1 /*
   2  * Copyright (c) 2009, 2015, 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 jdk.vm.ci.code;
  24 
  25 import static jdk.vm.ci.meta.MetaUtil.identityHashCodeString;
  26 import jdk.vm.ci.meta.JavaKind;
  27 import jdk.vm.ci.meta.LIRKind;
  28 import jdk.vm.ci.meta.PlatformKind;
  29 
  30 /**
  31  * Represents the target machine for a compiler, including the CPU architecture, the size of
  32  * pointers and references, alignment of stacks, caches, etc.
  33  */
  34 public class TargetDescription {
  35 
  36     public final Architecture arch;
  37 
  38     /**
  39      * Specifies if this is a multi-processor system.
  40      */
  41     public final boolean isMP;
  42 
  43     /**
  44      * Specifies if this target supports encoding objects inline in the machine code.
  45      */
  46     public final boolean inlineObjects;
  47 
  48     /**
  49      * The machine word size on this target.
  50      */
  51     public final int wordSize;
  52 
  53     /**
  54      * The {@link JavaKind} to be used for representing raw pointers and CPU registers in Java code.
  55      */
  56     public final JavaKind wordJavaKind;
  57 
  58     /**
  59      * The stack alignment requirement of the platform. For example, from Appendix D of <a
  60      * href="http://www.intel.com/Assets/PDF/manual/248966.pdf">Intel 64 and IA-32 Architectures
  61      * Optimization Reference Manual</a>:
  62      *
  63      * <pre>
  64      *     "It is important to ensure that the stack frame is aligned to a
  65      *      16-byte boundary upon function entry to keep local __m128 data,
  66      *      parameters, and XMM register spill locations aligned throughout
  67      *      a function invocation."
  68      * </pre>
  69      */
  70     public final int stackAlignment;
  71 
  72     /**
  73      * Maximum constant displacement at which a memory access can no longer be an implicit null
  74      * check.
  75      */
  76     public final int implicitNullCheckLimit;
  77 
  78     public TargetDescription(Architecture arch, boolean isMP, int stackAlignment, int implicitNullCheckLimit, boolean inlineObjects) {
  79         this.arch = arch;
  80         this.isMP = isMP;
  81         this.wordSize = arch.getWordSize();
  82         this.wordJavaKind = JavaKind.fromWordSize(wordSize);
  83         this.stackAlignment = stackAlignment;
  84         this.implicitNullCheckLimit = implicitNullCheckLimit;
  85         this.inlineObjects = inlineObjects;
  86 
  87         assert arch.getPlatformKind(wordJavaKind).equals(arch.getWordKind());
  88     }
  89 
  90     @Override
  91     public final int hashCode() {
  92         throw new UnsupportedOperationException();
  93     }
  94 
  95     @Override
  96     public final boolean equals(Object obj) {
  97         if (this == obj) {
  98             return true;
  99         }
 100         if (obj instanceof TargetDescription) {
 101             TargetDescription that = (TargetDescription) obj;
 102             // @formatter:off
 103             if (this.implicitNullCheckLimit == that.implicitNullCheckLimit &&
 104                 this.inlineObjects == that.inlineObjects &&
 105                 this.isMP == that.isMP &&
 106                 this.stackAlignment == that.stackAlignment &&
 107                 this.wordJavaKind.equals(that.wordJavaKind) &&
 108                 this.wordSize == that.wordSize &&
 109                 this.arch.equals(that.arch)) {
 110                 return true;
 111             }
 112             // @formatter:on
 113         }
 114         return false;
 115     }
 116 
 117     @Override
 118     public String toString() {
 119         return identityHashCodeString(this);
 120     }
 121 
 122     public LIRKind getLIRKind(JavaKind javaKind) {
 123         PlatformKind platformKind = arch.getPlatformKind(javaKind);
 124         if (javaKind.isObject()) {
 125             return LIRKind.reference(platformKind);
 126         } else {
 127             return LIRKind.value(platformKind);
 128         }
 129     }
 130 }