 8 values which include a dc component.
{
// Only the first element of each vector is DC.
const int16x8_t zbin = vrshrq_n_s16(vld1q_s16(zbin_ptr), 1);
const int16x8_t round = vrshrq_n_s16(vld1q_s16(round_ptr), 1);
const int16x8_t quant = vld1q_s16(quant_ptr);
const int16x8_t quant_shift = vld1q_s16(quant_shift_ptr);
const int16x8_t dequant = vld1q_s16(dequant_ptr);
// Add one because the eob does not index from 0.
const uint16x8_t iscan =
vreinterpretq_u16_s16(vaddq_s16(vld1q_s16(iscan_ptr), one));
const int16x8_t coeff = load_tran_low_to_s16q(coeff_ptr);
const int16x8_t coeff_sign = vshrq_n_s16(coeff, 15);
const int16x8_t coeff_abs = vabsq_s16(coeff);
const int16x8_t zbin_mask =
vreinterpretq_s16_u16(vcgeq_s16(coeff_abs, zbin));
const int16x8_t rounded = vqaddq_s16(coeff_abs, round);
// (round * quant * 2) >> 16 >> 1 == (round * quant) >> 16
int16x8_t qcoeff = vshrq_n_s16(vqdmulhq_s16(rounded, quant), 1);
int16x8_t dqcoeff;
int32x4_t dqcoeff_0, dqcoeff_1;
qcoeff = vaddq_s16(qcoeff, rounded);
// (qcoeff * quant_shift * 2) >> 16 == (qcoeff * quant_shift) >> 15
qcoeff = vqdmulhq_s16(qcoeff, quant_shift);
// Restore the sign bit.
qcoeff = veorq_s16(qcoeff, coeff_sign);
qcoeff = vsubq_s16(qcoeff, coeff_sign);
qcoeff = vandq_s16(qcoeff, zbin_mask);
// Set non-zero elements to -1 and use that to extract values for eob.
eob_max = vandq_u16(vtstq_s16(qcoeff, neg_one), iscan);
coeff_ptr += 8;
iscan_ptr += 8;
store_s16q_to_tran_low(qcoeff_ptr, qcoeff);
qcoeff_ptr += 8;
dqcoeff_0 = vmull_s16(vget_low_s16(qcoeff), vget_low_s16(dequant));
dqcoeff_1 = vmull_s16(vget_high_s16(qcoeff), vget_high_s16(dequant));
// Add 1 if negative to round towards zero because the C uses division.
dqcoeff_0 = vaddq_s32(dqcoeff_0, extract_sign_bit(dqcoeff_0));
dqcoeff_1 = vaddq_s32(dqcoeff_1, extract_sign_bit(dqcoeff_1));
dqcoeff =
vcombine_s16(vshrn_n_s32(dqcoeff_0, 1), vshrn_n_s32(dqcoeff_1, 1));
store_s16q_to_tran_low(dqcoeff_ptr, dqcoeff);
dqcoeff_ptr += 8;
}
{
const int16x8_t zbin = vrshrq_n_s16(vdupq_n_s16(zbin_ptr[1]), 1);
const int16x8_t round = vrshrq_n_s16(vdupq_n_s16(round_ptr[1]), 1);
const int16x8_t quant = vdupq_n_s16(quant_ptr[1]);
const int16x8_t quant_shift = vdupq_n_s16(quant_shift_ptr[1]);
const int16x8_t dequant = vdupq_n_s16(dequant_ptr[1]);
for (i = 1; i < 32 * 32 / 8; ++i) {
// Add one because the eob is not its index.
const uint16x8_t iscan =
vreinterpretq_u16_s16(vaddq_s16(vld1q_s16(iscan_ptr), one));
const int16x8_t coeff = load_tran_low_to_s16q(coeff_ptr);
const int16x8_t coeff_sign = vshrq_n_s16(coeff, 15);
const int16x8_t coeff_abs = vabsq_s16(coeff);
const int16x8_t zbin_mask =
vreinterpretq_s16_u16(vcgeq_s16(coeff_abs, zbin));
const int16x8_t rounded = vqaddq_s16(coeff_abs, round);
// (round * quant * 2) >> 16 >> 1 == (round * quant) >> 16
int16x8_t qcoeff = vshrq_n_s16(vqdmulhq_s16(rounded, quant), 1);
int16x8_t dqcoeff;
int32x4_t dqcoeff_0, dqcoeff_1;
qcoeff = vaddq_s16(qcoeff, rounded);
// (qcoeff * quant_shift * 2) >> 16 == (qcoeff * quant_shift) >> 15
qcoeff = vqdmulhq_s16(qcoeff, quant_shift);
// Restore the sign bit.
qcoeff = veorq_s16(qcoeff, coeff_sign);
qcoeff = vsubq_s16(qcoeff, coeff_sign);
qcoeff = vandq_s16(qcoeff, zbin_mask);
// Set non-zero elements to -1 and use that to extract values for eob.
eob_max =
vmaxq_u16(eob_max, vandq_u16(vtstq_s16(qcoeff, neg_one), iscan));
coeff_ptr += 8;
iscan_ptr += 8;
store_s16q_to_tran_low(qcoeff_ptr, qcoeff);
qcoeff_ptr += 8;
dqcoeff_0 = vmull_s16(vget_low_s16(qcoeff), vget_low_s16(dequant));
dqcoeff_1 = vmull_s16(vget_high_s16(qcoeff), vget_high_s16(dequant));
dqcoeff_0 = vaddq_s32(dqcoeff_0, extract_sign_bit(dqcoeff_0));
dqcoeff_1 = vaddq_s32(dqcoeff_1, extract_sign_bit(dqcoeff_1));
dqcoeff =
vcombine_s16(vshrn_n_s32(dqcoeff_0, 1), vshrn_n_s32(dqcoeff_1, 1));
store_s16q_to_tran_low(dqcoeff_ptr, dqcoeff);
dqcoeff_ptr += 8;
}
}
{
const uint16x4_t eob_max_0 =
vmax_u16(vget_low_u16(eob_max), vget_high_u16(eob_max));
const uint16x4_t eob_max_1 = vpmax_u16(eob_max_0, eob_max_0);
const uint16x4_t eob_max_2 = vpmax_u16(eob_max_1, eob_max_1);
vst1_lane_u16(eob_ptr, eob_max_2, 0);
}
}