compiler: Add cluster-level temp

devito/mpi/distributed.py

@@ -202,10 +202,7 @@ def __init__(self, shape, dimensions, input_comm=None, topology=None):
             self._input_comm = (input_comm or MPI.COMM_WORLD).Clone()
 
             # if len(shape) == 3:
-            #     topology = ('*', '*', 1)
-
-            # topology = ('*', '*', 1)
-            # topology = ('*', '*', 8)
+            #      topology = ('*', '*', 4)
 
             if topology is None:
                 # `MPI.Compute_dims` sets the dimension sizes to be as close to each other

devito/passes/clusters/cse.py

@@ -2,28 +2,33 @@
 from functools import singledispatch
 
 from sympy import Add, Function, Indexed, Mul, Pow
+from sympy.core.core import ordering_of_classes
 
 from devito.finite_differences.differentiable import IndexDerivative
 from devito.ir import Cluster, Scope, cluster_pass
 from devito.passes.clusters.utils import makeit_ssa
 from devito.symbolics import estimate_cost, q_leaf
 from devito.symbolics.manipulation import _uxreplace
 from devito.tools import as_list
-from devito.types import Eq, Temp as Temp0
+from devito.types import Eq, Temp
 
 __all__ = ['cse']
 
 
-class Temp(Temp0):
-    pass
+class CTemp(Temp):
+
+    """
+    A cluster-level Temp, similar to Temp, ensured to have different priority
+    """
+    ordering_of_classes.insert(ordering_of_classes.index('Temp') + 1, 'CTemp')
 
 
 @cluster_pass
 def cse(cluster, sregistry, options, *args):
     """
     Common sub-expressions elimination (CSE).
     """
-    make = lambda: Temp(name=sregistry.make_name(), dtype=cluster.dtype)
+    make = lambda: CTemp(name=sregistry.make_name(), dtype=cluster.dtype)
     exprs = _cse(cluster, make, min_cost=options['cse-min-cost'])
 
     return cluster.rebuild(exprs=exprs)
@@ -130,7 +135,7 @@ def _compact_temporaries(exprs, exclude):
     # safely be compacted; a generic Symbol could instead be accessed in a subsequent
     # Cluster, for example: `for (i = ...) { a = b; for (j = a ...) ...`
     mapper = {e.lhs: e.rhs for e in exprs
-              if isinstance(e.lhs, Temp) and q_leaf(e.rhs) and e.lhs not in exclude}
+              if isinstance(e.lhs, CTemp) and q_leaf(e.rhs) and e.lhs not in exclude}
 
     processed = []
     for e in exprs: