1 /*
   2  * Copyright (c) 2011, 2016, 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.spi;
  24 
  25 import org.graalvm.compiler.graph.Node;
  26 import org.graalvm.compiler.nodes.ValueNode;
  27 import org.graalvm.compiler.nodes.memory.address.AddressNode;
  28 
  29 import jdk.vm.ci.meta.JavaKind;
  30 
  31 /**
  32  * Provides a capability for replacing a higher node with one or more lower level nodes.
  33  */
  34 public interface LoweringProvider {
  35 
  36     void lower(Node n, LoweringTool tool);
  37 
  38     /**
  39      * Reconstructs the array index from an address node that was created as a lowering of an
  40      * indexed access to an array.
  41      *
  42      * @param elementKind the {@link JavaKind} of the array elements
  43      * @param address an {@link AddressNode} pointing to an element in an array
  44      * @return a node that gives the index of the element
  45      */
  46     ValueNode reconstructArrayIndex(JavaKind elementKind, AddressNode address);
  47 
  48     /**
  49      * Indicates whether the target platform supports comparison of integers of a particular bit
  50      * width. This check is used by optimizations that might introduce subword compares.
  51      */
  52     default boolean supportSubwordCompare(int bits) {
  53         // most platforms only support 32 and 64 bit compares
  54         return bits >= 32;
  55     }
  56 }