media/libopus/silk/sort.c

Thu, 22 Jan 2015 13:21:57 +0100

author
Michael Schloh von Bennewitz <michael@schloh.com>
date
Thu, 22 Jan 2015 13:21:57 +0100
branch
TOR_BUG_9701
changeset 15
b8a032363ba2
permissions
-rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

     1 /***********************************************************************
     2 Copyright (c) 2006-2011, Skype Limited. All rights reserved.
     3 Redistribution and use in source and binary forms, with or without
     4 modification, are permitted provided that the following conditions
     5 are met:
     6 - Redistributions of source code must retain the above copyright notice,
     7 this list of conditions and the following disclaimer.
     8 - Redistributions in binary form must reproduce the above copyright
     9 notice, this list of conditions and the following disclaimer in the
    10 documentation and/or other materials provided with the distribution.
    11 - Neither the name of Internet Society, IETF or IETF Trust, nor the
    12 names of specific contributors, may be used to endorse or promote
    13 products derived from this software without specific prior written
    14 permission.
    15 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
    16 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    17 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    18 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
    19 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
    20 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
    21 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
    22 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
    23 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
    24 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    25 POSSIBILITY OF SUCH DAMAGE.
    26 ***********************************************************************/
    28 #ifdef HAVE_CONFIG_H
    29 #include "config.h"
    30 #endif
    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:    http://en.wikipedia.org/wiki/Shell_sort   */
    38 #include "SigProc_FIX.h"
    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;
    50     /* Safety checks */
    51     silk_assert( K >  0 );
    52     silk_assert( L >  0 );
    53     silk_assert( L >= K );
    55     /* Write start indices in index vector */
    56     for( i = 0; i < K; i++ ) {
    57         idx[ i ] = i;
    58     }
    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     }
    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 }
    86 #ifdef FIXED_POINT
    87 /* This function is only used by the fixed-point build */
    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;
    98     /* Safety checks */
    99     silk_assert( K >  0 );
   100     silk_assert( L >  0 );
   101     silk_assert( L >= K );
   103     /* Write start indices in index vector */
   104     for( i = 0; i < K; i++ ) {
   105         idx[ i ] = i;
   106     }
   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     }
   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
   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;
   143     /* Safety checks */
   144     silk_assert( L >  0 );
   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 }

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