1 /*
   2  * Copyright (c) 2013, 2019, 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 
  24 
  25 package org.graalvm.compiler.lir.amd64;
  26 
  27 import org.graalvm.compiler.asm.amd64.AMD64MacroAssembler;
  28 import org.graalvm.compiler.lir.LIRInstructionClass;
  29 import org.graalvm.compiler.lir.Opcode;
  30 import org.graalvm.compiler.lir.StandardOp;
  31 import org.graalvm.compiler.lir.asm.CompilationResultBuilder;
  32 
  33 import jdk.vm.ci.amd64.AMD64Kind;
  34 import jdk.vm.ci.code.Register;
  35 import jdk.vm.ci.meta.JavaConstant;
  36 
  37 /**
  38  * Writes well known garbage values to registers.
  39  */
  40 @Opcode("ZAP_REGISTER")
  41 public final class AMD64ZapRegistersOp extends AMD64LIRInstruction implements StandardOp.ZapRegistersOp {
  42     public static final LIRInstructionClass<AMD64ZapRegistersOp> TYPE = LIRInstructionClass.create(AMD64ZapRegistersOp.class);
  43 
  44     /**
  45      * The registers that are zapped.
  46      */
  47     protected final Register[] zappedRegisters;
  48 
  49     /**
  50      * The garbage values that are written to the registers.
  51      */
  52     protected final JavaConstant[] zapValues;
  53 
  54     public AMD64ZapRegistersOp(Register[] zappedRegisters, JavaConstant[] zapValues) {
  55         super(TYPE);
  56         this.zappedRegisters = zappedRegisters;
  57         this.zapValues = zapValues;
  58     }
  59 
  60     @Override
  61     public void emitCode(CompilationResultBuilder crb, AMD64MacroAssembler masm) {
  62         for (int i = 0; i < zappedRegisters.length; i++) {
  63             Register reg = zappedRegisters[i];
  64             if (reg != null) {
  65                 AMD64Move.const2reg(crb, masm, reg, zapValues[i], AMD64Kind.QWORD);
  66             }
  67         }
  68     }
  69 }