114 lines
3.2 KiB
C
114 lines
3.2 KiB
C
/***********************************************************************
|
|
* *
|
|
* This software is part of the ast package *
|
|
* Copyright (c) 1996-2011 AT&T Intellectual Property *
|
|
* and is licensed under the *
|
|
* Eclipse Public License, Version 1.0 *
|
|
* by AT&T Intellectual Property *
|
|
* *
|
|
* A copy of the License is available at *
|
|
* http://www.eclipse.org/org/documents/epl-v10.html *
|
|
* (with md5 checksum b35adb5213ca9657e911e9befb180842) *
|
|
* *
|
|
* Information and Software Systems Research *
|
|
* AT&T Research *
|
|
* Florham Park NJ *
|
|
* *
|
|
* Glenn Fowler <gsf@research.att.com> *
|
|
* *
|
|
***********************************************************************/
|
|
#pragma prototyped
|
|
|
|
/*
|
|
* prng
|
|
*/
|
|
|
|
#include <fnv.h>
|
|
|
|
#define prng_description \
|
|
"32 bit PRNG (pseudo random number generator) hash."
|
|
#define prng_options "\
|
|
[+mpy?The 32 bit PRNG multiplier.]:[number:=0x01000193]\
|
|
[+add?The 32 bit PRNG addend.]:[number:=0]\
|
|
[+init?The PRNG initial value. 0xffffffff is used if \anumber\a is omitted.]:?[number:=0x811c9dc5]\
|
|
"
|
|
#define prng_match "prng"
|
|
#define prng_done long_done
|
|
#define prng_print long_print
|
|
#define prng_data long_data
|
|
#define prng_scale 0
|
|
|
|
typedef uint32_t Prngnum_t;
|
|
|
|
typedef struct Prng_s
|
|
{
|
|
_SUM_PUBLIC_
|
|
_SUM_PRIVATE_
|
|
_INTEGRAL_PRIVATE_
|
|
Prngnum_t init;
|
|
Prngnum_t mpy;
|
|
Prngnum_t add;
|
|
} Prng_t;
|
|
|
|
static Sum_t*
|
|
prng_open(const Method_t* method, const char* name)
|
|
{
|
|
register Prng_t* sum;
|
|
register const char* s;
|
|
register const char* t;
|
|
register const char* v;
|
|
register int i;
|
|
|
|
if (sum = newof(0, Prng_t, 1, 0))
|
|
{
|
|
sum->method = (Method_t*)method;
|
|
sum->name = name;
|
|
}
|
|
s = name;
|
|
while (*(t = s))
|
|
{
|
|
for (t = s, v = 0; *s && *s != '-'; s++)
|
|
if (*s == '=' && !v)
|
|
v = s;
|
|
i = (v ? v : s) - t;
|
|
if (isdigit(*t) || v && strneq(t, "mpy", i) && (t = v + 1))
|
|
sum->mpy = strtoul(t, NiL, 0);
|
|
else if (strneq(t, "add", i))
|
|
sum->add = v ? strtoul(v + 1, NiL, 0) : ~sum->add;
|
|
else if (strneq(t, "init", i))
|
|
sum->init = v ? strtoul(v + 1, NiL, 0) : ~sum->init;
|
|
if (*s == '-')
|
|
s++;
|
|
}
|
|
if (!sum->mpy)
|
|
{
|
|
sum->mpy = FNV_MULT;
|
|
if (!sum->init)
|
|
sum->init = FNV_INIT;
|
|
}
|
|
return (Sum_t*)sum;
|
|
}
|
|
|
|
static int
|
|
prng_init(Sum_t* p)
|
|
{
|
|
Prng_t* sum = (Prng_t*)p;
|
|
|
|
sum->sum = sum->init;
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
prng_block(Sum_t* p, const void* s, size_t n)
|
|
{
|
|
Prng_t* sum = (Prng_t*)p;
|
|
register Prngnum_t c = sum->sum;
|
|
register unsigned char* b = (unsigned char*)s;
|
|
register unsigned char* e = b + n;
|
|
|
|
while (b < e)
|
|
c = c * sum->mpy + sum->add + *b++;
|
|
sum->sum = c;
|
|
return 0;
|
|
}
|