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27
28 #ifdef HAVE_CONFIG_H
29 #include "config.h"
30 #endif
31
32 /* Insertion sort (fast for already almost sorted arrays): */
33 /* Best case: O(n) for an already sorted array */
34 /* Worst case: O(n^2) for an inversely sorted array */
35 /* */
36 /* Shell short: https://en.wikipedia.org/wiki/Shell_sort */
37
38 #include "SigProc_FIX.h"
39
silk_insertion_sort_increasing(opus_int32 * a,opus_int * idx,const opus_int L,const opus_int K)40 void silk_insertion_sort_increasing(
41 opus_int32 *a, /* I/O Unsorted / Sorted vector */
42 opus_int *idx, /* O Index vector for the sorted elements */
43 const opus_int L, /* I Vector length */
44 const opus_int K /* I Number of correctly sorted positions */
45 )
46 {
47 opus_int32 value;
48 opus_int i, j;
49
50 /* Safety checks */
51 celt_assert( K > 0 );
52 celt_assert( L > 0 );
53 celt_assert( L >= K );
54
55 /* Write start indices in index vector */
56 for( i = 0; i < K; i++ ) {
57 idx[ i ] = i;
58 }
59
60 /* Sort vector elements by value, increasing order */
61 for( i = 1; i < K; i++ ) {
62 value = a[ i ];
63 for( j = i - 1; ( j >= 0 ) && ( value < a[ j ] ); j-- ) {
64 a[ j + 1 ] = a[ j ]; /* Shift value */
65 idx[ j + 1 ] = idx[ j ]; /* Shift index */
66 }
67 a[ j + 1 ] = value; /* Write value */
68 idx[ j + 1 ] = i; /* Write index */
69 }
70
71 /* If less than L values are asked for, check the remaining values, */
72 /* but only spend CPU to ensure that the K first values are correct */
73 for( i = K; i < L; i++ ) {
74 value = a[ i ];
75 if( value < a[ K - 1 ] ) {
76 for( j = K - 2; ( j >= 0 ) && ( value < a[ j ] ); j-- ) {
77 a[ j + 1 ] = a[ j ]; /* Shift value */
78 idx[ j + 1 ] = idx[ j ]; /* Shift index */
79 }
80 a[ j + 1 ] = value; /* Write value */
81 idx[ j + 1 ] = i; /* Write index */
82 }
83 }
84 }
85
86 #ifdef FIXED_POINT
87 /* This function is only used by the fixed-point build */
silk_insertion_sort_decreasing_int16(opus_int16 * a,opus_int * idx,const opus_int L,const opus_int K)88 void silk_insertion_sort_decreasing_int16(
89 opus_int16 *a, /* I/O Unsorted / Sorted vector */
90 opus_int *idx, /* O Index vector for the sorted elements */
91 const opus_int L, /* I Vector length */
92 const opus_int K /* I Number of correctly sorted positions */
93 )
94 {
95 opus_int i, j;
96 opus_int value;
97
98 /* Safety checks */
99 celt_assert( K > 0 );
100 celt_assert( L > 0 );
101 celt_assert( L >= K );
102
103 /* Write start indices in index vector */
104 for( i = 0; i < K; i++ ) {
105 idx[ i ] = i;
106 }
107
108 /* Sort vector elements by value, decreasing order */
109 for( i = 1; i < K; i++ ) {
110 value = a[ i ];
111 for( j = i - 1; ( j >= 0 ) && ( value > a[ j ] ); j-- ) {
112 a[ j + 1 ] = a[ j ]; /* Shift value */
113 idx[ j + 1 ] = idx[ j ]; /* Shift index */
114 }
115 a[ j + 1 ] = value; /* Write value */
116 idx[ j + 1 ] = i; /* Write index */
117 }
118
119 /* If less than L values are asked for, check the remaining values, */
120 /* but only spend CPU to ensure that the K first values are correct */
121 for( i = K; i < L; i++ ) {
122 value = a[ i ];
123 if( value > a[ K - 1 ] ) {
124 for( j = K - 2; ( j >= 0 ) && ( value > a[ j ] ); j-- ) {
125 a[ j + 1 ] = a[ j ]; /* Shift value */
126 idx[ j + 1 ] = idx[ j ]; /* Shift index */
127 }
128 a[ j + 1 ] = value; /* Write value */
129 idx[ j + 1 ] = i; /* Write index */
130 }
131 }
132 }
133 #endif
134
silk_insertion_sort_increasing_all_values_int16(opus_int16 * a,const opus_int L)135 void silk_insertion_sort_increasing_all_values_int16(
136 opus_int16 *a, /* I/O Unsorted / Sorted vector */
137 const opus_int L /* I Vector length */
138 )
139 {
140 opus_int value;
141 opus_int i, j;
142
143 /* Safety checks */
144 celt_assert( L > 0 );
145
146 /* Sort vector elements by value, increasing order */
147 for( i = 1; i < L; i++ ) {
148 value = a[ i ];
149 for( j = i - 1; ( j >= 0 ) && ( value < a[ j ] ); j-- ) {
150 a[ j + 1 ] = a[ j ]; /* Shift value */
151 }
152 a[ j + 1 ] = value; /* Write value */
153 }
154 }
155