view src/os_cpu/windows_x86/vm/bytes_windows_x86.inline.hpp @ 453:c96030fff130

6684579: SoftReference processing can be made more efficient Summary: For current soft-ref clearing policies, we can decide at marking time if a soft-reference will definitely not be cleared, postponing the decision of whether it will definitely be cleared to the final reference processing phase. This can be especially beneficial in the case of concurrent collectors where the marking is usually concurrent but reference processing is usually not. Reviewed-by: jmasa
author ysr
date Thu, 20 Nov 2008 16:56:09 -0800
parents a61af66fc99e
children c18cbe5936b8
line wrap: on
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/*
 * Copyright 1998 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 */

#pragma warning(disable: 4035) // Disable warning 4035: no return value

// Efficient swapping of data bytes from Java byte
// ordering to native byte ordering and vice versa.
inline u2 Bytes::swap_u2(u2 x) {
#ifdef AMD64
  address p = (address) &x;
  return  ( (u2(p[0]) << 8 ) | ( u2(p[1])) );
#else
  __asm {
    mov ax, x
    xchg al, ah
  }
  // no return statement needed, result is already in ax
  // compiler warning C4035 disabled via warning pragma
#endif // AMD64
}

inline u4 Bytes::swap_u4(u4 x) {
#ifdef AMD64
  address p = (address) &x;
  return ( (u4(p[0]) << 24) | (u4(p[1]) << 16) | (u4(p[2]) << 8) | u4(p[3])) ;
#else
  __asm {
    mov eax, x
    bswap eax
  }
  // no return statement needed, result is already in eax
  // compiler warning C4035 disabled via warning pragma
#endif // AMD64
}

#ifdef AMD64
inline u8 Bytes::swap_u8(u8 x) {
  address p = (address) &x;
  return ( (u8(p[0]) << 56) | (u8(p[1]) << 48) | (u8(p[2]) << 40) | (u8(p[3]) << 32) |
           (u8(p[4]) << 24) | (u8(p[5]) << 16) | (u8(p[6]) << 8)  | u8(p[7])) ;
}

#else
// Helper function for swap_u8
inline u8 Bytes::swap_u8_base(u4 x, u4 y) {
  __asm {
    mov eax, y
    mov edx, x
    bswap eax
    bswap edx
  }
  // no return statement needed, result is already in edx:eax
  // compiler warning C4035 disabled via warning pragma
}

inline u8 Bytes::swap_u8(u8 x) {
  return swap_u8_base(*(u4*)&x, *(((u4*)&x)+1));
}
#endif // AMD64

#pragma warning(default: 4035) // Enable warning 4035: no return value