8210390: C2 still crashes with "assert(mode == ControlAroundStripMined && use...

8210390: C2 still crashes with "assert(mode == ControlAroundStripMined && use == sfpt) failed: missed a node"
Reviewed-by: thartmann, kvn

src/hotspot/share/opto/loopopts.cpp

@@ -3383,12 +3383,19 @@ void PhaseIdealLoop::reorg_offsets(IdealLoopTree *loop) {
       if (dom_lca(exit, u_ctrl) != exit) continue;
       // Hit!  Refactor use to use the post-incremented tripcounter.
       // Compute a post-increment tripcounter.
-      Node *opaq = new Opaque2Node( C, cle->incr() );
-      register_new_node(opaq, exit);
+      Node* c = exit;
+      if (cl->is_strip_mined()) {
+        IdealLoopTree* outer_loop = get_loop(cl->outer_loop());
+        if (!outer_loop->is_member(u_loop)) {
+          c = cl->outer_loop_exit();
+        }
+      }
+      Node *opaq = new Opaque2Node(C, cle->incr());
+      register_new_node(opaq, c);
       Node *neg_stride = _igvn.intcon(-cle->stride_con());
       set_ctrl(neg_stride, C->root());
-      Node *post = new AddINode( opaq, neg_stride);
-      register_new_node(post, exit);
+      Node *post = new AddINode(opaq, neg_stride);
+      register_new_node(post, c);
       _igvn.rehash_node_delayed(use);
       for (uint j = 1; j < use->req(); j++) {
         if (use->in(j) == phi)

test/hotspot/jtreg/compiler/loopstripmining/StripMinedLoopReorgOffsets.java

+/*
+ * Copyright (c) 2018, Red Hat, Inc. 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 8210390
+ * @summary C2 still crashes with "assert(mode == ControlAroundStripMined && use == sfpt) failed: missed a node"
+ *
+ * @run main/othervm -Xcomp StripMinedLoopReorgOffsets
+ *
+ */
+
+public class StripMinedLoopReorgOffsets {
+
+    public static final int N = 400;
+
+    public static long instanceCount=-4622920139809038929L;
+
+    public void mainTest(String[] strArr1) {
+
+        int i1=-211, i20=54720, i21=205, i22=2184, i23=58, i24=-50110, iArr3[]=new int[N];
+
+        for (i20 = 16; 331 > i20; ++i20) {
+            i1 = i20;
+            i21 += i1;
+            iArr3[i20] <<= (int)StripMinedLoopReorgOffsets.instanceCount;
+            for (i22 = 4; i22 < 80; i22++) {
+                i21 = i23;
+                i24 = 1;
+                while (++i24 < 2) {
+                    try {
+                        iArr3[i22] = (i23 / i1);
+                    } catch (ArithmeticException a_e) {}
+                }
+            }
+        }
+
+        System.out.println("i1 i20 = " + i1 + "," + i20);
+        System.out.println("i21 i22 i23 = " + i21 + "," + i22 + "," + i23);
+        System.out.println("i24 = " + i24);
+    }
+    public static void main(String[] strArr) {
+        StripMinedLoopReorgOffsets _instance = new StripMinedLoopReorgOffsets();
+        for (int i = 0; i < 10; i++ ) {
+            _instance.mainTest(strArr);
+        }
+    }
+}