source: S-port/trunk/Drivers/CMSIS/DSP/Source/BasicMathFunctions/arm_offset_f32.c

Last change on this file was 1, checked in by AlexLir, 3 years ago
File size: 3.9 KB
Line 
1/* ----------------------------------------------------------------------
2 * Project: CMSIS DSP Library
3 * Title: arm_offset_f32.c
4 * Description: Floating-point vector offset
5 *
6 * $Date: 27. January 2017
7 * $Revision: V.1.5.1
8 *
9 * Target Processor: Cortex-M cores
10 * -------------------------------------------------------------------- */
11/*
12 * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
13 *
14 * SPDX-License-Identifier: Apache-2.0
15 *
16 * Licensed under the Apache License, Version 2.0 (the License); you may
17 * not use this file except in compliance with the License.
18 * You may obtain a copy of the License at
19 *
20 * www.apache.org/licenses/LICENSE-2.0
21 *
22 * Unless required by applicable law or agreed to in writing, software
23 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
24 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
25 * See the License for the specific language governing permissions and
26 * limitations under the License.
27 */
28
29#include "arm_math.h"
30
31/**
32 * @ingroup groupMath
33 */
34
35/**
36 * @defgroup offset Vector Offset
37 *
38 * Adds a constant offset to each element of a vector.
39 *
40 * <pre>
41 * pDst[n] = pSrc[n] + offset, 0 <= n < blockSize.
42 * </pre>
43 *
44 * The functions support in-place computation allowing the source and
45 * destination pointers to reference the same memory buffer.
46 * There are separate functions for floating-point, Q7, Q15, and Q31 data types.
47 */
48
49/**
50 * @addtogroup offset
51 * @{
52 */
53
54/**
55 * @brief Adds a constant offset to a floating-point vector.
56 * @param[in] *pSrc points to the input vector
57 * @param[in] offset is the offset to be added
58 * @param[out] *pDst points to the output vector
59 * @param[in] blockSize number of samples in the vector
60 * @return none.
61 */
62
63
64void arm_offset_f32(
65 float32_t * pSrc,
66 float32_t offset,
67 float32_t * pDst,
68 uint32_t blockSize)
69{
70 uint32_t blkCnt; /* loop counter */
71
72#if defined (ARM_MATH_DSP)
73
74/* Run the below code for Cortex-M4 and Cortex-M3 */
75 float32_t in1, in2, in3, in4;
76
77 /*loop Unrolling */
78 blkCnt = blockSize >> 2U;
79
80 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
81 ** a second loop below computes the remaining 1 to 3 samples. */
82 while (blkCnt > 0U)
83 {
84 /* C = A + offset */
85 /* Add offset and then store the results in the destination buffer. */
86 /* read samples from source */
87 in1 = *pSrc;
88 in2 = *(pSrc + 1);
89
90 /* add offset to input */
91 in1 = in1 + offset;
92
93 /* read samples from source */
94 in3 = *(pSrc + 2);
95
96 /* add offset to input */
97 in2 = in2 + offset;
98
99 /* read samples from source */
100 in4 = *(pSrc + 3);
101
102 /* add offset to input */
103 in3 = in3 + offset;
104
105 /* store result to destination */
106 *pDst = in1;
107
108 /* add offset to input */
109 in4 = in4 + offset;
110
111 /* store result to destination */
112 *(pDst + 1) = in2;
113
114 /* store result to destination */
115 *(pDst + 2) = in3;
116
117 /* store result to destination */
118 *(pDst + 3) = in4;
119
120 /* update pointers to process next samples */
121 pSrc += 4U;
122 pDst += 4U;
123
124 /* Decrement the loop counter */
125 blkCnt--;
126 }
127
128 /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
129 ** No loop unrolling is used. */
130 blkCnt = blockSize % 0x4U;
131
132#else
133
134 /* Run the below code for Cortex-M0 */
135
136 /* Initialize blkCnt with number of samples */
137 blkCnt = blockSize;
138
139#endif /* #if defined (ARM_MATH_DSP) */
140
141 while (blkCnt > 0U)
142 {
143 /* C = A + offset */
144 /* Add offset and then store the result in the destination buffer. */
145 *pDst++ = (*pSrc++) + offset;
146
147 /* Decrement the loop counter */
148 blkCnt--;
149 }
150}
151
152/**
153 * @} end of offset group
154 */
Note: See TracBrowser for help on using the repository browser.