Mercurial > hg > graal-compiler
view graal/com.oracle.jvmci.meta/src/com/oracle/jvmci/meta/TriState.java @ 21591:6c5327245831
LinearScan: fix intervals context.
author | Josef Eisl <josef.eisl@jku.at> |
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date | Fri, 29 May 2015 10:59:03 +0200 |
parents | 48c1ebd24120 |
children |
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/* * Copyright (c) 2012, 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 com.oracle.jvmci.meta; /** * Represents a logic value that can be either {@link #TRUE}, {@link #FALSE}, or {@link #UNKNOWN}. */ public enum TriState { TRUE, FALSE, UNKNOWN; public static TriState get(boolean value) { return value ? TRUE : FALSE; } /** * This is optimistic about {@link #UNKNOWN} (it prefers known values over {@link #UNKNOWN}) and * pesimistic about known (it perfers {@link #TRUE} over {@link #FALSE}). */ public static TriState merge(TriState a, TriState b) { if (a == TRUE || b == TRUE) { return TRUE; } if (a == FALSE || b == FALSE) { return FALSE; } assert a == UNKNOWN && b == UNKNOWN; return UNKNOWN; } public boolean isTrue() { return this == TRUE; } public boolean isFalse() { return this == FALSE; } public boolean isUnknown() { return this == UNKNOWN; } public boolean isKnown() { return this != UNKNOWN; } public boolean toBoolean() { if (isTrue()) { return true; } else if (isFalse()) { return false; } else { throw new IllegalStateException("Cannot convert to boolean, TriState is in an unknown state"); } } }