1 /* ----------------------------------------------------------------------
2 * Project: CMSIS DSP Library
3 * Title: arm_offset_q7.c
4 * Description: Q7 vector offset
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 BasicOffset
37 @{
38 */
39
40 /**
41 @brief Adds a constant offset to a Q7 vector.
42 @param[in] pSrc points to the input vector
43 @param[in] offset is the offset to be added
44 @param[out] pDst points to the output vector
45 @param[in] blockSize number of samples in each vector
46 @return none
47
48 @par Scaling and Overflow Behavior
49 The function uses saturating arithmetic.
50 Results outside of the allowable Q7 range [0x80 0x7F] are saturated.
51 */
52 #if defined(ARM_MATH_MVEI) && !defined(ARM_MATH_AUTOVECTORIZE)
53
54 #include "arm_helium_utils.h"
55
arm_offset_q7(const q7_t * pSrc,q7_t offset,q7_t * pDst,uint32_t blockSize)56 void arm_offset_q7(
57 const q7_t * pSrc,
58 q7_t offset,
59 q7_t * pDst,
60 uint32_t blockSize)
61 {
62 uint32_t blkCnt; /* loop counters */
63 q7x16_t vecSrc;
64
65 /* Compute 16 outputs at a time */
66 blkCnt = blockSize >> 4;
67 while (blkCnt > 0U)
68 {
69 /*
70 * C = A + offset
71 * Add offset and then store the result in the destination buffer.
72 */
73 vecSrc = vld1q(pSrc);
74 vst1q(pDst, vqaddq(vecSrc, offset));
75 /*
76 * Decrement the blockSize loop counter
77 */
78 blkCnt--;
79 /*
80 * advance vector source and destination pointers
81 */
82 pSrc += 16;
83 pDst += 16;
84 }
85 /*
86 * tail
87 */
88 blkCnt = blockSize & 0xF;
89 if (blkCnt > 0U)
90 {
91 mve_pred16_t p0 = vctp8q(blkCnt);
92 vecSrc = vld1q(pSrc);
93 vstrbq_p(pDst, vqaddq(vecSrc, offset), p0);
94 }
95 }
96
97 #else
arm_offset_q7(const q7_t * pSrc,q7_t offset,q7_t * pDst,uint32_t blockSize)98 void arm_offset_q7(
99 const q7_t * pSrc,
100 q7_t offset,
101 q7_t * pDst,
102 uint32_t blockSize)
103 {
104 uint32_t blkCnt; /* Loop counter */
105
106 #if defined (ARM_MATH_LOOPUNROLL)
107
108 #if defined (ARM_MATH_DSP)
109 q31_t offset_packed; /* Offset packed to 32 bit */
110
111 /* Offset is packed to 32 bit in order to use SIMD32 for addition */
112 offset_packed = __PACKq7(offset, offset, offset, offset);
113 #endif
114
115 /* Loop unrolling: Compute 4 outputs at a time */
116 blkCnt = blockSize >> 2U;
117
118 while (blkCnt > 0U)
119 {
120 /* C = A + offset */
121
122 #if defined (ARM_MATH_DSP)
123 /* Add offset and store result in destination buffer (4 samples at a time). */
124 write_q7x4_ia (&pDst, __QADD8(read_q7x4_ia ((q7_t **) &pSrc), offset_packed));
125 #else
126 *pDst++ = (q7_t) __SSAT((q15_t) *pSrc++ + offset, 8);
127 *pDst++ = (q7_t) __SSAT((q15_t) *pSrc++ + offset, 8);
128 *pDst++ = (q7_t) __SSAT((q15_t) *pSrc++ + offset, 8);
129 *pDst++ = (q7_t) __SSAT((q15_t) *pSrc++ + offset, 8);
130 #endif
131
132 /* Decrement loop counter */
133 blkCnt--;
134 }
135
136 /* Loop unrolling: Compute remaining outputs */
137 blkCnt = blockSize % 0x4U;
138
139 #else
140
141 /* Initialize blkCnt with number of samples */
142 blkCnt = blockSize;
143
144 #endif /* #if defined (ARM_MATH_LOOPUNROLL) */
145
146 while (blkCnt > 0U)
147 {
148 /* C = A + offset */
149
150 /* Add offset and store result in destination buffer. */
151 *pDst++ = (q7_t) __SSAT((q15_t) *pSrc++ + offset, 8);
152
153 /* Decrement loop counter */
154 blkCnt--;
155 }
156
157 }
158 #endif /* defined(ARM_MATH_MVEI) */
159
160 /**
161 @} end of BasicOffset group
162 */
163