58 lines
1.2 KiB
C
58 lines
1.2 KiB
C
/*
|
|
* Copyright (C) 1995 Advanced RISC Machines Limited. All rights reserved.
|
|
*
|
|
* This software may be freely used, copied, modified, and distributed
|
|
* provided that the above copyright notice is preserved in all copies of the
|
|
* software.
|
|
*/
|
|
|
|
/*
|
|
* angel_bytesex.c - Code to support byte-sex independence
|
|
* Copyright: (C) 1991, Advanced RISC Machines Ltd., Cambridge, England.
|
|
*/
|
|
|
|
/*
|
|
* RCS $Revision$
|
|
* Checkin $Date$
|
|
*/
|
|
|
|
#include "angel_bytesex.h"
|
|
|
|
static int reversing_bytes = 0;
|
|
|
|
void bytesex_reverse(yes_or_no)
|
|
int yes_or_no;
|
|
{ reversing_bytes = yes_or_no;
|
|
}
|
|
|
|
int bytesex_reversing()
|
|
{
|
|
return reversing_bytes;
|
|
}
|
|
|
|
int32 bytesex_hostval(v)
|
|
int32 v;
|
|
{ /* Return v with the same endian-ness as the host */
|
|
/* This mess generates better ARM code than the more obvious mess */
|
|
/* and may eventually peephole to optimal code... */
|
|
if (reversing_bytes)
|
|
{ unsigned32 t;
|
|
/* t = v ^ (v ror 16) */
|
|
t = v ^ ((v << 16) | (((unsigned32)v) >> 16));
|
|
t &= ~0xff0000;
|
|
/* v = v ror 8 */
|
|
v = (v << 24) | (((unsigned32)v) >> 8);
|
|
v = v ^ (t >> 8);
|
|
}
|
|
return v;
|
|
}
|
|
|
|
int32 bytesex_hostval_16(v)
|
|
int32 v;
|
|
{
|
|
if (reversing_bytes) {
|
|
v = ((v >> 8) & 0xff) | ((v << 8) & 0xff00);
|
|
}
|
|
return v;
|
|
}
|