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package org.graalvm.compiler.lir.amd64;

import static org.graalvm.compiler.lir.amd64.AMD64SaveRegistersOp.prune;

import jdk.internal.vm.compiler.collections.EconomicSet;
import org.graalvm.compiler.asm.amd64.AMD64MacroAssembler;
import org.graalvm.compiler.lir.LIRInstructionClass;
import org.graalvm.compiler.lir.Opcode;
import org.graalvm.compiler.lir.StandardOp.SaveRegistersOp;
import org.graalvm.compiler.lir.asm.CompilationResultBuilder;
import org.graalvm.compiler.lir.framemap.FrameMap;

import jdk.vm.ci.code.Register;
import jdk.vm.ci.code.RegisterSaveLayout;
import jdk.vm.ci.meta.JavaConstant;

Writes well known garbage values to registers.
/** * Writes well known garbage values to registers. */
@Opcode("ZAP_REGISTER") public final class AMD64ZapRegistersOp extends AMD64LIRInstruction implements SaveRegistersOp { public static final LIRInstructionClass<AMD64ZapRegistersOp> TYPE = LIRInstructionClass.create(AMD64ZapRegistersOp.class);
The registers that are zapped.
/** * The registers that are zapped. */
protected final Register[] zappedRegisters;
The garbage values that are written to the registers.
/** * The garbage values that are written to the registers. */
protected final JavaConstant[] zapValues; public AMD64ZapRegistersOp(Register[] zappedRegisters, JavaConstant[] zapValues) { super(TYPE); this.zappedRegisters = zappedRegisters; this.zapValues = zapValues; } @Override public void emitCode(CompilationResultBuilder crb, AMD64MacroAssembler masm) { for (int i = 0; i < zappedRegisters.length; i++) { Register reg = zappedRegisters[i]; if (reg != null) { AMD64Move.const2reg(crb, masm, reg, zapValues[i]); } } } @Override public boolean supportsRemove() { return true; } @Override public int remove(EconomicSet<Register> doNotSave) { return prune(doNotSave, zappedRegisters); } @Override public RegisterSaveLayout getMap(FrameMap frameMap) { return new RegisterSaveLayout(new Register[0], new int[0]); } }