SquirrelJME/SquirrelJME

// -*- Mode: Java; indent-tabs-mode: t; tab-width: 4 -*-
// ---------------------------------------------------------------------------
// SquirrelJME
//     Copyright (C) Stephanie Gawroriski <xer@multiphasicapps.net>
// ---------------------------------------------------------------------------
// SquirrelJME is under the Mozilla Public License Version 2.0.
// See license.mkd for licensing and copyright information.
// ---------------------------------------------------------------------------

package cc.squirreljme.jvm;

import cc.squirreljme.jvm.mle.MathShelf;
import cc.squirreljme.runtime.cldc.annotation.SquirrelJMEVendorApi;
import cc.squirreljme.runtime.cldc.debug.Debugging;

/**
 * Software integer operations.
 *
 * @since 2019/05/27
 */
@SquirrelJMEVendorApi
@SuppressWarnings("MagicNumber")
public final class SoftInteger
{
    /**
     * Not used.
     *
     * @since 2019/05/27
     */
    private SoftInteger()
    {
    }
    
    /**
     * Converts to double.
     *
     * @param __a A.
     * @return The result.
     * @since 2019/05/24
     */
    @SquirrelJMEVendorApi
    public static double toDouble(int __a)
    {
        throw Debugging.todo();
    }
    
    /**
     * Converts to float.
     *
     * @param __a A.
     * @return The result.
     * @since 2019/05/24
     */
    @SquirrelJMEVendorApi
    public static float toFloat(int __a)
    {
        boolean sign = (__a < 0);
        
        // if ( ! (a & 0x7FFFFFFF) ) {
        if ((__a & 0x7FFF_FFFF) == 0)
        {
            // uZ.ui = sign ? packToF32UI( 1, 0x9E, 0 ) : 0;
            return Float.intBitsToFloat((sign ?
                SoftFloat.__packToF32UI(true, 0x9E, 0) :
                0));
        }
        
        int absA = sign ? -__a : __a;
        
        // return softfloat_normRoundPackToF32( sign, 0x9C, absA );
        return Float.intBitsToFloat(
            SoftFloat.__normRoundPackToF32(sign, 0x9C, absA));
    }
    
    /**
     * Converts to long.
     *
     * @param __a A.
     * @return The result.
     * @since 2019/05/24
     */
    @SquirrelJMEVendorApi
    public static long toLong(int __a)
    {
        // If the integer has the sign bit, then it will be sign extended
        // meaning all the upper bits get set
        if ((__a & 0x80000000) != 0)
            return MathShelf.longPack(__a, 0xFFFFFFFF);
        
        // Otherwise, the top is just zero
        else
            return MathShelf.longPack(__a, 0);
    }
}