//
// 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/fdtd-2d.c
// Author.............Cedric Nugteren
// Last modified on...08-May-2012
//

#include "common.h"

// This is 'fdtd-2d', a 2D finite different time domain kernel
int main(void) {
	int i,j,t;
	
	// Declare arrays on the stack
	float ex[NI][NJ];
	float ey[NI][NJ];
	float hz[NI][NJ];
	
	// Set the input data
	for (i=0; i<NI; i++) {
		for (j=0; j<NJ; j++) {
			ex[i][j] = ((float) i*(j+1)) / NI;
			ey[i][j] = ((float) i*(j+2)) / NJ;
			hz[i][j] = ((float) i*(j+3)) / NI;
		}
	}
	
	// Perform the computation
	for (t=0; t<TSTEPS; t++) {
		#pragma species kernel 0:0|void -> 0:0,0:NJ-1|element
		for (j=0; j<NJ; j++) {
			ey[0][j] = t;
		}
		#pragma species endkernel fdtd-2d-part1
		#pragma species kernel 1:NI-1,0:NJ-1|element ^ 1:NI-1,0:NJ-1|neighbourhood(-1:0,0:0) -> 1:NI-1,0:NJ-1|element
		for (i=1; i<NI; i++) {
			for (j=0; j<NJ; j++) {
				ey[i][j] = ey[i][j] - 0.5*(hz[i][j] - hz[i-1][j]);
			}
		}
		#pragma species endkernel fdtd-2d-part2
		#pragma species kernel 0:NI-1,1:NJ-1|element ^ 0:NI-1,1:NJ-1|neighbourhood(0:0,-1:0) -> 0:NI-1,1:NJ-1|element
		for (i=0; i<NI; i++) {
			for (j=1; j<NJ; j++) {
				ex[i][j] = ex[i][j] - 0.5*(hz[i][j] - hz[i][j-1]);
			}
		}
		#pragma species endkernel fdtd-2d-part3
		#pragma species kernel 0:NI-2,0:NJ-2|element ^ 0:NI-2,0:NJ-2|neighbourhood(0:0,0:1) ^ 0:NI-2,0:NJ-2|neighbourhood(0:1,0:0) -> 0:NI-2,0:NJ-2|element
		for (i=0; i<NI-1; i++) {
			for (j=0; j<NJ-1; j++) {
				hz[i][j] = hz[i][j] - 0.7*(ex[i][j+1] - ex[i][j] + ey[i+1][j] - ey[i][j]);
			}
		}
		#pragma species endkernel fdtd-2d-part4
	}
	
	// Clean-up and exit the function
	fflush(stdout);
	return 0;
}