[unix-history] / sys / kern / subr_rand.c

/*
 * Copyright (c) 1993 Regents of the University of California.
 * All rights reserved.
 *
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the Computer Systems
 *	Engineering Group at Lawrence Berkeley Laboratory.
 * 4. Neither the name of the University nor of the Laboratory may be used
 *    to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 */

/*
 * LBL BSD kernel random number generator (used by statclock).
 *
 * Written by Steve McCanne & Chris Torek (mccanne@ee.lbl.gov,
 * torek@ee.lbl.gov), November, 1992.
 *
 * This implementation is based on ``Two Fast Implementations of
 * the "Minimal Standard" Random Number Generator", David G. Carta,
 * Communications of the ACM, Jan 1990, Vol 33 No 1.
 */

#ifdef sparc
asm("\
	.global	_kernrand				;\
_kernrand:						;\
	sethi	%hi(16807), %o1			;\
	wr	%o1, %lo(16807), %y		;\
	set	0xffff, %o4			;\
	andcc	%g0, 0, %o2			;\
	mulscc  %o2, %o0, %o2			;\
	mulscc  %o2, %o0, %o2			;\
	mulscc  %o2, %o0, %o2			;\
	mulscc  %o2, %o0, %o2			;\
	mulscc  %o2, %o0, %o2			;\
	mulscc  %o2, %o0, %o2			;\
	mulscc  %o2, %o0, %o2			;\
	mulscc  %o2, %o0, %o2			;\
	mulscc  %o2, %o0, %o2			;\
	mulscc  %o2, %o0, %o2			;\
	mulscc  %o2, %o0, %o2			;\
	mulscc  %o2, %o0, %o2			;\
	mulscc  %o2, %o0, %o2			;\
	mulscc  %o2, %o0, %o2			;\
	mulscc  %o2, %o0, %o2			;\
	mulscc  %o2, %g0, %o2			;\
	rd	%y, %o3				;\
	srl	%o2, 16, %o1			;\
	and	%o4, %o2, %o0			;\
	sll	%o0, 15, %o0			;\
	srl	%o3, 17, %o3			;\
	or	%o3, %o0, %o0			;\
	addcc	%o0, %o1, %o0			;\
	bl	1f				;\
	 sethi	%hi(0x7fffffff), %o1		;\
	retl					;\
	nop					;\
1:						;\
	or	%o1, %lo(0x7fffffff), %o1	;\
	add	%o0, 1, %o0			;\
	retl					;\
	and	%o1, %o0, %o0			");
#else
long
kernrand(x)
	register long x;
{
	register long hi, lo, t;

	hi = x / 127773;
	lo = x % 127773;
	t = 16807 * lo - 2836 * hi;
	if (t > 0)
		return (t);
	else
		return (t + 0x7fffffff);
}
#endif
Commit	Line	Data
e3bf13c2 GW	1	/*
	2	* Copyright (c) 1993 Regents of the University of California.
	3	* All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	* 3. All advertising materials mentioning features or use of this software
	14	* must display the following acknowledgement:
	15	* This product includes software developed by the Computer Systems
	16	* Engineering Group at Lawrence Berkeley Laboratory.
	17	* 4. Neither the name of the University nor of the Laboratory may be used
	18	* to endorse or promote products derived from this software without
	19	* specific prior written permission.
	20	*
	21	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	22	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	23	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	24	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	25	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	26	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	27	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	28	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	29	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	30	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	31	* SUCH DAMAGE.
	32	*/
	33
	34	/*
	35	* LBL BSD kernel random number generator (used by statclock).
	36	*
	37	* Written by Steve McCanne & Chris Torek (mccanne@ee.lbl.gov,
	38	* torek@ee.lbl.gov), November, 1992.
	39	*
	40	* This implementation is based on ``Two Fast Implementations of
	41	* the "Minimal Standard" Random Number Generator", David G. Carta,
	42	* Communications of the ACM, Jan 1990, Vol 33 No 1.
	43	*/
	44
	45	#ifdef sparc
	46	asm("\
	47	.global _kernrand ;\
	48	_kernrand: ;\
	49	sethi %hi(16807), %o1 ;\
	50	wr %o1, %lo(16807), %y ;\
	51	set 0xffff, %o4 ;\
	52	andcc %g0, 0, %o2 ;\
	53	mulscc %o2, %o0, %o2 ;\
	54	mulscc %o2, %o0, %o2 ;\
	55	mulscc %o2, %o0, %o2 ;\
	56	mulscc %o2, %o0, %o2 ;\
	57	mulscc %o2, %o0, %o2 ;\
	58	mulscc %o2, %o0, %o2 ;\
	59	mulscc %o2, %o0, %o2 ;\
	60	mulscc %o2, %o0, %o2 ;\
	61	mulscc %o2, %o0, %o2 ;\
	62	mulscc %o2, %o0, %o2 ;\
	63	mulscc %o2, %o0, %o2 ;\
	64	mulscc %o2, %o0, %o2 ;\
65	mulscc %o2, %o0, %o2 ;\
66	mulscc %o2, %o0, %o2 ;\
67	mulscc %o2, %o0, %o2 ;\
68	mulscc %o2, %g0, %o2 ;\
69	rd %y, %o3 ;\
70	srl %o2, 16, %o1 ;\
71	and %o4, %o2, %o0 ;\
72	sll %o0, 15, %o0 ;\
73	srl %o3, 17, %o3 ;\
74	or %o3, %o0, %o0 ;\
75	addcc %o0, %o1, %o0 ;\
76	bl 1f ;\
77	sethi %hi(0x7fffffff), %o1 ;\
78	retl ;\
79	nop ;\
80	1: ;\
81	or %o1, %lo(0x7fffffff), %o1 ;\
82	add %o0, 1, %o0 ;\
83	retl ;\
84	and %o1, %o0, %o0 ");
85	#else
86	long
87	kernrand(x)
88	register long x;
89	{
90	register long hi, lo, t;
91
92	hi = x / 127773;
93	lo = x % 127773;
94	t = 16807 * lo - 2836 * hi;
95	if (t > 0)
96	return (t);
97	else
98	return (t + 0x7fffffff);
99	}
100	#endif