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Use Mersenne Twister 19937 pseudo-random number generator 

for the $random system task, and support the seed paramter.
This commit is contained in:
steve 2001-02-16 00:26:38 +00:00
parent 2b0aaec8ab
commit 4399042b8d
3 changed files with 133 additions and 85 deletions
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5
vpi/Makefile.in
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@ -18,7 +18,7 @@
# 59 Temple Place - Suite 330
# Boston, MA 02111-1307, USA
#
#ident "$Id: Makefile.in,v 1.20 2001/01/09 03:11:28 steve Exp $"
#ident "$Id: Makefile.in,v 1.21 2001/02/16 00:26:38 steve Exp $"
#
#
SHELL = /bin/sh
@ -54,7 +54,8 @@ all: system.vpi
mv $*.d dep
O = sys_table.o sys_display.o sys_finish.o sys_random.o \
sys_readmem.o sys_readmem_lex.o sys_time.o sys_vcd.o
sys_readmem.o sys_readmem_lex.o sys_time.o sys_vcd.o \
mt19937int.o
ifeq (@CYGWIN@,yes)
SYSTEM_VPI_LDFLAGS=-Wl,--enable-auto-image-base -L../vvm -lvvm -lvpip

115
vpi/mt19937int.c Normal file
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@ -0,0 +1,115 @@
/*
* NOTE: This code as been slightly modified to interface with the
* PLI implementations of $random. The copyright and license
* information are given in the comment block below.
*
* The Modifications include:
*
* Remove the "main" function, as this is being used for its functions.
*
* Change the function prototypes to use ANSI/ISO C syntax.
*/
/* A C-program for MT19937: Integer version (1998/4/6) */
/* genrand() generates one pseudorandom unsigned integer (32bit) */
/* which is uniformly distributed among 0 to 2^32-1 for each */
/* call. sgenrand(seed) set initial values to the working area */
/* of 624 words. Before genrand(), sgenrand(seed) must be */
/* called once. (seed is any 32-bit integer except for 0). */
/* Coded by Takuji Nishimura, considering the suggestions by */
/* Topher Cooper and Marc Rieffel in July-Aug. 1997. */
/* This library is free software; you can redistribute it and/or */
/* modify it under the terms of the GNU Library General Public */
/* License as published by the Free Software Foundation; either */
/* version 2 of the License, or (at your option) any later */
/* version. */
/* This library is distributed in the hope that it will be useful, */
/* but WITHOUT ANY WARRANTY; without even the implied warranty of */
/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. */
/* See the GNU Library General Public License for more details. */
/* You should have received a copy of the GNU Library General */
/* Public License along with this library; if not, write to the */
/* Free Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA */
/* 02111-1307 USA */
/* Copyright (C) 1997 Makoto Matsumoto and Takuji Nishimura. */
/* When you use this, send an email to: matumoto@math.keio.ac.jp */
/* with an appropriate reference to your work. */
/* REFERENCE */
/* M. Matsumoto and T. Nishimura, */
/* "Mersenne Twister: A 623-Dimensionally Equidistributed Uniform */
/* Pseudo-Random Number Generator", */
/* ACM Transactions on Modeling and Computer Simulation, */
/* Vol. 8, No. 1, January 1998, pp 3--30. */
/* Period parameters */
#define N 624
#define M 397
#define MATRIX_A 0x9908b0df /* constant vector a */
#define UPPER_MASK 0x80000000 /* most significant w-r bits */
#define LOWER_MASK 0x7fffffff /* least significant r bits */
/* Tempering parameters */
#define TEMPERING_MASK_B 0x9d2c5680
#define TEMPERING_MASK_C 0xefc60000
#define TEMPERING_SHIFT_U(y) (y >> 11)
#define TEMPERING_SHIFT_S(y) (y << 7)
#define TEMPERING_SHIFT_T(y) (y << 15)
#define TEMPERING_SHIFT_L(y) (y >> 18)
static unsigned long mt[N]; /* the array for the state vector */
static int mti=N+1; /* mti==N+1 means mt[N] is not initialized */
/* initializing the array with a NONZERO seed */
void
sgenrand(unsigned long seed)
{
/* setting initial seeds to mt[N] using */
/* the generator Line 25 of Table 1 in */
/* [KNUTH 1981, The Art of Computer Programming */
/* Vol. 2 (2nd Ed.), pp102] */
mt[0]= seed & 0xffffffff;
for (mti=1; mti<N; mti++)
mt[mti] = (69069 * mt[mti-1]) & 0xffffffff;
}
unsigned long
genrand()
{
unsigned long y;
static unsigned long mag01[2]={0x0, MATRIX_A};
/* mag01[x] = x * MATRIX_A for x=0,1 */
if (mti >= N) { /* generate N words at one time */
int kk;
if (mti == N+1) /* if sgenrand() has not been called, */
sgenrand(4357); /* a default initial seed is used */
for (kk=0;kk<N-M;kk++) {
y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK);
mt[kk] = mt[kk+M] ^ (y >> 1) ^ mag01[y & 0x1];
}
for (;kk<N-1;kk++) {
y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK);
mt[kk] = mt[kk+(M-N)] ^ (y >> 1) ^ mag01[y & 0x1];
}
y = (mt[N-1]&UPPER_MASK)|(mt[0]&LOWER_MASK);
mt[N-1] = mt[M-1] ^ (y >> 1) ^ mag01[y & 0x1];
mti = 0;
}
y = mt[mti++];
y ^= TEMPERING_SHIFT_U(y);
y ^= TEMPERING_SHIFT_S(y) & TEMPERING_MASK_B;
y ^= TEMPERING_SHIFT_T(y) & TEMPERING_MASK_C;
y ^= TEMPERING_SHIFT_L(y);
return y;
}

98
vpi/sys_random.c
View File

@ -17,7 +17,7 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#if !defined(WINNT) && !defined(macintosh)
#ident "$Id: sys_random.c,v 1.2 2000/07/08 22:41:07 steve Exp $"
#ident "$Id: sys_random.c,v 1.3 2001/02/16 00:26:38 steve Exp $"
#endif
# include <vpi_user.h>
@ -26,84 +26,10 @@
# include <math.h>
# include <limits.h>
#if 0
double uniform(long*seed, long start, long end)
{
union u_s {
float s;
unsigned stemp;
} u;
extern void sgenrand(unsigned long seed);
extern unsigned long genrand(void);
double d = 0.00000011920928955078125;
double a, b, c;
if ((*seed) == 0)
*seed = 259341593;
if (start >= end) {
a = 0.0;
b = 2147483647.0;
} else {
a = (double) start;
b = (double) end;
}
*seed = 69069 * (*seed) + 1;
u.stemp = *seed;
u.stemp = (u.stemp >> 9) | 0x3f800000;
c = (double) u.s;
c = c + (c*d);
c = ((b - a) * (c - 1.0)) + a;
return c;
}
#endif
#if 0
static long rtl_dist_uniform(long*seed, long start, long end)
{
double r;
long i;
if (start >= end)
return start;
if (end != LONG_MAX) {
end += 1;
r = uniform(seed, start, end);
if (r >= 0)
i = (long) r;
else
i = (long) (r-1);
if (i < start) i = start;
if (i >= end) i = end - 1;
} else if (start != LONG_MIN) {
start -= 1;
r = uniform(seed, start, end);
if (r >= 0)
i = (long) r;
else
i = (long) (r-1);
if (i <= start) i = start;
if (i > end) i = end;
} else {
r = (uniform(seed, start, end) + 2147483648.0) / 4294967295.0;
r = r * 4294967296.0 - 2147483648.0;
if (r >= 0)
i = (long) r;
else
i = (long) (r-1);
}
return i;
}
#else
static long rtl_dist_uniform(long*seed, long start, long end)
{
if (start >= end)
@ -116,7 +42,6 @@ static long rtl_dist_uniform(long*seed, long start, long end)
return random();
}
}
#endif
static int sys_dist_uniform_calltf(char*name)
@ -174,12 +99,11 @@ static int sys_dist_uniform_sizetf(char*x)
}
/*
* Implement the $random system function. For now, ignore any
* parameters and only produce a random number.
* Implement the $random system function using the ``Mersenne
* Twister'' random number generator MT19937.
*/
static int sys_random_calltf(char*name)
{
static long i_seed = 0;
s_vpi_value val;
vpiHandle call_handle;
vpiHandle argv;
@ -188,6 +112,8 @@ static int sys_random_calltf(char*name)
call_handle = vpi_handle(vpiSysTfCall, 0);
assert(call_handle);
/* Get the argument list and look for a seed. If it is there,
get the value and reseed the random number generator. */
argv = vpi_iterate(vpiArgument, call_handle);
if (argv) {
seed = vpi_scan(argv);
@ -195,19 +121,21 @@ static int sys_random_calltf(char*name)
val.format = vpiIntVal;
vpi_get_value(seed, &val);
i_seed = val.value.integer;
sgenrand(val.value.integer);
}
val.format = vpiIntVal;
val.value.integer = rtl_dist_uniform(&i_seed, LONG_MIN, LONG_MAX);
val.value.integer = genrand();
vpi_put_value(call_handle, &val, 0, vpiNoDelay);
#if 0
if (seed) {
val.format = vpiIntVal;
val.value.integer = i_seed;
vpi_put_value(seed, &val, 0, vpiNoDelay);
}
#endif
return 0;
}
@ -240,6 +168,10 @@ void sys_random_register()
/*
* $Log: sys_random.c,v $
* Revision 1.3 2001/02/16 00:26:38 steve
* Use Mersenne Twister 19937 pseudo-random number generator
* for the $random system task, and support the seed paramter.
*
* Revision 1.2 2000/07/08 22:41:07 steve
* Add the dist_uniform function.
*