/*

 * Copyright (c) 2006, 2010, 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.

 *

 */

#include "precompiled.hpp"

#include "runtime/sharedRuntime.hpp"

#include "utilities/copy.hpp"

// Copy bytes; larger units are filled atomically if everything is aligned.

void Copy::conjoint_memory_atomic(void* from, void* to, size_t size) {

  address src = (address) from;

  address dst = (address) to;

  uintptr_t bits = (uintptr_t) src | (uintptr_t) dst | (uintptr_t) size;

  // (Note:  We could improve performance by ignoring the low bits of size,

  // and putting a short cleanup loop after each bulk copy loop.

  // There are plenty of other ways to make this faster also,

  // and it's a slippery slope.  For now, let's keep this code simple

  // since the simplicity helps clarify the atomicity semantics of

  // this operation.  There are also CPU-specific assembly versions

  // which may or may not want to include such optimizations.)

  if (bits % sizeof(jlong) == 0) {

    Copy::conjoint_jlongs_atomic((jlong*) src, (jlong*) dst, size / sizeof(jlong));

  } else if (bits % sizeof(jint) == 0) {

    Copy::conjoint_jints_atomic((jint*) src, (jint*) dst, size / sizeof(jint));

  } else if (bits % sizeof(jshort) == 0) {

    Copy::conjoint_jshorts_atomic((jshort*) src, (jshort*) dst, size / sizeof(jshort));

  } else {

    // Not aligned, so no need to be atomic.

    Copy::conjoint_jbytes((void*) src, (void*) dst, size);

  }

}

// Fill bytes; larger units are filled atomically if everything is aligned.

void Copy::fill_to_memory_atomic(void* to, size_t size, jubyte value) {

  address dst = (address) to;

  uintptr_t bits = (uintptr_t) to | (uintptr_t) size;

  if (bits % sizeof(jlong) == 0) {

    jlong fill = (julong)( (jubyte)value ); // zero-extend

    if (fill != 0) {

      fill += fill << 8;

      fill += fill << 16;

      fill += fill << 32;

    }

    //Copy::fill_to_jlongs_atomic((jlong*) dst, size / sizeof(jlong));

    for (uintptr_t off = 0; off < size; off += sizeof(jlong)) {

      *(jlong*)(dst + off) = fill;

    }

  } else if (bits % sizeof(jint) == 0) {

    jint fill = (juint)( (jubyte)value ); // zero-extend

    if (fill != 0) {

      fill += fill << 8;

      fill += fill << 16;

    }

    //Copy::fill_to_jints_atomic((jint*) dst, size / sizeof(jint));

    for (uintptr_t off = 0; off < size; off += sizeof(jint)) {

      *(jint*)(dst + off) = fill;

    }

  } else if (bits % sizeof(jshort) == 0) {

    jshort fill = (jushort)( (jubyte)value ); // zero-extend

    fill += fill << 8;

    //Copy::fill_to_jshorts_atomic((jshort*) dst, size / sizeof(jshort));

    for (uintptr_t off = 0; off < size; off += sizeof(jshort)) {

      *(jshort*)(dst + off) = fill;

    }

  } else {

    // Not aligned, so no need to be atomic.

    Copy::fill_to_bytes(dst, size, value);

  }

}