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/*
* 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 random number generator.
*
* 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.
*/
static int randseed = 1;
void
srandom(int seed)
{
randseed = seed;
}
#if sparc && !__SUNPRO_C
#ifdef __svr4__
#define RANDOM "random"
#define RANDSEED "randseed"
#else
#define RANDOM "_random"
#define RANDSEED "_randseed"
#endif
asm("\
.global " RANDOM " ;\
" RANDOM ": ;\
sethi %hi(16807), %o1 ;\
wr %o1, %lo(16807), %y ;\
sethi %hi(" RANDSEED "), %g1 ;\
ld [%g1 + %lo(" RANDSEED ")], %o0 ;\
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 ;\
set 0xffff, %o4 ;\
and %o4, %o2, %o0 ;\
sll %o0, 15, %o0 ;\
srl %o3, 17, %o3 ;\
or %o3, %o0, %o0 ;\
addcc %o0, %o1, %o0 ;\
bneg 1f ;\
sethi %hi(0x7fffffff), %o1 ;\
retl ;\
st %o0, [%g1 + %lo(" RANDSEED ")] ;\
1: ;\
or %o1, %lo(0x7fffffff), %o1 ;\
add %o0, 1, %o0 ;\
and %o1, %o0, %o0 ;\
retl ;\
st %o0, [%g1 + %lo(" RANDSEED ")] ");
#else
int
random()
{
register int x = randseed;
register int hi, lo, t;
hi = x / 127773;
lo = x % 127773;
t = 16807 * lo - 2836 * hi;
if (t <= 0)
t += 0x7fffffff;
randseed = t;
return (t);
}
#endif
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