all scaling operations use blas scal

Author: PierreMarchand20

include/htool/hmatrix/linalg/add_hmatrix_matrix_product_row_major.hpp

@@ -86,8 +86,7 @@ void sequential_internal_add_hmatrix_matrix_product_row_major(char transa, char
 
     int incx(1), incy(1);
     if (CoefficientPrecision(beta) != CoefficientPrecision(1)) {
-        // TODO: use blas
-        std::transform(C, C + out_size, C, [&beta](CoefficientPrecision &c) { return c * beta; });
+        Blas<CoefficientPrecision>::scal(&out_size, &beta, C, &incx);
     }
 
     // Contribution champ lointain
@@ -141,8 +140,7 @@ void openmp_internal_add_hmatrix_matrix_product_row_major(char transa, char tran
 
     int incx(1), incy(1);
     if (CoefficientPrecision(beta) != CoefficientPrecision(1)) {
-        // TODO: use blas
-        std::transform(C, C + out_size, C, [&beta](CoefficientPrecision &c) { return c * beta; });
+        Blas<CoefficientPrecision>::scal(&out_size, &beta, C, &incx);
     }
 
     // Contribution champ lointain

include/htool/hmatrix/linalg/add_hmatrix_vector_product.hpp

@@ -81,7 +81,8 @@ void sequential_internal_add_hmatrix_vector_product(char trans, CoefficientPreci
     }
 
     if (CoefficientPrecision(beta) != CoefficientPrecision(1)) {
-        std::transform(out, out + out_size, out, [&beta](CoefficientPrecision &c) { return c * beta; });
+        int incx = 1;
+        Blas<CoefficientPrecision>::scal(&out_size, &beta, out, &incx);
     }
 
     // Contribution champ lointain
@@ -131,8 +132,7 @@ void openmp_internal_add_hmatrix_vector_product(char trans, CoefficientPrecision
 
     int incx(1), incy(1);
     if (CoefficientPrecision(beta) != CoefficientPrecision(1)) {
-        // TODO: use blas
-        std::transform(out, out + out_size, out, [&beta](CoefficientPrecision &c) { return c * beta; });
+        Blas<CoefficientPrecision>::scal(&out_size, &beta, out, &incx);
     }
 
 // Contribution champ lointain

include/htool/matrix/linalg/add_matrix_vector_product.hpp

@@ -16,8 +16,9 @@ void add_matrix_vector_product(char trans, T alpha, const Matrix<T> &A, const T
         int incx = 1;
         int incy = 1;
         Blas<T>::gemv(&trans, &nr, &nc, &alpha, A.data(), &lda, in, &incx, &beta, out, &incy);
-    } else if (nr) {
-        std::transform(out, out + nr, out, [&beta](T &c) { return c * beta; }); // LCOV_EXCL_LINE
+    } else if (nr) {                           // LCOV_EXCL_LINE
+        int incx = 1;                          // LCOV_EXCL_LINE
+        Blas<T>::scal(&nr, &beta, out, &incx); // LCOV_EXCL_LINE
     }
 }