1/***********************************************************************
2*                                                                      *
3*               This software is part of the ast package               *
4*          Copyright (c) 1985-2011 AT&T Intellectual Property          *
5*                      and is licensed under the                       *
6*                  Common Public License, Version 1.0                  *
7*                    by AT&T Intellectual Property                     *
8*                                                                      *
9*                A copy of the License is available at                 *
10*            http://www.opensource.org/licenses/cpl1.0.txt             *
11*         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
12*                                                                      *
13*              Information and Software Systems Research               *
14*                            AT&T Research                             *
15*                           Florham Park NJ                            *
16*                                                                      *
17*                 Glenn Fowler <gsf@research.att.com>                  *
18*                  David Korn <dgk@research.att.com>                   *
19*                   Phong Vo <kpv@research.att.com>                    *
20*                                                                      *
21***********************************************************************/
22#pragma prototyped
23/*
24 * K. P. Vo
25 * G. S. Fowler
26 * AT&T Research
27 *
28 * ``the best'' combined linear congruent checksum/hash/PRNG
29 */
30
31#ifndef _HASHPART_H
32#define _HASHPART_H
33
34#define HASH_ADD(h)	(0x9c39c33dL)
35
36#if __sparc__ || __sparc || sparc
37
38#define HASH_A(h,n)	((((h) << 2) - (h)) << (n))
39#define HASH_B(h,n)	((((h) << 4) - (h)) << (n))
40#define HASH_C(h,n)	((HASH_A(h,7) + HASH_B(h,0)) << (n))
41#define HASH_MPY(h)	(HASH_C(h,22)+HASH_C(h,10)+HASH_A(h,6)+HASH_A(h,3)+(h))
42
43#else
44
45#define HASH_MPY(h)	((h)*0x63c63cd9L)
46
47#endif
48
49#define HASHPART(h,c)	(h = HASH_MPY(h) + HASH_ADD(h) + (c))
50
51#endif
52