1 /* ----------------------------------------------------------------------
2 * Project: CMSIS DSP Library
3 * Title: arm_abs_q7.c
4 * Description: Q7 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 Q7 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 Conditions for optimum performance
48 Input and output buffers should be aligned by 32-bit
49 @par Scaling and Overflow Behavior
50 The function uses saturating arithmetic.
51 The Q7 value -1 (0x80) will be saturated to the maximum allowable positive value 0x7F.
52 */
53
54 #if defined(ARM_MATH_MVEI) && !defined(ARM_MATH_AUTOVECTORIZE)
55
56 #include "arm_helium_utils.h"
57
arm_abs_q7(const q7_t * pSrc,q7_t * pDst,uint32_t blockSize)58 void arm_abs_q7(
59 const q7_t * pSrc,
60 q7_t * pDst,
61 uint32_t blockSize)
62 {
63 uint32_t blkCnt; /* loop counters */
64 q7x16_t vecSrc;
65
66 /* Compute 16 outputs at a time */
67 blkCnt = blockSize >> 4;
68 while (blkCnt > 0U)
69 {
70 /*
71 * C = |A|
72 * Calculate absolute and then store the results in the destination buffer.
73 */
74 vecSrc = vld1q(pSrc);
75 vst1q(pDst, vqabsq(vecSrc));
76 /*
77 * Decrement the blockSize loop counter
78 */
79 blkCnt--;
80 /*
81 * advance vector source and destination pointers
82 */
83 pSrc += 16;
84 pDst += 16;
85 }
86 /*
87 * tail
88 */
89 blkCnt = blockSize & 0xF;
90 if (blkCnt > 0U)
91 {
92 mve_pred16_t p0 = vctp8q(blkCnt);
93 vecSrc = vld1q(pSrc);
94 vstrbq_p(pDst, vqabsq(vecSrc), p0);
95 }
96 }
97
98 #else
arm_abs_q7(const q7_t * pSrc,q7_t * pDst,uint32_t blockSize)99 void arm_abs_q7(
100 const q7_t * pSrc,
101 q7_t * pDst,
102 uint32_t blockSize)
103 {
104 uint32_t blkCnt; /* Loop counter */
105 q7_t in; /* Temporary input variable */
106
107 #if defined (ARM_MATH_LOOPUNROLL)
108
109 /* Loop unrolling: Compute 4 outputs at a time */
110 blkCnt = blockSize >> 2U;
111
112 while (blkCnt > 0U)
113 {
114 /* C = |A| */
115
116 /* Calculate absolute of input (if -1 then saturated to 0x7f) and store result in destination buffer. */
117 in = *pSrc++;
118 #if defined (ARM_MATH_DSP)
119 *pDst++ = (in > 0) ? in : (q7_t)__QSUB8(0, in);
120 #else
121 *pDst++ = (in > 0) ? in : ((in == (q7_t) 0x80) ? (q7_t) 0x7f : -in);
122 #endif
123
124 in = *pSrc++;
125 #if defined (ARM_MATH_DSP)
126 *pDst++ = (in > 0) ? in : (q7_t)__QSUB8(0, in);
127 #else
128 *pDst++ = (in > 0) ? in : ((in == (q7_t) 0x80) ? (q7_t) 0x7f : -in);
129 #endif
130
131 in = *pSrc++;
132 #if defined (ARM_MATH_DSP)
133 *pDst++ = (in > 0) ? in : (q7_t)__QSUB8(0, in);
134 #else
135 *pDst++ = (in > 0) ? in : ((in == (q7_t) 0x80) ? (q7_t) 0x7f : -in);
136 #endif
137
138 in = *pSrc++;
139 #if defined (ARM_MATH_DSP)
140 *pDst++ = (in > 0) ? in : (q7_t)__QSUB8(0, in);
141 #else
142 *pDst++ = (in > 0) ? in : ((in == (q7_t) 0x80) ? (q7_t) 0x7f : -in);
143 #endif
144
145 /* Decrement loop counter */
146 blkCnt--;
147 }
148
149 /* Loop unrolling: Compute remaining outputs */
150 blkCnt = blockSize % 0x4U;
151
152 #else
153
154 /* Initialize blkCnt with number of samples */
155 blkCnt = blockSize;
156
157 #endif /* #if defined (ARM_MATH_LOOPUNROLL) */
158
159 while (blkCnt > 0U)
160 {
161 /* C = |A| */
162
163 /* Calculate absolute of input (if -1 then saturated to 0x7f) and store result in destination buffer. */
164 in = *pSrc++;
165 #if defined (ARM_MATH_DSP)
166 *pDst++ = (in > 0) ? in : (q7_t) __QSUB8(0, in);
167 #else
168 *pDst++ = (in > 0) ? in : ((in == (q7_t) 0x80) ? (q7_t) 0x7f : -in);
169 #endif
170
171 /* Decrement loop counter */
172 blkCnt--;
173 }
174
175 }
176 #endif /* defined(ARM_MATH_MVEI) */
177
178 /**
179 @} end of BasicAbs group
180 */
181
