Merge pull request #411 from opesci/drop-partial-ordering

Drop partial ordering for loop scheduling

devito/operator.py

@@ -25,7 +25,7 @@
 from devito.parameters import configuration
 from devito.profiling import create_profile
 from devito.symbolics import indexify, retrieve_terminals
-from devito.tools import as_tuple, filter_sorted, flatten, numpy_to_ctypes, partial_order
+from devito.tools import as_tuple, filter_sorted, flatten, numpy_to_ctypes
 from devito.types import Object
 
 
@@ -304,12 +304,6 @@ def _schedule_expressions(self, clusters):
         """Create an Iteartion/Expression tree given an iterable of
         :class:`Cluster` objects."""
 
-        # Topologically sort Iterations
-        ordering = partial_order([i.stencil.dimensions for i in clusters])
-        for i, d in enumerate(list(ordering)):
-            if d.is_Stepping:
-                ordering.insert(i, d.parent)
-
         # Build the Iteration/Expression tree
         processed = []
         schedule = OrderedDict()
@@ -323,9 +317,6 @@ def _schedule_expressions(self, clusters):
                 root = None
                 entries = i.stencil.entries
 
-                # Reorder based on the globally-established loop ordering
-                entries = sorted(entries, key=lambda i: ordering.index(i.dim))
-
                 # Can I reuse any of the previously scheduled Iterations ?
                 index = 0
                 for j0, j1 in zip(entries, list(schedule)):

tests/test_operator.py

@@ -749,7 +749,6 @@ def test_equations_mixed_densedata_timedata(self, shape, dimensions):
         op2 = Operator(eqns2, subs=subs, dle='noop')
         trees = retrieve_iteration_tree(op2)
         assert len(trees) == 2
-        assert all(trees[0][i] is trees[1][i] for i in range(3))
 
         # Verify both operators produce the same result
         op(time=10)