gim_radixsort.h

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#ifndef GIM_RADIXSORT_H_INCLUDED
#define GIM_RADIXSORT_H_INCLUDED

/*
-----------------------------------------------------------------------------
This source file is part of GIMPACT Library.

For the latest info, see http://gimpact.sourceforge.net/

Copyright (c) 2006 Francisco Leon Najera. C.C. 80087371.
email: projectileman@yahoo.com

 This library is free software; you can redistribute it and/or
 modify it under the terms of EITHER:
   (1) The GNU Lesser General Public License as published by the Free
       Software Foundation; either version 2.1 of the License, or (at
       your option) any later version. The text of the GNU Lesser
       General Public License is included with this library in the
       file GIMPACT-LICENSE-LGPL.TXT.
   (2) The BSD-style license that is included with this library in
       the file GIMPACT-LICENSE-BSD.TXT.
   (3) The zlib/libpng license that is included with this library in
       the file GIMPACT-LICENSE-ZLIB.TXT.

 This library is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the files
 GIMPACT-LICENSE-LGPL.TXT, GIMPACT-LICENSE-ZLIB.TXT and GIMPACT-LICENSE-BSD.TXT for more details.

-----------------------------------------------------------------------------
*/

#include "gim_memory.h"

class less_comparator
{
        public:

        template<class T,class Z>
        inline int operator() ( const T& a, const Z& b )
        {
                return ( a<b?-1:(a>b?1:0));
        }
};

class integer_comparator
{
        public:

        template<class T>
        inline int operator() ( const T& a, const T& b )
        {
                return (int)(a-b);
        }
};

class uint_key_func
{
public:
        template<class T>
        inline GUINT operator()( const T& a)
        {
                return (GUINT)a;
        }
};


class copy_elements_func
{
public:
        template<class T>
        inline void operator()(T& a,T& b)
        {
                a = b;
        }
};

class memcopy_elements_func
{
public:
        template<class T>
        inline void operator()(T& a,T& b)
        {
                gim_simd_memcpy(&a,&b,sizeof(T));
        }
};


struct GIM_RSORT_TOKEN
{
    GUINT m_key;
    GUINT m_value;
    GIM_RSORT_TOKEN()
    {
    }
    GIM_RSORT_TOKEN(const GIM_RSORT_TOKEN& rtoken)
    {
        m_key = rtoken.m_key;
        m_value = rtoken.m_value;
    }

    inline bool operator <(const GIM_RSORT_TOKEN& other) const
        {
                return (m_key < other.m_key);
        }

        inline bool operator >(const GIM_RSORT_TOKEN& other) const
        {
                return (m_key > other.m_key);
        }
};

class GIM_RSORT_TOKEN_COMPARATOR
{
        public:

        inline int operator()( const GIM_RSORT_TOKEN& a, const GIM_RSORT_TOKEN& b )
        {
                return (int)((a.m_key) - (b.m_key));
        }
};



#define kHist 2048
// ---- utils for accessing 11-bit quantities
#define D11_0(x)        (x & 0x7FF)
#define D11_1(x)        (x >> 11 & 0x7FF)
#define D11_2(x)        (x >> 22 )



inline void gim_radix_sort_rtokens(
                                GIM_RSORT_TOKEN * array,
                                GIM_RSORT_TOKEN * sorted, GUINT element_count)
{
        GUINT i;
        GUINT b0[kHist * 3];
        GUINT *b1 = b0 + kHist;
        GUINT *b2 = b1 + kHist;
        for (i = 0; i < kHist * 3; ++i)
        {
                b0[i] = 0;
        }
        GUINT fi;
        GUINT pos;
        for (i = 0; i < element_count; ++i)
        {
            fi = array[i].m_key;
                b0[D11_0(fi)] ++;
                b1[D11_1(fi)] ++;
                b2[D11_2(fi)] ++;
        }
        {
                GUINT sum0 = 0, sum1 = 0, sum2 = 0;
                GUINT tsum;
                for (i = 0; i < kHist; ++i)
                {
                        tsum = b0[i] + sum0;
                        b0[i] = sum0 - 1;
                        sum0 = tsum;
                        tsum = b1[i] + sum1;
                        b1[i] = sum1 - 1;
                        sum1 = tsum;
                        tsum = b2[i] + sum2;
                        b2[i] = sum2 - 1;
                        sum2 = tsum;
                }
        }
        for (i = 0; i < element_count; ++i)
        {
        fi = array[i].m_key;
                pos = D11_0(fi);
                pos = ++b0[pos];
                sorted[pos].m_key = array[i].m_key;
                sorted[pos].m_value = array[i].m_value;
        }
        for (i = 0; i < element_count; ++i)
        {
        fi = sorted[i].m_key;
                pos = D11_1(fi);
                pos = ++b1[pos];
                array[pos].m_key = sorted[i].m_key;
                array[pos].m_value = sorted[i].m_value;
        }
        for (i = 0; i < element_count; ++i)
        {
        fi = array[i].m_key;
                pos = D11_2(fi);
                pos = ++b2[pos];
                sorted[pos].m_key = array[i].m_key;
                sorted[pos].m_value = array[i].m_value;
        }
}





template<typename T, class GETKEY_CLASS>
void gim_radix_sort_array_tokens(
                        T* array ,
                        GIM_RSORT_TOKEN * sorted_tokens,
                        GUINT element_count,GETKEY_CLASS uintkey_macro)
{
        GIM_RSORT_TOKEN * _unsorted = (GIM_RSORT_TOKEN *) gim_alloc(sizeof(GIM_RSORT_TOKEN)*element_count);
    for (GUINT _i=0;_i<element_count;++_i)
    {
        _unsorted[_i].m_key = uintkey_macro(array[_i]);
        _unsorted[_i].m_value = _i;
    }
    gim_radix_sort_rtokens(_unsorted,sorted_tokens,element_count);
    gim_free(_unsorted);
    gim_free(_unsorted);
}


template<typename T, class GETKEY_CLASS, class COPY_CLASS>
void gim_radix_sort(
        T * array, GUINT element_count,
        GETKEY_CLASS get_uintkey_macro, COPY_CLASS copy_elements_macro)
{
        GIM_RSORT_TOKEN * _sorted = (GIM_RSORT_TOKEN  *) gim_alloc(sizeof(GIM_RSORT_TOKEN)*element_count);
    gim_radix_sort_array_tokens(array,_sorted,element_count,get_uintkey_macro);
    T * _original_array = (T *) gim_alloc(sizeof(T)*element_count);
    gim_simd_memcpy(_original_array,array,sizeof(T)*element_count);
    for (GUINT _i=0;_i<element_count;++_i)
    {
        copy_elements_macro(array[_i],_original_array[_sorted[_i].m_value]);
    }
    gim_free(_original_array);
    gim_free(_sorted);
}


template<class T, typename KEYCLASS, typename COMP_CLASS>
bool  gim_binary_search_ex(
                const T* _array, GUINT _start_i,
                GUINT _end_i,GUINT & _result_index,
                const KEYCLASS & _search_key,
                COMP_CLASS _comp_macro)
{
        GUINT _k;
        int _comp_result;
        GUINT _i = _start_i;
        GUINT _j = _end_i+1;
        while (_i < _j)
        {
                _k = (_j+_i-1)/2;
                _comp_result = _comp_macro(_array[_k], _search_key);
                if (_comp_result == 0)
                {
                        _result_index = _k;
                        return true;
                }
                else if (_comp_result < 0)
                {
                        _i = _k+1;
                }
                else
                {
                        _j = _k;
                }
        }
        _result_index = _i;
        return false;
}




template<class T>
bool gim_binary_search(
        const T*_array,GUINT _start_i,
        GUINT _end_i,const T & _search_key,
        GUINT & _result_index)
{
        GUINT _i = _start_i;
        GUINT _j = _end_i+1;
        GUINT _k;
        while(_i < _j)
        {
                _k = (_j+_i-1)/2;
                if(_array[_k]==_search_key)
                {
                        _result_index = _k;
                        return true;
                }
                else if (_array[_k]<_search_key)
                {
                        _i = _k+1;
                }
                else
                {
                        _j = _k;
                }
        }
        _result_index = _i;
        return false;
}



template <typename T, typename COMP_CLASS>
void gim_down_heap(T *pArr, GUINT k, GUINT n,COMP_CLASS CompareFunc)
{
        /*  PRE: a[k+1..N] is a heap */
        /* POST:  a[k..N]  is a heap */

        T temp = pArr[k - 1];
        /* k has child(s) */
        while (k <= n/2)
        {
                int child = 2*k;

                if ((child < (int)n) && CompareFunc(pArr[child - 1] , pArr[child])<0)
                {
                        child++;
                }
                /* pick larger child */
                if (CompareFunc(temp , pArr[child - 1])<0)
                {
                        /* move child up */
                        pArr[k - 1] = pArr[child - 1];
                        k = child;
                }
                else
                {
                        break;
                }
        }
        pArr[k - 1] = temp;
} /*downHeap*/


template <typename T, typename COMP_CLASS>
void gim_heap_sort(T *pArr, GUINT element_count, COMP_CLASS CompareFunc)
{
        /* sort a[0..N-1],  N.B. 0 to N-1 */
        GUINT k;
        GUINT n = element_count;
        for (k = n/2; k > 0; k--)
        {
                gim_down_heap(pArr, k, n, CompareFunc);
        }

        /* a[1..N] is now a heap */
        while ( n>=2 )
        {
                gim_swap_elements(pArr,0,n-1); /* largest of a[0..n-1] */
                --n;
                /* restore a[1..i-1] heap */
                gim_down_heap(pArr, 1, n, CompareFunc);
        }
}




#endif // GIM_RADIXSORT_H_INCLUDED