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 #include <assert.h>
13 
14 #include "./vpx_config.h"
15 #include "./vpx_dsp_rtcd.h"
16 #include "vpx/vpx_integer.h"
17 #include "vpx_dsp/arm/mem_neon.h"
18 
vpx_subtract_block_neon(int rows,int cols,int16_t * diff,ptrdiff_t diff_stride,const uint8_t * src,ptrdiff_t src_stride,const uint8_t * pred,ptrdiff_t pred_stride)19 void vpx_subtract_block_neon(int rows, int cols, int16_t *diff,
20                              ptrdiff_t diff_stride, const uint8_t *src,
21                              ptrdiff_t src_stride, const uint8_t *pred,
22                              ptrdiff_t pred_stride) {
23   int r = rows, c;
24 
25   if (cols > 16) {
26     do {
27       for (c = 0; c < cols; c += 32) {
28         const uint8x16_t s0 = vld1q_u8(&src[c + 0]);
29         const uint8x16_t s1 = vld1q_u8(&src[c + 16]);
30         const uint8x16_t p0 = vld1q_u8(&pred[c + 0]);
31         const uint8x16_t p1 = vld1q_u8(&pred[c + 16]);
32         const uint16x8_t d0 = vsubl_u8(vget_low_u8(s0), vget_low_u8(p0));
33         const uint16x8_t d1 = vsubl_u8(vget_high_u8(s0), vget_high_u8(p0));
34         const uint16x8_t d2 = vsubl_u8(vget_low_u8(s1), vget_low_u8(p1));
35         const uint16x8_t d3 = vsubl_u8(vget_high_u8(s1), vget_high_u8(p1));
36         vst1q_s16(&diff[c + 0], vreinterpretq_s16_u16(d0));
37         vst1q_s16(&diff[c + 8], vreinterpretq_s16_u16(d1));
38         vst1q_s16(&diff[c + 16], vreinterpretq_s16_u16(d2));
39         vst1q_s16(&diff[c + 24], vreinterpretq_s16_u16(d3));
40       }
41       diff += diff_stride;
42       pred += pred_stride;
43       src += src_stride;
44     } while (--r);
45   } else if (cols > 8) {
46     do {
47       const uint8x16_t s = vld1q_u8(&src[0]);
48       const uint8x16_t p = vld1q_u8(&pred[0]);
49       const uint16x8_t d0 = vsubl_u8(vget_low_u8(s), vget_low_u8(p));
50       const uint16x8_t d1 = vsubl_u8(vget_high_u8(s), vget_high_u8(p));
51       vst1q_s16(&diff[0], vreinterpretq_s16_u16(d0));
52       vst1q_s16(&diff[8], vreinterpretq_s16_u16(d1));
53       diff += diff_stride;
54       pred += pred_stride;
55       src += src_stride;
56     } while (--r);
57   } else if (cols > 4) {
58     do {
59       const uint8x8_t s = vld1_u8(&src[0]);
60       const uint8x8_t p = vld1_u8(&pred[0]);
61       const uint16x8_t v_diff = vsubl_u8(s, p);
62       vst1q_s16(&diff[0], vreinterpretq_s16_u16(v_diff));
63       diff += diff_stride;
64       pred += pred_stride;
65       src += src_stride;
66     } while (--r);
67   } else {
68     assert(cols == 4);
69     do {
70       const uint8x8_t s = load_unaligned_u8(src, (int)src_stride);
71       const uint8x8_t p = load_unaligned_u8(pred, (int)pred_stride);
72       const uint16x8_t d = vsubl_u8(s, p);
73       vst1_s16(diff + 0 * diff_stride, vreinterpret_s16_u16(vget_low_u16(d)));
74       vst1_s16(diff + 1 * diff_stride, vreinterpret_s16_u16(vget_high_u16(d)));
75       diff += 2 * diff_stride;
76       pred += 2 * pred_stride;
77       src += 2 * src_stride;
78       r -= 2;
79     } while (r);
80   }
81 }
82