/*
 * Copyright (c) 2011, 2012, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
package com.oracle.graal.lir.amd64;

import static com.oracle.graal.api.code.ValueUtil.*;
import static com.oracle.graal.lir.LIRInstruction.OperandFlag.*;

import com.oracle.graal.api.meta.*;
import com.oracle.graal.asm.amd64.*;
import com.oracle.graal.graph.*;
import com.oracle.graal.lir.*;
import com.oracle.graal.lir.asm.*;

public enum AMD64Compare {
    ICMP,
    LCMP,
    ACMP,
    FCMP,
    DCMP;

    public static class CompareOp extends AMD64LIRInstruction {
        @Opcode private final AMD64Compare opcode;
        @Use({REG}) protected Value x;
        @Use({REG, STACK, CONST}) protected Value y;

        public CompareOp(AMD64Compare opcode, Value x, Value y) {
            this.opcode = opcode;
            this.x = x;
            this.y = y;
        }

        @Override
        public void emitCode(CompilationResultBuilder crb, AMD64MacroAssembler masm) {
            emit(crb, masm, opcode, x, y);
        }

        @Override
        protected void verify() {
            super.verify();
            assert (name().startsWith("I") && x.getKind() == Kind.Int && y.getKind().getStackKind() == Kind.Int) || (name().startsWith("L") && x.getKind() == Kind.Long && y.getKind() == Kind.Long) ||
                            (name().startsWith("A") && x.getKind() == Kind.Object && y.getKind() == Kind.Object) ||
                            (name().startsWith("F") && x.getKind() == Kind.Float && y.getKind() == Kind.Float) || (name().startsWith("D") && x.getKind() == Kind.Double && y.getKind() == Kind.Double);
        }
    }

    public static class CompareMemoryOp extends AMD64LIRInstruction {
        @Opcode private final AMD64Compare opcode;
        @Use({REG, COMPOSITE}) protected Value x;
        @Use({CONST, COMPOSITE}) protected Value y;
        @State protected LIRFrameState state;

        /**
         * Compare memory, constant or register, memory.
         */
        public CompareMemoryOp(AMD64Compare opcode, Value x, Value y, LIRFrameState state) {
            assert (x instanceof AMD64AddressValue && y instanceof Constant) || (x instanceof Variable && y instanceof AMD64AddressValue);
            this.opcode = opcode;
            this.x = x;
            this.y = y;
            this.state = state;
        }

        @Override
        public void emitCode(CompilationResultBuilder crb, AMD64MacroAssembler masm) {
            if (state != null) {
                crb.recordImplicitException(masm.position(), state);
            }
            emit(crb, masm, opcode, x, y);
        }

        @Override
        protected void verify() {
            super.verify();
            assert (x instanceof AMD64AddressValue && y instanceof Constant) || (x instanceof Variable && y instanceof AMD64AddressValue);
        }
    }

    public static void emit(CompilationResultBuilder crb, AMD64MacroAssembler masm, AMD64Compare opcode, Value x, Value y) {
        if (isRegister(x) && isRegister(y)) {
            switch (opcode) {
                case ICMP:
                    masm.cmpl(asIntReg(x), asIntReg(y));
                    break;
                case LCMP:
                    masm.cmpq(asLongReg(x), asLongReg(y));
                    break;
                case ACMP:
                    masm.cmpptr(asObjectReg(x), asObjectReg(y));
                    break;
                case FCMP:
                    masm.ucomiss(asFloatReg(x), asFloatReg(y));
                    break;
                case DCMP:
                    masm.ucomisd(asDoubleReg(x), asDoubleReg(y));
                    break;
                default:
                    throw GraalInternalError.shouldNotReachHere();
            }
        } else if (isRegister(x) && isConstant(y)) {
            boolean isZero = ((Constant) y).isDefaultForKind();
            switch (opcode) {
                case ICMP:
                    if (isZero) {
                        masm.testl(asIntReg(x), asIntReg(x));
                    } else {
                        masm.cmpl(asIntReg(x), crb.asIntConst(y));
                    }
                    break;
                case LCMP:
                    if (isZero) {
                        masm.testq(asLongReg(x), asLongReg(x));
                    } else {
                        masm.cmpq(asLongReg(x), crb.asIntConst(y));
                    }
                    break;
                case ACMP:
                    if (isZero) {
                        masm.testq(asObjectReg(x), asObjectReg(x));
                        break;
                    } else {
                        throw GraalInternalError.shouldNotReachHere("Only null object constants are allowed in comparisons");
                    }
                case FCMP:
                    masm.ucomiss(asFloatReg(x), (AMD64Address) crb.asFloatConstRef(y));
                    break;
                case DCMP:
                    masm.ucomisd(asDoubleReg(x), (AMD64Address) crb.asDoubleConstRef(y));
                    break;
                default:
                    throw GraalInternalError.shouldNotReachHere();
            }
        } else if (isRegister(x) && isStackSlot(y)) {
            switch (opcode) {
                case ICMP:
                    masm.cmpl(asIntReg(x), (AMD64Address) crb.asIntAddr(y));
                    break;
                case LCMP:
                    masm.cmpq(asLongReg(x), (AMD64Address) crb.asLongAddr(y));
                    break;
                case ACMP:
                    masm.cmpptr(asObjectReg(x), (AMD64Address) crb.asObjectAddr(y));
                    break;
                case FCMP:
                    masm.ucomiss(asFloatReg(x), (AMD64Address) crb.asFloatAddr(y));
                    break;
                case DCMP:
                    masm.ucomisd(asDoubleReg(x), (AMD64Address) crb.asDoubleAddr(y));
                    break;
                default:
                    throw GraalInternalError.shouldNotReachHere();
            }
        } else if (isRegister(x) && y instanceof AMD64AddressValue) {
            switch (opcode) {
                case ICMP:
                    masm.cmpl(asIntReg(x), ((AMD64AddressValue) y).toAddress());
                    break;
                case LCMP:
                    masm.cmpq(asLongReg(x), ((AMD64AddressValue) y).toAddress());
                    break;
                case ACMP:
                    masm.cmpptr(asObjectReg(x), ((AMD64AddressValue) y).toAddress());
                    break;
                case FCMP:
                    masm.ucomiss(asFloatReg(x), ((AMD64AddressValue) y).toAddress());
                    break;
                case DCMP:
                    masm.ucomisd(asDoubleReg(x), ((AMD64AddressValue) y).toAddress());
                    break;
                default:
                    throw GraalInternalError.shouldNotReachHere();
            }
        } else if (x instanceof AMD64AddressValue && isConstant(y)) {
            switch (opcode) {
                case ICMP:
                    masm.cmpl(((AMD64AddressValue) x).toAddress(), crb.asIntConst(y));
                    break;
                case LCMP:
                    if (crb.asLongConst(y) == (int) crb.asLongConst(y)) {
                        masm.cmpq(((AMD64AddressValue) x).toAddress(), (int) crb.asLongConst(y));
                    } else {
                        throw GraalInternalError.shouldNotReachHere();
                    }
                    break;
                default:
                    throw GraalInternalError.shouldNotReachHere();
            }
        }
    }
}