1 /* ----------------------------------------------------------------------
2 * Project: CMSIS DSP Library
3 * Title: arm_mult_q31.c
4 * Description: Q31 vector multiplication
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 BasicMult
37 @{
38 */
39
40 /**
41 @brief Q31 vector multiplication.
42 @param[in] pSrcA points to the first input vector.
43 @param[in] pSrcB points to the second input vector.
44 @param[out] pDst points to the output vector.
45 @param[in] blockSize number of samples in each vector.
46
47 @par Scaling and Overflow Behavior
48 The function uses saturating arithmetic.
49 Results outside of the allowable Q31 range[0x80000000 0x7FFFFFFF] are saturated.
50 */
51 #if defined(ARM_MATH_MVEI) && !defined(ARM_MATH_AUTOVECTORIZE)
52
53 #include "arm_helium_utils.h"
54
arm_mult_q31(const q31_t * pSrcA,const q31_t * pSrcB,q31_t * pDst,uint32_t blockSize)55 void arm_mult_q31(
56 const q31_t * pSrcA,
57 const q31_t * pSrcB,
58 q31_t * pDst,
59 uint32_t blockSize)
60 {
61 uint32_t blkCnt; /* loop counters */
62 q31x4_t vecA, vecB;
63
64 /* Compute 4 outputs at a time */
65 blkCnt = blockSize >> 2;
66 while (blkCnt > 0U)
67 {
68 /*
69 * C = A * B
70 * Multiply the inputs and then store the results in the destination buffer.
71 */
72 vecA = vld1q(pSrcA);
73 vecB = vld1q(pSrcB);
74 vst1q(pDst, vqdmulhq(vecA, vecB));
75 /*
76 * Decrement the blockSize loop counter
77 */
78 blkCnt--;
79 /*
80 * advance vector source and destination pointers
81 */
82 pSrcA += 4;
83 pSrcB += 4;
84 pDst += 4;
85 }
86 /*
87 * tail
88 */
89 blkCnt = blockSize & 3;
90 if (blkCnt > 0U)
91 {
92 mve_pred16_t p0 = vctp32q(blkCnt);
93 vecA = vld1q(pSrcA);
94 vecB = vld1q(pSrcB);
95 vstrwq_p(pDst, vqdmulhq(vecA, vecB), p0);
96 }
97 }
98
99 #else
arm_mult_q31(const q31_t * pSrcA,const q31_t * pSrcB,q31_t * pDst,uint32_t blockSize)100 void arm_mult_q31(
101 const q31_t * pSrcA,
102 const q31_t * pSrcB,
103 q31_t * pDst,
104 uint32_t blockSize)
105 {
106 uint32_t blkCnt; /* Loop counter */
107 q31_t out; /* Temporary output variable */
108
109 #if defined (ARM_MATH_LOOPUNROLL)
110
111 /* Loop unrolling: Compute 4 outputs at a time */
112 blkCnt = blockSize >> 2U;
113
114 while (blkCnt > 0U)
115 {
116 /* C = A * B */
117
118 /* Multiply inputs and store result in destination buffer. */
119 out = ((q63_t) *pSrcA++ * *pSrcB++) >> 32;
120 out = __SSAT(out, 31);
121 *pDst++ = out << 1U;
122
123 out = ((q63_t) *pSrcA++ * *pSrcB++) >> 32;
124 out = __SSAT(out, 31);
125 *pDst++ = out << 1U;
126
127 out = ((q63_t) *pSrcA++ * *pSrcB++) >> 32;
128 out = __SSAT(out, 31);
129 *pDst++ = out << 1U;
130
131 out = ((q63_t) *pSrcA++ * *pSrcB++) >> 32;
132 out = __SSAT(out, 31);
133 *pDst++ = out << 1U;
134
135 /* Decrement loop counter */
136 blkCnt--;
137 }
138
139 /* Loop unrolling: Compute remaining outputs */
140 blkCnt = blockSize % 0x4U;
141
142 #else
143
144 /* Initialize blkCnt with number of samples */
145 blkCnt = blockSize;
146
147 #endif /* #if defined (ARM_MATH_LOOPUNROLL) */
148
149 while (blkCnt > 0U)
150 {
151 /* C = A * B */
152
153 /* Multiply inputs and store result in destination buffer. */
154 out = ((q63_t) *pSrcA++ * *pSrcB++) >> 32;
155 out = __SSAT(out, 31);
156 *pDst++ = out << 1U;
157
158 /* Decrement loop counter */
159 blkCnt--;
160 }
161
162 }
163 #endif /* defined(ARM_MATH_MVEI) */
164
165 /**
166 @} end of BasicMult group
167 */
168
