8027622: java.time.Instant.create failing since hs25-b56

Reviewed-by: kvn, iveresov

src/share/vm/opto/compile.cpp

@@ -3018,7 +3018,13 @@ void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
           // Phi nodes shouldn't be moved. They would only match below if they
           // had the same control as the MathExactNode. The only time that
           // would happen is if the Phi is also an input to the MathExact
-          if (!out->is_Phi()) {
+          //
+          // Cmp nodes shouldn't have control set at all.
+          if (out->is_Phi() ||
+              out->is_Cmp()) {
+            continue;
+          }
+
           if (out->in(0) == NULL) {
             out->set_req(0, non_throwing);
           } else if (out->in(0) == ctrl) {
@@ -3027,7 +3033,6 @@ void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
         }
       }
     }
-    }
     break;
   default:
     assert( !n->is_Call(), "" );

test/compiler/intrinsics/mathexact/CompareTest.java

+/*
+ * Copyright (c) 2013, 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 8026722
+ * @summary Verify that the compare after addExact is a signed compare
+ * @compile CompareTest.java
+ * @run main CompareTest
+ *
+ */
+
+public class CompareTest {
+    public static long store = 0;
+    public static long addValue = 1231;
+
+    public static void main(String[] args) {
+        for (int i = 0; i < 20000; ++i) {
+            runTest(i, i);
+            runTest(i-1, i);
+        }
+    }
+
+    public static long create(long value, int v) {
+        if ((value | v) == 0) {
+            return 0;
+        }
+
+        // C2 turned this test into unsigned test when a control edge was set on the Cmp
+        if (value < -31557014167219200L || value > 31556889864403199L) {
+            throw new RuntimeException("error");
+        }
+
+        return value;
+    }
+
+    public static void runTest(long value, int value2) {
+        long res = Math.addExact(value, addValue);
+        store = create(res, Math.floorMod(value2, 100000));
+    }
+}