1 files changed, 87 insertions, 0 deletions
diff --git a/src/jdk/nashorn/internal/IntDeque.java b/src/jdk/nashorn/internal/IntDeque.java
new file mode 100644
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+++ b/src/jdk/nashorn/internal/IntDeque.java
@@ -0,0 +1,87 @@
+/*
+ * Copyright (c) 2010, 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ */
+
+package jdk.nashorn.internal;
+
+/**
+ * Small helper class for fast int deques
+ */
+public class IntDeque {
+    private int[] deque = new int[16];
+    private int nextFree = 0;
+
+    /**
+     * Push an int value
+     * @param value value
+     */
+    public void push(final int value) {
+        if (nextFree == deque.length) {
+            final int[] newDeque = new int[nextFree * 2];
+            System.arraycopy(deque, 0, newDeque, 0, nextFree);
+            deque = newDeque;
+        }
+        deque[nextFree++] = value;
+    }
+
+    /**
+     * Pop an int value
+     * @return value
+     */
+    public int pop() {
+        return deque[--nextFree];
+    }
+
+    /**
+     * Peek
+     * @return top value
+     */
+    public int peek() {
+        return deque[nextFree - 1];
+    }
+
+    /**
+     * Get the value of the top element and increment it.
+     * @return top value
+     */
+    public int getAndIncrement() {
+        return deque[nextFree - 1]++;
+    }
+
+    /**
+     * Decrement the value of the top element and return it.
+     * @return decremented top value
+     */
+    public int decrementAndGet() {
+        return --deque[nextFree - 1];
+    }
+
+    /**
+     * Check if deque is empty
+     * @return true if empty
+     */
+    public boolean isEmpty() {
+        return nextFree == 0;
+    }
+}