StdLib/Include/Ia32/machine/byte_swap.h

   1 /*      $NetBSD: byte_swap.h,v 1.10 2006/01/30 22:46:36 dsl Exp $       */
   2
   3 /*-
   4  * Copyright (c) 1998 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Charles M. Hannum.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. All advertising materials mentioning features or use of this software
  19  *    must display the following acknowledgement:
  20  *        This product includes software developed by the NetBSD
  21  *        Foundation, Inc. and its contributors.
  22  * 4. Neither the name of The NetBSD Foundation nor the names of its
  23  *    contributors may be used to endorse or promote products derived
  24  *    from this software without specific prior written permission.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  36  * POSSIBILITY OF SUCH DAMAGE.
  37  */
  38
  39 #ifndef _I386_BYTE_SWAP_H_
  40 #define _I386_BYTE_SWAP_H_
  41
  42 #include <sys/types.h>
  43
  44 #if defined(_KERNEL_OPT)
  45 #include "opt_cputype.h"
  46 #endif
  47
  48 #ifdef  __GNUC__
  49 #include <sys/types.h>
  50 __BEGIN_DECLS
  51
  52 #define __BYTE_SWAP_U32_VARIABLE __byte_swap_u32_variable
  53 static __inline uint32_t __byte_swap_u32_variable(uint32_t);
  54 static __inline uint32_t
  55 __byte_swap_u32_variable(uint32_t x)
  56 {
  57         __asm volatile (
  58 #if defined(_KERNEL) && !defined(_LKM) && !defined(I386_CPU)
  59             "bswap %1"
  60 #else
  61             "rorw $8, %w1\n\trorl $16, %1\n\trorw $8, %w1"
  62 #endif
  63             : "=r" (x) : "0" (x));
  64         return (x);
  65 }
  66
  67 #define __BYTE_SWAP_U16_VARIABLE __byte_swap_u16_variable
  68 static __inline uint16_t __byte_swap_u16_variable(uint16_t);
  69 static __inline uint16_t
  70 __byte_swap_u16_variable(uint16_t x)
  71 {
  72         __asm volatile ("rorw $8, %w1" : "=r" (x) : "0" (x));
  73         return (x);
  74 }
  75
  76 __END_DECLS
  77 #endif
  78
  79 #endif /* !_I386_BYTE_SWAP_H_ */