> On Fri, 30 Oct 1998, Bojan Antonovic wrote:
>
> <SNIP>
> >
> > Of course 128 bit integers are better for the LL-test then 64 bit integers.
And
> > 64 bit floating point numers are used very frequently in science
cumputation.
> > But concerning 128 FPU register I don`t know where te special use is, except
for
> > global economics.
> >
> > Bojan
> >
> >
>
> Bah! 128 bit floats are quite useful. Think about percision.
> There are segments within the 64 bit range where you get terrible decmil
> precision. (such as with any large number) This becomes a problem with
> scaling large numbers to small, working math, and then rescaling them to
> large numbers. I have seen this occur with many programs. 128 bit
> floats would be very nice for large numbers with decmils.
True and not true. To avoid to have very high precision there are reules how to
compute results of functions. For example if you want to add a serie of numers
first begin with the smallest and then raise up to the highest.
Am small example:
rounding after 2nd decimal after point
1.00E0 + 1.00E-1 = 1.01E0
but if you do 100 times
x:=1.00E0;
x:=x+1.00E-5;
you will have 1.00 as result, but the correct one is 2.00.
So it`s a myth that higher precision will give a better result.
Bojan
