speed up tree visitor somewhat by moving code out of the critical methods

Cython/Compiler/Visitor.pxd

+cimport cython
+
 cdef class BasicVisitor:
     cdef dict dispatch_table
     cpdef visit(self, obj)
+    cpdef find_handler(self, obj)
 
 cdef class TreeVisitor(BasicVisitor):
     cdef public list access_path
     cpdef visitchild(self, child, parent, attrname, idx)
+    @cython.locals(idx=int)
+    cpdef dict _visitchildren(self, parent, attrs)
 #    cpdef visitchildren(self, parent, attrs=*)
 
 cdef class VisitorTransform(TreeVisitor):

Cython/Compiler/Visitor.py

+# cython: infer_types=True
+
 #
 #   Tree visitor and transform framework
 #
@@ -19,10 +21,15 @@ class BasicVisitor(object):
         self.dispatch_table = {}
 
     def visit(self, obj):
-        cls = type(obj)
         try:
-            handler_method = self.dispatch_table[cls]
+            handler_method = self.dispatch_table[type(obj)]
         except KeyError:
+            handler_method = self.find_handler(obj)
+            self.dispatch_table[type(obj)] = handler_method
+        return handler_method(obj)
+
+    def find_handler(self, obj):
+        cls = type(obj)
         #print "Cache miss for class %s in visitor %s" % (
         #    cls.__name__, type(self).__name__)
         # Must resolve, try entire hierarchy
@@ -34,7 +41,7 @@ class BasicVisitor(object):
                 handler_method = getattr(self, pattern % mro_cls.__name__)
                 break
         if handler_method is None:
-                print type(self), type(obj)
+            print type(self), cls
             if hasattr(self, 'access_path') and self.access_path:
                 print self.access_path
                 if self.access_path:
@@ -42,8 +49,7 @@ class BasicVisitor(object):
                     print self.access_path[-1][0].__dict__
             raise RuntimeError("Visitor does not accept object: %s" % obj)
         #print "Caching " + cls.__name__
-            self.dispatch_table[cls] = handler_method
-        return handler_method(obj)
+        return handler_method
 
 class TreeVisitor(BasicVisitor):
     """
@@ -144,16 +150,8 @@ class TreeVisitor(BasicVisitor):
             stacktrace = stacktrace.tb_next
         return (last_traceback, nodes)
 
-    def visitchild(self, child, parent, attrname, idx):
-        self.access_path.append((parent, attrname, idx))
-        try:
-            result = self.visit(child)
-        except Errors.CompileError:
-            raise
-        except Exception, e:
+    def _raise_compiler_error(self, child, e):
         import sys
-            if DebugFlags.debug_no_exception_intercept:
-                raise
         trace = ['']
         for parent, attribute, index in self.access_path:
             node = getattr(parent, attribute)
@@ -174,10 +172,24 @@ class TreeVisitor(BasicVisitor):
         raise Errors.CompilerCrash(
             last_node.pos, self.__class__.__name__,
             u'\n'.join(trace), e, stacktrace)
+
+    def visitchild(self, child, parent, attrname, idx):
+        self.access_path.append((parent, attrname, idx))
+        try:
+            result = self.visit(child)
+        except Errors.CompileError:
+            raise
+        except Exception, e:
+            if DebugFlags.debug_no_exception_intercept:
+                raise
+            self._raise_compiler_error(child, e)
         self.access_path.pop()
         return result
 
     def visitchildren(self, parent, attrs=None):
+        return self._visitchildren(parent, attrs)
+
+    def _visitchildren(self, parent, attrs):
         """
         Visits the children of the given parent. If parent is None, returns
         immediately (returning None).
@@ -223,8 +235,7 @@ class VisitorTransform(TreeVisitor):
     are within a StatListNode or similar before doing this.)
     """
     def visitchildren(self, parent, attrs=None):
-        result = cython.declare(dict)
-        result = TreeVisitor.visitchildren(self, parent, attrs)
+        result = self._visitchildren(parent, attrs)
         for attr, newnode in result.iteritems():
             if not type(newnode) is list:
                 setattr(parent, attr, newnode)