/*

 * Copyright (c) 2009, 2016, 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 jdk.vm.ci.code;

import static jdk.vm.ci.meta.MetaUtil.identityHashCodeString;

import jdk.vm.ci.meta.JavaKind;

/**

 * Represents the target machine for a compiler, including the CPU architecture, the size of

 * pointers and references, alignment of stacks, caches, etc.

 */

public class TargetDescription {

    public final Architecture arch;

    /**

     * Specifies if this is a multi-processor system.

     */

    public final boolean isMP;

    /**

     * Specifies if this target supports encoding objects inline in the machine code.

     */

    public final boolean inlineObjects;

    /**

     * The machine word size on this target.

     */

    public final int wordSize;

    /**

     * The {@link JavaKind} to be used for representing raw pointers and CPU registers in Java code.

     */

    public final JavaKind wordJavaKind;

    /**

     * The stack alignment requirement of the platform. For example, from Appendix D of

     * <a href="http://www.intel.com/Assets/PDF/manual/248966.pdf">Intel 64 and IA-32 Architectures

     * Optimization Reference Manual</a>:

     *

     * <pre>

     *     "It is important to ensure that the stack frame is aligned to a

     *      16-byte boundary upon function entry to keep local __m128 data,

     *      parameters, and XMM register spill locations aligned throughout

     *      a function invocation."

     * </pre>

     */

    public final int stackAlignment;

    /**

     * Maximum constant displacement at which a memory access can no longer be an implicit null

     * check.

     */

    public final int implicitNullCheckLimit;

    public TargetDescription(Architecture arch, boolean isMP, int stackAlignment, int implicitNullCheckLimit, boolean inlineObjects) {

        this.arch = arch;

        this.isMP = isMP;

        this.wordSize = arch.getWordSize();

        this.wordJavaKind = JavaKind.fromWordSize(wordSize);

        this.stackAlignment = stackAlignment;

        this.implicitNullCheckLimit = implicitNullCheckLimit;

        this.inlineObjects = inlineObjects;

        assert arch.getPlatformKind(wordJavaKind).equals(arch.getWordKind());

    }

    @Override

    public final int hashCode() {

        throw new UnsupportedOperationException();

    }

    @Override

    public final boolean equals(Object obj) {

        if (this == obj) {

            return true;

        }

        if (obj instanceof TargetDescription) {

            TargetDescription that = (TargetDescription) obj;

            // @formatter:off

            if (this.implicitNullCheckLimit == that.implicitNullCheckLimit &&

                this.inlineObjects == that.inlineObjects &&

                this.isMP == that.isMP &&

                this.stackAlignment == that.stackAlignment &&

                this.wordJavaKind.equals(that.wordJavaKind) &&

                this.wordSize == that.wordSize &&

                this.arch.equals(that.arch)) {

                return true;

            }

            // @formatter:on

        }

        return false;

    }

    @Override

    public String toString() {

        return identityHashCodeString(this);

    }

}