re PR tree-optimization/84057 (ICE: Segmentation fault (in can_remove_branch_p))

2018-01-29  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/84057
	* tree-ssa-loop-ivcanon.c (unloop_loops): Deal with already
	removed paths when removing edges.

	* gcc.dg/graphite/pr84057.c: New testcase.

From-SVN: r257139

gcc/ChangeLog

+2018-01-29  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/84057
+	* tree-ssa-loop-ivcanon.c (unloop_loops): Deal with already
+	removed paths when removing edges.
+
 2018-01-27  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* doc/invoke.texi: Replace -mfunction-return==@var{choice} with

gcc/testsuite/ChangeLog

+2018-01-29  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/84057
+	* gcc.dg/graphite/pr84057.c: New testcase.
+
 2017-01-29  Thomas Koenig  <tkoenig@gcc.gnu.org>
 
 	PR fortran/84073

gcc/testsuite/gcc.dg/graphite/pr84057.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -fgraphite -funroll-loops -fno-tree-ccp -fno-tree-dce" } */
+
+int ue;
+
+void
+fr (int ct)
+{
+  int au = 0;
+  int *ra = &au;
+
+  while (au < 1)
+    {
+      au -= 0x7878788;
+      if (au != ct && ue != 0)
+	{
+	  while (au < 1)
+	    {
+	    }
+
+fc:
+	  while (ct != 0)
+	    {
+	    }
+	}
+    }
+
+  for (au = 0; au < 2; ++au)
+    if (ct != 0)
+      goto fc;
+}

gcc/tree-ssa-loop-ivcanon.c

@@ -660,14 +660,21 @@ unloop_loops (bitmap loop_closed_ssa_invalidated,
   loops_to_unloop.release ();
   loops_to_unloop_nunroll.release ();
 
-  /* Remove edges in peeled copies.  */
+  /* Remove edges in peeled copies.  Given remove_path removes dominated
+     regions we need to cope with removal of already removed paths.  */
   unsigned i;
   edge e;
+  auto_vec<int, 20> src_bbs;
+  src_bbs.reserve_exact (edges_to_remove.length ());
   FOR_EACH_VEC_ELT (edges_to_remove, i, e)
-    {
-      bool ok = remove_path (e, irred_invalidated, loop_closed_ssa_invalidated);
-      gcc_assert (ok);
-    }
+    src_bbs.quick_push (e->src->index);
+  FOR_EACH_VEC_ELT (edges_to_remove, i, e)
+    if (BASIC_BLOCK_FOR_FN (cfun, src_bbs[i]))
+      {
+	bool ok = remove_path (e, irred_invalidated,
+			       loop_closed_ssa_invalidated);
+	gcc_assert (ok);
+      }
   edges_to_remove.release ();
 }