1/*
2 * Copyright (c) 2016, 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 */
23package org.graalvm.compiler.lir.amd64;
24
25import org.graalvm.compiler.asm.amd64.AMD64MacroAssembler;
26import org.graalvm.compiler.lir.LIRInstructionClass;
27import org.graalvm.compiler.lir.Opcode;
28import org.graalvm.compiler.lir.asm.CompilationResultBuilder;
29
30import jdk.vm.ci.code.StackSlot;
31import jdk.vm.ci.meta.JavaConstant;
32
33/**
34 * Writes well known garbage values to stack slots.
35 */
36@Opcode("ZAP_STACK")
37public final class AMD64ZapStackOp extends AMD64LIRInstruction {
38    public static final LIRInstructionClass<AMD64ZapStackOp> TYPE = LIRInstructionClass.create(AMD64ZapStackOp.class);
39
40    /**
41     * The stack slots that are zapped.
42     */
43    @Def(OperandFlag.STACK) protected final StackSlot[] zappedStack;
44
45    /**
46     * The garbage values that are written to the stack.
47     */
48    protected final JavaConstant[] zapValues;
49
50    public AMD64ZapStackOp(StackSlot[] zappedStack, JavaConstant[] zapValues) {
51        super(TYPE);
52        this.zappedStack = zappedStack;
53        this.zapValues = zapValues;
54    }
55
56    @Override
57    public void emitCode(CompilationResultBuilder crb, AMD64MacroAssembler masm) {
58        for (int i = 0; i < zappedStack.length; i++) {
59            StackSlot slot = zappedStack[i];
60            if (slot != null) {
61                AMD64Move.const2stack(crb, masm, slot, zapValues[i]);
62            }
63        }
64    }
65}
66