/***********************************************************************
** PRIVATE FUNCTION: Random
** DESCRIPTION:
** Generate a pseudo-random number
** INPUTS: None
** OUTPUTS: None
** RETURN: A pseudo-random unsigned number, 32-bits wide
** SIDE EFFECTS:
** Updates random seed (a static)
** RESTRICTIONS:
** None
** MEMORY: NA
** ALGORITHM:
** Uses the current interval timer value, promoted to a 64 bit
** float as a multiplier for a static residue (which begins
** as an uninitialized variable). The result is bits [16..48)
** of the product. Seed is then updated with the return value
** promoted to a float-64.
***********************************************************************/
static PRUint32 Random(void)
{
PRUint32 rv;
PRUint64 shift;
static PRFloat64 seed = 0x58a9382; /* Just make sure it isn't 0! */
PRFloat64 random = seed * (PRFloat64)PR_IntervalNow();
LL_USHR(shift, *((PRUint64*)&random), 16);
LL_L2UI(rv, shift);
seed = (PRFloat64)rv;
return rv;
} /* Random */
/***********************************************************************
** PRIVATE FUNCTION: Random
** DESCRIPTION:
** Generate a pseudo-random number
** INPUTS: None
** OUTPUTS: None
** RETURN: A pseudo-random unsigned number, 32-bits wide
** SIDE EFFECTS:
** Updates random seed (a static)
** RESTRICTIONS:
** None
** MEMORY: NA
** ALGORITHM:
** Uses the current interval timer value, promoted to a 64 bit
** float as a multiplier for a static residue (which begins
** as an uninitialized variable). The result is bits [16..48)
** of the product. Seed is then updated with the return value
** promoted to a float-64.
***********************************************************************/
PRUint32 HammerData::Random()
{
PRUint32 rv;
PRUint64 shift;
RCInterval now = RCInterval(RCInterval::now);
PRFloat64 random = seed * (PRFloat64)((PRIntervalTime)now);
LL_USHR(shift, *((PRUint64*)&random), 16);
LL_L2UI(rv, shift);
seed = (PRFloat64)rv;
return rv;
} /* HammerData::Random */
static PLDHashNumber
HashKey(PLDHashTable *table, const void *key)
{
// xor the low 32 bits with the high 32 bits.
PRTime t = *static_cast<const PRTime *>(key);
PRInt64 h64, l64;
LL_USHR(h64, t, 32);
l64 = LL_INIT(0, 0xffffffff);
LL_AND(l64, l64, t);
PRInt32 h32, l32;
LL_L2I(h32, h64);
LL_L2I(l32, l64);
return PLDHashNumber(l32 ^ h32);
}
