Mercurial > hg > truffle
view agent/src/share/classes/sun/jvm/hotspot/debugger/MachineDescriptionTwosComplement.java @ 113:ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
Summary: Compressed oops in instances, arrays, and headers. Code contributors are coleenp, phh, never, swamyv
Reviewed-by: jmasa, kamg, acorn, tbell, kvn, rasbold
author | coleenp |
---|---|
date | Sun, 13 Apr 2008 17:43:42 -0400 |
parents | a61af66fc99e |
children | c18cbe5936b8 |
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/* * Copyright 2000-2001 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * CA 95054 USA or visit www.sun.com if you need additional information or * have any questions. * */ package sun.jvm.hotspot.debugger; /** Base class for all twos-complement machine descriptions, which handles the cIntegerType{Min,Max}Value methods. */ public abstract class MachineDescriptionTwosComplement { /** Handles 1, 2, 4, and 8-byte signed integers */ private static final long[] signedMinValues = { Byte.MIN_VALUE, Short.MIN_VALUE, Integer.MIN_VALUE, Long.MIN_VALUE }; /** Handles 1, 2, 4, and 8-byte signed integers */ private static final long[] signedMaxValues = { Byte.MAX_VALUE, Short.MAX_VALUE, Integer.MAX_VALUE, Long.MAX_VALUE }; /** Handles 1, 2, and 4-byte unsigned integers properly, with a bug in the 8-byte unsigned integer's constant */ private static final long[] unsignedMaxValues = { 255L, 65535L, 4294967295L, -1L }; public long cIntegerTypeMaxValue(long sizeInBytes, boolean isUnsigned) { if (isUnsigned) { // Would be nice to signal to the caller that 8-byte unsigned // integers are not supported properly, but it looks like doing // so at this level will cause problems above return tableLookup(sizeInBytes, unsignedMaxValues); } else { return tableLookup(sizeInBytes, signedMaxValues); } }; public long cIntegerTypeMinValue(long sizeInBytes, boolean isUnsigned) { if (isUnsigned) { return 0; } return tableLookup(sizeInBytes, signedMinValues); } // Nearly all of the supported machines are not LP64 */ public boolean isLP64() { return false; } private long tableLookup(long sizeInBytes, long[] table) { switch ((int) sizeInBytes) { case 1: return table[0]; case 2: return table[1]; case 4: return table[2]; case 8: return table[3]; default: throw new IllegalArgumentException("C integer type of " + sizeInBytes + " not supported"); } } }