re PR tree-optimization/51759 (miscompile writes past end of bitfield)

2012-01-09  Martin Jambor  <mjambor@suse.cz>

        PR tree-optimization/51759
	* g++.dg/ipa/pr51759.C: New test.

From-SVN: r183029

gcc/testsuite/ChangeLog

+2012-01-09  Martin Jambor  <mjambor@suse.cz>
+
+        PR tree-optimization/51759
+	* g++.dg/ipa/pr51759.C: New test.
+
 2012-01-09  Tobias Burnus  <burnus@net-b.de>
 
 	PR fortran/51758

gcc/testsuite/g++.dg/ipa/pr51759.C

+/* { dg-do run } */
+/* { dg-options "-O2"  } */
+
+extern "C" void abort (void);
+struct S
+{
+  void __attribute__((noinline)) set(unsigned val)
+    {
+      data = val;
+      if (data != val)
+        abort ();
+    }
+  int pad0;
+  unsigned pad1 : 8;
+  unsigned data : 24;
+  int pad2;
+};
+int main()
+{
+  S s;
+  s.pad2 = -1;
+  s.set(0);
+  if (s.pad2 != -1)
+    abort ();
+}
+