re PR tree-optimization/46107 (-ftree-loop-distribute-patterns caused…

re PR tree-optimization/46107 (-ftree-loop-distribute-patterns caused verify_loop_structure problem)

	PR tree-optimization/46107
	* cfgloopmanip.c (loop_version): Set irred_flag back into entry->flags
	if cfg_hook_duplicate_loop_to_header_edge failed.

	* gcc.c-torture/compile/pr46107.c: New test.

From-SVN: r166234

gcc/ChangeLog

+2010-11-03  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/46107
+	* cfgloopmanip.c (loop_version): Set irred_flag back into entry->flags
+	if cfg_hook_duplicate_loop_to_header_edge failed.
+
 2010-11-03  Ian Lance Taylor  <iant@google.com>
 
 	PR lto/46273

gcc/cfgloopmanip.c

 /* Loop manipulation code for GNU compiler.
-   Copyright (C) 2002, 2003, 2004, 2005, 2007, 2008, 2009 Free Software
-   Foundation, Inc.
+   Copyright (C) 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010
+   Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -1538,7 +1538,10 @@ loop_version (struct loop *loop,
   /* Duplicate loop.  */
   if (!cfg_hook_duplicate_loop_to_header_edge (loop, entry, 1,
 					       NULL, NULL, NULL, 0))
-    return NULL;
+    {
+      entry->flags |= irred_flag;
+      return NULL;
+    }
 
   /* After duplication entry edge now points to new loop head block.
      Note down new head as second_head.  */

gcc/testsuite/ChangeLog

 2010-11-03  Jakub Jelinek  <jakub@redhat.com>
 
+	PR tree-optimization/46107
+	* gcc.c-torture/compile/pr46107.c: New test.
+
 	PR debug/46252
 	* gcc.dg/pr46252.c: New test.
 

gcc/testsuite/gcc.c-torture/compile/pr46107.c

+/* PR tree-optimization/46107 */
+
+int foo (void) __attribute__ ((noreturn));
+
+void
+bar (int x, int *y, int z)
+{
+  static void *j[] = { &&l1, &&l2 };
+l1:
+  if (*y)
+    goto *j[z];
+  foo ();
+l2:
+  *y ^= (x & 1) ? -1 : 0;
+  goto *j[x];
+}