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comparison f103c8/Drivers/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_negate_q15.c @ 2:0c59e7a7782a

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Working on GPIO and RCC
author cin
date Mon, 16 Jan 2017 11:04:47 +0300
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1:a0b14b11ad9f 2:0c59e7a7782a
1 /* ----------------------------------------------------------------------
2 * Copyright (C) 2010-2014 ARM Limited. All rights reserved.
3 *
4 * $Date: 19. March 2015
5 * $Revision: V.1.4.5
6 *
7 * Project: CMSIS DSP Library
8 * Title: arm_negate_q15.c
9 *
10 * Description: Negates Q15 vectors.
11 *
12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
16 * are met:
17 * - Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 * - Redistributions in binary form must reproduce the above copyright
20 * notice, this list of conditions and the following disclaimer in
21 * the documentation and/or other materials provided with the
22 * distribution.
23 * - Neither the name of ARM LIMITED nor the names of its contributors
24 * may be used to endorse or promote products derived from this
25 * software without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
30 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
31 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
32 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
33 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
34 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
35 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
37 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
38 * POSSIBILITY OF SUCH DAMAGE.
39 * -------------------------------------------------------------------- */
40 #include "arm_math.h"
41
42 /**
43 * @ingroup groupMath
44 */
45
46 /**
47 * @addtogroup negate
48 * @{
49 */
50
51 /**
52 * @brief Negates the elements of a Q15 vector.
53 * @param[in] *pSrc points to the input vector
54 * @param[out] *pDst points to the output vector
55 * @param[in] blockSize number of samples in the vector
56 * @return none.
57 *
58 * \par Conditions for optimum performance
59 * Input and output buffers should be aligned by 32-bit
60 *
61 *
62 * <b>Scaling and Overflow Behavior:</b>
63 * \par
64 * The function uses saturating arithmetic.
65 * The Q15 value -1 (0x8000) will be saturated to the maximum allowable positive value 0x7FFF.
66 */
67
68 void arm_negate_q15(
69 q15_t * pSrc,
70 q15_t * pDst,
71 uint32_t blockSize)
72 {
73 uint32_t blkCnt; /* loop counter */
74 q15_t in;
75
76 #ifndef ARM_MATH_CM0_FAMILY
77
78 /* Run the below code for Cortex-M4 and Cortex-M3 */
79
80 q31_t in1, in2; /* Temporary variables */
81
82
83 /*loop Unrolling */
84 blkCnt = blockSize >> 2u;
85
86 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
87 ** a second loop below computes the remaining 1 to 3 samples. */
88 while(blkCnt > 0u)
89 {
90 /* C = -A */
91 /* Read two inputs at a time */
92 in1 = _SIMD32_OFFSET(pSrc);
93 in2 = _SIMD32_OFFSET(pSrc + 2);
94
95 /* negate two samples at a time */
96 in1 = __QSUB16(0, in1);
97
98 /* negate two samples at a time */
99 in2 = __QSUB16(0, in2);
100
101 /* store the result to destination 2 samples at a time */
102 _SIMD32_OFFSET(pDst) = in1;
103 /* store the result to destination 2 samples at a time */
104 _SIMD32_OFFSET(pDst + 2) = in2;
105
106
107 /* update pointers to process next samples */
108 pSrc += 4u;
109 pDst += 4u;
110
111 /* Decrement the loop counter */
112 blkCnt--;
113 }
114
115 /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
116 ** No loop unrolling is used. */
117 blkCnt = blockSize % 0x4u;
118
119 #else
120
121 /* Run the below code for Cortex-M0 */
122
123 /* Initialize blkCnt with number of samples */
124 blkCnt = blockSize;
125
126 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
127
128 while(blkCnt > 0u)
129 {
130 /* C = -A */
131 /* Negate and then store the result in the destination buffer. */
132 in = *pSrc++;
133 *pDst++ = (in == (q15_t) 0x8000) ? 0x7fff : -in;
134
135 /* Decrement the loop counter */
136 blkCnt--;
137 }
138 }
139
140 /**
141 * @} end of negate group
142 */