[unix-history] / usr / src / old / pcc / lint / lpass1 / hash.c

#ifndef lint
static char sccsid[] = "@(#)hash.c	1.2	(Berkeley)	%G%";
#endif lint

#include "config.h"

/*
 * Hash function.  Used for pass 2 symbol table and string table,
 * and structure/union name passing between passes.
 * The hash function is a modular hash of
 * the sum of the characters with the sum
 * rotated before each successive character
 * is added.
 * Only 15 bits are used.
 */
#ifdef FLEXNAMES
hashstr(s)
#else
hashstr(s, n)
register n;
#endif
register char *s;
{
	register i;

	i = 0;
#ifdef FLEXNAMES
	while (*s)
#else
	while (n-- > 0 && *s)
#endif
		i = (i << 3 | i >> 12 & 0x07) + *s++;
	return i & 0x7fff;
}
Commit	Line	Data
49531380	1	#ifndef lint
e3e0664b	2	static char sccsid[] = "@(#)hash.c 1.2 (Berkeley) %G%";
49531380 EW	3	#endif lint
49531380 EW	4
e3e0664b KB	5	#include "config.h"
e3e0664b KB	6
49531380 EW	7	/*
	8	* Hash function. Used for pass 2 symbol table and string table,
	9	* and structure/union name passing between passes.
	10	* The hash function is a modular hash of
	11	* the sum of the characters with the sum
	12	* rotated before each successive character
	13	* is added.
	14	* Only 15 bits are used.
	15	*/
	16	#ifdef FLEXNAMES
	17	hashstr(s)
	18	#else
	19	hashstr(s, n)
	20	register n;
	21	#endif
	22	register char *s;
	23	{
	24	register i;
	25
	26	i = 0;
	27	#ifdef FLEXNAMES
	28	while (*s)
	29	#else
	30	while (n-- > 0 && *s)
	31	#endif
	32	i = (i << 3 \| i >> 12 & 0x07) + *s++;
	33	return i & 0x7fff;
	34	}