/*

 * Copyright (c) 1994, 2003, 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.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * 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 sun.tools.tree;

import sun.tools.java.*;

import sun.tools.asm.Assembler;

import sun.tools.asm.Label;

/**

 * WARNING: The contents of this source file are not part of any

 * supported API.  Code that depends on them does so at its own risk:

 * they are subject to change or removal without notice.

 */

public

class EqualExpression extends BinaryEqualityExpression {

    /**

     * constructor

     */

    public EqualExpression(long where, Expression left, Expression right) {

        super(EQ, where, left, right);

    }

    /**

     * Evaluate

     */

    Expression eval(int a, int b) {

        return new BooleanExpression(where, a == b);

    }

    Expression eval(long a, long b) {

        return new BooleanExpression(where, a == b);

    }

    Expression eval(float a, float b) {

        return new BooleanExpression(where, a == b);

    }

    Expression eval(double a, double b) {

        return new BooleanExpression(where, a == b);

    }

    Expression eval(boolean a, boolean b) {

        return new BooleanExpression(where, a == b);

    }

    /**

     * Simplify

     */

    Expression simplify() {

        if (left.isConstant() && !right.isConstant()) {

            return new EqualExpression(where, right, left);

        }

        return this;

    }

    /**

     * Code

     */

    void codeBranch(Environment env, Context ctx, Assembler asm, Label lbl, boolean whenTrue) {

        left.codeValue(env, ctx, asm);

        switch (left.type.getTypeCode()) {

          case TC_BOOLEAN:

          case TC_INT:

            if (!right.equals(0)) {

                right.codeValue(env, ctx, asm);

                asm.add(where, whenTrue ? opc_if_icmpeq : opc_if_icmpne, lbl, whenTrue);

                return;

            }

            break;

          case TC_LONG:

            right.codeValue(env, ctx, asm);

            asm.add(where, opc_lcmp);

            break;

          case TC_FLOAT:

            right.codeValue(env, ctx, asm);

            asm.add(where, opc_fcmpl);

            break;

          case TC_DOUBLE:

            right.codeValue(env, ctx, asm);

            asm.add(where, opc_dcmpl);

            break;

          case TC_ARRAY:

          case TC_CLASS:

          case TC_NULL:

            if (right.equals(0)) {

                asm.add(where, whenTrue ? opc_ifnull : opc_ifnonnull, lbl, whenTrue);

            } else {

                right.codeValue(env, ctx, asm);

                asm.add(where, whenTrue ? opc_if_acmpeq : opc_if_acmpne, lbl, whenTrue);

            }

            return;

          default:

            throw new CompilerError("Unexpected Type");

        }

        asm.add(where, whenTrue ? opc_ifeq : opc_ifne, lbl, whenTrue);

    }

}