//
// This file is part of the Bones source-to-source compiler examples. The C-code
// is largely identical in terms of functionality and variable naming to the code
// found in PolyBench/C version 3.2. For more information on PolyBench/C or Bones
// please use the contact information below.
//
// == More information on PolyBench/C
// Contact............Louis-Noel Pouchet <pouchet@cse.ohio-state.edu>
// Web address........http://polybench.sourceforge.net/
// 
// == More information on Bones
// Contact............Cedric Nugteren <c.nugteren@tue.nl>
// Web address........http://parse.ele.tue.nl/bones/
//
// == File information
// Filename...........benchmark/cholesky.c
// Author.............Cedric Nugteren
// Last modified on...03-Jul-2012
//

#include "common.h"

// This is 'cholesky', a cholesky decomposition kernel
int main(void) {
	int i,j,k;
	float x[1];
	float p_i;
	
	// Declare arrays on the stack
	float A[N][N];
	float p[N];
	
	// Set the input data
	for (i=0; i<N; i++) {
		for (j=0; j<N; j++) {
			A[i][j] = i*2.3 + 1;
		}
	}
	
	// Perform the computation
	for (i=0; i<N; i++) {
		x[0] = A[i][i];
		#pragma species kernel i:i,0:i-1|element -> 0:0|shared
		for (j=0; j<=i-1; j++) {
			x[0] = x[0] - A[i][j] * A[i][j];
		}
		#pragma species endkernel cholesky-part1
		p[i] = 1.0 / sqrt(x[0]);
		p_i = p[i];
		#pragma species kernel i:i,i+1:N-1|element ^ i+1:N-1,0:i-1|chunk(0:0,0:i-1) ^ i:i,0:i-1|full -> 0:0|shared ^ i+1:N-1,i:i|element
		for (j=i+1; j<N; j++) {
			x[0] = A[i][j];
			for (k=0; k<=i-1; k++) {
				x[0] = x[0] - A[j][k] * A[i][k];
			}
			A[j][i] = x[0] * p_i;
		}
		#pragma species endkernel cholesky-part2
	}
	
	// Clean-up and exit the function
	fflush(stdout);
	return 0;
}