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 /*

  * 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);

   }

 }