1 /* ----------------------------------------------------------------------
2 * Project: CMSIS DSP Library
3 * Title: arm_abs_q31.c
4 * Description: Q31 vector absolute value
5 *
6 * $Date: 23 April 2021
7 * $Revision: V1.9.0
8 *
9 * Target Processor: Cortex-M and Cortex-A cores
10 * -------------------------------------------------------------------- */
11 /*
12 * Copyright (C) 2010-2021 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 "dsp/basic_math_functions.h"
30
31 /**
32 @ingroup groupMath
33 */
34
35 /**
36 @addtogroup BasicAbs
37 @{
38 */
39
40 /**
41 @brief Q31 vector absolute value.
42 @param[in] pSrc points to the input vector
43 @param[out] pDst points to the output vector
44 @param[in] blockSize number of samples in each vector
45 @return none
46
47 @par Scaling and Overflow Behavior
48 The function uses saturating arithmetic.
49 The Q31 value -1 (0x80000000) will be saturated to the maximum allowable positive value 0x7FFFFFFF.
50 */
51
52 #if defined(ARM_MATH_MVEI) && !defined(ARM_MATH_AUTOVECTORIZE)
53
54 #include "arm_helium_utils.h"
55
arm_abs_q31(const q31_t * pSrc,q31_t * pDst,uint32_t blockSize)56 void arm_abs_q31(
57 const q31_t * pSrc,
58 q31_t * pDst,
59 uint32_t blockSize)
60 {
61 uint32_t blkCnt; /* Loop counters */
62 q31x4_t vecSrc;
63
64 /* Compute 4 outputs at a time */
65 blkCnt = blockSize >> 2;
66
67 while (blkCnt > 0U)
68 {
69 /*
70 * C = |A|
71 * Calculate absolute and then store the results in the destination buffer.
72 */
73 vecSrc = vld1q(pSrc);
74 vst1q(pDst, vqabsq(vecSrc));
75 /*
76 * Decrement the blockSize loop counter
77 */
78 blkCnt--;
79 /*
80 * Advance vector source and destination pointers
81 */
82 pSrc += 4;
83 pDst += 4;
84 }
85 /*
86 * Tail
87 */
88 blkCnt = blockSize & 3;
89
90 if (blkCnt > 0U)
91 {
92 mve_pred16_t p0 = vctp32q(blkCnt);
93 vecSrc = vld1q(pSrc);
94 vstrwq_p(pDst, vqabsq(vecSrc), p0);
95 }
96 }
97
98 #else
arm_abs_q31(const q31_t * pSrc,q31_t * pDst,uint32_t blockSize)99 void arm_abs_q31(
100 const q31_t * pSrc,
101 q31_t * pDst,
102 uint32_t blockSize)
103 {
104 uint32_t blkCnt; /* Loop counter */
105 q31_t in; /* Temporary variable */
106
107 #if defined(ARM_MATH_NEON)
108 int32x4_t vec1;
109 int32x4_t res;
110
111 /* Compute 4 outputs at a time */
112 blkCnt = blockSize >> 2U;
113
114 while (blkCnt > 0U)
115 {
116 /* C = |A| */
117 /* Calculate absolute and then store the results in the destination buffer. */
118
119 vec1 = vld1q_s32(pSrc);
120 res = vqabsq_s32(vec1);
121 vst1q_s32(pDst, res);
122
123 /* Increment pointers */
124 pSrc += 4;
125 pDst += 4;
126
127 /* Decrement the blockSize loop counter */
128 blkCnt--;
129 }
130
131 /* Tail */
132 blkCnt = blockSize & 0x3;
133
134 #else
135 #if defined (ARM_MATH_LOOPUNROLL)
136
137 /* Loop unrolling: Compute 4 outputs at a time */
138 blkCnt = blockSize >> 2U;
139
140 while (blkCnt > 0U)
141 {
142 /* C = |A| */
143
144 /* Calculate absolute of input (if -1 then saturated to 0x7fffffff) and store result in destination buffer. */
145 in = *pSrc++;
146 #if defined (ARM_MATH_DSP)
147 *pDst++ = (in > 0) ? in : (q31_t)__QSUB(0, in);
148 #else
149 *pDst++ = (in > 0) ? in : ((in == INT32_MIN) ? INT32_MAX : -in);
150 #endif
151
152 in = *pSrc++;
153 #if defined (ARM_MATH_DSP)
154 *pDst++ = (in > 0) ? in : (q31_t)__QSUB(0, in);
155 #else
156 *pDst++ = (in > 0) ? in : ((in == INT32_MIN) ? INT32_MAX : -in);
157 #endif
158
159 in = *pSrc++;
160 #if defined (ARM_MATH_DSP)
161 *pDst++ = (in > 0) ? in : (q31_t)__QSUB(0, in);
162 #else
163 *pDst++ = (in > 0) ? in : ((in == INT32_MIN) ? INT32_MAX : -in);
164 #endif
165
166 in = *pSrc++;
167 #if defined (ARM_MATH_DSP)
168 *pDst++ = (in > 0) ? in : (q31_t)__QSUB(0, in);
169 #else
170 *pDst++ = (in > 0) ? in : ((in == INT32_MIN) ? INT32_MAX : -in);
171 #endif
172
173 /* Decrement loop counter */
174 blkCnt--;
175 }
176
177 /* Loop unrolling: Compute remaining outputs */
178 blkCnt = blockSize % 0x4U;
179
180 #else
181
182 /* Initialize blkCnt with number of samples */
183 blkCnt = blockSize;
184
185 #endif /* #if defined (ARM_MATH_LOOPUNROLL) */
186 #endif /* #if defined (ARM_MATH_NEON) */
187
188 while (blkCnt > 0U)
189 {
190 /* C = |A| */
191
192 /* Calculate absolute of input (if -1 then saturated to 0x7fffffff) and store result in destination buffer. */
193 in = *pSrc++;
194 #if defined (ARM_MATH_DSP)
195 *pDst++ = (in > 0) ? in : (q31_t)__QSUB(0, in);
196 #else
197 *pDst++ = (in > 0) ? in : ((in == INT32_MIN) ? INT32_MAX : -in);
198 #endif
199
200 /* Decrement loop counter */
201 blkCnt--;
202 }
203
204 }
205 #endif /* #if defined (ARM_MATH_MVEI) */
206 /**
207 @} end of BasicAbs group
208 */
209