bitmap_arch.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* Architecture specific definition for bitmap related routines.
* These may be implemented using ISA specific instructions.
*/
/*
* Find highest one bit set.
* Returns bit number + 1 of highest bit that is set, otherwise returns 0.
* High order bit is 31 (or 63 in _LP64 kernel).
*/
int
{
register int h = 1;
if (i == 0)
return (0);
#ifdef _LP64
if (i & 0xffffffff00000000ul) {
h += 32; i >>= 32;
}
#endif
if (i & 0xffff0000) {
h += 16; i >>= 16;
}
if (i & 0xff00) {
h += 8; i >>= 8;
}
if (i & 0xf0) {
h += 4; i >>= 4;
}
if (i & 0xc) {
h += 2; i >>= 2;
}
if (i & 0x2) {
h += 1;
}
return (h);
}
/*
* Find lowest one bit set.
* Returns bit number + 1 of lowest bit that is set, otherwise returns 0.
* Low order bit is 0.
*/
int
{
register int h = 1;
if (i == 0)
return (0);
#ifdef _LP64
if (!(i & 0xffffffff)) {
h += 32; i >>= 32;
}
#endif
if (!(i & 0xffff)) {
h += 16; i >>= 16;
}
if (!(i & 0xff)) {
h += 8; i >>= 8;
}
if (!(i & 0xf)) {
h += 4; i >>= 4;
}
if (!(i & 0x3)) {
h += 2; i >>= 2;
}
if (!(i & 0x1)) {
h += 1;
}
return (h);
}