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Moved radixsort out of bgfx.

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bkaradzic
2012-06-19 20:49:12 -07:00
parent 2e8941e515
commit 61d110306a
1 changed files with 111 additions and 0 deletions
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include/bx/radixsort.h Normal file
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/*
* Copyright 2010-2011 Branimir Karadzic. All rights reserved.
* License: http://www.opensource.org/licenses/BSD-2-Clause
*/
#ifndef __BX_RADIXSORT_H__
#define __BX_RADIXSORT_H__
#include "bx.h"
namespace bx
{
#define BX_RADIXSORT_BITS 11
#define BX_RADIXSORT_HISTOGRAM_SIZE (1<<BX_RADIXSORT_BITS)
#define BX_RADIXSORT_BIT_MASK (BX_RADIXSORT_HISTOGRAM_SIZE-1)
template <typename Ty>
void radixSort32(uint32_t* _keys, uint32_t* _tempKeys, Ty* _values, Ty* _tempValues, uint32_t _size)
{
uint16_t histogram[BX_RADIXSORT_HISTOGRAM_SIZE];
uint16_t shift = 0;
for (uint32_t pass = 0; pass < 3; ++pass)
{
memset(histogram, 0, sizeof(uint16_t)*BX_RADIXSORT_HISTOGRAM_SIZE);
for (uint32_t ii = 0; ii < _size; ++ii)
{
uint32_t key = _keys[ii];
uint16_t index = (key>>shift)&BX_RADIXSORT_BIT_MASK;
++histogram[index];
}
uint16_t offset = 0;
for (uint32_t ii = 0; ii < BX_RADIXSORT_HISTOGRAM_SIZE; ++ii)
{
uint16_t count = histogram[ii];
histogram[ii] = offset;
offset += count;
}
for (uint32_t ii = 0; ii < _size; ++ii)
{
uint32_t key = _keys[ii];
uint16_t index = (key>>shift)&BX_RADIXSORT_BIT_MASK;
uint16_t dest = histogram[index]++;
_tempKeys[dest] = key;
_tempValues[dest] = _values[ii];
}
uint32_t* swapKeys = _tempKeys;
_tempKeys = _keys;
_keys = swapKeys;
Ty* swapValues = _tempValues;
_tempValues = _values;
_values = swapValues;
shift += BX_RADIXSORT_BITS;
}
}
template <typename Ty>
void radixSort64(uint64_t* _keys, uint64_t* _tempKeys, Ty* _values, Ty* _tempValues, uint32_t _size)
{
uint16_t histogram[BX_RADIXSORT_HISTOGRAM_SIZE];
uint16_t shift = 0;
for (uint32_t pass = 0; pass < 6; ++pass)
{
memset(histogram, 0, sizeof(uint16_t)*BX_RADIXSORT_HISTOGRAM_SIZE);
for (uint32_t ii = 0; ii < _size; ++ii)
{
uint64_t key = _keys[ii];
uint16_t index = (key>>shift)&BX_RADIXSORT_BIT_MASK;
++histogram[index];
}
uint16_t offset = 0;
for (uint32_t ii = 0; ii < BX_RADIXSORT_HISTOGRAM_SIZE; ++ii)
{
uint16_t count = histogram[ii];
histogram[ii] = offset;
offset += count;
}
for (uint32_t ii = 0; ii < _size; ++ii)
{
uint64_t key = _keys[ii];
uint16_t index = (key>>shift)&BX_RADIXSORT_BIT_MASK;
uint16_t dest = histogram[index]++;
_tempKeys[dest] = key;
_tempValues[dest] = _values[ii];
}
uint64_t* swapKeys = _tempKeys;
_tempKeys = _keys;
_keys = swapKeys;
Ty* swapValues = _tempValues;
_tempValues = _values;
_values = swapValues;
shift += BX_RADIXSORT_BITS;
}
}
#undef BX_RADIXSORT_BITS
#undef BX_RADIXSORT_HISTOGRAM_SIZE
#undef BX_RADIXSORT_BIT_MASK
} // namespace bx
#endif // __BX_RADIXSORT_H__