1 /*
   2  * Copyright (c) 2015, 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 org.graalvm.compiler.lir.alloc.trace;
  24 
  25 import static org.graalvm.compiler.lir.LIRInstruction.OperandFlag.REG;
  26 import static org.graalvm.compiler.lir.LIRInstruction.OperandFlag.STACK;
  27 
  28 import java.util.EnumSet;
  29 
  30 import org.graalvm.compiler.lir.CompositeValue;
  31 import org.graalvm.compiler.lir.InstructionValueConsumer;
  32 import org.graalvm.compiler.lir.InstructionValueProcedure;
  33 import org.graalvm.compiler.lir.LIRInstruction;
  34 import org.graalvm.compiler.lir.LIRInstruction.OperandFlag;
  35 import org.graalvm.compiler.lir.LIRInstruction.OperandMode;
  36 
  37 import jdk.vm.ci.code.RegisterValue;
  38 import jdk.vm.ci.meta.AllocatableValue;
  39 
  40 /**
  41  * Represents a {@link #register} which has a shadow copy on the {@link #stackslot stack}.
  42  */
  43 public final class ShadowedRegisterValue extends CompositeValue {
  44     private static final EnumSet<OperandFlag> registerFlags = EnumSet.of(REG);
  45     private static final EnumSet<OperandFlag> stackslotFlags = EnumSet.of(STACK);
  46 
  47     @Component({REG}) protected RegisterValue register;
  48     @Component({STACK}) protected AllocatableValue stackslot;
  49 
  50     public ShadowedRegisterValue(RegisterValue register, AllocatableValue stackslot) {
  51         super(register.getValueKind());
  52         assert (register.getValueKind().equals(stackslot.getValueKind()));
  53         this.register = register;
  54         this.stackslot = stackslot;
  55     }
  56 
  57     public RegisterValue getRegister() {
  58         return register;
  59     }
  60 
  61     public AllocatableValue getStackSlot() {
  62         return stackslot;
  63     }
  64 
  65     @Override
  66     public CompositeValue forEachComponent(LIRInstruction inst, OperandMode mode, InstructionValueProcedure proc) {
  67         RegisterValue newRegister = (RegisterValue) proc.doValue(inst, register, mode, registerFlags);
  68         AllocatableValue newStackSlot = (AllocatableValue) proc.doValue(inst, stackslot, mode, stackslotFlags);
  69         if (register.equals(newRegister) || stackslot.equals(newStackSlot)) {
  70             return this;
  71         }
  72         return new ShadowedRegisterValue(newRegister, newStackSlot);
  73     }
  74 
  75     @Override
  76     protected void visitEachComponent(LIRInstruction inst, OperandMode mode, InstructionValueConsumer proc) {
  77         proc.visitValue(inst, register, mode, registerFlags);
  78         proc.visitValue(inst, stackslot, mode, stackslotFlags);
  79     }
  80 
  81     @Override
  82     public boolean equals(Object obj) {
  83         if (obj == null) {
  84             return false;
  85         }
  86         if (this == obj) {
  87             return true;
  88         }
  89         if (getClass() != obj.getClass()) {
  90             return false;
  91         }
  92         ShadowedRegisterValue other = (ShadowedRegisterValue) obj;
  93         assert register != null;
  94         assert stackslot != null;
  95         assert other.register != null;
  96         assert other.stackslot != null;
  97         if (!register.equals(other.register)) {
  98             return false;
  99         }
 100         if (!stackslot.equals(other.stackslot)) {
 101             return false;
 102         }
 103         return true;
 104     }
 105 
 106 }