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comparison f103c8/Drivers/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_scale_f32.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_scale_f32.c
9 *
10 * Description: Multiplies a floating-point vector by a scalar.
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 * @defgroup scale Vector Scale
49 *
50 * Multiply a vector by a scalar value. For floating-point data, the algorithm used is:
51 *
52 * <pre>
53 * pDst[n] = pSrc[n] * scale, 0 <= n < blockSize.
54 * </pre>
55 *
56 * In the fixed-point Q7, Q15, and Q31 functions, <code>scale</code> is represented by
57 * a fractional multiplication <code>scaleFract</code> and an arithmetic shift <code>shift</code>.
58 * The shift allows the gain of the scaling operation to exceed 1.0.
59 * The algorithm used with fixed-point data is:
60 *
61 * <pre>
62 * pDst[n] = (pSrc[n] * scaleFract) << shift, 0 <= n < blockSize.
63 * </pre>
64 *
65 * The overall scale factor applied to the fixed-point data is
66 * <pre>
67 * scale = scaleFract * 2^shift.
68 * </pre>
69 *
70 * The functions support in-place computation allowing the source and destination
71 * pointers to reference the same memory buffer.
72 */
73
74 /**
75 * @addtogroup scale
76 * @{
77 */
78
79 /**
80 * @brief Multiplies a floating-point vector by a scalar.
81 * @param[in] *pSrc points to the input vector
82 * @param[in] scale scale factor to be applied
83 * @param[out] *pDst points to the output vector
84 * @param[in] blockSize number of samples in the vector
85 * @return none.
86 */
87
88
89 void arm_scale_f32(
90 float32_t * pSrc,
91 float32_t scale,
92 float32_t * pDst,
93 uint32_t blockSize)
94 {
95 uint32_t blkCnt; /* loop counter */
96 #ifndef ARM_MATH_CM0_FAMILY
97
98 /* Run the below code for Cortex-M4 and Cortex-M3 */
99 float32_t in1, in2, in3, in4; /* temporary variabels */
100
101 /*loop Unrolling */
102 blkCnt = blockSize >> 2u;
103
104 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
105 ** a second loop below computes the remaining 1 to 3 samples. */
106 while(blkCnt > 0u)
107 {
108 /* C = A * scale */
109 /* Scale the input and then store the results in the destination buffer. */
110 /* read input samples from source */
111 in1 = *pSrc;
112 in2 = *(pSrc + 1);
113
114 /* multiply with scaling factor */
115 in1 = in1 * scale;
116
117 /* read input sample from source */
118 in3 = *(pSrc + 2);
119
120 /* multiply with scaling factor */
121 in2 = in2 * scale;
122
123 /* read input sample from source */
124 in4 = *(pSrc + 3);
125
126 /* multiply with scaling factor */
127 in3 = in3 * scale;
128 in4 = in4 * scale;
129 /* store the result to destination */
130 *pDst = in1;
131 *(pDst + 1) = in2;
132 *(pDst + 2) = in3;
133 *(pDst + 3) = in4;
134
135 /* update pointers to process next samples */
136 pSrc += 4u;
137 pDst += 4u;
138
139 /* Decrement the loop counter */
140 blkCnt--;
141 }
142
143 /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
144 ** No loop unrolling is used. */
145 blkCnt = blockSize % 0x4u;
146
147 #else
148
149 /* Run the below code for Cortex-M0 */
150
151 /* Initialize blkCnt with number of samples */
152 blkCnt = blockSize;
153
154 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
155
156 while(blkCnt > 0u)
157 {
158 /* C = A * scale */
159 /* Scale the input and then store the result in the destination buffer. */
160 *pDst++ = (*pSrc++) * scale;
161
162 /* Decrement the loop counter */
163 blkCnt--;
164 }
165 }
166
167 /**
168 * @} end of scale group
169 */