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 "./vpx_config.h"
14 #include "vpx/vpx_integer.h"
15 
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)16 void vpx_subtract_block_neon(int rows, int cols,
17                              int16_t *diff, ptrdiff_t diff_stride,
18                              const uint8_t *src, ptrdiff_t src_stride,
19                              const uint8_t *pred, ptrdiff_t pred_stride) {
20   int r, c;
21 
22   if (cols > 16) {
23     for (r = 0; r < rows; ++r) {
24       for (c = 0; c < cols; c += 32) {
25         const uint8x16_t v_src_00 = vld1q_u8(&src[c + 0]);
26         const uint8x16_t v_src_16 = vld1q_u8(&src[c + 16]);
27         const uint8x16_t v_pred_00 = vld1q_u8(&pred[c +  0]);
28         const uint8x16_t v_pred_16 = vld1q_u8(&pred[c + 16]);
29         const uint16x8_t v_diff_lo_00 = vsubl_u8(vget_low_u8(v_src_00),
30                                                  vget_low_u8(v_pred_00));
31         const uint16x8_t v_diff_hi_00 = vsubl_u8(vget_high_u8(v_src_00),
32                                                  vget_high_u8(v_pred_00));
33         const uint16x8_t v_diff_lo_16 = vsubl_u8(vget_low_u8(v_src_16),
34                                                  vget_low_u8(v_pred_16));
35         const uint16x8_t v_diff_hi_16 = vsubl_u8(vget_high_u8(v_src_16),
36                                                  vget_high_u8(v_pred_16));
37         vst1q_s16(&diff[c +  0], vreinterpretq_s16_u16(v_diff_lo_00));
38         vst1q_s16(&diff[c +  8], vreinterpretq_s16_u16(v_diff_hi_00));
39         vst1q_s16(&diff[c + 16], vreinterpretq_s16_u16(v_diff_lo_16));
40         vst1q_s16(&diff[c + 24], vreinterpretq_s16_u16(v_diff_hi_16));
41       }
42       diff += diff_stride;
43       pred += pred_stride;
44       src  += src_stride;
45     }
46   } else if (cols > 8) {
47     for (r = 0; r < rows; ++r) {
48       const uint8x16_t v_src = vld1q_u8(&src[0]);
49       const uint8x16_t v_pred = vld1q_u8(&pred[0]);
50       const uint16x8_t v_diff_lo = vsubl_u8(vget_low_u8(v_src),
51                                             vget_low_u8(v_pred));
52       const uint16x8_t v_diff_hi = vsubl_u8(vget_high_u8(v_src),
53                                             vget_high_u8(v_pred));
54       vst1q_s16(&diff[0], vreinterpretq_s16_u16(v_diff_lo));
55       vst1q_s16(&diff[8], vreinterpretq_s16_u16(v_diff_hi));
56       diff += diff_stride;
57       pred += pred_stride;
58       src  += src_stride;
59     }
60   } else if (cols > 4) {
61     for (r = 0; r < rows; ++r) {
62       const uint8x8_t v_src = vld1_u8(&src[0]);
63       const uint8x8_t v_pred = vld1_u8(&pred[0]);
64       const uint16x8_t v_diff = vsubl_u8(v_src, v_pred);
65       vst1q_s16(&diff[0], vreinterpretq_s16_u16(v_diff));
66       diff += diff_stride;
67       pred += pred_stride;
68       src  += src_stride;
69     }
70   } else {
71     for (r = 0; r < rows; ++r) {
72       for (c = 0; c < cols; ++c)
73         diff[c] = src[c] - pred[c];
74 
75       diff += diff_stride;
76       pred += pred_stride;
77       src  += src_stride;
78     }
79   }
80 }
81