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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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package com.oracle.svm.core.util;

import org.graalvm.word.Pointer;
import org.graalvm.word.PointerBase;
import org.graalvm.word.UnsignedWord;

import com.oracle.svm.core.annotate.Uninterruptible;

Utility methods on Pointers.
/**
 * Utility methods on Pointers.
 */
public final class PointerUtils {

    private PointerUtils() {
        // This is a class of static methods, so no need for any instances.
    }

    
Round a Pointer down to the nearest smaller multiple.
Params:
that – The Pointer to be rounded up.
multiple – The multiple to which that Pointer should be decreased.
Returns:
That Pointer, but rounded down./**
     * 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.
     */
    @Uninterruptible(reason = "Used in uninterruptible code.", mayBeInlined = true)
    public static Pointer roundDown(PointerBase that, UnsignedWord multiple) {
        return (Pointer) UnsignedUtils.roundDown((UnsignedWord) that, multiple);
    }

    
Round a Pointer up to the nearest larger multiple.
Params:
that – The Pointer to be rounded up.
multiple – The multiple to which that Pointer should be increased.
Returns:
That Pointer, but rounded up./**
     * 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.
     */
    @Uninterruptible(reason = "Used in uninterruptible code.", mayBeInlined = true)
    public static Pointer roundUp(PointerBase that, UnsignedWord multiple) {
        return (Pointer) UnsignedUtils.roundUp((UnsignedWord) that, multiple);
    }

    
Check that a Pointer is an even multiple.
Params:
that – The Pointer to be verified as a multiple.
multiple – The multiple against which the Pointer should be verified.
Returns:
true if that Pointer is a multiple, false otherwise./**
     * 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.
     */
    @Uninterruptible(reason = "Used in uninterruptible code.", mayBeInlined = true)
    public static boolean isAMultiple(PointerBase that, UnsignedWord multiple) {
        return UnsignedUtils.isAMultiple((UnsignedWord) that, multiple);
    }

    
Return the distance between two Pointers.
Params:
pointer1 – A first Pointer.
pointer2 – A second Pointer.
Returns:
The distance in bytes between the two Pointers./**
     * 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 UnsignedWord absoluteDifference(PointerBase pointer1, PointerBase pointer2) {
        Pointer p1 = (Pointer) pointer1;
        Pointer p2 = (Pointer) pointer2;
        final UnsignedWord result;
        if (p1.aboveOrEqual(p2)) {
            result = p1.subtract(p2);
        } else {
            result = p2.subtract(p1);
        }
        return result;
    }

    
The minimum of two Pointers.
Params:
x – A Pointer.
y – Another Pointer.
Returns:
The whichever Pointer is smaller./**
     * 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.
Params:
x – A Pointer.
y – Another Pointer.
Returns:
The whichever Pointer is larger./**
     * 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;
    }
}