misc: Refactoring and misc code style improvments

Author: EdCaunt

devito/ir/support/basic.py

@@ -317,7 +317,8 @@ def lex_le(self, other):
     def lex_lt(self, other):
         return self.timestamp < other.timestamp
 
-    # Note: memoization yields mild compiler speedup
+    # Note: memoization yields mild compiler speedup. Will need to be made
+    # thread-safe for multithreading the compiler.
     @memoized_meth
     def distance(self, other):
         """
@@ -369,7 +370,7 @@ def distance(self, other):
                 # To avoid evaluating expensive symbolic Lt or Gt operations,
                 # we pre-empt such operations by checking if the values to be compared
                 # to are symbolic, and skip this case if not.
-                if not any(isinstance(i, sympy.core.Basic)
+                if not any(isinstance(i, sympy.Basic)
                            for i in (sit.symbolic_min, sit.symbolic_max)):
 
                     for v in (self[n], other[n]):

devito/passes/clusters/cse.py

@@ -13,7 +13,7 @@
 from devito.finite_differences.differentiable import IndexDerivative
 from devito.ir import Cluster, Scope, cluster_pass
 from devito.symbolics import estimate_cost, q_leaf, q_terminal
-from devito.symbolics.search import retrieve_ctemps
+from devito.symbolics.search import search
 from devito.symbolics.manipulation import _uxreplace
 from devito.tools import DAG, as_list, as_tuple, frozendict, extract_dtype
 from devito.types import Eq, Symbol, Temp
@@ -26,11 +26,15 @@ class CTemp(Temp):
     """
     A cluster-level Temp, similar to Temp, ensured to have different priority
     """
-    is_CTemp = True
 
     ordering_of_classes.insert(ordering_of_classes.index('Temp') + 1, 'CTemp')
 
 
+def retrieve_ctemps(exprs, mode='all'):
+    """Shorthand to retrieve the CTemps in `exprs`"""
+    return search(exprs, lambda expr: isinstance(expr, CTemp), mode, 'dfs')
+
+
 @cluster_pass
 def cse(cluster, sregistry=None, options=None, **kwargs):
     """
@@ -229,12 +233,12 @@ def _compact(exprs, exclude):
     mapper = {e.lhs: e.rhs for e in candidates if q_leaf(e.rhs)}
 
     # Find all the CTemps in expression right-hand-sides without removing duplicates
-    ctemps = retrieve_ctemps([e.rhs for e in exprs])
-    ctemp_count = Counter(ctemps)
+    ctemps = retrieve_ctemps(e.rhs for e in exprs)
 
     # If there are ctemps in the expressions, then add any to the mapper which only
     # appear once
     if ctemps:
+        ctemp_count = Counter(ctemps)
         mapper.update({e.lhs: e.rhs for e in candidates
                        if ctemp_count[e.lhs] == 1})
 

devito/passes/clusters/misc.py

@@ -361,7 +361,6 @@ def is_cross(source, sink):
                 # (intuitively, "the loop nests are to be kept separated")
                 # * All ClusterGroups between `cg0` and `cg1` must precede `cg1`
                 # * All ClusterGroups after `cg1` cannot precede `cg1`
-
                 if any(i.cause & prefix for i in scope.d_anti_gen()):
                     for cg2 in cgroups[n:cgroups.index(cg1)]:
                         dag.add_edge(cg2, cg1)

devito/symbolics/queries.py

@@ -32,13 +32,6 @@ def q_symbol(expr):
         return False
 
 
-def q_ctemp(expr):
-    try:
-        return expr.is_CTemp
-    except AttributeError:
-        return False
-
-
 def q_comp_acc(expr):
     return isinstance(expr, ComponentAccess)
 

devito/symbolics/search.py

@@ -1,7 +1,7 @@
 import sympy
 
 from devito.symbolics.queries import (q_indexed, q_function, q_terminal, q_leaf,
-                                      q_symbol, q_ctemp, q_dimension, q_derivative)
+                                      q_symbol, q_dimension, q_derivative)
 from devito.tools import as_tuple
 
 __all__ = ['retrieve_indexed', 'retrieve_functions', 'retrieve_function_carriers',
@@ -159,11 +159,6 @@ def retrieve_symbols(exprs, mode='all'):
     return search(exprs, q_symbol, mode, 'dfs')
 
 
-def retrieve_ctemps(exprs, mode='all'):
-    """Shorthand to retrieve the CTemps in `exprs`"""
-    return search(exprs, q_ctemp, mode, 'dfs')
-
-
 def retrieve_function_carriers(exprs, mode='all'):
     """
     Shorthand to retrieve the DiscreteFunction carriers in ``exprs``. An

devito/types/basic.py

@@ -298,7 +298,6 @@ class Basic(CodeSymbol):
     is_Object = False
     is_LocalObject = False
     is_LocalType = False
-    is_CTemp = False
 
     # Created by the user
     is_Input = False