blob: 9aff1802c621530ec39afd2e42d21862986bcbb2 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
|
/* ----------------------------------------------------------------------
* Project: CMSIS DSP Library
* Title: arm_abs_q15.c
* Description: Q15 vector absolute value
*
* $Date: 18. March 2019
* $Revision: V1.6.0
*
* Target Processor: Cortex-M cores
* -------------------------------------------------------------------- */
/*
* Copyright (C) 2010-2019 ARM Limited or its affiliates. All rights reserved.
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the License); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an AS IS BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "arm_math.h"
/**
@ingroup groupMath
*/
/**
@addtogroup BasicAbs
@{
*/
/**
@brief Q15 vector absolute value.
@param[in] pSrc points to the input vector
@param[out] pDst points to the output vector
@param[in] blockSize number of samples in each vector
@return none
@par Scaling and Overflow Behavior
The function uses saturating arithmetic.
The Q15 value -1 (0x8000) will be saturated to the maximum allowable positive value 0x7FFF.
*/
void arm_abs_q15(
const q15_t * pSrc,
q15_t * pDst,
uint32_t blockSize)
{
uint32_t blkCnt; /* Loop counter */
q15_t in; /* Temporary input variable */
#if defined (ARM_MATH_LOOPUNROLL)
/* Loop unrolling: Compute 4 outputs at a time */
blkCnt = blockSize >> 2U;
while (blkCnt > 0U)
{
/* C = |A| */
/* Calculate absolute of input (if -1 then saturated to 0x7fff) and store result in destination buffer. */
in = *pSrc++;
#if defined (ARM_MATH_DSP)
*pDst++ = (in > 0) ? in : (q15_t)__QSUB16(0, in);
#else
*pDst++ = (in > 0) ? in : ((in == (q15_t) 0x8000) ? 0x7fff : -in);
#endif
in = *pSrc++;
#if defined (ARM_MATH_DSP)
*pDst++ = (in > 0) ? in : (q15_t)__QSUB16(0, in);
#else
*pDst++ = (in > 0) ? in : ((in == (q15_t) 0x8000) ? 0x7fff : -in);
#endif
in = *pSrc++;
#if defined (ARM_MATH_DSP)
*pDst++ = (in > 0) ? in : (q15_t)__QSUB16(0, in);
#else
*pDst++ = (in > 0) ? in : ((in == (q15_t) 0x8000) ? 0x7fff : -in);
#endif
in = *pSrc++;
#if defined (ARM_MATH_DSP)
*pDst++ = (in > 0) ? in : (q15_t)__QSUB16(0, in);
#else
*pDst++ = (in > 0) ? in : ((in == (q15_t) 0x8000) ? 0x7fff : -in);
#endif
/* Decrement loop counter */
blkCnt--;
}
/* Loop unrolling: Compute remaining outputs */
blkCnt = blockSize % 0x4U;
#else
/* Initialize blkCnt with number of samples */
blkCnt = blockSize;
#endif /* #if defined (ARM_MATH_LOOPUNROLL) */
while (blkCnt > 0U)
{
/* C = |A| */
/* Calculate absolute of input (if -1 then saturated to 0x7fff) and store result in destination buffer. */
in = *pSrc++;
#if defined (ARM_MATH_DSP)
*pDst++ = (in > 0) ? in : (q15_t)__QSUB16(0, in);
#else
*pDst++ = (in > 0) ? in : ((in == (q15_t) 0x8000) ? 0x7fff : -in);
#endif
/* Decrement loop counter */
blkCnt--;
}
}
/**
@} end of BasicAbs group
*/
|
