/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1985-2010 AT&T Intellectual Property *
* and is licensed under the *
* Common Public License, Version 1.0 *
* by AT&T Intellectual Property *
* *
* A copy of the License is available at *
* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* David Korn <dgk@research.att.com> *
* Phong Vo <kpv@research.att.com> *
* *
***********************************************************************/
#pragma prototyped
/*
* Glenn Fowler
* AT&T Research
*
* internal representation conversion support
*/
#include <ast.h>
#include <swap.h>
/*
* swap n bytes according to op
* from==to is ok
*/
void*
{
register char* f = (char*)from;
register char* t = (char*)to;
register int c;
switch (op & (n - 1))
{
case 0:
if (t != f)
memcpy(t, f, n);
break;
case 1:
for (n >>= 1; n--; f += 2, t += 2)
{
c = f[0]; t[0] = f[1]; t[1] = c;
}
break;
case 2:
for (n >>= 2; n--; f += 4, t += 4)
{
c = f[0]; t[0] = f[2]; t[2] = c;
c = f[1]; t[1] = f[3]; t[3] = c;
}
break;
case 3:
for (n >>= 2; n--; f += 4, t += 4)
{
c = f[0]; t[0] = f[3]; t[3] = c;
c = f[1]; t[1] = f[2]; t[2] = c;
}
break;
case 4:
for (n >>= 3; n--; f += 8, t += 8)
{
c = f[0]; t[0] = f[4]; t[4] = c;
c = f[1]; t[1] = f[5]; t[5] = c;
c = f[2]; t[2] = f[6]; t[6] = c;
c = f[3]; t[3] = f[7]; t[7] = c;
}
break;
case 5:
for (n >>= 3; n--; f += 8, t += 8)
{
c = f[0]; t[0] = f[5]; t[5] = c;
c = f[1]; t[1] = f[4]; t[4] = c;
c = f[2]; t[2] = f[7]; t[7] = c;
c = f[3]; t[3] = f[6]; t[6] = c;
}
break;
case 6:
for (n >>= 3; n--; f += 8, t += 8)
{
c = f[0]; t[0] = f[6]; t[6] = c;
c = f[1]; t[1] = f[7]; t[7] = c;
c = f[2]; t[2] = f[4]; t[4] = c;
c = f[3]; t[3] = f[5]; t[5] = c;
}
break;
case 7:
for (n >>= 3; n--; f += 8, t += 8)
{
c = f[0]; t[0] = f[7]; t[7] = c;
c = f[1]; t[1] = f[6]; t[6] = c;
c = f[2]; t[2] = f[5]; t[5] = c;
c = f[3]; t[3] = f[4]; t[4] = c;
}
break;
}
return to;
}