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/*

 * byteorder.h

 *

 *        This file contains inline implementation of function to

 *          deal with endian conversion.

 *

 * It is a stripped down version of linux ppc file...

 *

 * Copyright (C) 1999  Eric Valette (valette@crf.canon.fr)

 *                     Canon Centre Recherche France.

 *

 *  The license and distribution terms for this file may be

 *  found in found in the file LICENSE in this distribution or at

 *  http://www.OARcorp.com/rtems/license.html.

 *

 *  $Id: byteorder.h,v 1.2 2001-09-27 12:01:30 chris Exp $

 */

#ifndef _PPC_BYTEORDER_H

#define _PPC_BYTEORDER_H

/*

 *  $Id: byteorder.h,v 1.2 2001-09-27 12:01:30 chris Exp $

 */

#ifdef __GNUC__

extern __inline__ unsigned ld_le16(volatile unsigned short *addr)

{

        unsigned val;

        __asm__ __volatile__ ("lhbrx %0,0,%1" : "=r" (val) : "r" (addr), "m" (*addr));

        return val;

}

extern __inline__ void st_le16(volatile unsigned short *addr, unsigned val)

{

        __asm__ __volatile__ ("sthbrx %1,0,%2" : "=m" (*addr) : "r" (val), "r" (addr));

}

extern __inline__ unsigned ld_le32(volatile unsigned *addr)

{

        unsigned val;

        __asm__ __volatile__ ("lwbrx %0,0,%1" : "=r" (val) : "r" (addr), "m" (*addr));

        return val;

}

extern __inline__ void st_le32(volatile unsigned *addr, unsigned val)

{

        __asm__ __volatile__ ("stwbrx %1,0,%2" : "=m" (*addr) : "r" (val), "r" (addr));

}

/* alas, egcs sounds like it has a bug in this code that doesn't use the

   inline asm correctly, and can cause file corruption. Until I hear that

   it's fixed, I can live without the extra speed. I hope. */

#if !(__GNUC__ >= 2 && __GNUC_MINOR__ >= 90)

#if 0

#  define __arch_swab16(x) ld_le16(&x)

#  define __arch_swab32(x) ld_le32(&x)

#else

static __inline__ __const__ __unsigned short ___arch__swab16(__unsigned short value)

{

        __unsigned int tmp;

        __asm__("rlwimi %0,%0,8,0xff0000"

            : "=r" (tmp)

            : "0" (value));

        return (tmp&0x00ffff00)>>8;

}

static __inline__ __const__ __unsigned int ___arch__swab32(__unsigned int value)

{

        __unsigned int result;

        __asm__("rotlwi %0,%1,24\n\t"

            "rlwimi %0,%1,8,0xff\n\t"

            "rlwimi %0,%1,8,0xff0000"

            : "=&r" (result)

            : "r" (value));

        return result;

}

#define __arch__swab32(x) ___arch__swab32(x)

#define __arch__swab16(x) ___arch__swab16(x)

#endif /* 0 */

#endif

/* The same, but returns converted value from the location pointer by addr. */

#define __arch__swab16p(addr) ld_le16(addr)

#define __arch__swab32p(addr) ld_le32(addr)

/* The same, but do the conversion in situ, ie. put the value back to addr. */

#define __arch__swab16s(addr) st_le16(addr,*addr)

#define __arch__swab32s(addr) st_le32(addr,*addr)

#endif /* __GNUC__ */

#endif /* _PPC_BYTEORDER_H */