Vertical loop fusion and demotion of temporaries

loki/batch/tests/test_scheduler.py

@@ -2887,21 +2887,22 @@ def test_pipeline_config_compose(config):
     assert isinstance(pipeline, Pipeline)
 
     # Check that the pipeline is correctly composed
-    assert len(pipeline.transformations) == 7
+    assert len(pipeline.transformations) == 8
     assert type(pipeline.transformations[0]).__name__ == 'RemoveCodeTransformation'
-    assert type(pipeline.transformations[1]).__name__ == 'SCCBaseTransformation'
-    assert type(pipeline.transformations[2]).__name__ == 'SCCDevectorTransformation'
-    assert type(pipeline.transformations[3]).__name__ == 'SCCDemoteTransformation'
-    assert type(pipeline.transformations[4]).__name__ == 'SCCRevectorTransformation'
-    assert type(pipeline.transformations[5]).__name__ == 'SCCAnnotateTransformation'
-    assert type(pipeline.transformations[6]).__name__ == 'ModuleWrapTransformation'
+    assert type(pipeline.transformations[1]).__name__ == 'SCCFuseVerticalLoops'
+    assert type(pipeline.transformations[2]).__name__ == 'SCCBaseTransformation'
+    assert type(pipeline.transformations[3]).__name__ == 'SCCDevectorTransformation'
+    assert type(pipeline.transformations[4]).__name__ == 'SCCDemoteTransformation'
+    assert type(pipeline.transformations[5]).__name__ == 'SCCRevectorTransformation'
+    assert type(pipeline.transformations[6]).__name__ == 'SCCAnnotateTransformation'
+    assert type(pipeline.transformations[7]).__name__ == 'ModuleWrapTransformation'
 
     # Check for some specified and default constructor flags
     assert pipeline.transformations[0].call_names == ('dr_hook',)
     assert pipeline.transformations[0].remove_imports is False
-    assert isinstance(pipeline.transformations[1].horizontal, Dimension)
-    assert pipeline.transformations[1].horizontal.size == 'KLON'
-    assert pipeline.transformations[1].horizontal.index == 'JL'
-    assert pipeline.transformations[1].directive == 'openacc'
-    assert pipeline.transformations[2].trim_vector_sections is True
-    assert pipeline.transformations[6].replace_ignore_items is True
+    assert isinstance(pipeline.transformations[2].horizontal, Dimension)
+    assert pipeline.transformations[2].horizontal.size == 'KLON'
+    assert pipeline.transformations[2].horizontal.index == 'JL'
+    assert pipeline.transformations[2].directive == 'openacc'
+    assert pipeline.transformations[3].trim_vector_sections is True
+    assert pipeline.transformations[7].replace_ignore_items is True

loki/transformations/single_column/__init__.py

@@ -13,3 +13,4 @@
 from loki.transformations.single_column.scc_cuf import * # noqa
 from loki.transformations.single_column.vector import * # noqa
 from loki.transformations.single_column.scc_low_level import * # noqa
+from loki.transformations.single_column.vertical import * # noqa

loki/transformations/single_column/scc.py

@@ -19,7 +19,7 @@
 from loki.transformations.single_column.vector import (
     SCCDevectorTransformation, SCCDemoteTransformation, SCCRevectorTransformation
 )
-
+from loki.transformations.single_column.vertical import SCCFuseVerticalLoops
 
 __all__ = [
     'SCCVectorPipeline', 'SCCHoistPipeline', 'SCCStackPipeline', 'SCCRawStackPipeline'
@@ -75,6 +75,7 @@
 """
 SCCVectorPipeline = partial(
     Pipeline, classes=(
+        SCCFuseVerticalLoops,
         SCCBaseTransformation,
         SCCDevectorTransformation,
         SCCDemoteTransformation,
@@ -121,6 +122,7 @@
 """
 SCCHoistPipeline = partial(
     Pipeline, classes=(
+        SCCFuseVerticalLoops,
         SCCBaseTransformation,
         SCCDevectorTransformation,
         SCCDemoteTransformation,
@@ -166,6 +168,7 @@
 """
 SCCStackPipeline = partial(
     Pipeline, classes=(
+        SCCFuseVerticalLoops,
         SCCBaseTransformation,
         SCCDevectorTransformation,
         SCCDemoteTransformation,

loki/transformations/single_column/tests/test_scc_vertical.py

@@ -0,0 +1,255 @@
+# (C) Copyright 2018- ECMWF.
+# This software is licensed under the terms of the Apache Licence Version 2.0
+# which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
+# In applying this licence, ECMWF does not waive the privileges and immunities
+# granted to it by virtue of its status as an intergovernmental organisation
+# nor does it submit to any jurisdiction.
+
+import pytest
+
+from loki import Subroutine, Dimension
+from loki.frontend import available_frontends
+from loki.ir import FindNodes, Loop, FindVariables
+from loki.transformations.single_column import SCCFuseVerticalLoops
+
+
+@pytest.fixture(scope='module', name='horizontal')
+def fixture_horizontal():
+    return Dimension(
+        name='horizontal', size='nlon', index='jl',
+        bounds=('start', 'end'), aliases=('nproma',)
+    )
+
+@pytest.fixture(scope='module', name='horizontal_bounds_aliases')
+def fixture_horizontal_bounds_aliases():
+    return Dimension(
+        name='horizontal_bounds_aliases', size='nlon', index='jl',
+        bounds=('start', 'end'), aliases=('nproma',),
+        bounds_aliases=('bnds%start', 'bnds%end')
+    )
+
+@pytest.fixture(scope='module', name='vertical')
+def fixture_vertical():
+    return Dimension(name='vertical', size='nz', index='jk', aliases=('nlev',))
+
+@pytest.fixture(scope='module', name='blocking')
+def fixture_blocking():
+    return Dimension(name='blocking', size='nb', index='b')
+
+
+@pytest.mark.parametrize('frontend', available_frontends())
+def test_simple_scc_fuse_verticals_transformation(frontend, horizontal, vertical):
+    """
+    Test simple example of vertical loop fusion and demotion of temporaries.
+    """
+
+    fcode_kernel = """
+  SUBROUTINE compute_column(start, end, nlon, nz, q, t)
+    INTEGER, INTENT(IN) :: start, end  ! Iteration indices
+    INTEGER, INTENT(IN) :: nlon, nz    ! Size of the horizontal and vertical
+    REAL, INTENT(INOUT) :: t(nlon,nz)
+    REAL, INTENT(INOUT) :: q(nlon,nz)
+    REAL :: temp_t(nlon, nz)
+    REAL :: temp_q(nlon, nz)
+    INTEGER :: jl, JK
+    REAL :: c
+
+    c = 5.345
+    !$loki loop-fusion group(1)
+    DO JK = 1, nz
+      DO jl = start, end
+        temp_t(jl, jk) = c
+        temp_q(jl, JK) = c
+      END DO
+    END DO
+
+    !$loki loop-fusion group(1)
+    DO jk = 2, nz
+      DO jl = start, end
+        t(jl, jk) = temp_t(jl, jk) * jk
+        q(jl, jk) = q(jl, jk-1) + t(jl, jk) * temp_q(jl, jk)
+      END DO
+    END DO
+
+    ! The scaling is purposefully upper-cased
+    DO JL = START, END
+      Q(JL, NZ) = Q(JL, NZ) * C
+    END DO
+  END SUBROUTINE compute_column
+"""
+    kernel = Subroutine.from_source(fcode_kernel, frontend=frontend)
+
+    # Ensure we have three loops in the kernel prior to transformation
+    kernel_loops = FindNodes(Loop).visit(kernel.body)
+    assert len(kernel_loops) == 5
+
+    # no-op as 'compute_column' is not within apply_to
+    SCCFuseVerticalLoops(vertical=vertical, apply_to=('another_kernel',)).apply(kernel, role='kernel')
+    # Ensure we have three loops in the kernel prior to transformation
+    kernel_loops = FindNodes(Loop).visit(kernel.body)
+    assert len(kernel_loops) == 5
+
+    # actual loop fusion and demotion ... (as apply_to is not provided and therefore all routines are dispatched)
+    SCCFuseVerticalLoops(vertical=vertical).apply(kernel, role='kernel')
+
+    # Ensure the two vertical loops are fused
+    kernel_loops = FindNodes(Loop).visit(kernel.body)
+    assert len(kernel_loops) == 4
+    assert kernel_loops[0].variable.name.lower() == 'jk'
+    assert kernel_loops[-1].variable.name.lower() == 'jl'
+    assert len([loop for loop in kernel_loops if loop.variable.name.lower() == 'jk']) == 1
+    kernel_var_map = kernel.variable_map
+    assert kernel_var_map['temp_t'].shape == (horizontal.size,)
+    assert kernel_var_map['temp_q'].shape == (horizontal.size,)
+    kernel_vars = [var for var in FindVariables().visit(kernel.body) if var.name.lower() in ['temp_t', 'temp_q']]
+    for var in kernel_vars:
+        assert var.shape == (horizontal.size,)
+        assert var.dimensions == (horizontal.index,)
+
+
+@pytest.mark.parametrize('frontend', available_frontends())
+@pytest.mark.parametrize('ignore', (False, True))
+def test_scc_fuse_verticals_transformation(frontend, horizontal, vertical, ignore):
+    """
+    Test somewhat more sophisticated example of vertical loop fusion
+    and demotion of temporaries.
+    """
+
+    fcode_kernel = f"""
+  SUBROUTINE compute_column(start, end, nlon, nz, q, t)
+    INTEGER, INTENT(IN) :: start, end  ! Iteration indices
+    INTEGER, INTENT(IN) :: nlon, nz    ! Size of the horizontal and vertical
+    REAL, INTENT(INOUT) :: t(nlon,nz)
+    REAL, INTENT(INOUT) :: q(nlon,nz)
+    REAL :: temp_t(nlon, nz)
+    REAL :: temp_t2(nlon, nz)
+    REAL :: temp_q(nlon, nz)
+    REAL :: temp_q2(nlon, nz)
+    REAL :: temp_cld(nlon, nz, 5)
+    INTEGER :: jl, jk, jm
+    REAL :: c
+
+    {'!$loki k-caching ignore(temp_q2)' if ignore else ''}
+
+    c = 5.345
+    !$loki loop-fusion group(1-init)
+    DO jk = 1, nz
+      DO jl = start, end
+        temp_t(jl, jk) = c
+        temp_q(jl, jk) = c
+        temp_t2(jl, jk) = 2*c
+      END DO
+    END DO
+
+    !$loki loop-fusion group(1)
+    !$loki loop-interchange
+    DO jm=1,5
+      DO jk = 1, nz
+        DO jl = start, end
+          temp_cld(jl, jk, jm) = 3.1415
+        END DO
+      END DO
+    END DO
+
+    DO jl = start, end
+      q(jl, jk) = 0.
+    END DO
+
+    !$loki loop-fusion group(1) insert
+    DO jk = 2, nz
+      DO jl = start, end
+        t(jl, jk) = temp_t(jl, jk) * temp_t2(jl, jk-1) * temp_cld(jl, jk, 1)
+        q(jl, jk) = q(jl, jk-1) + t(jl, jk) * temp_q(jl, jk)
+      END DO
+    END DO
+
+    CALL nested_kernel(start, end, nlon, nz, q)
+
+    !$loki loop-fusion group(2)
+    DO jk = 2, nz
+      DO jl = start, end
+        temp_q2(jl, jk) = 3.1415
+      END DO
+    END DO
+
+    !$loki loop-fusion group(2)
+    DO jk = 2, nz
+      DO jl = start, end
+        t(jl, jk) = t(jl, jk) + 3.1415
+        q(jl, jk) = q(jl, jk-1) + t(jl, jk) * temp_q(jl, jk) + temp_q2(jl, jk)
+      END DO
+    END DO
+
+    ! The scaling is purposefully upper-cased
+    DO JL = START, END
+      Q(JL, NZ) = Q(JL, NZ) * C
+    END DO
+  END SUBROUTINE compute_column
+"""
+
+
+    kernel = Subroutine.from_source(fcode_kernel, frontend=frontend)
+
+    # Ensure we have three loops in the kernel prior to transformation
+    kernel_loops = FindNodes(Loop).visit(kernel.body)
+    assert len(kernel_loops) == 13
+    SCCFuseVerticalLoops(vertical=vertical).apply(kernel, role='kernel')
+
+    # Ensure the two vertical loops are fused
+    kernel_loops = FindNodes(Loop).visit(kernel.body)
+    assert len(kernel_loops) == 12
+    vertical_loops = [loop for loop in kernel_loops if loop.variable.name.lower() == vertical.index]
+    assert len(vertical_loops) == 3
+
+    shape1D = (horizontal.size,)
+    shape2D = (horizontal.size, vertical.size)
+    dimension1D = (horizontal.index,)
+    dimension2D = (horizontal.index,vertical.index)
+    dimension2DI1 = (horizontal.index, f'{vertical.index}-1')
+
+    vertical_loop_0_vars = FindVariables().visit(vertical_loops[0].body)
+    vertical_loop_0_var_names = [var.name.lower() for var in vertical_loop_0_vars]
+    vertical_loop_0_var_dict = dict(zip(vertical_loop_0_var_names, vertical_loop_0_vars))
+    assert 'temp_t2' in vertical_loop_0_var_names
+    assert 'temp_t' not in vertical_loop_0_var_names
+    assert 'temp_q' not in vertical_loop_0_var_names
+    assert 'temp_q2' not in vertical_loop_0_var_names
+    assert 'temp_cld' not in vertical_loop_0_var_names
+    assert vertical_loop_0_var_dict['temp_t2'].shape == shape2D
+    assert vertical_loop_0_var_dict['temp_t2'].dimensions == dimension2D
+
+    vertical_loop_1_vars = FindVariables().visit(vertical_loops[1].body)
+    vertical_loop_1_var_names = [var.name.lower() for var in vertical_loop_1_vars]
+    vertical_loop_1_var_dict = dict(zip(vertical_loop_1_var_names, vertical_loop_1_vars))
+    assert 'temp_t2' in vertical_loop_1_var_names
+    assert 'temp_t' in vertical_loop_1_var_names
+    assert 'temp_q' in vertical_loop_1_var_names
+    assert 'temp_q2' not in vertical_loop_1_vars
+    assert 'temp_cld' in vertical_loop_1_var_names
+    assert vertical_loop_1_var_dict['temp_t2'].shape == shape2D
+    assert vertical_loop_1_var_dict['temp_t2'].dimensions == dimension2DI1
+    assert vertical_loop_1_var_dict['temp_t'].shape == shape1D
+    assert vertical_loop_1_var_dict['temp_t'].dimensions == dimension1D
+    assert vertical_loop_1_var_dict['temp_q'].shape == shape2D
+    assert vertical_loop_1_var_dict['temp_q'].dimensions == dimension2D
+    assert vertical_loop_1_var_dict['temp_cld'].shape == shape1D + (5,)
+    assert vertical_loop_1_var_dict['temp_cld'].dimensions in (dimension1D + (1,), dimension1D + ('jm',))
+
+    vertical_loop_2_vars = FindVariables().visit(vertical_loops[2].body)
+    vertical_loop_2_var_names = [var.name.lower() for var in vertical_loop_2_vars]
+    vertical_loop_2_var_dict = dict(zip(vertical_loop_2_var_names, vertical_loop_2_vars))
+    assert 'temp_t2' not in vertical_loop_2_var_names
+    assert 'temp_t' not in vertical_loop_2_var_names
+    assert 'temp_q' in vertical_loop_2_var_names
+    assert 'temp_q2' in vertical_loop_2_var_names
+    assert 'temp_cld' not in vertical_loop_2_var_names
+    assert vertical_loop_2_var_dict['temp_q'].shape == shape2D
+    assert vertical_loop_2_var_dict['temp_q'].dimensions == dimension2D
+    assert vertical_loop_2_var_dict['temp_q2'].shape == shape2D if ignore else shape1D
+    assert vertical_loop_2_var_dict['temp_q2'].dimensions == dimension2D if ignore else dimension1D
+
+    kernel_var_map = kernel.variable_map
+    assert kernel_var_map['temp_t'].shape == shape1D
+    assert kernel_var_map['temp_t2'].shape == shape2D
+    assert kernel_var_map['temp_q'].shape == shape2D
+    assert kernel_var_map['temp_q2'].shape == shape2D if ignore else shape1D