1 /* 2 ** OSSP uuid - Universally Unique Identifier 3 ** Copyright (c) 2004-2008 Ralf S. Engelschall <rse@engelschall.com> 4 ** Copyright (c) 2004-2008 The OSSP Project <http://www.ossp.org/> 5 ** 6 ** This file is part of OSSP uuid, a library for the generation 7 ** of UUIDs which can found at http://www.ossp.org/pkg/lib/uuid/ 8 ** 9 ** Permission to use, copy, modify, and distribute this software for 10 ** any purpose with or without fee is hereby granted, provided that 11 ** the above copyright notice and this permission notice appear in all 12 ** copies. 13 ** 14 ** THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED 15 ** WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 16 ** MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17 ** IN NO EVENT SHALL THE AUTHORS AND COPYRIGHT HOLDERS AND THEIR 18 ** CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 19 ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 20 ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 21 ** USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 22 ** ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 23 ** OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 24 ** OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 ** SUCH DAMAGE. 26 ** 27 ** uuid_bm.c: bitmask API implementation 28 */ 29 30 #ifndef __UUID_BM_H__ 31 #define __UUID_BM_H__ 32 33 /* 34 * Bitmask Calculation Macros (up to 32 bit only) 35 * (Notice: bit positions are counted n...0, i.e. lowest bit is position 0) 36 */ 37 38 /* generate a bitmask consisting of 1 bits from (and including) 39 bit position `l' (left) to (and including) bit position `r' */ 40 #define BM_MASK(l,r) \ 41 ((((unsigned int)1<<(((l)-(r))+1))-1)<<(r)) 42 43 /* extract a value v from a word w at position `l' to `r' and return value */ 44 #define BM_GET(w,l,r) \ 45 (((w)>>(r))&BM_MASK((l)-(r),0)) 46 47 /* insert a value v into a word w at position `l' to `r' and return word */ 48 #define BM_SET(w,l,r,v) \ 49 ((w)|(((v)&BM_MASK((l)-(r),0))<<(r))) 50 51 /* generate a single bit `b' (0 or 1) at bit position `n' */ 52 #define BM_BIT(n,b) \ 53 ((b)<<(n)) 54 55 /* generate a quad word octet of bits (a half byte, i.e. bit positions 3 to 0) */ 56 #define BM_QUAD(b3,b2,b1,b0) \ 57 (BM_BIT(3,(b3))|BM_BIT(2,(b2))|BM_BIT(1,(b1))|BM_BIT(0,(b0))) 58 59 /* generate an octet word of bits (a byte, i.e. bit positions 7 to 0) */ 60 #define BM_OCTET(b7,b6,b5,b4,b3,b2,b1,b0) \ 61 ((BM_QUAD(b7,b6,b5,b4)<<4)|BM_QUAD(b3,b2,b1,b0)) 62 63 /* generate the value 2^n */ 64 #define BM_POW2(n) \ 65 BM_BIT(n,1) 66 67 /* shift word w k bits to the left or to the right */ 68 #define BM_SHL(w,k) \ 69 ((w)<<(k)) 70 #define BM_SHR(w,k) \ 71 ((w)>>(k)) 72 73 /* rotate word w (of bits n..0) k bits to the left or to the right */ 74 #define BM_ROL(w,n,k) \ 75 ((BM_SHL((w),(k))&BM_MASK(n,0))|BM_SHR(((w)&BM_MASK(n,0)),(n)-(k))) 76 #define BM_ROR(w,n,k) \ 77 ((BM_SHR(((w)&BM_MASK(n,0)),(k)))|BM_SHL(((w),(n)-(k))&BM_MASK(n,0))) 78 79 #endif /* __UUID_BM_H__ */ 80 81