Swapped Pointers for u and uhelp after iteration

Copying of matrix uhelp to u each time is avoided, by swapping pointers.
Signed-off-by: Gaurav Kukreja <mailme.gaurav@gmail.com>

heat-seq/heat.c

@@ -26,6 +26,8 @@ int main( int argc, char *argv[] )
     FILE *infile, *resfile;
     char *resfilename;
 
+	double *tmp;
+
     // algorithmic parameters
     algoparam_t param;
     int np;
@@ -115,6 +117,9 @@ int main( int argc, char *argv[] )
 		case 0: // JACOBI
       
 		    relax_jacobi(param.u, param.uhelp, np, np);
+			tmp = param.u;
+			param.u = param.uhelp;
+			param.uhelp = tmp;
 		    residual = residual_jacobi( param.u, np, np);
 		    break;
 

heat-seq/misc.c

@@ -58,6 +58,7 @@ int initialize( algoparam_t *param )
 		    (param->heatsrcs[i].range-dist) /
 		    param->heatsrcs[i].range *
 		    param->heatsrcs[i].temp;
+		(param->uhelp)[j] = (param->u)[j];
 	    }
 	}
       
@@ -74,6 +75,7 @@ int initialize( algoparam_t *param )
 		    (param->heatsrcs[i].range-dist) / 
 		    param->heatsrcs[i].range * 
 		    param->heatsrcs[i].temp;
+		(param->uhelp)[(np-1)*np+j] = (param->u)[(np-1)*np+j];
 	    }
 	}
       
@@ -90,6 +92,7 @@ int initialize( algoparam_t *param )
 		    (param->heatsrcs[i].range-dist) / 
 		    param->heatsrcs[i].range *
 		    param->heatsrcs[i].temp;
+		(param->uhelp)[ j*np ] = (param->u)[ j*np ];
 	    }
 	}
       
@@ -106,6 +109,7 @@ int initialize( algoparam_t *param )
 		    (param->heatsrcs[i].range-dist) /
 		    param->heatsrcs[i].range *
 		    param->heatsrcs[i].temp;
+		(param->uhelp)[ j*np+(np-1) ] = (param->u)[ j*np+(np-1) ];
 	    }
 	}
     }

heat-seq/relax_jacobi.c

@@ -53,14 +53,4 @@ void relax_jacobi( double *u, double *utmp,
 				     u[ (i+1)*sizex + j     ]); // bottom
 	}
     }
-  
-    // copy from utmp to u
-
-    for( i=1; i<sizey-1; i++ )
-    {
-	for( j=1; j<sizex-1; j++ )
-        {
-	    u[ i*sizex+j ] = utmp[ i*sizex+j ];
-	}
-    }
 }