commit 443712c075426eec018222b0147f7f5350f3c0b3
Author: Maxim Kuvyrkov <maxim@codesourcery.com>
Date:   Thu Mar 17 08:27:33 2011 -0700

    Improve detect_type_change

diff --git a/gcc/ipa-prop.c b/gcc/ipa-prop.c
index 3e56e70..491bb11 100644
--- a/gcc/ipa-prop.c
+++ b/gcc/ipa-prop.c
@@ -320,6 +320,7 @@ stmt_may_be_vtbl_ptr_store (gimple stmt)
   else if (is_gimple_assign (stmt))
     {
       tree lhs = gimple_assign_lhs (stmt);
+      tree rhs;
 
       if (!AGGREGATE_TYPE_P (TREE_TYPE (lhs)))
 	{
@@ -334,6 +335,13 @@ stmt_may_be_vtbl_ptr_store (gimple stmt)
 	     if there is a field corresponding to the offset and if so, proceed
 	     almost like if it was a component ref.  */
 	}
+
+      /* Assume that only ADDR_EXPRs can be assigned to vtables.
+	 In particular, ignore *ptr = <const_int> when searching for aliasing
+	 entries.  */
+      rhs = gimple_assign_rhs1 (stmt);
+      if (TREE_CODE (rhs) != ADDR_EXPR)
+	return false;
     }
   return true;
 }