compiler: lift buffer ispace into property

Author: mloubout

devito/passes/clusters/buffering.py

@@ -439,6 +439,27 @@ def __init__(self, f, b, clusters):
 
         self.indices = extract_indices(f, self.dim, clusters)
 
+    def __repr__(self):
+        return "Descriptor[%s -> %s]" % (self.f, self.b)
+
+    @property
+    def size(self):
+        return self.xd.symbolic_size
+
+    @property
+    def exprs(self):
+        return flatten(c.exprs for c in self.clusters)
+
+    @property
+    def itdims(self):
+        """
+        The Dimensions defining an IterationSpace in which the buffer
+        may be accessed.
+        """
+        return (self.xd, self.dim.root)
+
+    @cached_property
+    def ispace(self):
         # The IterationSpace within which the buffer will be accessed
         # NOTE: The `key` is to avoid Clusters including `f` but not directly
         # using it in an expression, such as HaloTouch Clusters
@@ -448,20 +469,22 @@ def key(c):
             return bufferdim or timeonly
 
         ispaces = set()
-        for c in clusters:
+        for c in self.clusters:
             if not key(c):
                 continue
 
             # Skip wild clusters (e.g. HaloTouch Clusters)
             if c.is_wild:
                 continue
+
             # Iterations space and buffering dims
             ispace = c.ispace
             edims = [d for d in self.bdims if d not in ispace.dimensions]
             if not edims:
                 ispaces.add(ispace)
             else:
-                # Add all missing buffering dimensions
+                # Add all missing buffering dimensions and reorder to
+                # avoid duplicates with different ordering
                 ispaces.add(ispace.insert(self.dim, edims).reorder())
 
         if len(ispaces) > 1:
@@ -471,31 +494,10 @@ def key(c):
             ispaces = {i.lift(self.bdims, v=stamp) for i in ispaces}
 
             if len(ispaces) > 1:
-                print(ispaces)
                 raise CompilationError("Unsupported `buffering` over different "
                                        "IterationSpaces")
 
-        assert len(ispaces) == 1, "Unexpected form of `buffering`"
-        self.ispace = ispaces.pop()
-
-    def __repr__(self):
-        return "Descriptor[%s -> %s]" % (self.f, self.b)
-
-    @property
-    def size(self):
-        return self.xd.symbolic_size
-
-    @property
-    def exprs(self):
-        return flatten(c.exprs for c in self.clusters)
-
-    @property
-    def itdims(self):
-        """
-        The Dimensions defining an IterationSpace in which the buffer
-        may be accessed.
-        """
-        return (self.xd, self.dim.root)
+        return ispaces.pop()
 
     @cached_property
     def subdims_mapper(self):