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1 /* ----------------------------------------------------------------------
2  * Project:      CMSIS DSP Library
3  * Title:        arm_q15_to_q31.c
4  * Description:  Converts the elements of the Q15 vector to Q31 vector
5  *
6  * $Date:        18. March 2019
7  * $Revision:    V1.6.0
8  *
9  * Target Processor: Cortex-M cores
10  * -------------------------------------------------------------------- */
11 /*
12  * Copyright (C) 2010-2019 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 "arm_math.h"
30 
31 /**
32   @ingroup groupSupport
33  */
34 
35 /**
36   @addtogroup q15_to_x
37   @{
38  */
39 
40 /**
41   @brief         Converts the elements of the Q15 vector to Q31 vector.
42   @param[in]     pSrc       points to the Q15 input vector
43   @param[out]    pDst       points to the Q31 output vector
44   @param[in]     blockSize  number of samples in each vector
45   @return        none
46 
47   @par           Details
48                    The equation used for the conversion process is:
49   <pre>
50       pDst[n] = (q31_t) pSrc[n] << 16;   0 <= n < blockSize.
51   </pre>
52  */
53 #if defined(ARM_MATH_MVEI)
arm_q15_to_q31(const q15_t * pSrc,q31_t * pDst,uint32_t blockSize)54 void arm_q15_to_q31(
55   const q15_t * pSrc,
56         q31_t * pDst,
57         uint32_t blockSize)
58 {
59 
60   uint32_t blkCnt;
61 
62   q31x4_t         vecDst;
63 
64   blkCnt = blockSize>> 2;
65   while (blkCnt > 0U)
66   {
67 
68         /* C = (q31_t)A << 16 */
69         /* convert from q15 to q31 and then store the results in the destination buffer */
70         /* load q15 + 32-bit widening */
71         vecDst = vldrhq_s32((q15_t const *) pSrc);
72         vecDst = vshlq_n(vecDst, 16);
73         vstrwq_s32(pDst, vecDst);
74 
75         /*
76          * Decrement the blockSize loop counter
77          * Advance vector source and destination pointers
78          */
79         pDst += 4;
80         pSrc += 4;
81         blkCnt --;
82     }
83 
84   blkCnt = blockSize & 3;
85   while (blkCnt > 0U)
86   {
87     /* C = (q31_t) A << 16 */
88 
89     /* Convert from q15 to q31 and store result in destination buffer */
90     *pDst++ = (q31_t) *pSrc++ << 16;
91 
92     /* Decrement loop counter */
93     blkCnt--;
94   }
95 }
96 #else
arm_q15_to_q31(const q15_t * pSrc,q31_t * pDst,uint32_t blockSize)97 void arm_q15_to_q31(
98   const q15_t * pSrc,
99         q31_t * pDst,
100         uint32_t blockSize)
101 {
102         uint32_t blkCnt;                               /* Loop counter */
103   const q15_t *pIn = pSrc;                             /* Source pointer */
104 
105 #if defined (ARM_MATH_LOOPUNROLL)
106         q31_t in1, in2;
107         q31_t out1, out2, out3, out4;
108 #endif
109 
110 #if defined (ARM_MATH_LOOPUNROLL)
111 
112   /* Loop unrolling: Compute 4 outputs at a time */
113   blkCnt = blockSize >> 2U;
114 
115   while (blkCnt > 0U)
116   {
117     /* C = (q31_t)A << 16 */
118 
119     /* Convert from q15 to q31 and store result in destination buffer */
120     in1 = read_q15x2_ia ((q15_t **) &pIn);
121     in2 = read_q15x2_ia ((q15_t **) &pIn);
122 
123 #ifndef ARM_MATH_BIG_ENDIAN
124 
125     /* extract lower 16 bits to 32 bit result */
126     out1 = in1 << 16U;
127     /* extract upper 16 bits to 32 bit result */
128     out2 = in1 & 0xFFFF0000;
129     /* extract lower 16 bits to 32 bit result */
130     out3 = in2 << 16U;
131     /* extract upper 16 bits to 32 bit result */
132     out4 = in2 & 0xFFFF0000;
133 
134 #else
135 
136     /* extract upper 16 bits to 32 bit result */
137     out1 = in1 & 0xFFFF0000;
138     /* extract lower 16 bits to 32 bit result */
139     out2 = in1 << 16U;
140     /* extract upper 16 bits to 32 bit result */
141     out3 = in2 & 0xFFFF0000;
142     /* extract lower 16 bits to 32 bit result */
143     out4 = in2 << 16U;
144 
145 #endif /* #ifndef ARM_MATH_BIG_ENDIAN */
146 
147     *pDst++ = out1;
148     *pDst++ = out2;
149     *pDst++ = out3;
150     *pDst++ = out4;
151 
152     /* Decrement loop counter */
153     blkCnt--;
154   }
155 
156   /* Loop unrolling: Compute remaining outputs */
157   blkCnt = blockSize % 0x4U;
158 
159 #else
160 
161   /* Initialize blkCnt with number of samples */
162   blkCnt = blockSize;
163 
164 #endif /* #if defined (ARM_MATH_LOOPUNROLL) */
165 
166   while (blkCnt > 0U)
167   {
168     /* C = (q31_t) A << 16 */
169 
170     /* Convert from q15 to q31 and store result in destination buffer */
171     *pDst++ = (q31_t) *pIn++ << 16;
172 
173     /* Decrement loop counter */
174     blkCnt--;
175   }
176 
177 }
178 #endif /* defined(ARM_MATH_MVEI) */
179 
180 /**
181   @} end of q15_to_x group
182  */
183