Mercurial > pub > halpp

comparison f103c8/Drivers/CMSIS/DSP_Lib/Source/StatisticsFunctions/arm_power_q7.c @ 2:0c59e7a7782a

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Working on GPIO and RCC
author cin
date Mon, 16 Jan 2017 11:04:47 +0300
parents
children
comparison
equal deleted inserted replaced
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_power_q7.c
9 *
10 * Description: Sum of the squares of the elements of a Q7 vector.
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 groupStats
45 */
46
47 /**
48 * @addtogroup power
49 * @{
50 */
51
52 /**
53 * @brief Sum of the squares of the elements of a Q7 vector.
54 * @param[in] *pSrc points to the input vector
55 * @param[in] blockSize length of the input vector
56 * @param[out] *pResult sum of the squares value returned here
57 * @return none.
58 *
59 * @details
60 * <b>Scaling and Overflow Behavior:</b>
61 *
62 * \par
63 * The function is implemented using a 32-bit internal accumulator.
64 * The input is represented in 1.7 format.
65 * Intermediate multiplication yields a 2.14 format, and this
66 * result is added without saturation to an accumulator in 18.14 format.
67 * With 17 guard bits in the accumulator, there is no risk of overflow, and the
68 * full precision of the intermediate multiplication is preserved.
69 * Finally, the return result is in 18.14 format.
70 *
71 */
72
73 void arm_power_q7(
74 q7_t * pSrc,
75 uint32_t blockSize,
76 q31_t * pResult)
77 {
78 q31_t sum = 0; /* Temporary result storage */
79 q7_t in; /* Temporary variable to store input */
80 uint32_t blkCnt; /* loop counter */
81
82 #ifndef ARM_MATH_CM0_FAMILY
83
84 /* Run the below code for Cortex-M4 and Cortex-M3 */
85
86 q31_t input1; /* Temporary variable to store packed input */
87 q31_t in1, in2; /* Temporary variables to store input */
88
89 /*loop Unrolling */
90 blkCnt = blockSize >> 2u;
91
92 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
93 ** a second loop below computes the remaining 1 to 3 samples. */
94 while(blkCnt > 0u)
95 {
96 /* Reading two inputs of pSrc vector and packing */
97 input1 = *__SIMD32(pSrc)++;
98
99 in1 = __SXTB16(__ROR(input1, 8));
100 in2 = __SXTB16(input1);
101
102 /* C = A[0] * A[0] + A[1] * A[1] + A[2] * A[2] + ... + A[blockSize-1] * A[blockSize-1] */
103 /* calculate power and accumulate to accumulator */
104 sum = __SMLAD(in1, in1, sum);
105 sum = __SMLAD(in2, in2, sum);
106
107 /* Decrement the loop counter */
108 blkCnt--;
109 }
110
111 /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
112 ** No loop unrolling is used. */
113 blkCnt = blockSize % 0x4u;
114
115 #else
116
117 /* Run the below code for Cortex-M0 */
118
119 /* Loop over blockSize number of values */
120 blkCnt = blockSize;
121
122 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
123
124 while(blkCnt > 0u)
125 {
126 /* C = A[0] * A[0] + A[1] * A[1] + A[2] * A[2] + ... + A[blockSize-1] * A[blockSize-1] */
127 /* Compute Power and then store the result in a temporary variable, sum. */
128 in = *pSrc++;
129 sum += ((q15_t) in * in);
130
131 /* Decrement the loop counter */
132 blkCnt--;
133 }
134
135 /* Store the result in 18.14 format */
136 *pResult = sum;
137 }
138
139 /**
140 * @} end of power group
141 */