/opencl/oclfft

//
// File:       fft_kernelstring.cpp
//
// Version:    <1.0>
//
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////////////////////////////////////////////////////////////////////////////////////////////////////


#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <iostream>
#include <sstream>
#include <string.h>
#include <assert.h>
#include "fft_internal.h"
#include "clFFT.h"

using namespace std;

#define max(A,B) ((A) > (B) ? (A) : (B))
#define min(A,B) ((A) < (B) ? (A) : (B))

static string 
num2str(int num)
{
	char temp[200];
	sprintf(temp, "%d", num);
	return string(temp);
}

// For any n, this function decomposes n into factors for loacal memory tranpose 
// based fft. Factors (radices) are sorted such that the first one (radixArray[0])
// is the largest. This base radix determines the number of registers used by each
// work item and product of remaining radices determine the size of work group needed.
// To make things concrete with and example, suppose n = 1024. It is decomposed into
// 1024 = 16 x 16 x 4. Hence kernel uses float2 a[16], for local in-register fft and 
// needs 16 x 4 = 64 work items per work group. So kernel first performance 64 length
// 16 ffts (64 work items working in parallel) following by transpose using local 
// memory followed by again 64 length 16 ffts followed by transpose using local memory
// followed by 256 length 4 ffts. For the last step since with size of work group is 
// 64 and each work item can array for 16 values, 64 work items can compute 256 length
// 4 ffts by each work item computing 4 length 4 ffts. 
// Similarly for n = 2048 = 8 x 8 x 8 x 4, each work group has 8 x 8 x 4 = 256 work
// iterms which each computes 256 (in-parallel) length 8 ffts in-register, followed
// by transpose using local memory, followed by 256 length 8 in-register ffts, followed
// by transpose using local memory, followed by 256 length 8 in-register ffts, followed
// by transpose using local memory, followed by 512 length 4 in-register ffts. Again,
// for the last step, each work item computes two length 4 in-register ffts and thus
// 256 work items are needed to compute all 512 ffts. 
// For n = 32 = 8 x 4, 4 work items first compute 4 in-register 
// lenth 8 ffts, followed by transpose using local memory followed by 8 in-register
// length 4 ffts, where each work item computes two length 4 ffts thus 4 work items
// can compute 8 length 4 ffts. However if work group size of say 64 is choosen, 
// each work group can compute 64/ 4 = 16 size 32 ffts (batched transform). 
// Users can play with these parameters to figure what gives best performance on
// their particular device i.e. some device have less register space thus using
// smaller base radix can avoid spilling ... some has small local memory thus 
// using smaller work group size may be required etc

static void 
getRadixArray(unsigned int n, unsigned int *radixArray, unsigned int *numRadices, unsigned int maxRadix)
{
    if(maxRadix > 1)
    {
        maxRadix = min(n, maxRadix);
        unsigned int cnt = 0;
        while(n > maxRadix)
        {
            radixArray[cnt++] = maxRadix;
            n /= maxRadix;
        }
        radixArray[cnt++] = n;
        *numRadices = cnt;
        return;
    }

	switch(n) 
	{
		case 2:
			*numRadices = 1;
			radixArray[0] = 2;
			break;
			
		case 4:
			*numRadices = 1;
			radixArray[0] = 4;
			break;
			
		case 8:
			*numRadices = 1;
			radixArray[0] = 8;
			break;
			
		case 16:
			*numRadices = 2;
			radixArray[0] = 8; radixArray[1] = 2; 
			break;
			
		case 32:
			*numRadices = 2;
			radixArray[0] = 8; radixArray[1] = 4;
			break;
			
		case 64:
			*numRadices = 2;
			radixArray[0] = 8; radixArray[1] = 8;
			break;
			
		case 128:
			*numRadices = 3;
			radixArray[0] = 8; radixArray[1] = 4; radixArray[2] = 4;
			break;
			
		case 256:
			*numRadices = 4;
			radixArray[0] = 4; radixArray[1] = 4; radixArray[2] = 4; radixArray[3] = 4;
			break;
			
		case 512:
			*numRadices = 3;
			radixArray[0] = 8; radixArray[1] = 8; radixArray[2] = 8;
			break;			
			
		case 1024:
			*numRadices = 3;
			radixArray[0] = 16; radixArray[1] = 16; radixArray[2] = 4;
			break;	
		case 2048:
			*numRadices = 4;
			radixArray[0] = 8; radixArray[1] = 8; radixArray[2] = 8; radixArray[3] = 4;
			break;
		default:
			*numRadices = 0;
			return;
	}
}

static void
insertHeader(string &kernelString, string &kernelName, clFFT_DataFormat dataFormat)
{
	if(dataFormat == clFFT_SplitComplexFormat) 
		kernelString += string("__kernel void ") + kernelName + string("(__global float *in_real, __global float *in_imag, __global float *out_real, __global float *out_imag, int dir, int S)\n");
	else 
		kernelString += string("__kernel void ") + kernelName + string("(__global float2 *in, __global float2 *out, int dir, int S)\n");
}

static void 
insertVariables(string &kStream, int maxRadix)
{
	kStream += string("    int i, j, r, indexIn, indexOut, index, tid, bNum, xNum, k, l;\n");
    kStream += string("    int s, ii, jj, offset;\n");
	kStream += string("    float2 w;\n");
	kStream += string("    float ang, angf, ang1;\n");
    kStream += string("    __local float *lMemStore, *lMemLoad;\n");
    kStream += string("    float2 a[") +  num2str(maxRadix) + string("];\n");
    kStream += string("    int lId = get_local_id( 0 );\n");
    kStream += string("    int groupId = get_group_id( 0 );\n");
}

static void
formattedLoad(string &kernelString, int aIndex, int gIndex, clFFT_DataFormat dataFormat)
{
	if(dataFormat == clFFT_InterleavedComplexFormat)
		kernelString += string("        a[") + num2str(aIndex) + string("] = in[") + num2str(gIndex) + string("];\n");
	else
	{
		kernelString += string("        a[") + num2str(aIndex) + string("].x = in_real[") + num2str(gIndex) + string("];\n");
		kernelString += string("        a[") + num2str(aIndex) + string("].y = in_imag[") + num2str(gIndex) + string("];\n");
	}
}

static void
formattedStore(string &kernelString, int aIndex, int gIndex, clFFT_DataFormat dataFormat)
{
	if(dataFormat == clFFT_InterleavedComplexFormat)
		kernelString += string("        out[") + num2str(gIndex) + string("] = a[") + num2str(aIndex) + string("];\n");
	else
	{
		kernelString += string("        out_real[") + num2str(gIndex) + string("] = a[") + num2str(aIndex) + string("].x;\n");
		kernelString += string("        out_imag[") + num2str(gIndex) + string("] = a[") + num2str(aIndex) + string("].y;\n");
	}
}

static int
insertGlobalLoadsAndTranspose(string &kernelString, int N, int numWorkItemsPerXForm, int numXFormsPerWG, int R0, int mem_coalesce_width, clFFT_DataFormat dataFormat)
{
	int log2NumWorkItemsPerXForm = (int) log2(numWorkItemsPerXForm);
	int groupSize = numWorkItemsPerXForm * numXFormsPerWG;
	int i, j;
	int lMemSize = 0;
	
	if(numXFormsPerWG > 1)
	    kernelString += string("        s = S & ") + num2str(numXFormsPerWG - 1) + string(";\n");
	
    if(numWorkItemsPerXForm >= mem_coalesce_width)
    {   		
		if(numXFormsPerWG > 1)
		{
            kernelString += string("    ii = lId & ") + num2str(numWorkItemsPerXForm-1) + string(";\n");
            kernelString += string("    jj = lId >> ") + num2str(log2NumWorkItemsPerXForm) + string(";\n");
            kernelString += string("    if( !s || (groupId < get_num_groups(0)-1) || (jj < s) ) {\n");
			kernelString += string("        offset = mad24( mad24(groupId, ") + num2str(numXFormsPerWG) + string(", jj), ") + num2str(N) + string(", ii );\n");
			if(dataFormat == clFFT_InterleavedComplexFormat)
			{
			    kernelString += string("        in += offset;\n");
			    kernelString += string("        out += offset;\n");
			}
			else
			{
			    kernelString += string("        in_real += offset;\n");
				kernelString += string("        in_imag += offset;\n");
			    kernelString += string("        out_real += offset;\n");
				kernelString += string("        out_imag += offset;\n");
			}
			for(i = 0; i < R0; i++)
				formattedLoad(kernelString, i, i*numWorkItemsPerXForm, dataFormat);
			kernelString += string("    }\n");
		}
		else
		{
			kernelString += string("    ii = lId;\n");
			kernelString += string("    jj = 0;\n");
			kernelString += string("    offset =  mad24(groupId, ") + num2str(N) + string(", ii);\n");
			if(dataFormat == clFFT_InterleavedComplexFormat)
			{
			    kernelString += string("        in += offset;\n");
			    kernelString += string("        out += offset;\n");
			}
			else
			{
			    kernelString += string("        in_real += offset;\n");
				kernelString += string("        in_imag += offset;\n");
			    kernelString += string("        out_real += offset;\n");
				kernelString += string("        out_imag += offset;\n");
			}
			for(i = 0; i < R0; i++)
				formattedLoad(kernelString, i, i*numWorkItemsPerXForm, dataFormat);
		}
    }
    else if( N >= mem_coalesce_width )
    {
        int numInnerIter = N / mem_coalesce_width;
        int numOuterIter = numXFormsPerWG / ( groupSize / mem_coalesce_width );
		
        kernelString += string("    ii = lId & ") + num2str(mem_coalesce_width - 1) + string(";\n");
        kernelString += string("    jj = lId >> ") + num2str((int)log2(mem_coalesce_width)) + string(";\n");
        kernelString += string("    lMemStore = sMem + mad24( jj, ") + num2str(N + numWorkItemsPerXForm) + string(", ii );\n");
        kernelString += string("    offset = mad24( groupId, ") + num2str(numXFormsPerWG) + string(", jj);\n");
        kernelString += string("    offset = mad24( offset, ") + num2str(N) + string(", ii );\n");
		if(dataFormat == clFFT_InterleavedComplexFormat)
		{
			kernelString += string("        in += offset;\n");
			kernelString += string("        out += offset;\n");
		}
		else
		{
			kernelString += string("        in_real += offset;\n");
			kernelString += string("        in_imag += offset;\n");
			kernelString += string("        out_real += offset;\n");
			kernelString += string("        out_imag += offset;\n");
		}
        
		kernelString += string("if((groupId == get_num_groups(0)-1) && s) {\n");
        for(i = 0; i < numOuterIter; i++ )
        {
            kernelString += string("    if( jj < s ) {\n");
			for(j = 0; j < numInnerIter; j++ ) 
				formattedLoad(kernelString, i * numInnerIter + j, j * mem_coalesce_width + i * ( groupSize / mem_coalesce_width ) * N, dataFormat);
			kernelString += string("    }\n"); 
			if(i != numOuterIter - 1)
			    kernelString += string("    jj += ") + num2str(groupSize / mem_coalesce_width) + string(";\n");			 
        }
		kernelString += string("}\n ");
		kernelString += string("else {\n");
        for(i = 0; i < numOuterIter; i++ )
        {
			for(j = 0; j < numInnerIter; j++ ) 
				formattedLoad(kernelString, i * numInnerIter + j, j * mem_coalesce_width + i * ( groupSize / mem_coalesce_width ) * N, dataFormat);			
        }		
		kernelString += string("}\n");
        
		kernelString += string("    ii = lId & ") + num2str(numWorkItemsPerXForm - 1) + string(";\n");
		kernelString += string("    jj = lId >> ") + num2str(log2NumWorkItemsPerXForm) + string(";\n");
        kernelString += string("    lMemLoad  = sMem + mad24( jj, ") + num2str(N + numWorkItemsPerXForm) + string(", ii);\n");  
		
        for( i = 0; i < numOuterIter; i++ )
		{
			for( j = 0; j < numInnerIter; j++ )
			{	
				kernelString += string("    lMemStore[") + num2str(j * mem_coalesce_width + i * ( groupSize / mem_coalesce_width ) * (N + numWorkItemsPerXForm )) + string("] = a[") + 
				                num2str(i * numInnerIter + j) + string("].x;\n");
			}
		}	
        kernelString += string("    barrier( CLK_LOCAL_MEM_FENCE );\n");
        
        for( i = 0; i < R0; i++ )
			kernelString += string("    a[") + num2str(i) + string("].x = lMemLoad[") + num2str(i * numWorkItemsPerXForm) + string("];\n");            
		kernelString += string("    barrier( CLK_LOCAL_MEM_FENCE );\n");  

	    for( i = 0; i < numOuterIter; i++ )
		{
			for( j = 0; j < numInnerIter; j++ )
			{	
				kernelString += string("    lMemStore[") + num2str(j * mem_coalesce_width + i * ( groupSize / mem_coalesce_width ) * (N + numWorkItemsPerXForm )) + string("] = a[") + 
								num2str(i * numInnerIter + j) + string("].y;\n");
			}
	    }	
		kernelString += string("    barrier( CLK_LOCAL_MEM_FENCE );\n");
																						   
		for( i = 0; i < R0; i++ )
			kernelString += string("    a[") + num2str(i) + string("].y = lMemLoad[") + num2str(i * numWorkItemsPerXForm) + string("];\n");            
		kernelString += string("    barrier( CLK_LOCAL_MEM_FENCE );\n");  
		
		lMemSize = (N + numWorkItemsPerXForm) * numXFormsPerWG;
    }  
    else
    {
        kernelString += string("    offset = mad24( groupId,  ") + num2str(N * numXFormsPerWG) + string(", lId );\n");
		if(dataFormat == clFFT_InterleavedComplexFormat)
		{
			kernelString += string("        in += offset;\n");
			kernelString += string("        out += offset;\n");
		}
		else
		{
			kernelString += string("        in_real += offset;\n");
			kernelString += string("        in_imag += offset;\n");
			kernelString += string("        out_real += offset;\n");
			kernelString += string("        out_imag += offset;\n");
		}
        
        kernelString += string("    ii = lId & ") + num2str(N-1) + string(";\n");
        kernelString += string("    jj = lId >> ") + num2str((int)log2(N)) + string(";\n");
        kernelString += string("    lMemStore = sMem + mad24( jj, ") + num2str(N + numWorkItemsPerXForm) + string(", ii );\n");
        
		kernelString += string("if((groupId == get_num_groups(0)-1) && s) {\n");
        for( i = 0; i < R0; i++ )
        {
            kernelString += string("    if(jj < s )\n");
			formattedLoad(kernelString, i, i*groupSize, dataFormat);
			if(i != R0 - 1)
			    kernelString += string("    jj += ") + num2str(groupSize / N) + string(";\n");
        }
		kernelString += string("}\n");
		kernelString += string("else {\n");
        for( i = 0; i < R0; i++ )
        {
			formattedLoad(kernelString, i, i*groupSize, dataFormat);
        }		
		kernelString += string("}\n");
        
		if(numWorkItemsPerXForm > 1)
		{
            kernelString += string("    ii = lId & ") + num2str(numWorkItemsPerXForm - 1) + string(";\n");
            kernelString += string("    jj = lId >> ") + num2str(log2NumWorkItemsPerXForm) + string(";\n");
            kernelString += string("    lMemLoad = sMem + mad24( jj, ") + num2str(N + numWorkItemsPerXForm) + string(", ii );\n"); 
		}
		else 
		{
            kernelString += string("    ii = 0;\n");
            kernelString += string("    jj = lId;\n");
            kernelString += string("    lMemLoad = sMem + mul24( jj, ") + num2str(N + numWorkItemsPerXForm) + string(");\n"); 			
		}

		
        for( i = 0; i < R0; i++ )
            kernelString += string("    lMemStore[") + num2str(i * ( groupSize / N ) * ( N + numWorkItemsPerXForm )) + string("] = a[") + num2str(i) + string("].x;\n"); 
        kernelString += string("    barrier( CLK_LOCAL_MEM_FENCE );\n"); 
        
        for( i = 0; i < R0; i++ )
            kernelString += string("    a[") + num2str(i) + string("].x = lMemLoad[") + num2str(i * numWorkItemsPerXForm) + string("];\n");
		kernelString += string("    barrier( CLK_LOCAL_MEM_FENCE );\n");
        
        for( i = 0; i < R0; i++ )
            kernelString += string("    lMemStore[") + num2str(i * ( groupSize / N ) * ( N + numWorkItemsPerXForm )) + string("] = a[") + num2str(i) + string("].y;\n"); 
        kernelString += string("    barrier( CLK_LOCAL_MEM_FENCE );\n"); 
        
        for( i = 0; i < R0; i++ )
            kernelString += string("    a[") + num2str(i) + string("].y = lMemLoad[") + num2str(i * numWorkItemsPerXForm) + string("];\n");
		kernelString += string("    barrier( CLK_LOCAL_MEM_FENCE );\n");
		
		lMemSize = (N + numWorkItemsPerXForm) * numXFormsPerWG;
    }
	
	return lMemSize;
}

static int
insertGlobalStoresAndTranspose(string &kernelString, int N, int maxRadix, int Nr, int numWorkItemsPerXForm, int numXFormsPerWG, int mem_coalesce_width, clFFT_DataFormat dataFormat)
{
	int groupSize = numWorkItemsPerXForm * numXFormsPerWG;
	int i, j, k, ind;
	int lMemSize = 0;
	int numIter = maxRadix / Nr;
	string indent = string("");
	
    if( numWorkItemsPerXForm >= mem_coalesce_width )
    {   
		if(numXFormsPerWG > 1)
		{
            kernelString += string("    if( !s || (groupId < get_num_groups(0)-1) || (jj < s) ) {\n");
			indent = string("    ");
		}	
		for(i = 0; i < maxRadix; i++) 
		{
			j = i % numIter;
			k = i / numIter;
			ind = j * Nr + k;
			formattedStore(kernelString, ind, i*numWorkItemsPerXForm, dataFormat);
		}
		if(numXFormsPerWG > 1)
		    kernelString += string("    }\n");
    }
    else if( N >= mem_coalesce_width )
    {
        int numInnerIter = N / mem_coalesce_width;
        int numOuterIter = numXFormsPerWG / ( groupSize / mem_coalesce_width );
		
        kernelString += string("    lMemLoad  = sMem + mad24( jj, ") + num2str(N + numWorkItemsPerXForm) + string(", ii );\n");  
        kernelString += string("    ii = lId & ") + num2str(mem_coalesce_width - 1) + string(";\n");
        kernelString += string("    jj = lId >> ") + num2str((int)log2(mem_coalesce_width)) + string(";\n");
        kernelString += string("    lMemStore = sMem + mad24( jj,") + num2str(N + numWorkItemsPerXForm) + string(", ii );\n");
		
        for( i = 0; i < maxRadix; i++ )
		{
			j = i % numIter;
			k = i / numIter;
			ind = j * Nr + k;
            kernelString += string("    lMemLoad[") + num2str(i*numWorkItemsPerXForm) + string("] = a[") + num2str(ind) + string("].x;\n");            
		}	
        kernelString += string("    barrier( CLK_LOCAL_MEM_FENCE );\n");         
		
        for( i = 0; i < numOuterIter; i++ )
			for( j = 0; j < numInnerIter; j++ )
				kernelString += string("    a[") + num2str(i*numInnerIter + j) + string("].x = lMemStore[") + num2str(j*mem_coalesce_width + i*( groupSize / mem_coalesce_width )*(N + numWorkItemsPerXForm)) + string("];\n");
        kernelString += string("    barrier( CLK_LOCAL_MEM_FENCE );\n");
		
        for( i = 0; i < maxRadix; i++ )
		{
			j = i % numIter;
			k = i / numIter;
			ind = j * Nr + k;
            kernelString += string("    lMemLoad[") + num2str(i*numWorkItemsPerXForm) + string("] = a[") + num2str(ind) + string("].y;\n");            
		}	
        kernelString += string("    barrier( CLK_LOCAL_MEM_FENCE );\n");         
		
        for( i = 0; i < numOuterIter; i++ )
			for( j = 0; j < numInnerIter; j++ )
				kernelString += string("    a[") + num2str(i*numInnerIter + j) + string("].y = lMemStore[") + num2str(j*mem_coalesce_width + i*( groupSize / mem_coalesce_width )*(N + numWorkItemsPerXForm)) + string("];\n");
        kernelString += string("    barrier( CLK_LOCAL_MEM_FENCE );\n"); 
		
		kernelString += string("if((groupId == get_num_groups(0)-1) && s) {\n");
		for(i = 0; i < numOuterIter; i++ )
        {
            kernelString += string("    if( jj < s ) {\n");
			for(j = 0; j < numInnerIter; j++ ) 
				formattedStore(kernelString, i*numInnerIter + j, j*mem_coalesce_width + i*(groupSize/mem_coalesce_width)*N, dataFormat); 
			kernelString += string("    }\n"); 
			if(i != numOuterIter - 1)
			    kernelString += string("    jj += ") + num2str(groupSize / mem_coalesce_width) + string(";\n");			 
        }
		kernelString += string("}\n");
		kernelString += string("else {\n");
		for(i = 0; i < numOuterIter; i++ )
        {
			for(j = 0; j < numInnerIter; j++ ) 
				formattedStore(kernelString, i*numInnerIter + j, j*mem_coalesce_width + i*(groupSize/mem_coalesce_width)*N, dataFormat); 
        }		
		kernelString += string("}\n");
		
		lMemSize = (N + numWorkItemsPerXForm) * numXFormsPerWG;
	}   	
    else
    {   
        kernelString += string("    lMemLoad  = sMem + mad24( jj,") + num2str(N + numWorkItemsPerXForm) + string(", ii );\n");  
        
		kernelString += string("    ii = lId & ") + num2str(N - 1) + string(";\n");
        kernelString += string("    jj = lId >> ") + num2str((int) log2(N)) + string(";\n");
        kernelString += string("    lMemStore = sMem + mad24( jj,") + num2str(N + numWorkItemsPerXForm) + string(", ii );\n");
        
        for( i = 0; i < maxRadix; i++ )
		{
			j = i % numIter;
			k = i / numIter;
			ind = j * Nr + k;
            kernelString += string("    lMemLoad[") + num2str(i*numWorkItemsPerXForm) + string("] = a[") + num2str(ind) + string("].x;\n");
		}	
        kernelString += string("    barrier( CLK_LOCAL_MEM_FENCE );\n");
        
        for( i = 0; i < maxRadix; i++ )
            kernelString += string("    a[") + num2str(i) + string("].x = lMemStore[") + num2str(i*( groupSize / N )*( N + numWorkItemsPerXForm )) + string("];\n"); 
        kernelString += string("    barrier( CLK_LOCAL_MEM_FENCE );\n"); 
        
        for( i = 0; i < maxRadix; i++ )
		{
			j = i % numIter;
			k = i / numIter;
			ind = j * Nr + k;
            kernelString += string("    lMemLoad[") + num2str(i*numWorkItemsPerXForm) + string("] = a[") + num2str(ind) + string("].y;\n");
		}	
        kernelString += string("    barrier( CLK_LOCAL_MEM_FENCE );\n");
        
        for( i = 0; i < maxRadix; i++ )
            kernelString += string("    a[") + num2str(i) + string("].y = lMemStore[") + num2str(i*( groupSize / N )*( N + numWorkItemsPerXForm )) + string("];\n"); 
        kernelString += string("    barrier( CLK_LOCAL_MEM_FENCE );\n"); 
        
		kernelString += string("if((groupId == get_num_groups(0)-1) && s) {\n");
		for( i = 0; i < maxRadix; i++ )
        {
            kernelString += string("    if(jj < s ) {\n");
			formattedStore(kernelString, i, i*groupSize, dataFormat);
			kernelString += string("    }\n");
			if( i != maxRadix - 1)
				kernelString += string("    jj +=") + num2str(groupSize / N) + string(";\n");
        } 
		kernelString += string("}\n");
		kernelString += string("else {\n");
		for( i = 0; i < maxRadix; i++ )
        {
			formattedStore(kernelString, i, i*groupSize, dataFormat);
        } 		
		kernelString += string("}\n");
		
		lMemSize = (N + numWorkItemsPerXForm) * numXFormsPerWG;
    }
	
	return lMemSize;
}

static void 
insertfftKernel(string &kernelString, int Nr, int numIter)
{
	int i;
	for(i = 0; i < numIter; i++) 
	{
		kernelString += string("    fftKernel") + num2str(Nr) + string("(a+") + num2str(i*Nr) + string(", dir);\n");
	}
}

static void
insertTwiddleKernel(string &kernelString, int Nr, int numIter, int Nprev, int len, int numWorkItemsPerXForm)
{
	int z, k;
	int logNPrev = log2(Nprev);
	
	for(z = 0; z < numIter; z++) 
	{
		if(z == 0)
		{
			if(Nprev > 1)
			    kernelString += string("    angf = (float) (ii >> ") + num2str(logNPrev) + string(");\n");
			else
				kernelString += string("    angf = (float) ii;\n");
		}	
		else
		{
			if(Nprev > 1)
			    kernelString += string("    angf = (float) ((") + num2str(z*numWorkItemsPerXForm) + string(" + ii) >>") + num2str(logNPrev) + string(");\n"); 
			else
				kernelString += string("    angf = (float) (") + num2str(z*numWorkItemsPerXForm) + string(" + ii);\n");
		}	
	
		for(k = 1; k < Nr; k++) {
			int ind = z*Nr + k;
			//float fac =  (float) (2.0 * M_PI * (double) k / (double) len);
			kernelString += string("    ang = dir * ( 2.0f * M_PI * ") + num2str(k) + string(".0f / ") + num2str(len) + string(".0f )") + string(" * angf;\n");
			kernelString += string("    w = (float2)(native_cos(ang), native_sin(ang));\n");
			kernelString += string("    a[") + num2str(ind) + string("] = complexMul(a[") + num2str(ind) + string("], w);\n");
		}
	}
}

static int
getPadding(int numWorkItemsPerXForm, int Nprev, int numWorkItemsReq, int numXFormsPerWG, int Nr, int numBanks, int *offset, int *midPad)
{
	if((numWorkItemsPerXForm <= Nprev) || (Nprev >= numBanks))
		*offset = 0;
	else {
		int numRowsReq = ((numWorkItemsPerXForm < numBanks) ? numWorkItemsPerXForm : numBanks) / Nprev;
		int numColsReq = 1;
		if(numRowsReq > Nr)
			numColsReq = numRowsReq / Nr;
		numColsReq = Nprev * numColsReq;
		*offset = numColsReq;
	}
	
	if(numWorkItemsPerXForm >= numBanks || numXFormsPerWG == 1)
		*midPad = 0;
	else {
		int bankNum = ( (numWorkItemsReq + *offset) * Nr ) & (numBanks - 1);
		if( bankNum >= numWorkItemsPerXForm )
			*midPad = 0;
		else
			*midPad = numWorkItemsPerXForm - bankNum;
	}
	
	int lMemSize = ( numWorkItemsReq + *offset) * Nr * numXFormsPerWG + *midPad * (numXFormsPerWG - 1);
	return lMemSize;
}


static void 
insertLocalStores(string &kernelString, int numIter, int Nr, int numWorkItemsPerXForm, int numWorkItemsReq, int offset, string &comp)
{
	int z, k;

	for(z = 0; z < numIter; z++) {
		for(k = 0; k < Nr; k++) {
			int index = k*(numWorkItemsReq + offset) + z*numWorkItemsPerXForm;
			kernelString += string("    lMemStore[") + num2str(index) + string("] = a[") + num2str(z*Nr + k) + string("].") + comp + string(";\n");
		}
	}
	kernelString += string("    barrier(CLK_LOCAL_MEM_FENCE);\n");
}

static void 
insertLocalLoads(string &kernelString, int n, int Nr, int Nrn, int Nprev, int Ncurr, int numWorkItemsPerXForm, int numWorkItemsReq, int offset, string &comp)
{
	int numWorkItemsReqN = n / Nrn;										
	int interBlockHNum = max( Nprev / numWorkItemsPerXForm, 1 );			
	int interBlockHStride = numWorkItemsPerXForm;							
	int vertWidth = max(numWorkItemsPerXForm / Nprev, 1);					
	vertWidth = min( vertWidth, Nr);									
	int vertNum = Nr / vertWidth;										
	int vertStride = ( n / Nr + offset ) * vertWidth;					
	int iter = max( numWorkItemsReqN / numWorkItemsPerXForm, 1);
	int intraBlockHStride = (numWorkItemsPerXForm / (Nprev*Nr)) > 1 ? (numWorkItemsPerXForm / (Nprev*Nr)) : 1;
	intraBlockHStride *= Nprev;
	
	int stride = numWorkItemsReq / Nrn;									
	int i;
	for(i = 0; i < iter; i++) {
		int ii = i / (interBlockHNum * vertNum);
		int zz = i % (interBlockHNum * vertNum);
		int jj = zz % interBlockHNum;
		int kk = zz / interBlockHNum;
		int z;
		for(z = 0; z < Nrn; z++) {
			int st = kk * vertStride + jj * interBlockHStride + ii * intraBlockHStride + z * stride;
			kernelString += string("    a[") + num2str(i*Nrn + z) + string("].") + comp + string(" = lMemLoad[") + num2str(st) + string("];\n");
		}
	}
	kernelString += string("    barrier(CLK_LOCAL_MEM_FENCE);\n");
}

static void
insertLocalLoadIndexArithmatic(string &kernelString, int Nprev, int Nr, int numWorkItemsReq, int numWorkItemsPerXForm, int numXFormsPerWG, int offset, int midPad)
{	
	int Ncurr = Nprev * Nr;
	int logNcurr = log2(Ncurr);
	int logNprev = log2(Nprev);
	int incr = (numWorkItemsReq + offset) * Nr + midPad;
	
	if(Ncurr < numWorkItemsPerXForm) 
	{
		if(Nprev == 1)
		    kernelString += string("    j = ii & ") + num2str(Ncurr - 1) + string(";\n");
		else
			kernelString += string("    j = (ii & ") + num2str(Ncurr - 1) + string(") >> ") + num2str(logNprev) + string(";\n");
		
		if(Nprev == 1) 
			kernelString += string("    i = ii >> ") + num2str(logNcurr) + string(";\n");
		else 
			kernelString += string("    i = mad24(ii >> ") + num2str(logNcurr) + string(", ") + num2str(Nprev) + string(", ii & ") + num2str(Nprev - 1) + string(");\n"); 
	}	
	else 
	{
		if(Nprev == 1)
		    kernelString += string("    j = ii;\n");
		else
			kernelString += string("    j = ii >> ") + num2str(logNprev) + string(";\n");
		if(Nprev == 1) 
			kernelString += string("    i = 0;\n"); 
		else 
			kernelString += string("    i = ii & ") + num2str(Nprev - 1) + string(";\n");
	}

    if(numXFormsPerWG > 1)
        kernelString += string("    i = mad24(jj, ") + num2str(incr) + string(", i);\n");		

    kernelString += string("    lMemLoad = sMem + mad24(j, ") + num2str(numWorkItemsReq + offset) + string(", i);\n"); 
}

static void
insertLocalStoreIndexArithmatic(string &kernelString, int numWorkItemsReq, int numXFormsPerWG, int Nr, int offset, int midPad)
{
	if(numXFormsPerWG == 1) {
		kernelString += string("    lMemStore = sMem + ii;\n");		
	}
	else {
		kernelString += string("    lMemStore = sMem + mad24(jj, ") + num2str((numWorkItemsReq + offset)*Nr + midPad) + string(", ii);\n");	
	}
}


static void
createLocalMemfftKernelString(cl_fft_plan *plan)
{
	unsigned int radixArray[10];
	unsigned int numRadix;
	 
	unsigned int n = plan->n.x;
	
	assert(n <= plan->max_work_item_per_workgroup * plan->max_radix && "signal lenght too big for local mem fft\n");
	
	getRadixArray(n, radixArray, &numRadix, 0);
	assert(numRadix > 0 && "no radix array supplied\n");
	
	if(n/radixArray[0] > plan->max_work_item_per_workgroup)
	    getRadixArray(n, radixArray, &numRadix, plan->max_radix);

	assert(radixArray[0] <= plan->max_radix && "max radix choosen is greater than allowed\n");
	assert(n/radixArray[0] <= plan->max_work_item_per_workgroup && "required work items per xform greater than maximum work items allowed per work group for local mem fft\n");
	
	unsigned int tmpLen = 1;
	unsigned int i;
	for(i = 0; i < numRadix; i++)
	{	
		assert( radixArray[i] && !( (radixArray[i] - 1) & radixArray[i] ) );
	    tmpLen *= radixArray[i];
	}
	assert(tmpLen == n && "product of radices choosen doesnt match the length of signal\n");
	
	int offset, midPad;
	string localString(""), kernelName("");
	
	clFFT_DataFormat dataFormat = plan->format;
	string *kernelString = plan->kernel_string;
	
	
	cl_fft_kernel_info **kInfo = &plan->kernel_info;
	int kCount = 0;
	
	while(*kInfo)
	{
		kInfo = &(*kInfo)->next;
		kCount++;
	}
	
	kernelName = string("fft") + num2str(kCount);
	
	*kInfo = (cl_fft_kernel_info *) malloc(sizeof(cl_fft_kernel_info));
	(*kInfo)->kernel = 0;
	(*kInfo)->lmem_size = 0;
	(*kInfo)->num_workgroups = 0;
	(*kInfo)->num_workitems_per_workgroup = 0;
	(*kInfo)->dir = cl_fft_kernel_x;
	(*kInfo)->in_place_possible = 1;
	(*kInfo)->next = NULL;
	(*kInfo)->kernel_name = (char *) malloc(sizeof(char)*(kernelName.size()+1));
	strcpy((*kInfo)->kernel_name, kernelName.c_str());
	
	unsigned int numWorkItemsPerXForm = n / radixArray[0];
	unsigned int numWorkItemsPerWG = numWorkItemsPerXForm <= 64 ? 64 : numWorkItemsPerXForm; 
	assert(numWorkItemsPerWG <= plan->max_work_item_per_workgroup);
	int numXFormsPerWG = numWorkItemsPerWG / numWorkItemsPerXForm;
	(*kInfo)->num_workgroups = 1;
    (*kInfo)->num_xforms_per_workgroup = numXFormsPerWG;
	(*kInfo)->num_workitems_per_workgroup = numWorkItemsPerWG;
	
	unsigned int *N = radixArray;
	unsigned int maxRadix = N[0];
	unsigned int lMemSize = 0;
		
	insertVariables(localString, maxRadix);
	
	lMemSize = insertGlobalLoadsAndTranspose(localString, n, numWorkItemsPerXForm, numXFormsPerWG, maxRadix, plan->min_mem_coalesce_width, dataFormat);
	(*kInfo)->lmem_size = (lMemSize > (*kInfo)->lmem_size) ? lMemSize : (*kInfo)->lmem_size;
	
	string xcomp = string("x");
	string ycomp = string("y");
	
	unsigned int Nprev = 1;
	unsigned int len = n;
	unsigned int r;
	for(r = 0; r < numRadix; r++) 
	{
		int numIter = N[0] / N[r];
		int numWorkItemsReq = n / N[r];
		int Ncurr = Nprev * N[r];
		insertfftKernel(localString, N[r], numIter);
		
		if(r < (numRadix - 1)) {
			insertTwiddleKernel(localString, N[r], numIter, Nprev, len, numWorkItemsPerXForm);
			lMemSize = getPadding(numWorkItemsPerXForm, Nprev, numWorkItemsReq, numXFormsPerWG, N[r], plan->num_local_mem_banks, &offset, &midPad);
			(*kInfo)->lmem_size = (lMemSize > (*kInfo)->lmem_size) ? lMemSize : (*kInfo)->lmem_size;
			insertLocalStoreIndexArithmatic(localString, numWorkItemsReq, numXFormsPerWG, N[r], offset, midPad);
			insertLocalLoadIndexArithmatic(localString, Nprev, N[r], numWorkItemsReq, numWorkItemsPerXForm, numXFormsPerWG, offset, midPad);
			insertLocalStores(localString, numIter, N[r], numWorkItemsPerXForm, numWorkItemsReq, offset, xcomp);
			insertLocalLoads(localString, n, N[r], N[r+1], Nprev, Ncurr, numWorkItemsPerXForm, numWorkItemsReq, offset, xcomp);
			insertLocalStores(localString, numIter, N[r], numWorkItemsPerXForm, numWorkItemsReq, offset, ycomp);
			insertLocalLoads(localString, n, N[r], N[r+1], Nprev, Ncurr, numWorkItemsPerXForm, numWorkItemsReq, offset, ycomp);
			Nprev = Ncurr;
			len = len / N[r];
		}
	}
	
	lMemSize = insertGlobalStoresAndTranspose(localString, n, maxRadix, N[numRadix - 1], numWorkItemsPerXForm, numXFormsPerWG, plan->min_mem_coalesce_width, dataFormat);
	(*kInfo)->lmem_size = (lMemSize > (*kInfo)->lmem_size) ? lMemSize : (*kInfo)->lmem_size;
	
	insertHeader(*kernelString, kernelName, dataFormat);
	*kernelString += string("{\n");
	if((*kInfo)->lmem_size)
        *kernelString += string("    __local float sMem[") + num2str((*kInfo)->lmem_size) + string("];\n");
	*kernelString += localString;
	*kernelString += string("}\n");
}

// For n larger than what can be computed using local memory fft, global transposes
// multiple kernel launces is needed. For these sizes, n can be decomposed using
// much larger base radices i.e. say n = 262144 = 128 x 64 x 32. Thus three kernel
// launches will be needed, first computing 64 x 32, length 128 ffts, second computing
// 128 x 32 length 64 ffts, and finally a kernel computing 128 x 64 length 32 ffts. 
// Each of these base radices can futher be divided into factors so that each of these 
// base ffts can be computed within one kernel launch using in-register ffts and local 
// memory transposes i.e for the first kernel above which computes 64 x 32 ffts on length 
// 128, 128 can be decomposed into 128 = 16 x 8 i.e. 8 work items can compute 8 length 
// 16 ffts followed by transpose using local memory followed by each of these eight 
// work items computing 2 length 8 ffts thus computing 16 length 8 ffts in total. This 
// means only 8 work items are needed for computing one length 128 fft. If we choose
// work group size of say 64, we can compute 64/8 = 8 length 128 ffts within one
// work group. Since we need to compute 64 x 32 length 128 ffts in first kernel, this 
// means we need to launch 64 x 32 / 8 = 256 work groups with 64 work items in each 
// work group where each work group is computing 8 length 128 ffts where each length
// 128 fft is computed by 8 work items. Same logic can be applied to other two kernels
// in this example. Users can play with difference base radices and difference 
// decompositions of base radices to generates different kernels and see which gives
// best performance. Following function is just fixed to use 128 as base radix

void
getGlobalRadixInfo(int n, int *radix, int *R1, int *R2, int *numRadices)
{
	int baseRadix = min(n, 128);
	
	int numR = 0;
	int N = n;
	while(N > baseRadix) 
	{
		N /= baseRadix;
		numR++;
	}
	
	for(int i = 0; i < numR; i++)
		radix[i] = baseRadix;
	
	radix[numR] = N;
	numR++;
	*numRadices = numR;
		
	for(int i = 0; i < numR; i++)
	{
		int B = radix[i];
		if(B <= 8)
		{
			R1[i] = B;
			R2[i] = 1;
			continue;
		}
		
		int r1 = 2; 
		int r2 = B / r1;
	    while(r2 > r1)
	    {
		   r1 *=2;
		   r2 = B / r1;
	    }
		R1[i] = r1;
		R2[i] = r2;
	}	
}

static void
createGlobalFFTKernelString(cl_fft_plan *plan, int n, int BS, cl_fft_kernel_dir dir, int vertBS)
{		
	int i, j, k, t;
	int radixArr[10] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
    int R1Arr[10] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
    int R2Arr[10] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
	int radix, R1, R2;
	int numRadices;
	
	int maxThreadsPerBlock = plan->max_work_item_per_workgroup;
	int maxArrayLen = plan->max_radix;
	int batchSize = plan->min_mem_coalesce_width;	
	clFFT_DataFormat dataFormat = plan->format;
	int vertical = (dir == cl_fft_kernel_x) ? 0 : 1;	
	
	getGlobalRadixInfo(n, radixArr, R1Arr, R2Arr, &numRadices);
		
	int numPasses = numRadices;
	
	string localString(""), kernelName("");
	string *kernelString = plan->kernel_string;
	cl_fft_kernel_info **kInfo = &plan->kernel_info; 
	int kCount = 0;
	
	while(*kInfo)
	{
		kInfo = &(*kInfo)->next;
		kCount++;
	}
	
	int N = n;
	int m = (int)log2(n);
	int Rinit = vertical ? BS : 1;
	batchSize = vertical ? min(BS, batchSize) : batchSize;
	int passNum;
	
	for(passNum = 0; passNum < numPasses; passNum++) 
	{
		
		localString.clear();
		kernelName.clear();
		
		radix = radixArr[passNum];
		R1 = R1Arr[passNum];
		R2 = R2Arr[passNum];
				
		int strideI = Rinit;
		for(i = 0; i < numPasses; i++)
			if(i != passNum)
				strideI *= radixArr[i];
		
		int strideO = Rinit;
		for(i = 0; i < passNum; i++)
			strideO *= radixArr[i];
		
		int threadsPerXForm = R2;
		batchSize = R2 == 1 ? plan->max_work_item_per_workgroup : batchSize;
		batchSize = min(batchSize, strideI);
		int threadsPerBlock = batchSize * threadsPerXForm;
		threadsPerBlock = min(threadsPerBlock, maxThreadsPerBlock);
		batchSize = threadsPerBlock / threadsPerXForm;
		assert(R2 <= R1);
		assert(R1*R2 == radix);
		assert(R1 <= maxArrayLen);
		assert(threadsPerBlock <= maxThreadsPerBlock);
		
		int numIter = R1 / R2;
		int gInInc = threadsPerBlock / batchSize;
		
		
		int lgStrideO = log2(strideO);
		int numBlocksPerXForm = strideI / batchSize;
		int numBlocks = numBlocksPerXForm;
		if(!vertical)
			numBlocks *= BS;
		else
			numBlocks *= vertBS;
		
		kernelName = string("fft") + num2str(kCount);
		*kInfo = (cl_fft_kernel_info *) malloc(sizeof(cl_fft_kernel_info));
		(*kInfo)->kernel = 0;
		if(R2 == 1)
			(*kInfo)->lmem_size = 0;
		else
		{
		    if(strideO == 1)
		        (*kInfo)->lmem_size = (radix + 1)*batchSize;
		    else
			    (*kInfo)->lmem_size = threadsPerBlock*R1;
		}
		(*kInfo)->num_workgroups = numBlocks;
        (*kInfo)->num_xforms_per_workgroup = 1;
		(*kInfo)->num_workitems_per_workgroup = threadsPerBlock;
		(*kInfo)->dir = dir;
		if( (passNum == (numPasses - 1)) && (numPasses & 1) )
		    (*kInfo)->in_place_possible = 1;
		else
			(*kInfo)->in_place_possible = 0;
		(*kInfo)->next = NULL;
		(*kInfo)->kernel_name = (char *) malloc(sizeof(char)*(kernelName.size()+1));
		strcpy((*kInfo)->kernel_name, kernelName.c_str());
		
		insertVariables(localString, R1);
						
		if(vertical) 
		{
			localString += string("xNum = groupId >> ") + num2str((int)log2(numBlocksPerXForm)) + string(";\n");
			localString += string("groupId = groupId & ") + num2str(numBlocksPerXForm - 1) + string(";\n");
			localString += string("indexIn = mad24(groupId, ") + num2str(batchSize) + string(", xNum << ") + num2str((int)log2(n*BS)) + string(");\n");
			localString += string("tid = mul24(groupId, ") + num2str(batchSize) + string(");\n");
			localString += string("i = tid >> ") + num2str(lgStrideO) + string(";\n");
			localString += string("j = tid & ") + num2str(strideO - 1) + string(";\n");
			int stride = radix*Rinit;
			for(i = 0; i < passNum; i++)
				stride *= radixArr[i];
			localString += string("indexOut = mad24(i, ") + num2str(stride) + string(", j + ") + string("(xNum << ") + num2str((int) log2(n*BS)) + string("));\n");
			localString += string("bNum = groupId;\n");
		}
		else 
		{
			int lgNumBlocksPerXForm = log2(numBlocksPerXForm);
			localString += string("bNum = groupId & ") + num2str(numBlocksPerXForm - 1) + string(";\n");
			localString += string("xNum = groupId >> ") + num2str(lgNumBlocksPerXForm) + string(";\n");
			localString += string("indexIn = mul24(bNum, ") + num2str(batchSize) + string(");\n");
			localString += string("tid = indexIn;\n");
			localString += string("i = tid >> ") + num2str(lgStrideO) + string(";\n");
			localString += string("j = tid & ") + num2str(strideO - 1) + string(";\n"); 
			int stride = radix*Rinit;
			for(i = 0; i < passNum; i++)
				stride *= radixArr[i];
			localString += string("indexOut = mad24(i, ") + num2str(stride) + string(", j);\n");			
			localString += string("indexIn += (xNum << ") + num2str(m) + string(");\n");
			localString += string("indexOut += (xNum << ") + num2str(m) + string(");\n");	
		}
		
		// Load Data
		int lgBatchSize = log2(batchSize);
		localString += string("tid = lId;\n");
		localString += string("i = tid & ") + num2str(batchSize - 1) + string(";\n");
		localString += string("j = tid >> ") + num2str(lgBatchSize) + string(";\n"); 
		localString += string("indexIn += mad24(j, ") + num2str(strideI) + string(", i);\n");

		if(dataFormat == clFFT_SplitComplexFormat) 
		{
			localString += string("in_real += indexIn;\n");
			localString += string("in_imag += indexIn;\n");			
			for(j = 0; j < R1; j++)
				localString += string("a[") + num2str(j) + string("].x = in_real[") + num2str(j*gInInc*strideI) + string("];\n");
			for(j = 0; j < R1; j++) 
				localString += string("a[") + num2str(j) + string("].y = in_imag[") + num2str(j*gInInc*strideI) + string("];\n");
		}
		else 
		{
			localString += string("in += indexIn;\n");
			for(j = 0; j < R1; j++)
				localString += string("a[") + num2str(j) + string("] = in[") + num2str(j*gInInc*strideI) + string("];\n");
	    }
		
		localString += string("fftKernel") + num2str(R1) + string("(a, dir);\n");							  
		
		if(R2 > 1)
		{
		    // twiddle
		    for(k = 1; k < R1; k++) 
		    {
			    localString += string("ang = dir*(2.0f*M_PI*") + num2str(k) + string("/") + num2str(radix) + string(")*j;\n");
			    localString += string("w = (float2)(native_cos(ang), native_sin(ang));\n");
			    localString += string("a[") + num2str(k) + string("] = complexMul(a[") + num2str(k) + string("], w);\n"); 
		    }
		
		    // shuffle
		    numIter = R1 / R2;	
		    localString += string("indexIn = mad24(j, ") + num2str(threadsPerBlock*numIter) + string(", i);\n");
		    localString += string("lMemStore = sMem + tid;\n");
		    localString += string("lMemLoad = sMem + indexIn;\n");
		    for(k = 0; k < R1; k++) 
			    localString += string("lMemStore[") + num2str(k*threadsPerBlock) + string("] = a[") + num2str(k) + string("].x;\n");
		    localString += string("barrier(CLK_LOCAL_MEM_FENCE);\n");	
		    for(k = 0; k < numIter; k++)
			    for(t = 0; t < R2; t++)
				    localString += string("a[") + num2str(k*R2+t) + string("].x = lMemLoad[") + num2str(t*batchSize + k*threadsPerBlock) + string("];\n");
		    localString += string("barrier(CLK_LOCAL_MEM_FENCE);\n");
		    for(k = 0; k < R1; k++) 
			    localString += string("lMemStore[") + num2str(k*threadsPerBlock) + string("] = a[") + num2str(k) + string("].y;\n");
		    localString += string("barrier(CLK_LOCAL_MEM_FENCE);\n");	
		    for(k = 0; k < numIter; k++)
			    for(t = 0; t < R2; t++)
				    localString += string("a[") + num2str(k*R2+t) + string("].y = lMemLoad[") + num2str(t*batchSize + k*threadsPerBlock) + string("];\n");
		    localString += string("barrier(CLK_LOCAL_MEM_FENCE);\n");
		
		    for(j = 0; j < numIter; j++)
			    localString += string("fftKernel") + num2str(R2) + string("(a + ") + num2str(j*R2) + string(", dir);\n");
		}
		
		// twiddle
		if(passNum < (numPasses - 1)) 
		{
			localString += string("l = ((bNum << ") + num2str(lgBatchSize) + string(") + i) >> ") + num2str(lgStrideO) + string(";\n");
			localString += string("k = j << ") + num2str((int)log2(R1/R2)) + string(";\n"); 
			localString += string("ang1 = dir*(2.0f*M_PI/") + num2str(N) + string(")*l;\n");
			for(t = 0; t < R1; t++) 
			{
				localString += string("ang = ang1*(k + ") + num2str((t%R2)*R1 + (t/R2)) + string(");\n");
				localString += string("w = (float2)(native_cos(ang), native_sin(ang));\n");
				localString += string("a[") + num2str(t) + string("] = complexMul(a[") + num2str(t) + string("], w);\n");
			}
		}
		
		// Store Data
		if(strideO == 1) 
		{
			
			localString += string("lMemStore = sMem + mad24(i, ") + num2str(radix + 1) + string(", j << ") + num2str((int)log2(R1/R2)) + string(");\n");
			localString += string("lMemLoad = sMem + mad24(tid >> ") + num2str((int)log2(radix)) + string(", ") + num2str(radix+1) + string(", tid & ") + num2str(radix-1) + string(");\n");
			
			for(int i = 0; i < R1/R2; i++)
				for(int j = 0; j < R2; j++)
					localString += string("lMemStore[ ") + num2str(i + j*R1) + string("] = a[") + num2str(i*R2+j) + string("].x;\n");
			localString += string("barrier(CLK_LOCAL_MEM_FENCE);\n");
			if(threadsPerBlock >= radix)
            {
                for(int i = 0; i < R1; i++)
                localString += string("a[") + num2str(i) + string("].x = lMemLoad[") + num2str(i*(radix+1)*(threadsPerBlock/radix)) + string("];\n");
            }
            else
            {
                int innerIter = radix/threadsPerBlock;
                int outerIter = R1/innerIter;
                for(int i = 0; i < outerIter; i++)
                    for(int j = 0; j < innerIter; j++)
                        localString += string("a[") + num2str(i*innerIter+j) + string("].x = lMemLoad[") + num2str(j*threadsPerBlock + i*(radix+1)) + string("];\n");
            }
			localString += string("barrier(CLK_LOCAL_MEM_FENCE);\n");
			
			for(int i = 0; i < R1/R2; i++)
				for(int j = 0; j < R2; j++)
					localString += string("lMemStore[ ") + num2str(i + j*R1) + string("] = a[") + num2str(i*R2+j) + string("].y;\n");
			localString += string("barrier(CLK_LOCAL_MEM_FENCE);\n");
			if(threadsPerBlock >= radix)
            {
                for(int i = 0; i < R1; i++)
                    localString += string("a[") + num2str(i) + string("].y = lMemLoad[") + num2str(i*(radix+1)*(threadsPerBlock/radix)) + string("];\n");
            }
            else
            {
                int innerIter = radix/threadsPerBlock;
                int outerIter = R1/innerIter;
                for(int i = 0; i < outerIter; i++)
                    for(int j = 0; j < innerIter; j++)
                        localString += string("a[") + num2str(i*innerIter+j) + string("].y = lMemLoad[") + num2str(j*threadsPerBlock + i*(radix+1)) + string("];\n");
            }
			localString += string("barrier(CLK_LOCAL_MEM_FENCE);\n");
			
			localString += string("indexOut += tid;\n");
			if(dataFormat == clFFT_SplitComplexFormat) {
				localString += string("out_real += indexOut;\n");
				localString += string("out_imag += indexOut;\n");
				for(k = 0; k < R1; k++)
					localString += string("out_real[") + num2str(k*threadsPerBlock) + string("] = a[") + num2str(k) + string("].x;\n");
				for(k = 0; k < R1; k++)
					localString += string("out_imag[") + num2str(k*threadsPerBlock) + string("] = a[") + num2str(k) + string("].y;\n");
			}
			else {
				localString += string("out += indexOut;\n");
				for(k = 0; k < R1; k++)
					localString += string("out[") + num2str(k*threadsPerBlock) + string("] = a[") + num2str(k) + string("];\n");				
			}
		 
		}
		else 
		{
			localString += string("indexOut += mad24(j, ") + num2str(numIter*strideO) + string(", i);\n");
			if(dataFormat == clFFT_SplitComplexFormat) {
				localString += string("out_real += indexOut;\n");
				localString += string("out_imag += indexOut;\n");			
				for(k = 0; k < R1; k++)
					localString += string("out_real[") + num2str(((k%R2)*R1 + (k/R2))*strideO) + string("] = a[") + num2str(k) + string("].x;\n");
				for(k = 0; k < R1; k++)
					localString += string("out_imag[") + num2str(((k%R2)*R1 + (k/R2))*strideO) + string("] = a[") + num2str(k) + string("].y;\n");
			}
			else {
				localString += string("out += indexOut;\n");
				for(k = 0; k < R1; k++)
					localString += string("out[") + num2str(((k%R2)*R1 + (k/R2))*strideO) + string("] = a[") + num2str(k) + string("];\n");
			}
		}
		
		insertHeader(*kernelString, kernelName, dataFormat);
		*kernelString += string("{\n");
		if((*kInfo)->lmem_size)
			*kernelString += string("    __local float sMem[") + num2str((*kInfo)->lmem_size) + string("];\n");
		*kernelString += localString;
		*kernelString += string("}\n");		
		
		N /= radix;
		kInfo = &(*kInfo)->next;
		kCount++;
	}
}

void FFT1D(cl_fft_plan *plan, cl_fft_kernel_dir dir)
{	
    unsigned int radixArray[10];
    unsigned int numRadix;
    
	switch(dir)
	{
		case cl_fft_kernel_x:
		    if(plan->n.x > plan->max_localmem_fft_size)
		    {
		        createGlobalFFTKernelString(plan, plan->n.x, 1, cl_fft_kernel_x, 1);
		    }
		    else if(plan->n.x > 1)
		    {
		        getRadixArray(plan->n.x, radixArray, &numRadix, 0);
		        if(plan->n.x / radixArray[0] <= plan->max_work_item_per_workgroup)
		        {
				    createLocalMemfftKernelString(plan);
				}
			    else
			    {
			        getRadixArray(plan->n.x, radixArray, &numRadix, plan->max_radix);
			        if(plan->n.x / radixArray[0] <= plan->max_work_item_per_workgroup)
			            createLocalMemfftKernelString(plan);
			        else
				        createGlobalFFTKernelString(plan, plan->n.x, 1, cl_fft_kernel_x, 1);
				}
		    }
			break;
			
		case cl_fft_kernel_y:
			if(plan->n.y > 1)
			    createGlobalFFTKernelString(plan, plan->n.y, plan->n.x, cl_fft_kernel_y, 1);
			break;
			
		case cl_fft_kernel_z:
			if(plan->n.z > 1)
			    createGlobalFFTKernelString(plan, plan->n.z, plan->n.x*plan->n.y, cl_fft_kernel_z, 1);
		default:
			return;
	}
}