ref: a6fdfda44c0c637b0c99bfa5e583bf691c58bca7
dir: /vp8/common/arm/neon/iwalsh_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>
void vp8_short_inv_walsh4x4_neon(int16_t *input, int16_t *mb_dqcoeff) {
int16x8_t q0s16, q1s16, q2s16, q3s16;
int16x4_t d4s16, d5s16, d6s16, d7s16;
int16x4x2_t v2tmp0, v2tmp1;
int32x2x2_t v2tmp2, v2tmp3;
int16x8_t qAdd3;
q0s16 = vld1q_s16(input);
q1s16 = vld1q_s16(input + 8);
// 1st for loop
d4s16 = vadd_s16(vget_low_s16(q0s16), vget_high_s16(q1s16));
d6s16 = vadd_s16(vget_high_s16(q0s16), vget_low_s16(q1s16));
d5s16 = vsub_s16(vget_low_s16(q0s16), vget_high_s16(q1s16));
d7s16 = vsub_s16(vget_high_s16(q0s16), vget_low_s16(q1s16));
q2s16 = vcombine_s16(d4s16, d5s16);
q3s16 = vcombine_s16(d6s16, d7s16);
q0s16 = vaddq_s16(q2s16, q3s16);
q1s16 = vsubq_s16(q2s16, q3s16);
v2tmp2 = vtrn_s32(vreinterpret_s32_s16(vget_low_s16(q0s16)),
vreinterpret_s32_s16(vget_low_s16(q1s16)));
v2tmp3 = vtrn_s32(vreinterpret_s32_s16(vget_high_s16(q0s16)),
vreinterpret_s32_s16(vget_high_s16(q1s16)));
v2tmp0 = vtrn_s16(vreinterpret_s16_s32(v2tmp2.val[0]),
vreinterpret_s16_s32(v2tmp3.val[0]));
v2tmp1 = vtrn_s16(vreinterpret_s16_s32(v2tmp2.val[1]),
vreinterpret_s16_s32(v2tmp3.val[1]));
// 2nd for loop
d4s16 = vadd_s16(v2tmp0.val[0], v2tmp1.val[1]);
d6s16 = vadd_s16(v2tmp0.val[1], v2tmp1.val[0]);
d5s16 = vsub_s16(v2tmp0.val[0], v2tmp1.val[1]);
d7s16 = vsub_s16(v2tmp0.val[1], v2tmp1.val[0]);
q2s16 = vcombine_s16(d4s16, d5s16);
q3s16 = vcombine_s16(d6s16, d7s16);
qAdd3 = vdupq_n_s16(3);
q0s16 = vaddq_s16(q2s16, q3s16);
q1s16 = vsubq_s16(q2s16, q3s16);
q0s16 = vaddq_s16(q0s16, qAdd3);
q1s16 = vaddq_s16(q1s16, qAdd3);
q0s16 = vshrq_n_s16(q0s16, 3);
q1s16 = vshrq_n_s16(q1s16, 3);
// store
vst1_lane_s16(mb_dqcoeff, vget_low_s16(q0s16), 0);
mb_dqcoeff += 16;
vst1_lane_s16(mb_dqcoeff, vget_high_s16(q0s16), 0);
mb_dqcoeff += 16;
vst1_lane_s16(mb_dqcoeff, vget_low_s16(q1s16), 0);
mb_dqcoeff += 16;
vst1_lane_s16(mb_dqcoeff, vget_high_s16(q1s16), 0);
mb_dqcoeff += 16;
vst1_lane_s16(mb_dqcoeff, vget_low_s16(q0s16), 1);
mb_dqcoeff += 16;
vst1_lane_s16(mb_dqcoeff, vget_high_s16(q0s16), 1);
mb_dqcoeff += 16;
vst1_lane_s16(mb_dqcoeff, vget_low_s16(q1s16), 1);
mb_dqcoeff += 16;
vst1_lane_s16(mb_dqcoeff, vget_high_s16(q1s16), 1);
mb_dqcoeff += 16;
vst1_lane_s16(mb_dqcoeff, vget_low_s16(q0s16), 2);
mb_dqcoeff += 16;
vst1_lane_s16(mb_dqcoeff, vget_high_s16(q0s16), 2);
mb_dqcoeff += 16;
vst1_lane_s16(mb_dqcoeff, vget_low_s16(q1s16), 2);
mb_dqcoeff += 16;
vst1_lane_s16(mb_dqcoeff, vget_high_s16(q1s16), 2);
mb_dqcoeff += 16;
vst1_lane_s16(mb_dqcoeff, vget_low_s16(q0s16), 3);
mb_dqcoeff += 16;
vst1_lane_s16(mb_dqcoeff, vget_high_s16(q0s16), 3);
mb_dqcoeff += 16;
vst1_lane_s16(mb_dqcoeff, vget_low_s16(q1s16), 3);
mb_dqcoeff += 16;
vst1_lane_s16(mb_dqcoeff, vget_high_s16(q1s16), 3);
mb_dqcoeff += 16;
return;
}