1 /* 2 * Copyright (c) 2013, 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.amd64; 24 25 import static org.graalvm.compiler.lir.amd64.AMD64SaveRegistersOp.prune; 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.SaveRegistersOp; 31 import org.graalvm.compiler.lir.asm.CompilationResultBuilder; 32 import org.graalvm.compiler.lir.framemap.FrameMap; 33 import org.graalvm.util.EconomicSet; 34 35 import jdk.vm.ci.code.Register; 36 import jdk.vm.ci.code.RegisterSaveLayout; 37 import jdk.vm.ci.meta.JavaConstant; 38 39 /** 40 * Writes well known garbage values to registers. 41 */ 42 @Opcode("ZAP_REGISTER") 43 public final class AMD64ZapRegistersOp extends AMD64LIRInstruction implements SaveRegistersOp { 44 public static final LIRInstructionClass<AMD64ZapRegistersOp> TYPE = LIRInstructionClass.create(AMD64ZapRegistersOp.class); 45 46 /** 47 * The registers that are zapped. 48 */ 49 protected final Register[] zappedRegisters; 50 51 /** 52 * The garbage values that are written to the registers. 53 */ 54 protected final JavaConstant[] zapValues; 55 56 public AMD64ZapRegistersOp(Register[] zappedRegisters, JavaConstant[] zapValues) { 57 super(TYPE); 58 this.zappedRegisters = zappedRegisters; 59 this.zapValues = zapValues; 60 } 61 62 @Override 63 public void emitCode(CompilationResultBuilder crb, AMD64MacroAssembler masm) { 64 for (int i = 0; i < zappedRegisters.length; i++) { 65 Register reg = zappedRegisters[i]; 66 if (reg != null) { 67 AMD64Move.const2reg(crb, masm, reg, zapValues[i]); 68 } 69 } 70 } 71 72 @Override 73 public boolean supportsRemove() { 74 return true; 75 } 76 77 @Override 78 public int remove(EconomicSet<Register> doNotSave) { 79 return prune(doNotSave, zappedRegisters); 80 } 81 82 @Override 83 public RegisterSaveLayout getMap(FrameMap frameMap) { 84 return new RegisterSaveLayout(new Register[0], new int[0]); 85 } 86 }