Gracefully fallback to loop based matrix multiply

shogun-toolbox · Jul 27, 2012 · 1a157fe · 1a157fe
1 parent bea8e08
commit 1a157fe
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Showing 2 changed files with 14 additions and 3 deletions.
diff --git a/src/shogun/lib/SGMatrix.cpp b/src/shogun/lib/SGMatrix.cpp
@@ -623,14 +623,25 @@ SGMatrix<float64_t> SGMatrix<T>::matrix_multiply(
 
 	/* allocate result matrix */
 	SGMatrix<float64_t> C(rows_A, cols_B);
-
+	C.zero();
+#ifdef HAVE_LAPACK
 	/* multiply */
 	cblas_dgemm(CblasColMajor,
 			transpose_A ? CblasTrans : CblasNoTrans,
 			transpose_B ? CblasTrans : CblasNoTrans,
 			rows_A, cols_B, cols_A, scale,
 			A.matrix, A.num_rows, B.matrix, B.num_rows,
 			0.0, C.matrix, C.num_rows);
+#else
+	for (int32_t i=0; i<rows_A; i++)
+	{
+		for (int32_t j=0; j<cols_B; j++)
+		{
+			for (int32_t k=0; k<cols_A; k++)
+				C(i,j) += A(i,k)*B(k,j);
+		}
+	}
+#endif
 
 	return C;
 }

diff --git a/src/shogun/lib/SGMatrix.h b/src/shogun/lib/SGMatrix.h
@@ -196,7 +196,7 @@ template<class T> class SGMatrix : public SGReferencedData
 		 */
 		void compute_few_eigenvectors(double* matrix_, double*& eigenvalues, double*& eigenvectors,
                                       int n, int il, int iu);
-
+#endif
 		/* Computes scale* A*B, where A and B may be transposed.
 		 * Asserts for matching inner dimensions.
 		 * @param A matrix A
@@ -209,7 +209,7 @@ template<class T> class SGMatrix : public SGReferencedData
 				SGMatrix<float64_t> A, SGMatrix<float64_t> B,
 				bool transpose_A=false, bool transpose_B=false,
 				float64_t scale=1.0);
-
+#ifdef HAVE_LAPACK
 		/// inverses square matrix in-place
 		static void inverse(SGMatrix<float64_t> matrix);