1 /*
2 * Copyright (c) 2014 The WebM project authors. All Rights Reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10
11 #include <arm_neon.h>
12
13 #include "./vp8_rtcd.h"
14
15 static const int16_t cospi8sqrt2minus1 = 20091;
16 // 35468 exceeds INT16_MAX and gets converted to a negative number. Because of
17 // the way it is used in vqdmulh, where the result is doubled, it can be divided
18 // by 2 beforehand. This saves compensating for the negative value as well as
19 // shifting the result.
20 static const int16_t sinpi8sqrt2 = 35468 >> 1;
21
vp8_short_idct4x4llm_neon(int16_t * input,unsigned char * pred_ptr,int pred_stride,unsigned char * dst_ptr,int dst_stride)22 void vp8_short_idct4x4llm_neon(int16_t *input, unsigned char *pred_ptr,
23 int pred_stride, unsigned char *dst_ptr,
24 int dst_stride) {
25 int i;
26 uint32x2_t d6u32 = vdup_n_u32(0);
27 uint8x8_t d1u8;
28 int16x4_t d2, d3, d4, d5, d10, d11, d12, d13;
29 uint16x8_t q1u16;
30 int16x8_t q1s16, q2s16, q3s16, q4s16;
31 int32x2x2_t v2tmp0, v2tmp1;
32 int16x4x2_t v2tmp2, v2tmp3;
33
34 d2 = vld1_s16(input);
35 d3 = vld1_s16(input + 4);
36 d4 = vld1_s16(input + 8);
37 d5 = vld1_s16(input + 12);
38
39 // 1st for loop
40 q1s16 = vcombine_s16(d2, d4); // Swap d3 d4 here
41 q2s16 = vcombine_s16(d3, d5);
42
43 q3s16 = vqdmulhq_n_s16(q2s16, sinpi8sqrt2);
44 q4s16 = vqdmulhq_n_s16(q2s16, cospi8sqrt2minus1);
45
46 d12 = vqadd_s16(vget_low_s16(q1s16), vget_high_s16(q1s16)); // a1
47 d13 = vqsub_s16(vget_low_s16(q1s16), vget_high_s16(q1s16)); // b1
48
49 q4s16 = vshrq_n_s16(q4s16, 1);
50
51 q4s16 = vqaddq_s16(q4s16, q2s16);
52
53 d10 = vqsub_s16(vget_low_s16(q3s16), vget_high_s16(q4s16)); // c1
54 d11 = vqadd_s16(vget_high_s16(q3s16), vget_low_s16(q4s16)); // d1
55
56 d2 = vqadd_s16(d12, d11);
57 d3 = vqadd_s16(d13, d10);
58 d4 = vqsub_s16(d13, d10);
59 d5 = vqsub_s16(d12, d11);
60
61 v2tmp0 = vtrn_s32(vreinterpret_s32_s16(d2), vreinterpret_s32_s16(d4));
62 v2tmp1 = vtrn_s32(vreinterpret_s32_s16(d3), vreinterpret_s32_s16(d5));
63 v2tmp2 = vtrn_s16(vreinterpret_s16_s32(v2tmp0.val[0]),
64 vreinterpret_s16_s32(v2tmp1.val[0]));
65 v2tmp3 = vtrn_s16(vreinterpret_s16_s32(v2tmp0.val[1]),
66 vreinterpret_s16_s32(v2tmp1.val[1]));
67
68 // 2nd for loop
69 q1s16 = vcombine_s16(v2tmp2.val[0], v2tmp3.val[0]);
70 q2s16 = vcombine_s16(v2tmp2.val[1], v2tmp3.val[1]);
71
72 q3s16 = vqdmulhq_n_s16(q2s16, sinpi8sqrt2);
73 q4s16 = vqdmulhq_n_s16(q2s16, cospi8sqrt2minus1);
74
75 d12 = vqadd_s16(vget_low_s16(q1s16), vget_high_s16(q1s16)); // a1
76 d13 = vqsub_s16(vget_low_s16(q1s16), vget_high_s16(q1s16)); // b1
77
78 q4s16 = vshrq_n_s16(q4s16, 1);
79
80 q4s16 = vqaddq_s16(q4s16, q2s16);
81
82 d10 = vqsub_s16(vget_low_s16(q3s16), vget_high_s16(q4s16)); // c1
83 d11 = vqadd_s16(vget_high_s16(q3s16), vget_low_s16(q4s16)); // d1
84
85 d2 = vqadd_s16(d12, d11);
86 d3 = vqadd_s16(d13, d10);
87 d4 = vqsub_s16(d13, d10);
88 d5 = vqsub_s16(d12, d11);
89
90 d2 = vrshr_n_s16(d2, 3);
91 d3 = vrshr_n_s16(d3, 3);
92 d4 = vrshr_n_s16(d4, 3);
93 d5 = vrshr_n_s16(d5, 3);
94
95 v2tmp0 = vtrn_s32(vreinterpret_s32_s16(d2), vreinterpret_s32_s16(d4));
96 v2tmp1 = vtrn_s32(vreinterpret_s32_s16(d3), vreinterpret_s32_s16(d5));
97 v2tmp2 = vtrn_s16(vreinterpret_s16_s32(v2tmp0.val[0]),
98 vreinterpret_s16_s32(v2tmp1.val[0]));
99 v2tmp3 = vtrn_s16(vreinterpret_s16_s32(v2tmp0.val[1]),
100 vreinterpret_s16_s32(v2tmp1.val[1]));
101
102 q1s16 = vcombine_s16(v2tmp2.val[0], v2tmp2.val[1]);
103 q2s16 = vcombine_s16(v2tmp3.val[0], v2tmp3.val[1]);
104
105 // dc_only_idct_add
106 for (i = 0; i < 2; i++, q1s16 = q2s16) {
107 d6u32 = vld1_lane_u32((const uint32_t *)pred_ptr, d6u32, 0);
108 pred_ptr += pred_stride;
109 d6u32 = vld1_lane_u32((const uint32_t *)pred_ptr, d6u32, 1);
110 pred_ptr += pred_stride;
111
112 q1u16 = vaddw_u8(vreinterpretq_u16_s16(q1s16), vreinterpret_u8_u32(d6u32));
113 d1u8 = vqmovun_s16(vreinterpretq_s16_u16(q1u16));
114
115 vst1_lane_u32((uint32_t *)dst_ptr, vreinterpret_u32_u8(d1u8), 0);
116 dst_ptr += dst_stride;
117 vst1_lane_u32((uint32_t *)dst_ptr, vreinterpret_u32_u8(d1u8), 1);
118 dst_ptr += dst_stride;
119 }
120 return;
121 }
122