1 /*
2 * Copyright (C) 2010-2020 Arm Limited or its affiliates. All rights reserved.
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 *
6 * Licensed under the Apache License, Version 2.0 (the License); you may
7 * not use this file except in compliance with the License.
8 * You may obtain a copy of the License at
9 *
10 * www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
14 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18
19 /* ----------------------------------------------------------------------
20 * Project: CMSIS NN Library
21 * Title: arm_relu_q7.c
22 * Description: Q7 version of ReLU
23 *
24 * $Date: 09. October 2020
25 * $Revision: V.1.0.3
26 *
27 * Target Processor: Cortex-M cores
28 *
29 * -------------------------------------------------------------------- */
30
31 #include "arm_nnfunctions.h"
32 #include "arm_nnsupportfunctions.h"
33
34 /**
35 * @ingroup groupNN
36 */
37
38 /**
39 * @addtogroup Acti
40 * @{
41 */
42
43 /**
44 * @brief Q7 RELU function
45 * @param[in,out] data pointer to input
46 * @param[in] size number of elements
47 *
48 * @details
49 *
50 * Optimized relu with QSUB instructions.
51 *
52 */
53
arm_relu_q7(q7_t * data,uint16_t size)54 void arm_relu_q7(q7_t *data, uint16_t size)
55 {
56
57 #if defined(ARM_MATH_DSP)
58 /* Run the following code for M cores with DSP extension */
59
60 uint16_t i = size >> 2;
61 q7_t *input = data;
62 q7_t *output = data;
63 q31_t in;
64 q31_t buf;
65 q31_t mask;
66
67 while (i)
68 {
69 in = read_q7x4_ia(&input);
70
71 /* extract the first bit */
72 buf = (int32_t)__ROR((uint32_t)in & 0x80808080, 7);
73
74 /* if MSB=1, mask will be 0xFF, 0x0 otherwise */
75 mask = __QSUB8(0x00000000, buf);
76
77 write_q7x4_ia(&output, in & (~mask));
78
79 i--;
80 }
81
82 i = size & 0x3;
83 while (i)
84 {
85 if (*input < 0)
86 {
87 *input = 0;
88 }
89 input++;
90 i--;
91 }
92
93 #else
94 /* Run the following code as reference implementation for cores without DSP extension */
95
96 uint16_t i;
97
98 for (i = 0; i < size; i++)
99 {
100 if (data[i] < 0)
101 data[i] = 0;
102 }
103
104 #endif
105 }
106
107 /**
108 * @} end of Acti group
109 */
110
