ZealOS/src/Kernel/KMathB.CC

F64 Clamp(F64 d,F64 lo,F64 hi)
{//Clamp to F64 [] range.
	if (d<lo)
		return lo;
	if (d>hi)
		return hi;
	return d;
}

F64 Min(F64 n1,F64 n2)
{//Min of two F64s.
	if (n1<=n2)
		return n1;
	else
		return n2;
}

F64 Max(F64 n1,F64 n2)
{//Max of two F64s.
	if (n1>=n2)
		return n1;
	else
		return n2;
}

F64 Pow10I64(I64 i)
{//F64 int powers of ten.
	if (i>308)
		return ì;
	else if (i<-308)
		return 0.0;
	else
		return pow10_I64[i+309];
}

U64 FloorU64(U64 num,U64 to)
{//Int multiples of num.
	return num-num%to;
}

U64 CeilU64(U64 num,U64 to)
{//Int multiples of num.
	num+=to-1;
	return num-num%to;
}

I64 RoundI64(I64 num,I64 to)
{//Int multiples of num.
	return num-num%to;
}

I64 FloorI64(I64 num,I64 to)
{//Int multiples of num.
	if (num>=0)
		return num-num%to;
	else {
		num++;
		return num-num%to-to;
	}
}

I64 CeilI64(I64 num,I64 to)
{//Int multiples of num.
	if (num>=0) {
		num+=to-1;
		return num-num%to;
	} else {
		num+=to-1;
		return num-num%to-to;
	}
}

//See $LK,"::/Doc/Credits.DD"$.
#define LIN_CONGRUE_A 	6364136223846793005
#define LIN_CONGRUE_C 	1442695040888963407

I64 RandInt()
{//Don't use this. Use the functions below.
	I64 res = Fs->rand_seed;
	res = LIN_CONGRUE_A * res ^ (res & 0xFFFFFFFF0000) >> 16 + LIN_CONGRUE_C;
	if (!Bt(&Fs->task_flags, TASKf_NONTIMER_RAND))
		res ^= GetTSC;
	Fs->rand_seed = res;
	return res;
}

U8 RandU8()
{//Random U8.
	return RandInt & U8_MAX;
}

I16 RandI16()
{//Random I16.
	I64 res = RandInt;
	return res.i16[0];
}

U16 RandU16()
{//Random U16.
	return RandInt & U16_MAX;
}

I32 RandI32()
{//Random I32.
	I64 res = RandInt;
	return res.i32[0];
}

U32 RandU32()
{//Random U32.
	return RandInt & U32_MAX;
}

I64 RandI64()
{//Random I64.
	return RandInt;
}

U64 RandU64()
{//Random U64.
	return RandInt;
}

F64 Rand()
{//Random F64.
	return (RandInt & 0x3FFFFFFFFFFFFFFF) / ToF64(0x4000000000000000);
}

I64 Seed(I64 seed=0,CTask *task=NULL)
{//Set $LK,"Rand",A="MN:Rand"$() seed. Zero for timer-based.
	if (!task) task=Fs;
	if (seed) {
		LBts(&task->task_flags,TASKf_NONTIMER_RAND);
		return task->rand_seed=seed;
	} else {
		LBtr(&task->task_flags,TASKf_NONTIMER_RAND);
		return task->rand_seed^=GetTSC;
	}
}