ref: 468e77b9ea78a5a7d60fb86d016b833982860d9c
dir: /vpx_dsp/arm/fwd_txfm_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 "./vpx_config.h"
#include "./vpx_dsp_rtcd.h"
#include "vpx_dsp/txfm_common.h"
#include "vpx_dsp/vpx_dsp_common.h"
#include "vpx_dsp/arm/idct_neon.h"
#include "vpx_dsp/arm/mem_neon.h"
void vpx_fdct8x8_neon(const int16_t *input, tran_low_t *final_output,
int stride) {
int i;
// stage 1
int16x8_t input_0 = vshlq_n_s16(vld1q_s16(&input[0 * stride]), 2);
int16x8_t input_1 = vshlq_n_s16(vld1q_s16(&input[1 * stride]), 2);
int16x8_t input_2 = vshlq_n_s16(vld1q_s16(&input[2 * stride]), 2);
int16x8_t input_3 = vshlq_n_s16(vld1q_s16(&input[3 * stride]), 2);
int16x8_t input_4 = vshlq_n_s16(vld1q_s16(&input[4 * stride]), 2);
int16x8_t input_5 = vshlq_n_s16(vld1q_s16(&input[5 * stride]), 2);
int16x8_t input_6 = vshlq_n_s16(vld1q_s16(&input[6 * stride]), 2);
int16x8_t input_7 = vshlq_n_s16(vld1q_s16(&input[7 * stride]), 2);
for (i = 0; i < 2; ++i) {
int16x8_t out_0, out_1, out_2, out_3, out_4, out_5, out_6, out_7;
const int16x8_t v_s0 = vaddq_s16(input_0, input_7);
const int16x8_t v_s1 = vaddq_s16(input_1, input_6);
const int16x8_t v_s2 = vaddq_s16(input_2, input_5);
const int16x8_t v_s3 = vaddq_s16(input_3, input_4);
const int16x8_t v_s4 = vsubq_s16(input_3, input_4);
const int16x8_t v_s5 = vsubq_s16(input_2, input_5);
const int16x8_t v_s6 = vsubq_s16(input_1, input_6);
const int16x8_t v_s7 = vsubq_s16(input_0, input_7);
// fdct4(step, step);
int16x8_t v_x0 = vaddq_s16(v_s0, v_s3);
int16x8_t v_x1 = vaddq_s16(v_s1, v_s2);
int16x8_t v_x2 = vsubq_s16(v_s1, v_s2);
int16x8_t v_x3 = vsubq_s16(v_s0, v_s3);
// fdct4(step, step);
int32x4_t v_t0_lo = vaddl_s16(vget_low_s16(v_x0), vget_low_s16(v_x1));
int32x4_t v_t0_hi = vaddl_s16(vget_high_s16(v_x0), vget_high_s16(v_x1));
int32x4_t v_t1_lo = vsubl_s16(vget_low_s16(v_x0), vget_low_s16(v_x1));
int32x4_t v_t1_hi = vsubl_s16(vget_high_s16(v_x0), vget_high_s16(v_x1));
int32x4_t v_t2_lo = vmull_n_s16(vget_low_s16(v_x2), cospi_24_64);
int32x4_t v_t2_hi = vmull_n_s16(vget_high_s16(v_x2), cospi_24_64);
int32x4_t v_t3_lo = vmull_n_s16(vget_low_s16(v_x3), cospi_24_64);
int32x4_t v_t3_hi = vmull_n_s16(vget_high_s16(v_x3), cospi_24_64);
v_t2_lo = vmlal_n_s16(v_t2_lo, vget_low_s16(v_x3), cospi_8_64);
v_t2_hi = vmlal_n_s16(v_t2_hi, vget_high_s16(v_x3), cospi_8_64);
v_t3_lo = vmlsl_n_s16(v_t3_lo, vget_low_s16(v_x2), cospi_8_64);
v_t3_hi = vmlsl_n_s16(v_t3_hi, vget_high_s16(v_x2), cospi_8_64);
v_t0_lo = vmulq_n_s32(v_t0_lo, cospi_16_64);
v_t0_hi = vmulq_n_s32(v_t0_hi, cospi_16_64);
v_t1_lo = vmulq_n_s32(v_t1_lo, cospi_16_64);
v_t1_hi = vmulq_n_s32(v_t1_hi, cospi_16_64);
{
const int16x4_t a = vrshrn_n_s32(v_t0_lo, DCT_CONST_BITS);
const int16x4_t b = vrshrn_n_s32(v_t0_hi, DCT_CONST_BITS);
const int16x4_t c = vrshrn_n_s32(v_t1_lo, DCT_CONST_BITS);
const int16x4_t d = vrshrn_n_s32(v_t1_hi, DCT_CONST_BITS);
const int16x4_t e = vrshrn_n_s32(v_t2_lo, DCT_CONST_BITS);
const int16x4_t f = vrshrn_n_s32(v_t2_hi, DCT_CONST_BITS);
const int16x4_t g = vrshrn_n_s32(v_t3_lo, DCT_CONST_BITS);
const int16x4_t h = vrshrn_n_s32(v_t3_hi, DCT_CONST_BITS);
out_0 = vcombine_s16(a, c); // 00 01 02 03 40 41 42 43
out_2 = vcombine_s16(e, g); // 20 21 22 23 60 61 62 63
out_4 = vcombine_s16(b, d); // 04 05 06 07 44 45 46 47
out_6 = vcombine_s16(f, h); // 24 25 26 27 64 65 66 67
}
// Stage 2
v_x0 = vsubq_s16(v_s6, v_s5);
v_x1 = vaddq_s16(v_s6, v_s5);
v_t0_lo = vmull_n_s16(vget_low_s16(v_x0), cospi_16_64);
v_t0_hi = vmull_n_s16(vget_high_s16(v_x0), cospi_16_64);
v_t1_lo = vmull_n_s16(vget_low_s16(v_x1), cospi_16_64);
v_t1_hi = vmull_n_s16(vget_high_s16(v_x1), cospi_16_64);
{
const int16x4_t a = vrshrn_n_s32(v_t0_lo, DCT_CONST_BITS);
const int16x4_t b = vrshrn_n_s32(v_t0_hi, DCT_CONST_BITS);
const int16x4_t c = vrshrn_n_s32(v_t1_lo, DCT_CONST_BITS);
const int16x4_t d = vrshrn_n_s32(v_t1_hi, DCT_CONST_BITS);
const int16x8_t ab = vcombine_s16(a, b);
const int16x8_t cd = vcombine_s16(c, d);
// Stage 3
v_x0 = vaddq_s16(v_s4, ab);
v_x1 = vsubq_s16(v_s4, ab);
v_x2 = vsubq_s16(v_s7, cd);
v_x3 = vaddq_s16(v_s7, cd);
}
// Stage 4
v_t0_lo = vmull_n_s16(vget_low_s16(v_x3), cospi_4_64);
v_t0_hi = vmull_n_s16(vget_high_s16(v_x3), cospi_4_64);
v_t0_lo = vmlal_n_s16(v_t0_lo, vget_low_s16(v_x0), cospi_28_64);
v_t0_hi = vmlal_n_s16(v_t0_hi, vget_high_s16(v_x0), cospi_28_64);
v_t1_lo = vmull_n_s16(vget_low_s16(v_x1), cospi_12_64);
v_t1_hi = vmull_n_s16(vget_high_s16(v_x1), cospi_12_64);
v_t1_lo = vmlal_n_s16(v_t1_lo, vget_low_s16(v_x2), cospi_20_64);
v_t1_hi = vmlal_n_s16(v_t1_hi, vget_high_s16(v_x2), cospi_20_64);
v_t2_lo = vmull_n_s16(vget_low_s16(v_x2), cospi_12_64);
v_t2_hi = vmull_n_s16(vget_high_s16(v_x2), cospi_12_64);
v_t2_lo = vmlsl_n_s16(v_t2_lo, vget_low_s16(v_x1), cospi_20_64);
v_t2_hi = vmlsl_n_s16(v_t2_hi, vget_high_s16(v_x1), cospi_20_64);
v_t3_lo = vmull_n_s16(vget_low_s16(v_x3), cospi_28_64);
v_t3_hi = vmull_n_s16(vget_high_s16(v_x3), cospi_28_64);
v_t3_lo = vmlsl_n_s16(v_t3_lo, vget_low_s16(v_x0), cospi_4_64);
v_t3_hi = vmlsl_n_s16(v_t3_hi, vget_high_s16(v_x0), cospi_4_64);
{
const int16x4_t a = vrshrn_n_s32(v_t0_lo, DCT_CONST_BITS);
const int16x4_t b = vrshrn_n_s32(v_t0_hi, DCT_CONST_BITS);
const int16x4_t c = vrshrn_n_s32(v_t1_lo, DCT_CONST_BITS);
const int16x4_t d = vrshrn_n_s32(v_t1_hi, DCT_CONST_BITS);
const int16x4_t e = vrshrn_n_s32(v_t2_lo, DCT_CONST_BITS);
const int16x4_t f = vrshrn_n_s32(v_t2_hi, DCT_CONST_BITS);
const int16x4_t g = vrshrn_n_s32(v_t3_lo, DCT_CONST_BITS);
const int16x4_t h = vrshrn_n_s32(v_t3_hi, DCT_CONST_BITS);
out_1 = vcombine_s16(a, c); // 10 11 12 13 50 51 52 53
out_3 = vcombine_s16(e, g); // 30 31 32 33 70 71 72 73
out_5 = vcombine_s16(b, d); // 14 15 16 17 54 55 56 57
out_7 = vcombine_s16(f, h); // 34 35 36 37 74 75 76 77
}
// transpose 8x8
// Can't use transpose_s16_8x8() because the values are arranged in two 4x8
// columns.
{
// 00 01 02 03 40 41 42 43
// 10 11 12 13 50 51 52 53
// 20 21 22 23 60 61 62 63
// 30 31 32 33 70 71 72 73
// 04 05 06 07 44 45 46 47
// 14 15 16 17 54 55 56 57
// 24 25 26 27 64 65 66 67
// 34 35 36 37 74 75 76 77
const int32x4x2_t r02_s32 =
vtrnq_s32(vreinterpretq_s32_s16(out_0), vreinterpretq_s32_s16(out_2));
const int32x4x2_t r13_s32 =
vtrnq_s32(vreinterpretq_s32_s16(out_1), vreinterpretq_s32_s16(out_3));
const int32x4x2_t r46_s32 =
vtrnq_s32(vreinterpretq_s32_s16(out_4), vreinterpretq_s32_s16(out_6));
const int32x4x2_t r57_s32 =
vtrnq_s32(vreinterpretq_s32_s16(out_5), vreinterpretq_s32_s16(out_7));
const int16x8x2_t r01_s16 =
vtrnq_s16(vreinterpretq_s16_s32(r02_s32.val[0]),
vreinterpretq_s16_s32(r13_s32.val[0]));
const int16x8x2_t r23_s16 =
vtrnq_s16(vreinterpretq_s16_s32(r02_s32.val[1]),
vreinterpretq_s16_s32(r13_s32.val[1]));
const int16x8x2_t r45_s16 =
vtrnq_s16(vreinterpretq_s16_s32(r46_s32.val[0]),
vreinterpretq_s16_s32(r57_s32.val[0]));
const int16x8x2_t r67_s16 =
vtrnq_s16(vreinterpretq_s16_s32(r46_s32.val[1]),
vreinterpretq_s16_s32(r57_s32.val[1]));
input_0 = r01_s16.val[0];
input_1 = r01_s16.val[1];
input_2 = r23_s16.val[0];
input_3 = r23_s16.val[1];
input_4 = r45_s16.val[0];
input_5 = r45_s16.val[1];
input_6 = r67_s16.val[0];
input_7 = r67_s16.val[1];
// 00 10 20 30 40 50 60 70
// 01 11 21 31 41 51 61 71
// 02 12 22 32 42 52 62 72
// 03 13 23 33 43 53 63 73
// 04 14 24 34 44 54 64 74
// 05 15 25 35 45 55 65 75
// 06 16 26 36 46 56 66 76
// 07 17 27 37 47 57 67 77
}
} // for
{
// from vpx_dct_sse2.c
// Post-condition (division by two)
// division of two 16 bits signed numbers using shifts
// n / 2 = (n - (n >> 15)) >> 1
const int16x8_t sign_in0 = vshrq_n_s16(input_0, 15);
const int16x8_t sign_in1 = vshrq_n_s16(input_1, 15);
const int16x8_t sign_in2 = vshrq_n_s16(input_2, 15);
const int16x8_t sign_in3 = vshrq_n_s16(input_3, 15);
const int16x8_t sign_in4 = vshrq_n_s16(input_4, 15);
const int16x8_t sign_in5 = vshrq_n_s16(input_5, 15);
const int16x8_t sign_in6 = vshrq_n_s16(input_6, 15);
const int16x8_t sign_in7 = vshrq_n_s16(input_7, 15);
input_0 = vhsubq_s16(input_0, sign_in0);
input_1 = vhsubq_s16(input_1, sign_in1);
input_2 = vhsubq_s16(input_2, sign_in2);
input_3 = vhsubq_s16(input_3, sign_in3);
input_4 = vhsubq_s16(input_4, sign_in4);
input_5 = vhsubq_s16(input_5, sign_in5);
input_6 = vhsubq_s16(input_6, sign_in6);
input_7 = vhsubq_s16(input_7, sign_in7);
// store results
store_s16q_to_tran_low(final_output + 0 * 8, input_0);
store_s16q_to_tran_low(final_output + 1 * 8, input_1);
store_s16q_to_tran_low(final_output + 2 * 8, input_2);
store_s16q_to_tran_low(final_output + 3 * 8, input_3);
store_s16q_to_tran_low(final_output + 4 * 8, input_4);
store_s16q_to_tran_low(final_output + 5 * 8, input_5);
store_s16q_to_tran_low(final_output + 6 * 8, input_6);
store_s16q_to_tran_low(final_output + 7 * 8, input_7);
}
}