In-place triangular matrix vector product + tests

include/experimental/__p1673_bits/blas2_matrix_vector_product.hpp

@@ -225,6 +225,29 @@ struct is_custom_tri_mat_vec_product_with_update_avail<
   >
   : std::true_type{};
 
+// In-place triangular matrix-vector product with update
+template <class Exec, class A_t, class Tri_t, class D_t, class Y_t, class = void>
+struct is_custom_tri_mat_vec_product_with_inplace_avail : std::false_type {};
+
+template <class Exec, class A_t, class Tri_t, class D_t, class Y_t>
+struct is_custom_tri_mat_vec_product_with_inplace_avail<
+  Exec, A_t, Tri_t, D_t, Y_t,
+  std::enable_if_t<
+    std::is_void_v<
+      decltype(triangular_matrix_vector_product
+	       (std::declval<Exec>(),
+		std::declval<A_t>(),
+		std::declval<Tri_t>(),
+		std::declval<D_t>(),
+		std::declval<Y_t>()
+		)
+	       )
+      >
+    && !linalg::impl::is_inline_exec_v<Exec>
+    >
+  >
+  : std::true_type{};
+
 } // end anonymous namespace
 
 namespace impl {
@@ -1278,6 +1301,117 @@ void triangular_matrix_vector_product(
   triangular_matrix_vector_product(impl::default_exec_t{}, A, t, d, x, y, z);
 }
 
+// In-place triangular matrix-vector product: y := A * y
+
+MDSPAN_TEMPLATE_REQUIRES(
+         class ElementType_A,
+	     class SizeType_A,
+	     ::std::size_t numRows_A,
+         ::std::size_t numCols_A,
+         class Layout_A,
+         class Accessor_A,
+         class Triangle,
+         class DiagonalStorage,
+         class ElementType_y,
+         class SizeType_y,
+         ::std::size_t ext_y,
+         class Layout_y,
+         class Accessor_y,
+         /* requires */ (impl::always_unique_mapping_v<Layout_A, extents<SizeType_A, numRows_A, numCols_A>>)
+)
+void triangular_matrix_vector_product(
+  linalg::impl::inline_exec_t&& /* exec */,
+  mdspan<ElementType_A, extents<SizeType_A, numRows_A, numCols_A> , Layout_A, Accessor_A> A,
+  Triangle t,
+  DiagonalStorage d,
+  mdspan<ElementType_y, extents<SizeType_y, ext_y>, Layout_y, Accessor_y> y)
+{
+  using size_type = std::common_type_t<SizeType_A, SizeType_y>;
+  constexpr bool explicitDiagonal =
+    std::is_same_v<DiagonalStorage, explicit_diagonal_t>;
+
+  if constexpr (std::is_same_v<Triangle, lower_triangle_t>) {
+    for (size_type k = 0; k < A.extent(1); ++k) {
+      size_type j = A.extent(1) - (k + size_type(1));
+      ElementType_y tmp = y(j);
+      for (size_type i = j + size_type(1); i < A.extent(0); ++i) {
+        y(i) += A(i,j) * tmp;
+      }
+      if constexpr (explicitDiagonal) {
+        y(j) = y(j) * A(j,j);
+      }
+    }
+  }
+  else {
+    for (size_type j = 0; j < A.extent(1); ++j) {
+      ElementType_y tmp = y(j);
+      for (size_type i = 0; i < j; ++i) {
+        y(i) += A(i,j) * tmp;
+      }
+      if constexpr (explicitDiagonal) {
+        y(j) = y(j) * A(j,j);
+      }
+    }
+  }
+}
+
+template<class ExecutionPolicy,
+         class ElementType_A,
+         class SizeType_A,
+         ::std::size_t numRows_A,
+         ::std::size_t numCols_A,
+         class Layout_A,
+         class Accessor_A,
+         class Triangle,
+         class DiagonalStorage,
+         class ElementType_y,
+         class SizeType_y, ::std::size_t ext_y,
+         class Layout_y,
+         class Accessor_y>
+void triangular_matrix_vector_product(
+  ExecutionPolicy&& exec,
+  mdspan<ElementType_A, extents<SizeType_A, numRows_A, numCols_A>, Layout_A, Accessor_A> A,
+  Triangle t,
+  DiagonalStorage d,
+  mdspan<ElementType_y, extents<SizeType_y, ext_y>, Layout_y, Accessor_y> y)
+{
+  constexpr bool use_custom = is_custom_tri_mat_vec_product_with_inplace_avail<
+    decltype(execpolicy_mapper(exec)),
+    decltype(A), decltype(t), decltype(d), decltype(y)
+    >::value;
+
+  if constexpr(use_custom) {
+    triangular_matrix_vector_product(execpolicy_mapper(exec), A, t, d, y);
+  } else {
+    triangular_matrix_vector_product(linalg::impl::inline_exec_t(), A, t, d, y);
+  }
+}
+
+MDSPAN_TEMPLATE_REQUIRES(
+         class ElementType_A,
+    	 class SizeType_A,
+    	 ::std::size_t numRows_A,
+         ::std::size_t numCols_A,
+         class Layout_A,
+         class Accessor_A,
+         class Triangle,
+         class DiagonalStorage,
+         class ElementType_y,
+         class SizeType_y,
+         ::std::size_t ext_y,
+         class Layout_y,
+         class Accessor_y,
+         /* requires */ (impl::always_unique_mapping_v<Layout_A, extents<SizeType_A, numRows_A, numCols_A>>)
+)
+void triangular_matrix_vector_product(
+  mdspan<ElementType_A, extents<SizeType_A, numRows_A, numCols_A>, Layout_A, Accessor_A> A,
+  Triangle t,
+  DiagonalStorage d,
+  mdspan<ElementType_y, extents<SizeType_y, ext_y>, Layout_y, Accessor_y> y)
+{
+  triangular_matrix_vector_product(linalg::impl::default_exec_t(), A, t, d, y);
+}
+
 } // end namespace linalg
 } // end inline namespace __p1673_version_0
 } // end namespace MDSPAN_IMPL_PROPOSED_NAMESPACE

tests/native/CMakeLists.txt

@@ -44,4 +44,5 @@ linalg_add_test(syr)
 linalg_add_test(syrk)
 linalg_add_test(transposed)
 linalg_add_test(trmm)
+linalg_add_test(trmv)
 linalg_add_test(trsm)