[PATCH, PR40323] Prevent infinite looping in ipa-prop.c

[Martin Jambor <mjambor at suse dot cz>]

Hi,

the following patch prevents a bogus infinite loop in ipa-prop.c when
building jump functions for member pointers.

I have bootstrapped and tegression tested the patch on x86_64-linux.

OK for trunk (in particular, is the tescase OK and at the right place)?

Thanks,

Martin

2009-06-02  Martin Jambor  <mjambor@suse.cz>

	PR tree-optimization/40323
	* ipa-prop.c (get_ssa_def_if_simple_copy): Break if not single
	assignment.

	* testsuite/g++.dg/torture/pr40323.C: New file.

Index: gcc/testsuite/g++.dg/torture/pr40323.C
===================================================================
--- gcc/testsuite/g++.dg/torture/pr40323.C	(revision 0)
+++ gcc/testsuite/g++.dg/torture/pr40323.C	(revision 0)
@@ -0,0 +1,68 @@
+/* Testcase for PR 40323.  */
+/* { dg-do compile } */
+/* { dg-options "-O3 -fno-early-inlining"  } */
+/* { dg-options "-O3 -fno-early-inlining -fpie" { target { ! nonpic } } } */
+
+extern void do_something (const char *, int);
+
+class Parent
+{
+private:
+  const char *data;
+
+public:
+  Parent (const char *d) : data(d)
+  {}
+
+  int funcOne (int delim) const;
+};
+
+class AnotherParent
+{
+private:
+  double d;
+public:
+  AnotherParent (void) : d(0)
+  {}
+};
+
+
+class Child : public AnotherParent, Parent
+{
+private:
+  int zzz;
+public:
+  Child (const char *d) : Parent(d)
+  {}
+};
+
+
+int Parent::funcOne (int delim) const
+{
+  int i;
+  for (i = 0; i < delim; i++)
+    do_something(data, i);
+
+  return 1;
+}
+
+int docalling (int (Child::* f)(int delim) const)
+{
+  Child S ("muhehehe");
+
+  return (S.*f)(4);
+}
+
+typedef int (Parent::* my_mp_type)(int delim);
+
+int main (int argc, char *argv[])
+{
+  int i;
+  int (Parent::* f)(int ) const;
+  int (Child::* g)(int ) const;
+  
+  f = &Parent::funcOne;
+  g = (int (Child::* )(int) const) f;
+  i = docalling (g);
+  return i;
+}
Index: gcc/ipa-prop.c
===================================================================
--- gcc/ipa-prop.c	(revision 148082)
+++ gcc/ipa-prop.c	(working copy)
@@ -440,6 +440,8 @@ get_ssa_def_if_simple_copy (tree rhs)
 
       if (gimple_assign_single_p (def_stmt))
 	rhs = gimple_assign_rhs1 (def_stmt);
+      else
+	break;
     }
   return rhs;
 }