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comparison f103c8/Drivers/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_abs_q7.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_abs_q7.c
9 *
10 * Description: Q7 vector absolute value.
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
41 #include "arm_math.h"
42
43 /**
44 * @ingroup groupMath
45 */
46
47 /**
48 * @addtogroup BasicAbs
49 * @{
50 */
51
52 /**
53 * @brief Q7 vector absolute value.
54 * @param[in] *pSrc points to the input buffer
55 * @param[out] *pDst points to the output buffer
56 * @param[in] blockSize number of samples in each vector
57 * @return none.
58 *
59 * \par Conditions for optimum performance
60 * Input and output buffers should be aligned by 32-bit
61 *
62 *
63 * <b>Scaling and Overflow Behavior:</b>
64 * \par
65 * The function uses saturating arithmetic.
66 * The Q7 value -1 (0x80) will be saturated to the maximum allowable positive value 0x7F.
67 */
68
69 void arm_abs_q7(
70 q7_t * pSrc,
71 q7_t * pDst,
72 uint32_t blockSize)
73 {
74 uint32_t blkCnt; /* loop counter */
75 q7_t in; /* Input value1 */
76
77 #ifndef ARM_MATH_CM0_FAMILY
78
79 /* Run the below code for Cortex-M4 and Cortex-M3 */
80 q31_t in1, in2, in3, in4; /* temporary input variables */
81 q31_t out1, out2, out3, out4; /* temporary output variables */
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 inputs */
92 in1 = (q31_t) * pSrc;
93 in2 = (q31_t) * (pSrc + 1);
94 in3 = (q31_t) * (pSrc + 2);
95
96 /* find absolute value */
97 out1 = (in1 > 0) ? in1 : (q31_t)__QSUB8(0, in1);
98
99 /* read input */
100 in4 = (q31_t) * (pSrc + 3);
101
102 /* find absolute value */
103 out2 = (in2 > 0) ? in2 : (q31_t)__QSUB8(0, in2);
104
105 /* store result to destination */
106 *pDst = (q7_t) out1;
107
108 /* find absolute value */
109 out3 = (in3 > 0) ? in3 : (q31_t)__QSUB8(0, in3);
110
111 /* find absolute value */
112 out4 = (in4 > 0) ? in4 : (q31_t)__QSUB8(0, in4);
113
114 /* store result to destination */
115 *(pDst + 1) = (q7_t) out2;
116
117 /* store result to destination */
118 *(pDst + 2) = (q7_t) out3;
119
120 /* store result to destination */
121 *(pDst + 3) = (q7_t) out4;
122
123 /* update pointers to process next samples */
124 pSrc += 4u;
125 pDst += 4u;
126
127 /* Decrement the loop counter */
128 blkCnt--;
129 }
130
131 /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
132 ** No loop unrolling is used. */
133 blkCnt = blockSize % 0x4u;
134 #else
135
136 /* Run the below code for Cortex-M0 */
137 blkCnt = blockSize;
138
139 #endif /* #define ARM_MATH_CM0_FAMILY */
140
141 while(blkCnt > 0u)
142 {
143 /* C = |A| */
144 /* Read the input */
145 in = *pSrc++;
146
147 /* Store the Absolute result in the destination buffer */
148 *pDst++ = (in > 0) ? in : ((in == (q7_t) 0x80) ? 0x7f : -in);
149
150 /* Decrement the loop counter */
151 blkCnt--;
152 }
153 }
154
155 /**
156 * @} end of BasicAbs group
157 */