From 6c0d3de3aacfaa095e9f05fd666e96522a6273fc Mon Sep 17 00:00:00 2001
From: Daniel Arndt <daniel.arndt@iwr.uni-heidelberg.de>
Date: Thu, 16 Aug 2018 23:07:04 +0200
Subject: [PATCH] Add GMRES test for CUDAWrappers::Vector

---
 tests/cuda/solver_03.cu     | 85 +++++++++++++++++++++++++++++++++++++
 tests/cuda/solver_03.output |  6 +++
 2 files changed, 91 insertions(+)
 create mode 100644 tests/cuda/solver_03.cu
 create mode 100644 tests/cuda/solver_03.output

diff --git a/tests/cuda/solver_03.cu b/tests/cuda/solver_03.cu
new file mode 100644
index 0000000000..89250f5110
--- /dev/null
+++ b/tests/cuda/solver_03.cu
@@ -0,0 +1,85 @@
+// ---------------------------------------------------------------------
+//
+// Copyright (C) 2018 by the deal.II authors
+//
+// This file is part of the deal.II library.
+//
+// The deal.II library is free software; you can use it, redistribute
+// it, and/or modify it under the terms of the GNU Lesser General
+// Public License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+// The full text of the license can be found in the file LICENSE.md at
+// the top level directory of deal.II.
+//
+// ---------------------------------------------------------------------
+
+// Check that dealii::SolverGMRES works with CUDAWrappers::SparseMatrix
+
+#include <deal.II/base/cuda.h>
+#include <deal.II/base/exceptions.h>
+
+#include <deal.II/lac/cuda_sparse_matrix.h>
+#include <deal.II/lac/precondition.h>
+#include <deal.II/lac/read_write_vector.h>
+#include <deal.II/lac/solver_control.h>
+#include <deal.II/lac/solver_gmres.h>
+#include <deal.II/lac/vector.h>
+
+#include "../testmatrix.h"
+#include "../tests.h"
+
+void
+test(Utilities::CUDA::Handle &cuda_handle)
+{
+  // Build the sparse matrix on the host
+  const unsigned int   problem_size = 10;
+  unsigned int         size         = (problem_size - 1) * (problem_size - 1);
+  FDMatrix             testproblem(problem_size, problem_size);
+  SparsityPattern      structure(size, size, 5);
+  SparseMatrix<double> A;
+  testproblem.five_point_structure(structure);
+  structure.compress();
+  A.reinit(structure);
+  testproblem.five_point(A);
+
+  // Solve on the host
+  PreconditionIdentity prec_no;
+  SolverControl        control(100, 1.e-10);
+  SolverGMRES<>        cg_host(control);
+  Vector<double>       sol_host(size);
+  Vector<double>       rhs_host(size);
+  for (unsigned int i = 0; i < size; ++i)
+    rhs_host[i] = static_cast<double>(i);
+  cg_host.solve(A, sol_host, rhs_host, prec_no);
+
+  // Solve on the device
+  CUDAWrappers::SparseMatrix<double>          A_dev(cuda_handle, A);
+  LinearAlgebra::CUDAWrappers::Vector<double> sol_dev(size);
+  LinearAlgebra::CUDAWrappers::Vector<double> rhs_dev(size);
+  LinearAlgebra::ReadWriteVector<double>      rw_vector(size);
+  for (unsigned int i = 0; i < size; ++i)
+    rw_vector[i] = static_cast<double>(i);
+  rhs_dev.import(rw_vector, VectorOperation::insert);
+  SolverGMRES<LinearAlgebra::CUDAWrappers::Vector<double>> cg_dev(control);
+  cg_dev.solve(A_dev, sol_dev, rhs_dev, prec_no);
+
+  // Check the result
+  rw_vector.import(sol_dev, VectorOperation::insert);
+  for (unsigned int i = 0; i < size; ++i)
+    AssertThrow(std::fabs(rw_vector[i] - sol_host[i]) < 1e-8,
+                ExcInternalError());
+}
+
+int
+main()
+{
+  initlog();
+  deallog.depth_console(0);
+
+  Utilities::CUDA::Handle cuda_handle;
+  test(cuda_handle);
+
+  deallog << "OK" << std::endl;
+
+  return 0;
+}
diff --git a/tests/cuda/solver_03.output b/tests/cuda/solver_03.output
new file mode 100644
index 0000000000..b8e4a2e2fb
--- /dev/null
+++ b/tests/cuda/solver_03.output
@@ -0,0 +1,6 @@
+
+DEAL:GMRES::Starting value 416.989
+DEAL:GMRES::Convergence step 32 value 4.50651e-11
+DEAL:GMRES::Starting value 416.989
+DEAL:GMRES::Convergence step 32 value 4.50477e-11
+DEAL::OK
-- 
2.39.5