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_nn_activations_q7.c
22 * Description: Q7 neural network activation function using direct table look-up
23 *
24 * $Date: 09. October 2020
25 * $Revision: V.1.0.1
26 *
27 * Target Processor: Cortex-M cores
28 *
29 * -------------------------------------------------------------------- */
30
31 #include "arm_nn_tables.h"
32 #include "arm_nnfunctions.h"
33
34 /**
35 * @ingroup groupNN
36 */
37
38 /**
39 * @addtogroup Acti
40 * @{
41 */
42
43 /**
44 * @brief Q7 neural network activation function using direct table look-up
45 * @param[in,out] data pointer to input
46 * @param[in] size number of elements
47 * @param[in] int_width bit-width of the integer part, assume to be smaller than 3
48 * @param[in] type type of activation functions
49 *
50 * @details
51 *
52 * This is the direct table look-up approach.
53 *
54 * Assume here the integer part of the fixed-point is <= 3.
55 * More than 3 just not making much sense, makes no difference with
56 * saturation followed by any of these activation functions.
57 */
58
arm_nn_activations_direct_q7(q7_t * data,uint16_t size,uint16_t int_width,arm_nn_activation_type type)59 void arm_nn_activations_direct_q7(q7_t *data, uint16_t size, uint16_t int_width, arm_nn_activation_type type)
60 {
61 uint16_t i = size;
62 q7_t *pIn = data;
63 q7_t *pOut = data;
64 q7_t in;
65 q7_t out;
66 uint16_t shift_size = 3 - int_width;
67 const q7_t *lookup_table;
68 switch (type)
69 {
70 case ARM_SIGMOID:
71 lookup_table = sigmoidTable_q7;
72 break;
73 case ARM_TANH:
74 default:
75 lookup_table = tanhTable_q7;
76 break;
77 }
78 while (i)
79 {
80 in = *pIn++;
81 out = lookup_table[(uint8_t)(in >> shift_size)];
82 *pOut++ = out;
83 i--;
84 }
85 }
86
87 /**
88 * @} end of Acti group
89 */
90
