re PR tree-optimization/78731 (Possible bug with switch when optimization is turned on.)

2016-12-14  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/78731
	* gcc.dg/torture/pr78731.c: New testcase.

From-SVN: r243644

gcc/testsuite/ChangeLog

+2016-12-14  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/78731
+	* gcc.dg/torture/pr78731.c: New testcase.
+
 2016-12-14  Martin Liska  <mliska@suse.cz>
 
 	* gcc.dg/tree-ssa/20040703-1.c: Update scanned pattern.

gcc/testsuite/gcc.dg/torture/pr78731.c

+/* { dg-do run } */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#define GENERAL 1
+#define BRACKETS 2
+#define QUOTES 3
+
+void __attribute__((noinline,noclone))
+foo(char *qb, char* into)
+{
+  int state = QUOTES;
+  int save_state = BRACKETS;
+
+  while (qb)
+    {
+      switch (state)
+	{
+	case BRACKETS:
+	  exit(0);
+	case GENERAL:
+	  abort ();
+	case QUOTES:
+	  state = save_state;
+	  save_state = GENERAL;
+	  break;
+	default: ;
+	}
+      printf("State %d btw GENERAL %d\n", state, GENERAL);
+    }
+  abort ();
+}
+
+int main()
+{
+  char *b = "123";
+  char out[4];
+  foo(b, out);
+  return 0;
+}