[pypy-commit] pypy less-stringly-ops: Add HLOperation.constfold()

[rlamy]

Author: Ronan Lamy <ronan.lamy at gmail.com>
Branch: less-stringly-ops
Changeset: r66239:c97160d9f9cc
Date: 2013-08-09 19:14 +0100
http://bitbucket.org/pypy/pypy/changeset/c97160d9f9cc/

Log:	Add HLOperation.constfold()

diff --git a/rpython/flowspace/operation.py b/rpython/flowspace/operation.py
--- a/rpython/flowspace/operation.py
+++ b/rpython/flowspace/operation.py
@@ -42,12 +42,18 @@
         return sc_operator
 
     def eval(self, frame):
+        result = self.constfold()
+        if result is not None:
+            return result
         return frame.do_op(self)
 
+    def constfold(self):
+        return None
+
 class PureOperation(HLOperation):
     pure = True
 
-    def eval(self, frame):
+    def constfold(self):
         args = []
         if all(w_arg.foldable() for w_arg in self.args):
             args = [w_arg.value for w_arg in self.args]
@@ -77,7 +83,6 @@
                         # type cannot sanely appear in flow graph,
                         # store operation with variable result instead
                         pass
-        return frame.do_op(self)
 
 
 def add_operator(name, arity, symbol, pyfunc=None, pure=False, ovf=False):