ref: 1ae97b4a4db010ee87bedca5943c64f55d43f6f7
dir: /vp8/common/arm/neon/idct_dequant_full_2x_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>
static const int16_t cospi8sqrt2minus1 = 20091;
static const int16_t sinpi8sqrt2 = 17734;
// because the lowest bit in 0x8a8c is 0, we can pre-shift this
void idct_dequant_full_2x_neon(int16_t *q, int16_t *dq, unsigned char *dst,
int stride) {
unsigned char *dst0, *dst1;
int32x2_t d28, d29, d30, d31;
int16x8_t q0, q1, q2, q3, q4, q5, q6, q7, q8, q9, q10, q11;
int16x8_t qEmpty = vdupq_n_s16(0);
int32x4x2_t q2tmp0, q2tmp1;
int16x8x2_t q2tmp2, q2tmp3;
int16x4_t dLow0, dLow1, dHigh0, dHigh1;
d28 = d29 = d30 = d31 = vdup_n_s32(0);
// load dq
q0 = vld1q_s16(dq);
dq += 8;
q1 = vld1q_s16(dq);
// load q
q2 = vld1q_s16(q);
vst1q_s16(q, qEmpty);
q += 8;
q3 = vld1q_s16(q);
vst1q_s16(q, qEmpty);
q += 8;
q4 = vld1q_s16(q);
vst1q_s16(q, qEmpty);
q += 8;
q5 = vld1q_s16(q);
vst1q_s16(q, qEmpty);
// load src from dst
dst0 = dst;
dst1 = dst + 4;
d28 = vld1_lane_s32((const int32_t *)dst0, d28, 0);
dst0 += stride;
d28 = vld1_lane_s32((const int32_t *)dst1, d28, 1);
dst1 += stride;
d29 = vld1_lane_s32((const int32_t *)dst0, d29, 0);
dst0 += stride;
d29 = vld1_lane_s32((const int32_t *)dst1, d29, 1);
dst1 += stride;
d30 = vld1_lane_s32((const int32_t *)dst0, d30, 0);
dst0 += stride;
d30 = vld1_lane_s32((const int32_t *)dst1, d30, 1);
dst1 += stride;
d31 = vld1_lane_s32((const int32_t *)dst0, d31, 0);
d31 = vld1_lane_s32((const int32_t *)dst1, d31, 1);
q2 = vmulq_s16(q2, q0);
q3 = vmulq_s16(q3, q1);
q4 = vmulq_s16(q4, q0);
q5 = vmulq_s16(q5, q1);
// vswp
dLow0 = vget_low_s16(q2);
dHigh0 = vget_high_s16(q2);
dLow1 = vget_low_s16(q4);
dHigh1 = vget_high_s16(q4);
q2 = vcombine_s16(dLow0, dLow1);
q4 = vcombine_s16(dHigh0, dHigh1);
dLow0 = vget_low_s16(q3);
dHigh0 = vget_high_s16(q3);
dLow1 = vget_low_s16(q5);
dHigh1 = vget_high_s16(q5);
q3 = vcombine_s16(dLow0, dLow1);
q5 = vcombine_s16(dHigh0, dHigh1);
q6 = vqdmulhq_n_s16(q4, sinpi8sqrt2);
q7 = vqdmulhq_n_s16(q5, sinpi8sqrt2);
q8 = vqdmulhq_n_s16(q4, cospi8sqrt2minus1);
q9 = vqdmulhq_n_s16(q5, cospi8sqrt2minus1);
q10 = vqaddq_s16(q2, q3);
q11 = vqsubq_s16(q2, q3);
q8 = vshrq_n_s16(q8, 1);
q9 = vshrq_n_s16(q9, 1);
q4 = vqaddq_s16(q4, q8);
q5 = vqaddq_s16(q5, q9);
q2 = vqsubq_s16(q6, q5);
q3 = vqaddq_s16(q7, q4);
q4 = vqaddq_s16(q10, q3);
q5 = vqaddq_s16(q11, q2);
q6 = vqsubq_s16(q11, q2);
q7 = vqsubq_s16(q10, q3);
q2tmp0 = vtrnq_s32(vreinterpretq_s32_s16(q4), vreinterpretq_s32_s16(q6));
q2tmp1 = vtrnq_s32(vreinterpretq_s32_s16(q5), vreinterpretq_s32_s16(q7));
q2tmp2 = vtrnq_s16(vreinterpretq_s16_s32(q2tmp0.val[0]),
vreinterpretq_s16_s32(q2tmp1.val[0]));
q2tmp3 = vtrnq_s16(vreinterpretq_s16_s32(q2tmp0.val[1]),
vreinterpretq_s16_s32(q2tmp1.val[1]));
// loop 2
q8 = vqdmulhq_n_s16(q2tmp2.val[1], sinpi8sqrt2);
q9 = vqdmulhq_n_s16(q2tmp3.val[1], sinpi8sqrt2);
q10 = vqdmulhq_n_s16(q2tmp2.val[1], cospi8sqrt2minus1);
q11 = vqdmulhq_n_s16(q2tmp3.val[1], cospi8sqrt2minus1);
q2 = vqaddq_s16(q2tmp2.val[0], q2tmp3.val[0]);
q3 = vqsubq_s16(q2tmp2.val[0], q2tmp3.val[0]);
q10 = vshrq_n_s16(q10, 1);
q11 = vshrq_n_s16(q11, 1);
q10 = vqaddq_s16(q2tmp2.val[1], q10);
q11 = vqaddq_s16(q2tmp3.val[1], q11);
q8 = vqsubq_s16(q8, q11);
q9 = vqaddq_s16(q9, q10);
q4 = vqaddq_s16(q2, q9);
q5 = vqaddq_s16(q3, q8);
q6 = vqsubq_s16(q3, q8);
q7 = vqsubq_s16(q2, q9);
q4 = vrshrq_n_s16(q4, 3);
q5 = vrshrq_n_s16(q5, 3);
q6 = vrshrq_n_s16(q6, 3);
q7 = vrshrq_n_s16(q7, 3);
q2tmp0 = vtrnq_s32(vreinterpretq_s32_s16(q4), vreinterpretq_s32_s16(q6));
q2tmp1 = vtrnq_s32(vreinterpretq_s32_s16(q5), vreinterpretq_s32_s16(q7));
q2tmp2 = vtrnq_s16(vreinterpretq_s16_s32(q2tmp0.val[0]),
vreinterpretq_s16_s32(q2tmp1.val[0]));
q2tmp3 = vtrnq_s16(vreinterpretq_s16_s32(q2tmp0.val[1]),
vreinterpretq_s16_s32(q2tmp1.val[1]));
q4 = vreinterpretq_s16_u16(
vaddw_u8(vreinterpretq_u16_s16(q2tmp2.val[0]), vreinterpret_u8_s32(d28)));
q5 = vreinterpretq_s16_u16(
vaddw_u8(vreinterpretq_u16_s16(q2tmp2.val[1]), vreinterpret_u8_s32(d29)));
q6 = vreinterpretq_s16_u16(
vaddw_u8(vreinterpretq_u16_s16(q2tmp3.val[0]), vreinterpret_u8_s32(d30)));
q7 = vreinterpretq_s16_u16(
vaddw_u8(vreinterpretq_u16_s16(q2tmp3.val[1]), vreinterpret_u8_s32(d31)));
d28 = vreinterpret_s32_u8(vqmovun_s16(q4));
d29 = vreinterpret_s32_u8(vqmovun_s16(q5));
d30 = vreinterpret_s32_u8(vqmovun_s16(q6));
d31 = vreinterpret_s32_u8(vqmovun_s16(q7));
dst0 = dst;
dst1 = dst + 4;
vst1_lane_s32((int32_t *)dst0, d28, 0);
dst0 += stride;
vst1_lane_s32((int32_t *)dst1, d28, 1);
dst1 += stride;
vst1_lane_s32((int32_t *)dst0, d29, 0);
dst0 += stride;
vst1_lane_s32((int32_t *)dst1, d29, 1);
dst1 += stride;
vst1_lane_s32((int32_t *)dst0, d30, 0);
dst0 += stride;
vst1_lane_s32((int32_t *)dst1, d30, 1);
dst1 += stride;
vst1_lane_s32((int32_t *)dst0, d31, 0);
vst1_lane_s32((int32_t *)dst1, d31, 1);
return;
}