8238812: assert(false) failed: bad AD file

src/hotspot/share/opto/phaseX.cpp

@@ -1552,6 +1552,18 @@ void PhaseIterGVN::add_users_to_worklist( Node *n ) {
         }
       }
       if (use_op == Op_CmpI) {
+        // Put If on worklist to enable fold_compares optimization (see IfNode::cmpi_folds)
+        if (use->outcnt() > 0) {
+          for (uint i = 0; i < use->outcnt(); i++) {
+            Node* bol = use->raw_out(i);
+            if (bol->outcnt() > 0) {
+              Node* iff = bol->raw_out(0);
+              if (iff->Opcode() == Op_If && iff->outcnt() == 2) {
+                add_users_to_worklist0(bol);
+              }
+            }
+          }
+        }
         Node* phi = countedloop_phi_from_cmp((CmpINode*)use, n);
         if (phi != NULL) {
           // If an opaque node feeds into the limit condition of a

test/hotspot/jtreg/compiler/c2/Test8238812.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright (c) 2020, 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 8238812
+ * @summary Fix c2 assert(false) failed: bad AD file
+ * @run main/othervm -XX:CompileCommand=compileonly,compiler.c2.Test8238812::test
+ *                   -XX:CompileCommand=dontinline,compiler.c2.Test8238812::test
+ *                   -Xbatch -XX:+UnlockDiagnosticVMOptions -XX:-TieredCompilation -XX:+UseSwitchProfiling
+ *                   compiler.c2.Test8238812
+ */
+
+package compiler.c2;
+
+public class Test8238812 {
+
+    public static void test() {
+        int i4, i5=99, i6, i9=89;
+        for (i4 = 12; i4 < 365; i4++) {
+            for (i6 = 5; i6 > 1; i6--) {
+                switch ((i6 * 5) + 11) {
+                case 13:
+                case 19:
+                case 26:
+                case 31:
+                case 35:
+                case 41:
+                case 43:
+                case 61:
+                case 71:
+                case 83:
+                case 314:
+                    i9 = i5;
+                    break;
+                }
+            }
+        }
+    }
+
+    public static void main(String[] strArr) {
+        for (int i = 0; i < 10; i++) {
+            test();
+        }
+    }
+
+}