1 /* ----------------------------------------------------------------------
2 * Project: CMSIS DSP Library
3 * Title: arm_selection_sort_f32.c
4 * Description: Floating point selection sort
5 *
6 * $Date: 23 April 2021
7 * $Revision: V1.9.0
8 *
9 * Target Processor: Cortex-M and Cortex-A cores
10 * -------------------------------------------------------------------- */
11 /*
12 * Copyright (C) 2010-2021 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_sorting.h"
30
31 /**
32 @ingroup groupSupport
33 */
34
35 /**
36 @addtogroup Sorting
37 @{
38 */
39
40 /**
41 * @private
42 * @param[in] S points to an instance of the sorting structure.
43 * @param[in] pSrc points to the block of input data.
44 * @param[out] pDst points to the block of output data
45 * @param[in] blockSize number of samples to process.
46 *
47 * @par Algorithm
48 * The Selection sort algorithm is a comparison algorithm that
49 * divides the input array into a sorted and an unsorted sublist
50 * (initially the sorted sublist is empty and the unsorted sublist
51 * is the input array), looks for the smallest (or biggest)
52 * element in the unsorted sublist, swapping it with the leftmost
53 * one, and moving the sublists boundary one element to the right.
54 *
55 * @par It's an in-place algorithm. In order to obtain an out-of-place
56 * function, a memcpy of the source vector is performed.
57 */
58
arm_selection_sort_f32(const arm_sort_instance_f32 * S,float32_t * pSrc,float32_t * pDst,uint32_t blockSize)59 void arm_selection_sort_f32(
60 const arm_sort_instance_f32 * S,
61 float32_t * pSrc,
62 float32_t * pDst,
63 uint32_t blockSize)
64 {
65 uint32_t i, j, k;
66 uint8_t dir = S->dir;
67 float32_t temp;
68
69 float32_t * pA;
70
71 if(pSrc != pDst) // out-of-place
72 {
73 memcpy(pDst, pSrc, blockSize*sizeof(float32_t) );
74 pA = pDst;
75 }
76 else
77 pA = pSrc;
78
79 /* Move the boundary one element to the right */
80 for (i=0; i<blockSize-1; i++)
81 {
82 /* Initialize the minimum/maximum as the first element */
83 k = i;
84
85 /* Look in the unsorted list to find the minimum/maximum value */
86 for (j=i+1; j<blockSize; j++)
87 {
88 if (dir==(pA[j] < pA[k]) )
89 {
90 /* Update value */
91 k = j;
92 }
93 }
94
95 if (k != i)
96 {
97 /* Swap the minimum/maximum with the leftmost element */
98 temp=pA[i];
99 pA[i]=pA[k];
100 pA[k]=temp;
101 }
102 }
103 }
104
105 /**
106 @} end of Sorting group
107 */
108
