1 // Tencent is pleased to support the open source community by making ncnn available.
2 //
3 // Copyright (C) 2017 THL A29 Limited, a Tencent company. All rights reserved.
4 //
5 // Licensed under the BSD 3-Clause License (the "License"); you may not use this file except
6 // in compliance with the License. You may obtain a copy of the License at
7 //
8 // https://opensource.org/licenses/BSD-3-Clause
9 //
10 // Unless required by applicable law or agreed to in writing, software distributed
11 // under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
12 // CONDITIONS OF ANY KIND, either express or implied. See the License for the
13 // specific language governing permissions and limitations under the License.
14 
15 #include "lrn_arm.h"
16 
17 #include <math.h>
18 
19 #if __ARM_NEON
20 #include "neon_mathfun.h"
21 
22 #include <arm_neon.h>
23 #endif // __ARM_NEON
24 
25 namespace ncnn {
26 
forward_inplace(Mat & bottom_top_blob,const Option & opt) const27 int LRN_arm::forward_inplace(Mat& bottom_top_blob, const Option& opt) const
28 {
29     int w = bottom_top_blob.w;
30     int h = bottom_top_blob.h;
31     int channels = bottom_top_blob.c;
32     size_t elemsize = bottom_top_blob.elemsize;
33     int size = w * h;
34 
35     // squared values with local_size padding
36     Mat square_blob;
37     square_blob.create(w, h, channels, elemsize, opt.workspace_allocator);
38     if (square_blob.empty())
39         return -100;
40 
41     #pragma omp parallel for num_threads(opt.num_threads)
42     for (int q = 0; q < channels; q++)
43     {
44         const float* ptr = bottom_top_blob.channel(q);
45         float* outptr = square_blob.channel(q);
46 
47 #if __ARM_NEON
48         int nn = size >> 2;
49         int remain = size - (nn << 2);
50 #else
51         int remain = size;
52 #endif // __ARM_NEON
53 
54 #if __ARM_NEON
55         for (; nn > 0; nn--)
56         {
57             float32x4_t _p = vld1q_f32(ptr);
58             float32x4_t _outp = vmulq_f32(_p, _p);
59             vst1q_f32(outptr, _outp);
60 
61             ptr += 4;
62             outptr += 4;
63         }
64 #endif // __ARM_NEON
65         for (; remain > 0; remain--)
66         {
67             *outptr = *ptr * *ptr;
68 
69             ptr++;
70             outptr++;
71         }
72     }
73 
74     if (region_type == NormRegion_ACROSS_CHANNELS)
75     {
76         Mat square_sum;
77         square_sum.create(w, h, channels, elemsize, opt.workspace_allocator);
78         if (square_sum.empty())
79             return -100;
80         square_sum.fill(0.f);
81 
82         const float alpha_div_size = alpha / local_size;
83 
84         #pragma omp parallel for num_threads(opt.num_threads)
85         for (int q = 0; q < channels; q++)
86         {
87             // square sum
88             for (int p = q - local_size / 2; p <= q + local_size / 2; p++)
89             {
90                 if (p < 0 || p >= channels)
91                     continue;
92 
93                 const float* sptr = square_blob.channel(p);
94                 float* ssptr = square_sum.channel(q);
95 
96 #if __ARM_NEON
97                 int nn = size >> 2;
98                 int remain = size - (nn << 2);
99 #else
100                 int remain = size;
101 #endif // __ARM_NEON
102 
103 #if __ARM_NEON
104                 for (; nn > 0; nn--)
105                 {
106                     float32x4_t _sp = vld1q_f32(sptr);
107                     float32x4_t _ssp = vld1q_f32(ssptr);
108                     _ssp = vaddq_f32(_ssp, _sp);
109                     vst1q_f32(ssptr, _ssp);
110 
111                     sptr += 4;
112                     ssptr += 4;
113                 }
114 #endif // __ARM_NEON
115                 for (; remain > 0; remain--)
116                 {
117                     *ssptr += *sptr;
118                     sptr++;
119                     ssptr++;
120                 }
121             }
122 
123             float* ptr = bottom_top_blob.channel(q);
124             float* ssptr = square_sum.channel(q);
125 
126 #if __ARM_NEON
127             int nn = size >> 2;
128             int remain = size - (nn << 2);
129 #else
130             int remain = size;
131 #endif // __ARM_NEON
132 
133 #if __ARM_NEON
134             float32x4_t _bias = vdupq_n_f32(bias);
135             float32x4_t _ads = vdupq_n_f32(alpha_div_size);
136             float32x4_t _mb = vdupq_n_f32(-beta);
137             for (; nn > 0; nn--)
138             {
139                 float32x4_t _p = vld1q_f32(ptr);
140                 float32x4_t _ssp = vld1q_f32(ssptr);
141                 _ssp = vmulq_f32(_ssp, _ads);
142                 _ssp = vaddq_f32(_ssp, _bias);
143                 _ssp = pow_ps(_ssp, _mb);
144                 _p = vmulq_f32(_p, _ssp);
145                 vst1q_f32(ptr, _p);
146 
147                 ssptr += 4;
148                 ptr += 4;
149             }
150 #endif // __ARM_NEON
151             for (; remain > 0; remain--)
152             {
153                 *ptr = *ptr * pow(bias + alpha_div_size * *ssptr, -beta);
154 
155                 ssptr++;
156                 ptr++;
157             }
158         }
159     }
160     else if (region_type == NormRegion_WITHIN_CHANNEL)
161     {
162         int outw = w;
163         int outh = h;
164 
165         Mat square_blob_bordered = square_blob;
166         int pad = local_size / 2;
167         if (pad > 0)
168         {
169             Option opt_b = opt;
170             opt_b.blob_allocator = opt.workspace_allocator;
171             copy_make_border(square_blob, square_blob_bordered, pad, local_size - pad - 1, pad, local_size - pad - 1, BORDER_CONSTANT, 0.f, opt_b);
172             if (square_blob_bordered.empty())
173                 return -100;
174 
175             w = square_blob_bordered.w;
176             h = square_blob_bordered.h;
177         }
178 
179         const int maxk = local_size * local_size;
180 
181         const float alpha_div_size = alpha / maxk;
182 
183         // norm window offsets
184         std::vector<int> _space_ofs(maxk);
185         int* space_ofs = &_space_ofs[0];
186         {
187             int p1 = 0;
188             int p2 = 0;
189             int gap = w - local_size;
190             for (int i = 0; i < local_size; i++)
191             {
192                 for (int j = 0; j < local_size; j++)
193                 {
194                     space_ofs[p1] = p2;
195                     p1++;
196                     p2++;
197                 }
198                 p2 += gap;
199             }
200         }
201 
202         #pragma omp parallel for num_threads(opt.num_threads)
203         for (int q = 0; q < channels; q++)
204         {
205             float* ptr = bottom_top_blob.channel(q);
206             const Mat m = square_blob_bordered.channel(q);
207 
208             for (int i = 0; i < outh; i++)
209             {
210                 for (int j = 0; j < outw; j++)
211                 {
212                     const float* sptr = m.row(i) + j;
213 
214                     float ss = 0.f;
215 
216                     for (int k = 0; k < maxk; k++)
217                     {
218                         float val = sptr[space_ofs[k]];
219                         ss += val;
220                     }
221 
222                     ptr[j] = ptr[j] * pow(bias + alpha_div_size * ss, -beta);
223                 }
224 
225                 ptr += outw;
226             }
227         }
228     }
229 
230     return 0;
231 }
232 
233 } // namespace ncnn
234