# HG changeset patch
# User neliasso
# Date 1527005948 -7200
#      Tue May 22 18:19:08 2018 +0200
# Node ID ab80eddca92c34a722167dc9f7fee3378f86aa6d
# Parent  4befb3c9c75802bf2becaa99defa7110b7bcdb7c
8203425: assert(is_Loop()) failed: invalid node class
Reviewed-by:

diff --git a/src/hotspot/share/opto/loopnode.cpp b/src/hotspot/share/opto/loopnode.cpp
--- a/src/hotspot/share/opto/loopnode.cpp
+++ b/src/hotspot/share/opto/loopnode.cpp
@@ -2711,9 +2711,31 @@
   if( !_verify_me && !_verify_only && _ltree_root->_child ) {
     C->print_method(PHASE_BEFORE_BEAUTIFY_LOOPS, 3);
     if( _ltree_root->_child->beautify_loops( this ) ) {
-      // IdealLoopTree::split_outer_loop may produce phi-nodes with a single in edge.
-      // Transform them away.
-      _igvn.optimize();
+      if (_igvn._worklist.size() > orig_worklist_size) {
+        // IdealLoopTree::split_outer_loop may reduce phi-nodes to loop invariants,
+        // and we want to get rid of them
+        _igvn.optimize();
+        orig_worklist_size = _igvn._worklist.size();
+
+        // Re-build loop tree
+        _ltree_root->_child = NULL;
+        _nodes.clear();
+        reallocate_preorders();
+        build_loop_tree();
+
+        // Check for bailout, and return
+        if (C->failing()) {
+          return;
+        }
+
+        // Reset loop nesting depth
+        _ltree_root->set_nest( 0 );
+
+        // The loop structure may have changed - redo beautify loops
+        C->print_method(PHASE_BEFORE_BEAUTIFY_LOOPS, 3);
+        _ltree_root->_child->beautify_loops( this );
+        C->print_method(PHASE_AFTER_BEAUTIFY_LOOPS, 3);
+      }
 
       // Re-build loop tree!
       _ltree_root->_child = NULL;