ipa-prop.c (detect_type_change): Shor circuit testing of type changes on THIS pointer.

	* ipa-prop.c (detect_type_change): Shor circuit testing of
	type changes on THIS pointer.

	* g++.dg/ipa/devirrt-22.C: Fix template.

From-SVN: r207495

gcc/ChangeLog

+2014-02-04  Jan Hubicka  <hubicka@ucw.cz>
+
+	* ipa-prop.c (detect_type_change): Shor circuit testing of
+	type changes on THIS pointer.
+
 2014-02-04  John David Anglin  <danglin@gcc.gnu.org>
 
 	PR target/59777

gcc/ipa-prop.c

@@ -688,6 +688,19 @@ detect_type_change (tree arg, tree base, tree comp_type, gimple call,
       || !BINFO_VTABLE (TYPE_BINFO (comp_type)))
     return false;
 
+  /* C++ methods are not allowed to change THIS pointer unless they
+     are constructors or destructors.  */
+  if (TREE_CODE	(base) == MEM_REF
+      && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME
+      && SSA_NAME_IS_DEFAULT_DEF (TREE_OPERAND (base, 0))
+      && TREE_CODE (SSA_NAME_VAR (TREE_OPERAND (base, 0))) == PARM_DECL
+      && TREE_CODE (TREE_TYPE (current_function_decl)) == METHOD_TYPE
+      && !DECL_CXX_CONSTRUCTOR_P (current_function_decl)
+      && !DECL_CXX_DESTRUCTOR_P (current_function_decl)
+      && (SSA_NAME_VAR (TREE_OPERAND (base, 0))
+	  == DECL_ARGUMENTS (current_function_decl)))
+    return false;
+
   ao_ref_init (&ao, arg);
   ao.base = base;
   ao.offset = offset;

gcc/testsuite/ChangeLog

+2014-02-04  Jan Hubicka  <hubicka@ucw.cz>
+
+	* g++.dg/ipa/devirrt-22.C: Fix template.
+
 2014-02-04  Marek Polacek  <polacek@redhat.com>
 
 	PR c/60036

gcc/testsuite/g++.dg/ipa/devirt-22.C

@@ -37,5 +37,5 @@ void update_sources() {
 /* Note that we miss one devirtualization because we are not able to track the
    vtbl store in destructor.  
    Previously we devirtualized to C::m_fn1 instead of B::m_fn1.  */
-/* { dg-final { scan-tree-dump-times "Discovered a virtual call to a known target" 1 "cp"  } } */
+/* { dg-final { scan-ipa-dump-times "Discovered a virtual call to a known target" 1 "cp"  } } */
 /* { dg-final { cleanup-ipa-dump "cp" } } */