[refactor] have the benchmarks use the new tileids

Modify the benchmarks to use the new functions.

benchmarks/dgemm_noprefetch.c

@@ -35,9 +35,9 @@ void do_work()
 			{
 				size_t aoff, boff, coff;
 				double *ap, *bp, *cp;
-				aoff = i*ndims[1] + k;
-				boff = k*ndims[1] + j;
-				coff = i*ndims[1] + j;
+				aoff = aml_tiling_tileid(&tiling_col, i, k);
+				boff = aml_tiling_tileid(&tiling_row, k, j);
+				coff = aml_tiling_tileid(&tiling_row, i, j);
 				ap = aml_tiling_tilestart(&tiling_col, a, aoff);
 				bp = aml_tiling_tilestart(&tiling_row, b, boff);
 				cp = aml_tiling_tilestart(&tiling_row, c, coff);

benchmarks/dgemm_prefetch.c

@@ -53,7 +53,7 @@ void do_work()
 				double *ap, *bp, *cp;
 				ap = aml_tiling_tilestart(&tiling_row, prea, i);
 				bp = aml_tiling_tilestart(&tiling_row, preb, j);
-				coff = i*ndims[1] + j;
+				coff = aml_tiling_tileid(&tiling_row, i, j);
 				cp = aml_tiling_tilestart(&tiling_row, c, coff);
 				cblas_dgemm(CblasRowMajor, CblasNoTrans, CblasNoTrans, ldc, lda, ldb, 1.0, ap, lda, bp, ldb, 1.0, cp, ldc);
 			}