ossp-pkg/uuid/uuid_bm.h
1.9
/*
** OSSP uuid - Universally Unique Identifier
** Copyright (c) 2004-2008 Ralf S. Engelschall <rse@engelschall.com>
** Copyright (c) 2004-2008 The OSSP Project <http://www.ossp.org/>
**
** This file is part of OSSP uuid, a library for the generation
** of UUIDs which can found at http://www.ossp.org/pkg/lib/uuid/
**
** Permission to use, copy, modify, and distribute this software for
** any purpose with or without fee is hereby granted, provided that
** the above copyright notice and this permission notice appear in all
** copies.
**
** THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 AUTHORS AND COPYRIGHT HOLDERS AND THEIR
** 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.
**
** uuid_bm.c: bitmask API implementation
*/
#ifndef __UUID_BM_H__
#define __UUID_BM_H__
/*
* Bitmask Calculation Macros (up to 32 bit only)
* (Notice: bit positions are counted n...0, i.e. lowest bit is position 0)
*/
/* generate a bitmask consisting of 1 bits from (and including)
bit position `l' (left) to (and including) bit position `r' */
#define BM_MASK(l,r) \
((((unsigned int)1<<(((l)-(r))+1))-1)<<(r))
/* extract a value v from a word w at position `l' to `r' and return value */
#define BM_GET(w,l,r) \
(((w)>>(r))&BM_MASK((l)-(r),0))
/* insert a value v into a word w at position `l' to `r' and return word */
#define BM_SET(w,l,r,v) \
((w)|(((v)&BM_MASK((l)-(r),0))<<(r)))
/* generate a single bit `b' (0 or 1) at bit position `n' */
#define BM_BIT(n,b) \
((b)<<(n))
/* generate a quad word octet of bits (a half byte, i.e. bit positions 3 to 0) */
#define BM_QUAD(b3,b2,b1,b0) \
(BM_BIT(3,(b3))|BM_BIT(2,(b2))|BM_BIT(1,(b1))|BM_BIT(0,(b0)))
/* generate an octet word of bits (a byte, i.e. bit positions 7 to 0) */
#define BM_OCTET(b7,b6,b5,b4,b3,b2,b1,b0) \
((BM_QUAD(b7,b6,b5,b4)<<4)|BM_QUAD(b3,b2,b1,b0))
/* generate the value 2^n */
#define BM_POW2(n) \
BM_BIT(n,1)
/* shift word w k bits to the left or to the right */
#define BM_SHL(w,k) \
((w)<<(k))
#define BM_SHR(w,k) \
((w)>>(k))
/* rotate word w (of bits n..0) k bits to the left or to the right */
#define BM_ROL(w,n,k) \
((BM_SHL((w),(k))&BM_MASK(n,0))|BM_SHR(((w)&BM_MASK(n,0)),(n)-(k)))
#define BM_ROR(w,n,k) \
((BM_SHR(((w)&BM_MASK(n,0)),(k)))|BM_SHL(((w),(n)-(k))&BM_MASK(n,0)))
#endif /* __UUID_BM_H__ */
