From fb5e8683b0ff9325c4cbdaca055059801b0ef5ac Mon Sep 17 00:00:00 2001
From: Stefan Behnel <stefan_ml@behnel.de>
Date: Sun, 8 Dec 2013 11:15:59 +0100
Subject: [PATCH] discard ExprStatNodes with constant expressions

---
 Cython/Compiler/Optimize.py | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Cython/Compiler/Optimize.py b/Cython/Compiler/Optimize.py
index 27a10d9..d1a53d6 100644
--- a/Cython/Compiler/Optimize.py
+++ b/Cython/Compiler/Optimize.py
@@ -3402,6 +3402,13 @@ class ConstantFolding(Visitor.VisitorTransform, SkipDeclarations):
                 return node
         return None
 
+    def visit_ExprStatNode(self, node):
+        self.visitchildren(node)
+        # drop unused constant expressions
+        if node.expr.has_constant_result():
+            return None
+        return node
+
     # in the future, other nodes can have their own handler method here
     # that can replace them with a constant result node
 
-- 
2.7.4