re PR rtl-optimization/56466 (ICE in verify_loop_structure, at cfgloop.c:1629 (loop with header n not in loop tree !))

PR rtl-optimization/56466
        * loop-unroll.c (unroll_and_peel_loops): Call fix_loop_structure
        if we're changing a loop.
        (peel_loops_completely): Likewise.

From-SVN: r196335

gcc/ChangeLog

@@ -1,3 +1,10 @@
+2013-02-28  Marek Polacek  <polacek@redhat.com>
+
+	PR rtl-optimization/56466
+	* loop-unroll.c (unroll_and_peel_loops): Call fix_loop_structure
+	if we're changing a loop.
+	(peel_loops_completely): Likewise.
+
 2013-02-28  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/55813

gcc/loop-unroll.c

@@ -207,7 +207,7 @@ void
 unroll_and_peel_loops (int flags)
 {
   struct loop *loop;
-  bool check;
+  bool changed = false;
   loop_iterator li;
 
   /* First perform complete loop peeling (it is almost surely a win,
@@ -220,7 +220,6 @@ unroll_and_peel_loops (int flags)
   /* Scan the loops, inner ones first.  */
   FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST)
     {
-      check = true;
       /* And perform the appropriate transformations.  */
       switch (loop->lpt_decision.decision)
 	{
@@ -229,30 +228,33 @@ unroll_and_peel_loops (int flags)
 	  gcc_unreachable ();
 	case LPT_PEEL_SIMPLE:
 	  peel_loop_simple (loop);
+	  changed = true;
 	  break;
 	case LPT_UNROLL_CONSTANT:
 	  unroll_loop_constant_iterations (loop);
+	  changed = true;
 	  break;
 	case LPT_UNROLL_RUNTIME:
 	  unroll_loop_runtime_iterations (loop);
+	  changed = true;
 	  break;
 	case LPT_UNROLL_STUPID:
 	  unroll_loop_stupid (loop);
+	  changed = true;
 	  break;
 	case LPT_NONE:
-	  check = false;
 	  break;
 	default:
 	  gcc_unreachable ();
 	}
-      if (check)
-	{
-#ifdef ENABLE_CHECKING
-	  verify_loop_structure ();
-#endif
-	}
     }
 
+    if (changed)
+      {
+	calculate_dominance_info (CDI_DOMINATORS);
+	fix_loop_structure (NULL);
+      }
+
   iv_analysis_done ();
 }
 
@@ -283,6 +285,7 @@ peel_loops_completely (int flags)
 {
   struct loop *loop;
   loop_iterator li;
+  bool changed = false;
 
   /* Scan the loops, the inner ones first.  */
   FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST)
@@ -306,11 +309,15 @@ peel_loops_completely (int flags)
 	{
 	  report_unroll_peel (loop, locus);
 	  peel_loop_completely (loop);
-#ifdef ENABLE_CHECKING
-	  verify_loop_structure ();
-#endif
+	  changed = true;
 	}
     }
+
+    if (changed)
+      {
+	calculate_dominance_info (CDI_DOMINATORS);
+	fix_loop_structure (NULL);
+      }
 }
 
 /* Decide whether unroll or peel loops (depending on FLAGS) and how much.  */

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2013-02-27  Marek Polacek  <polacek@redhat.com>
+
+	PR rtl-optimization/56466
+	* gcc.dg/pr56466.c: New test.
+
 2013-02-28  Naveen H.S  <Naveen.Hurugalawadi@caviumnetworks.com>
 
 	* gcc.dg/tree-ssa/slsr-1.c: Allow widening multiplications.

gcc/testsuite/gcc.dg/pr56466.c

@@ -0,0 +1,31 @@
+/* PR rtl-optimization/56466 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -w -funroll-loops" } */
+
+int a, b, c;
+
+void
+f (void)
+{
+  for (; b; b++)
+    {
+      if (0)
+	for (; b < 0; b++)
+	  if (1 % 0)
+	    {
+	      while (1)
+		{
+		  a = 0;
+		lbl1:
+		  c++;
+		}
+	    lbl2:
+	      ;
+	    }
+
+      goto lbl1;
+    }
+
+  a = 0;
+  goto lbl2;
+}