Added test case to test multiple field swaps in one kernel

tests/field/CMakeLists.txt

@@ -72,4 +72,9 @@ waLBerla_generate_target_from_python(NAME CodegenPoissonGeneratedKernel FILE cod
       OUT_FILES Poisson.cpp Poisson.h )
 waLBerla_compile_test( FILES codegen/CodegenPoisson.cpp DEPENDS gui timeloop CodegenPoissonGeneratedKernel)
 waLBerla_execute_test( NAME CodegenPoisson )
+
+waLBerla_generate_target_from_python(NAME CodeGenMultipleFieldSwaps FILE codegen/MultipleFieldSwaps.py
+        OUT_FILES MultipleFieldSwaps.cpp MultipleFieldSwaps.h )
+waLBerla_compile_test( FILES codegen/MultipleFieldSwaps.cpp DEPENDS gui timeloop CodeGenMultipleFieldSwaps)
+waLBerla_execute_test( NAME MultipleFieldSwaps )
 endif()

tests/field/codegen/MultipleFieldSwaps.cpp

+//======================================================================================================================
+//
+//  This file is part of waLBerla. waLBerla is free software: you can
+//  redistribute it and/or modify it under the terms of the GNU General Public
+//  License as published by the Free Software Foundation, either version 3 of
+//  the License, or (at your option) any later version.
+//
+//  waLBerla is distributed in the hope that it will be useful, but WITHOUT
+//  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+//  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+//  for more details.
+//
+//  You should have received a copy of the GNU General Public License along
+//  with waLBerla (see COPYING.txt). If not, see <http://www.gnu.org/licenses/>.
+//
+//! \file MultipleFieldSwaps.cpp
+//! \author Markus Holzer <markus.holzer@fau.de>
+//
+//======================================================================================================================
+
+#include "MultipleFieldSwaps.h"
+#include "blockforest/Initialization.h"
+#include "blockforest/communication/UniformDirectScheme.h"
+
+#include "core/Environment.h"
+#include "core/debug/TestSubsystem.h"
+
+#include "field/AddToStorage.h"
+
+#include "stencil/D2Q9.h"
+
+
+using namespace walberla;
+
+typedef GhostLayerField<double,1> ScalarField;
+void testMultipleFieldSwaps()
+{
+   uint_t xSize = 5;
+   uint_t ySize = 5;
+   // Create blocks
+   shared_ptr< StructuredBlockForest > blocks = blockforest::createUniformBlockGrid (
+      uint_t(1) , uint_t(1),  uint_t(1),  // number of blocks in x,y,z direction
+      xSize, ySize, uint_t(1),            // how many cells per block (x,y,z)
+      real_t(1),                          // dx: length of one cell in physical coordinates
+      false,                              // one block per process - "false" means all blocks to one process
+      true, true, true );                 // full periodicity
+
+
+   BlockDataID fieldID_1 = field::addToStorage<ScalarField>(blocks, "Field_1", real_t(1.0));
+   BlockDataID fieldID_2 = field::addToStorage<ScalarField>(blocks, "Field_2", real_t(1.0));
+   BlockDataID fieldID_3 = field::addToStorage<ScalarField>(blocks, "Field_3", real_t(1.0));
+
+   pystencils::MultipleFieldSwaps kernel(fieldID_1, fieldID_2, fieldID_3);
+
+   for (auto &block: *blocks)
+      kernel(&block);
+
+   for (auto& block : *blocks)
+   {
+      auto field_1 = block.getData< ScalarField >(fieldID_1);
+      auto field_2 = block.getData< ScalarField >(fieldID_2);
+      auto field_3 = block.getData< ScalarField >(fieldID_3);
+      // clang-format off
+      WALBERLA_FOR_ALL_CELLS_XYZ(field_1, Cell globalCell;
+         blocks->transformBlockLocalToGlobalCell(globalCell, block, Cell(x, y, z));
+         WALBERLA_CHECK_FLOAT_EQUAL(field_1->get(x, y, z), real_t(2.0))
+         WALBERLA_CHECK_FLOAT_EQUAL(field_2->get(x, y, z), real_t(2.0))
+         WALBERLA_CHECK_FLOAT_EQUAL(field_3->get(x, y, z), real_t(2.0))
+      )
+      // clang-format on
+   }
+}
+
+
+
+int main( int argc, char ** argv )
+{
+   mpi::Environment env( argc, argv );
+   debug::enterTestMode();
+
+   testMultipleFieldSwaps();
+
+   return EXIT_SUCCESS;
+}
\ No newline at end of file

tests/field/codegen/MultipleFieldSwaps.py

+import pystencils as ps
+from pystencils_walberla import CodeGeneration, generate_sweep
+
+with CodeGeneration() as ctx:
+    src_1, dst_1 = ps.fields("src1, src1_tmp: [2D]", layout='fzyx')
+    src_2, dst_2 = ps.fields("src2, src2_tmp: [2D]", layout='fzyx')
+    src_3, dst_3 = ps.fields("src3, src3_tmp: [2D]", layout='fzyx')
+
+    assignments = ps.AssignmentCollection([ps.Assignment(dst_1.center, 2 * src_1.center),
+                                           ps.Assignment(dst_2.center, 2 * src_2.center),
+                                           ps.Assignment(dst_3.center, 2 * src_3.center)])
+
+    generate_sweep(ctx, 'MultipleFieldSwaps', assignments,
+                   field_swaps=[(src_1, dst_1), (src_2, dst_2), (src_3, dst_3)])