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minix/include/sys/bitops.h
Ben Gras 2fe8fb192f Full switch to clang/ELF. Drop ack. Simplify. 
There is important information about booting non-ack images in
docs/UPDATING. ack/aout-format images can't be built any more, and
booting clang/ELF-format ones is a little different. Updating to the
new boot monitor is recommended.

Changes in this commit:

	. drop boot monitor -> allowing dropping ack support
	. facility to copy ELF boot files to /boot so that old boot monitor
	  can still boot fairly easily, see UPDATING
	. no more ack-format libraries -> single-case libraries
	. some cleanup of OBJECT_FMT, COMPILER_TYPE, etc cases
	. drop several ack toolchain commands, but not all support
	  commands (e.g. aal is gone but acksize is not yet).
	. a few libc files moved to netbsd libc dir
	. new /bin/date as minix date used code in libc/
	. test compile fix
	. harmonize includes
	. /usr/lib is no longer special: without ack, /usr/lib plays no
	  kind of special bootstrapping role any more and bootstrapping
	  is done exclusively through packages, so releases depend even
	  less on the state of the machine making them now.
	. rename nbsd_lib* to lib*
	. reduce mtree
2012-02-14 14:52:02 +01:00

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/* $NetBSD: bitops.h,v 1.7 2010/03/21 14:28:15 christos Exp $ */
/*-
* Copyright (c) 2007, 2010 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Christos Zoulas and Joerg Sonnenberger.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _SYS_BITOPS_H_
#define _SYS_BITOPS_H_
#include <sys/stdint.h>
/*
* Find First Set functions
*/
#ifndef ffs32
static __inline int __unused
ffs32(uint32_t _n)
{
int _v;
if (!_n)
return 0;
_v = 1;
if ((_n & 0x0000FFFFU) == 0) {
_n >>= 16;
_v += 16;
}
if ((_n & 0x000000FFU) == 0) {
_n >>= 8;
_v += 8;
}
if ((_n & 0x0000000FU) == 0) {
_n >>= 4;
_v += 4;
}
if ((_n & 0x00000003U) == 0) {
_n >>= 2;
_v += 2;
}
if ((_n & 0x00000001U) == 0) {
_n >>= 1;
_v += 1;
}
return _v;
}
#endif
#ifndef ffs64
static __inline int __unused
ffs64(uint64_t _n)
{
int _v;
if (!_n)
return 0;
_v = 1;
if ((_n & 0x00000000FFFFFFFFULL) == 0) {
_n >>= 32;
_v += 32;
}
if ((_n & 0x000000000000FFFFULL) == 0) {
_n >>= 16;
_v += 16;
}
if ((_n & 0x00000000000000FFULL) == 0) {
_n >>= 8;
_v += 8;
}
if ((_n & 0x000000000000000FULL) == 0) {
_n >>= 4;
_v += 4;
}
if ((_n & 0x0000000000000003ULL) == 0) {
_n >>= 2;
_v += 2;
}
if ((_n & 0x0000000000000001ULL) == 0) {
_n >>= 1;
_v += 1;
}
return _v;
}
#endif
/*
* Find Last Set functions
*/
#ifndef fls32
static __inline int __unused
fls32(uint32_t _n)
{
int _v;
if (!_n)
return 0;
_v = 32;
if ((_n & 0xFFFF0000U) == 0) {
_n <<= 16;
_v -= 16;
}
if ((_n & 0xFF000000U) == 0) {
_n <<= 8;
_v -= 8;
}
if ((_n & 0xF0000000U) == 0) {
_n <<= 4;
_v -= 4;
}
if ((_n & 0xC0000000U) == 0) {
_n <<= 2;
_v -= 2;
}
if ((_n & 0x80000000U) == 0) {
_n <<= 1;
_v -= 1;
}
return _v;
}
#endif
#ifndef fls64
static __inline int __unused
fls64(uint64_t _n)
{
int _v;
if (!_n)
return 0;
_v = 64;
if ((_n & 0xFFFFFFFF00000000ULL) == 0) {
_n <<= 32;
_v -= 32;
}
if ((_n & 0xFFFF000000000000ULL) == 0) {
_n <<= 16;
_v -= 16;
}
if ((_n & 0xFF00000000000000ULL) == 0) {
_n <<= 8;
_v -= 8;
}
if ((_n & 0xF000000000000000ULL) == 0) {
_n <<= 4;
_v -= 4;
}
if ((_n & 0xC000000000000000ULL) == 0) {
_n <<= 2;
_v -= 2;
}
if ((_n & 0x8000000000000000ULL) == 0) {
_n <<= 1;
_v -= 1;
}
return _v;
}
#endif
/*
* Integer logarithm, returns -1 on error. Inspired by the linux
* version written by David Howells.
*/
#define _ilog2_helper(_n, _x) ((_n) & (1ULL << (_x))) ? _x :
#define ilog2(_n) \
( \
__builtin_constant_p(_n) ? ( \
_ilog2_helper(_n, 63) \
_ilog2_helper(_n, 62) \
_ilog2_helper(_n, 61) \
_ilog2_helper(_n, 60) \
_ilog2_helper(_n, 59) \
_ilog2_helper(_n, 58) \
_ilog2_helper(_n, 57) \
_ilog2_helper(_n, 56) \
_ilog2_helper(_n, 55) \
_ilog2_helper(_n, 54) \
_ilog2_helper(_n, 53) \
_ilog2_helper(_n, 52) \
_ilog2_helper(_n, 51) \
_ilog2_helper(_n, 50) \
_ilog2_helper(_n, 49) \
_ilog2_helper(_n, 48) \
_ilog2_helper(_n, 47) \
_ilog2_helper(_n, 46) \
_ilog2_helper(_n, 45) \
_ilog2_helper(_n, 44) \
_ilog2_helper(_n, 43) \
_ilog2_helper(_n, 42) \
_ilog2_helper(_n, 41) \
_ilog2_helper(_n, 40) \
_ilog2_helper(_n, 39) \
_ilog2_helper(_n, 38) \
_ilog2_helper(_n, 37) \
_ilog2_helper(_n, 36) \
_ilog2_helper(_n, 35) \
_ilog2_helper(_n, 34) \
_ilog2_helper(_n, 33) \
_ilog2_helper(_n, 32) \
_ilog2_helper(_n, 31) \
_ilog2_helper(_n, 30) \
_ilog2_helper(_n, 29) \
_ilog2_helper(_n, 28) \
_ilog2_helper(_n, 27) \
_ilog2_helper(_n, 26) \
_ilog2_helper(_n, 25) \
_ilog2_helper(_n, 24) \
_ilog2_helper(_n, 23) \
_ilog2_helper(_n, 22) \
_ilog2_helper(_n, 21) \
_ilog2_helper(_n, 20) \
_ilog2_helper(_n, 19) \
_ilog2_helper(_n, 18) \
_ilog2_helper(_n, 17) \
_ilog2_helper(_n, 16) \
_ilog2_helper(_n, 15) \
_ilog2_helper(_n, 14) \
_ilog2_helper(_n, 13) \
_ilog2_helper(_n, 12) \
_ilog2_helper(_n, 11) \
_ilog2_helper(_n, 10) \
_ilog2_helper(_n, 9) \
_ilog2_helper(_n, 8) \
_ilog2_helper(_n, 7) \
_ilog2_helper(_n, 6) \
_ilog2_helper(_n, 5) \
_ilog2_helper(_n, 4) \
_ilog2_helper(_n, 3) \
_ilog2_helper(_n, 2) \
_ilog2_helper(_n, 1) \
_ilog2_helper(_n, 0) \
-1) : ((sizeof(_n) >= 4 ? fls64(_n) : fls32(_n)) - 1) \
)
static __inline void
fast_divide32_prepare(uint32_t _div, uint32_t * __restrict _m,
uint8_t *__restrict _s1, uint8_t *__restrict _s2)
{
uint64_t _mt;
int _l;
_l = fls32(_div - 1);
_mt = 0x100000000ULL * ((1ULL << _l) - _div);
*_m = (uint32_t)(_mt / _div + 1);
*_s1 = (_l > 1) ? 1 : _l;
*_s2 = (_l == 0) ? 0 : _l - 1;
}
/* ARGSUSED */
static __inline uint32_t
fast_divide32(uint32_t _v, uint32_t _div, uint32_t _m, uint8_t _s1,
uint8_t _s2)
{
uint32_t _t;
_t = (uint32_t)(((uint64_t)_v * _m) >> 32);
return (_t + ((_v - _t) >> _s1)) >> _s2;
}
static __inline uint32_t
fast_remainder32(uint32_t _v, uint32_t _div, uint32_t _m, uint8_t _s1,
uint8_t _s2)
{
return _v - _div * fast_divide32(_v, _div, _m, _s1, _s2);
}
#endif /* _SYS_BITOPS_H_ */
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