1 /*
   2  * Copyright (c) 2014, 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 package org.graalvm.compiler.nodes.calc;
  24 
  25 import org.graalvm.compiler.core.common.calc.Condition;
  26 import org.graalvm.compiler.nodes.ValueNode;
  27 import org.graalvm.compiler.nodes.ValueNodeInterface;
  28 
  29 import jdk.vm.ci.meta.Constant;
  30 import jdk.vm.ci.meta.ConstantReflectionProvider;
  31 
  32 /**
  33  * Represents a conversion between primitive types.
  34  */
  35 public interface ConvertNode extends ValueNodeInterface {
  36 
  37     ValueNode getValue();
  38 
  39     Constant convert(Constant c, ConstantReflectionProvider constantReflection);
  40 
  41     Constant reverse(Constant c, ConstantReflectionProvider constantReflection);
  42 
  43     /**
  44      * Check whether a conversion is lossless.
  45      *
  46      * @return true iff reverse(convert(c)) == c for all c
  47      */
  48     boolean isLossless();
  49 
  50     /**
  51      * Check whether a conversion preserves comparison order.
  52      *
  53      * @param op a comparison operator
  54      * @return true iff (c1 op c2) == (convert(c1) op convert(c2)) for all c1, c2
  55      */
  56     default boolean preservesOrder(Condition op) {
  57         return isLossless();
  58     }
  59 
  60     /**
  61      * Check whether a conversion preserves comparison order against a particular constant value.
  62      *
  63      * @param op a comparison operator
  64      * @param value
  65      * @param constantReflection
  66      * @return true iff (c1 op value) == (convert(c1) op convert(value)) for value and all c1
  67      */
  68     default boolean preservesOrder(Condition op, Constant value, ConstantReflectionProvider constantReflection) {
  69         return preservesOrder(op);
  70     }
  71 }