8073792: assert((get_length_if_constant(phase) == -1) == !ary_src->size()->is_con()) failed: inconsistent

Assert in array copy code broken when array size becomes known during igvn

Reviewed-by: kvn, vlivanov

hotspot/src/share/vm/opto/arraycopynode.cpp

@@ -121,7 +121,8 @@ int ArrayCopyNode::get_count(PhaseGVN *phase) const {
       // length input to ArrayCopyNode is constant, length of input
       // array must be too.
 
-      assert((get_length_if_constant(phase) == -1) == !ary_src->size()->is_con(), "inconsistent");
+      assert((get_length_if_constant(phase) == -1) == !ary_src->size()->is_con() ||
+             phase->is_IterGVN(), "inconsistent");
 
       if (ary_src->size()->is_con()) {
         return ary_src->size()->get_con();

hotspot/test/compiler/arraycopy/TestArrayCloneBadAssert.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2015, 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 8073792
+ * @summary assert broken when array size becomes known during igvn
+ * @run main/othervm -Xcomp -XX:CompileOnly=TestArrayCloneBadAssert.m TestArrayCloneBadAssert
+ *
+ */
+
+public class TestArrayCloneBadAssert {
+
+    static final int[] array = new int[5];
+
+    static int[] m(int[] arr) {
+        int i = 0;
+        for (; i < 2; i++) {
+        }
+        if (i == 2) {
+            arr = array;
+        }
+        return arr.clone();
+    }
+
+    static public void main(String[] args) {
+        int[] arr = new int[5];
+        m(arr);
+    }
+}

hotspot/test/compiler/arraycopy/TestArrayCopyAsLoadsStores.java

@@ -25,8 +25,8 @@
  * @test
  * @bug 6912521
  * @summary small array copy as loads/stores
- * @run main/othervm -XX:-BackgroundCompilation -XX:-UseOnStackReplacement -XX:CompileCommand=dontinline,TestArrayCopyAsLoadsStores::m* -XX:TypeProfileLevel=200 TestArrayCopyAsLoadsStores
+ * @run main/othervm -ea -XX:-BackgroundCompilation -XX:-UseOnStackReplacement -XX:CompileCommand=dontinline,TestArrayCopyAsLoadsStores::m* -XX:TypeProfileLevel=200 TestArrayCopyAsLoadsStores
- * @run main/othervm -XX:-BackgroundCompilation -XX:-UseOnStackReplacement -XX:CompileCommand=dontinline,TestArrayCopyAsLoadsStores::m* -XX:+IgnoreUnrecognizedVMOptions -XX:+StressArrayCopyMacroNode -XX:TypeProfileLevel=200 TestArrayCopyAsLoadsStores
+ * @run main/othervm -ea -XX:-BackgroundCompilation -XX:-UseOnStackReplacement -XX:CompileCommand=dontinline,TestArrayCopyAsLoadsStores::m* -XX:+IgnoreUnrecognizedVMOptions -XX:+StressArrayCopyMacroNode -XX:TypeProfileLevel=200 TestArrayCopyAsLoadsStores
  *
  */
 
@@ -392,7 +392,6 @@ public class TestArrayCopyAsLoadsStores {
             break;
         }
         case ZERO: {
-            assert isIntArray;
             if (isIntArray) {
                 src = zero_int_src;
             } else {