| /* |
| * 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 extends PointerBase> 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 extends PointerBase> 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 extends PointerBase> T max(T x, T y) { |
| return (((Pointer) x).aboveOrEqual((Pointer) y)) ? x : y; |
| } |
| } |