re PR rtl-optimization/55270 (ICE in get_loop_body, at cfgloop.c:823)

2013-01-29  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/55270
	* tree-ssa-dom.c (eliminate_degenerate_phis): If we changed
	the CFG, schedule loops for fixup.

	* gcc.dg/torture/pr55270.c: New testcase.

From-SVN: r195533

gcc/ChangeLog

+2013-01-29  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/55270
+	* tree-ssa-dom.c (eliminate_degenerate_phis): If we changed
+	the CFG, schedule loops for fixup.
+
 2013-01-29  Nick Clifton  <nickc@redhat.com>
 
 	* config/rl78/rl78.c (rl78_regno_mode_code_ok_for_base_p): Allow

gcc/testsuite/ChangeLog

+2013-01-29  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/55270
+	* gcc.dg/torture/pr55270.c: New testcase.
+
 2013-01-28  Jakub Jelinek  <jakub@redhat.com>
 
 	PR rtl-optimization/56117

gcc/testsuite/gcc.dg/torture/pr55270.c

+/* { dg-do compile } */
+
+unsigned a, b, c;
+
+void f(void)
+{
+  for(; a; a++)
+    {
+      long *p1 = (long *)&b;
+
+      if(*p1)
+	return;
+
+      if(b && (*p1 = b) || c && ++*p1)
+	{
+	  unsigned *p2 = &b;
+
+	  for(*p2 = 0; *p2 < 1;)
+	    for(; b; b++);
+	}
+    }
+}

gcc/tree-ssa-dom.c

@@ -3006,7 +3006,12 @@ eliminate_degenerate_phis (void)
     }
 
   if (cfg_altered)
-    free_dominance_info (CDI_DOMINATORS);
+    {
+      free_dominance_info (CDI_DOMINATORS);
+      /* If we changed the CFG schedule loops for fixup by cfgcleanup.  */
+      if (current_loops)
+	loops_state_set (LOOPS_NEED_FIXUP);
+    }
 
   /* Propagation of const and copies may make some EH edges dead.  Purge
      such edges from the CFG as needed.  */