--- /dev/null 2016-05-31 09:42:47.975716356 -0700 +++ new/src/jdk.vm.compiler/share/classes/org.graalvm.compiler.word/src/org/graalvm/compiler/word/PointerUtils.java 2016-12-09 00:57:30.100505834 -0800 @@ -0,0 +1,135 @@ +/* + * Copyright (c) 2015, 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. + */ +package org.graalvm.compiler.word; + +/** + * Utility methods on Pointers. + */ +public final class PointerUtils { + + private PointerUtils() { + // This is a class of static methods, so no need for any instances. + } + + /** + * The value of a null Pointer. + * + * @return A null Pointer value. + */ + @SuppressWarnings("unchecked") + public static T nullPointer() { + return (T) Word.zero(); + } + + /** + * Predicate to check for the null Pointer value. + * + * @return Whether that Pointer is the null Pointer. + */ + public static boolean isNull(ComparableWord that) { + return that.equal(nullPointer()); + } + + /** + * Predicate to check for a non-null Pointer value. + * + * @return Whether that Pointer is not the null Pointer. + */ + public static boolean isNonNull(ComparableWord that) { + return that.notEqual(nullPointer()); + } + + /** + * Round a Pointer down to the nearest smaller multiple. + * + * @param that The Pointer to be rounded up. + * @param multiple The multiple to which that Pointer should be decreased. + * @return That Pointer, but rounded down. + */ + public static Pointer roundDown(PointerBase that, Unsigned multiple) { + return (Pointer) UnsignedUtils.roundDown((Unsigned) that, multiple); + } + + /** + * Round a Pointer up to the nearest larger multiple. + * + * @param that The Pointer to be rounded up. + * @param multiple The multiple to which that Pointer should be increased. + * @return That Pointer, but rounded up. + */ + public static Pointer roundUp(PointerBase that, Unsigned multiple) { + return (Pointer) UnsignedUtils.roundUp((Unsigned) that, multiple); + } + + /** + * Check that a Pointer is an even multiple. + * + * @param that The Pointer to be verified as a multiple. + * @param multiple The multiple against which the Pointer should be verified. + * @return true if that Pointer is a multiple, false otherwise. + */ + public static boolean isAMultiple(PointerBase that, Unsigned multiple) { + return that.equal(PointerUtils.roundDown(that, multiple)); + } + + /** + * Return the distance between two Pointers. + * + * @param pointer1 A first Pointer. + * @param pointer2 A second Pointer. + * @return The distance in bytes between the two Pointers. + */ + public static Unsigned absoluteDifference(PointerBase pointer1, PointerBase pointer2) { + Pointer p1 = (Pointer) pointer1; + Pointer p2 = (Pointer) pointer2; + final Unsigned result; + if (p1.aboveOrEqual(p2)) { + result = p1.subtract(p2); + } else { + result = p2.subtract(p1); + } + return result; + } + + /** + * The minimum of two Pointers. + * + * @param x A Pointer. + * @param y Another Pointer. + * @return The whichever Pointer is smaller. + */ + public static T min(T x, T y) { + return (((Pointer) x).belowOrEqual((Pointer) y)) ? x : y; + } + + /** + * The maximum of two Pointers. + * + * @param x A Pointer. + * @param y Another Pointer. + * @return The whichever Pointer is larger. + */ + public static T max(T x, T y) { + return (((Pointer) x).aboveOrEqual((Pointer) y)) ? x : y; + } +}