/usr/include/flann/util/cuda/heap.h is in libflann-dev 1.8.4-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 | #ifndef FLANN_UTIL_CUDA_HEAP_H
#define FLANN_UTIL_CUDA_HEAP_H
/*
Copyright (c) 2011, Andreas Mützel <andreas.muetzel@gmx.net>
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
* Neither the name of the <organization> nor the
names of its contributors may be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY Andreas Mützel <andreas.muetzel@gmx.net> ''AS IS'' AND ANY
EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL Andreas Mützel <andreas.muetzel@gmx.net> BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
namespace flann
{
namespace cuda
{
template <class T>
__device__ __host__ void swap( T& x, T& y )
{
T t=x;
x=y;
y=t;
}
namespace heap
{
//! moves an element down the heap until all children are smaller than the elemnent
//! if c is a less-than comparator, it do this until all children are larger
template <class GreaterThan, class RandomAccessIterator>
__host__ __device__ void
sift_down( RandomAccessIterator array, size_t begin, size_t length, GreaterThan c = GreaterThan() )
{
while( 2*begin+1 < length ) {
size_t left = 2*begin+1;
size_t right = 2*begin+2;
size_t largest=begin;
if((left < length)&& c(array[left], array[largest]) ) largest=left;
if((right < length)&& c(array[right], array[largest]) ) largest=right;
if( largest != begin ) {
cuda::swap( array[begin], array[largest] );
begin=largest;
}
else return;
}
}
//! creates a max-heap in the array beginning at begin of length "length"
//! if c is a less-than comparator, it will create a min-heap
template <class GreaterThan, class RandomAccessIterator>
__host__ __device__ void
make_heap( RandomAccessIterator begin, size_t length, GreaterThan c = GreaterThan() )
{
int i=length/2-1;
while( i>=0 ) {
sift_down( begin, i, length, c );
i--;
}
}
//! verifies if the array is a max-heap
//! if c is a less-than comparator, it will verify if it is a min-heap
template <class GreaterThan, class RandomAccessIterator>
__host__ __device__ bool
is_heap( RandomAccessIterator begin, size_t length, GreaterThan c = GreaterThan() )
{
for( unsigned i=0; i<length; i++ ) {
if((2*i+1 < length)&& c(begin[2*i+1],begin[i]) ) return false;
if((2*i+2 < length)&& c(begin[2*i+2],begin[i]) ) return false;
}
return true;
}
//! moves an element down the heap until all children are smaller than the elemnent
//! if c is a less-than comparator, it do this until all children are larger
template <class GreaterThan, class RandomAccessIterator, class RandomAccessIterator2>
__host__ __device__ void
sift_down( RandomAccessIterator key, RandomAccessIterator2 value, size_t begin, size_t length, GreaterThan c = GreaterThan() )
{
while( 2*begin+1 < length ) {
size_t left = 2*begin+1;
size_t right = 2*begin+2;
size_t largest=begin;
if((left < length)&& c(key[left], key[largest]) ) largest=left;
if((right < length)&& c(key[right], key[largest]) ) largest=right;
if( largest != begin ) {
cuda::swap( key[begin], key[largest] );
cuda::swap( value[begin], value[largest] );
begin=largest;
}
else return;
}
}
//! creates a max-heap in the array beginning at begin of length "length"
//! if c is a less-than comparator, it will create a min-heap
template <class GreaterThan, class RandomAccessIterator, class RandomAccessIterator2>
__host__ __device__ void
make_heap( RandomAccessIterator key, RandomAccessIterator2 value, size_t length, GreaterThan c = GreaterThan() )
{
int i=length/2-1;
while( i>=0 ) {
sift_down( key, value, i, length, c );
i--;
}
}
}
}
}
#endif
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