--- a/src/hotspot/share/opto/loopnode.hpp	Mon Oct 28 11:27:27 2019 +0100
+++ b/src/hotspot/share/opto/loopnode.hpp	Wed Oct 23 12:51:53 2019 +0200
@@ -1378,7 +1378,7 @@
   bool exceeding_node_budget(uint required = 0) {
     assert(C->live_nodes() < C->max_node_limit(), "sanity");
     uint available = C->max_node_limit() - C->live_nodes();
-    return available < required + _nodes_required;
+    return available < required + _nodes_required + REQUIRE_MIN;
   }
 
   uint require_nodes(uint require, uint minreq = REQUIRE_MIN) {

--- a/src/hotspot/share/opto/loopopts.cpp	Mon Oct 28 11:27:27 2019 +0100
+++ b/src/hotspot/share/opto/loopopts.cpp	Wed Oct 23 12:51:53 2019 +0200
@@ -3159,7 +3159,8 @@
   Node_List worklist(area);
   Node_List sink_list(area);
 
-  if (!may_require_nodes(loop->est_loop_clone_sz(2))) {
+  uint estimate = loop->est_loop_clone_sz(1);
+  if (exceeding_node_budget(estimate)) {
     return false;
   }
 
@@ -3184,8 +3185,7 @@
 
   // Set of non-cfg nodes to peel are those that are control
   // dependent on the cfg nodes.
-  uint i;
-  for(i = 0; i < loop->_body.size(); i++ ) {
+  for (uint i = 0; i < loop->_body.size(); i++) {
     Node *n = loop->_body.at(i);
     Node *n_c = has_ctrl(n) ? get_ctrl(n) : n;
     if (peel.test(n_c->_idx)) {
@@ -3200,7 +3200,7 @@
 
   // Get a post order schedule of nodes in the peel region
   // Result in right-most operand.
-  scheduled_nodelist(loop, peel, peel_list );
+  scheduled_nodelist(loop, peel, peel_list);
 
   assert(is_valid_loop_partition(loop, peel, peel_list, not_peel), "bad partition");
 
@@ -3220,25 +3220,21 @@
   // Evacuate nodes in peel region into the not_peeled region if possible
   uint new_phi_cnt = 0;
   uint cloned_for_outside_use = 0;
-  for (i = 0; i < peel_list.size();) {
+  for (uint i = 0; i < peel_list.size();) {
     Node* n = peel_list.at(i);
 #ifndef PRODUCT
   if (TracePartialPeeling) n->dump();
 #endif
     bool incr = true;
-    if ( !n->is_CFG() ) {
-
-      if ( has_use_in_set(n, not_peel) ) {
-
+    if (!n->is_CFG()) {
+      if (has_use_in_set(n, not_peel)) {
         // If not used internal to the peeled region,
         // move "n" from peeled to not_peeled region.
-
-        if ( !has_use_internal_to_set(n, peel, loop) ) {
-
+        if (!has_use_internal_to_set(n, peel, loop)) {
           // if not pinned and not a load (which maybe anti-dependent on a store)
           // and not a CMove (Matcher expects only bool->cmove).
           if (n->in(0) == NULL && !n->is_Load() && !n->is_CMove()) {
-            cloned_for_outside_use += clone_for_use_outside_loop( loop, n, worklist );
+            cloned_for_outside_use += clone_for_use_outside_loop(loop, n, worklist);
             sink_list.push(n);
             peel     >>= n->_idx; // delete n from peel set.
             not_peel <<= n->_idx; // add n to not_peel set.
@@ -3254,7 +3250,7 @@
         } else {
           // Otherwise check for special def-use cases that span
           // the peel/not_peel boundary such as bool->if
-          clone_for_special_use_inside_loop( loop, n, not_peel, sink_list, worklist );
+          clone_for_special_use_inside_loop(loop, n, not_peel, sink_list, worklist);
           new_phi_cnt++;
         }
       }
@@ -3262,7 +3258,11 @@
     if (incr) i++;
   }
 
-  if (new_phi_cnt > old_phi_cnt + PartialPeelNewPhiDelta) {
+  estimate += cloned_for_outside_use + new_phi_cnt;
+  bool exceed_node_budget = !may_require_nodes(estimate);
+  bool exceed_phi_limit = new_phi_cnt > old_phi_cnt + PartialPeelNewPhiDelta;
+
+  if (exceed_node_budget || exceed_phi_limit) {
 #ifndef PRODUCT
     if (TracePartialPeeling) {
       tty->print_cr("\nToo many new phis: %d  old %d new cmpi: %c",
@@ -3310,7 +3310,7 @@
 
   const uint clone_exit_idx = 1;
   const uint orig_exit_idx  = 2;
-  assert(is_valid_clone_loop_form( loop, peel_list, orig_exit_idx, clone_exit_idx ), "bad clone loop");
+  assert(is_valid_clone_loop_form(loop, peel_list, orig_exit_idx, clone_exit_idx), "bad clone loop");
 
   Node* head_clone             = old_new[head->_idx];
   LoopNode* new_head_clone     = old_new[new_head->_idx]->as_Loop();
@@ -3318,7 +3318,7 @@
 
   // Add phi if "def" node is in peel set and "use" is not
 
-  for(i = 0; i < peel_list.size(); i++ ) {
+  for (uint i = 0; i < peel_list.size(); i++) {
     Node *def  = peel_list.at(i);
     if (!def->is_CFG()) {
       for (DUIterator_Fast jmax, j = def->fast_outs(jmax); j < jmax; j++) {
@@ -3374,7 +3374,7 @@
   //          cloned-not_peeled  in(0)    in(0)
   //          orig-peeled
 
-  for(i = 0; i < loop->_body.size(); i++ ) {
+  for (uint i = 0; i < loop->_body.size(); i++) {
     Node *n = loop->_body.at(i);
     if (!n->is_CFG()           && n->in(0) != NULL        &&
         not_peel.test(n->_idx) && peel.test(n->in(0)->_idx)) {

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/compiler/loopopts/LoopRotateBadNodeBudget.java	Wed Oct 23 12:51:53 2019 +0200
@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8231565
+ * @summary Node estimate for loop rotate is not correct/sufficient:
+ *          assert(delta <= 2 * required) failed: Bad node estimate ...
+ *
+ * @requires !vm.graal.enabled
+ *
+ * @run main/othervm -XX:PartialPeelNewPhiDelta=5 LoopRotateBadNodeBudget
+ * @run main/othervm -Xbatch -XX:PartialPeelNewPhiDelta=5 LoopRotateBadNodeBudget
+ *
+ * @run main/othervm LoopRotateBadNodeBudget
+ * @run main/othervm -Xbatch LoopRotateBadNodeBudget
+ *
+ * NOTE: Test-case seldom manifesting the problem on fast machines.
+ */
+
+public class LoopRotateBadNodeBudget {
+
+    int h;
+    float j(int a, int b) {
+        double d = 0.19881;
+        int c, e[] = new int[9];
+        c = 1;
+        while (++c < 12)
+            switch ((c % 7 * 5) + 122) {
+                case 156:
+                case 46128:
+                case 135:
+                case 148:
+                case 127:
+                    break;
+                default:
+            }
+        while ((d += 2) < 62)
+            ;
+        long k = l(e);
+        return k;
+    }
+    long l(int[] a) {
+        long m = 0;
+        for (int i = 0; i < a.length; i++)
+            m = a[i];
+        return m;
+    }
+    void f(String[] g) {
+        int i = 2;
+        for (; i < 20000; ++i)
+            j(3, h);
+    }
+    public static void main(String[] o) {
+        try {
+            LoopRotateBadNodeBudget n = new LoopRotateBadNodeBudget();
+            n.f(o);
+        } catch (Exception ex) {
+        }
+    }
+}