Re: Numerical calculations: Why not use fixed point types for everything?

[Ada novice <shai.lesh@gmx.com>]

On Thursday, January 17, 2013 5:25:30 PM UTC+1, Adam Beneschan wrote:

> (2) Many processors have built-in support for mathematical functions on floating-point values (square root, trig functions, log, e**x).  If your program does lots of those, you'll probably want to use floating-point numbers instead of calling library functions to do the computation (slow) or constantly converting back and forth between fixed- and floating-point.
> 
> 
>                               -- Adam

Thanks to all of you for your inputs. So if I am just writing a program that won't be run on a separate DSP platform but only on my computer, then I can go for fixed-point representation as long as I am not working with excessively large or excessively small values.

I have read (John Mc Cormick: Building parallel...with Ada's book) that fixed point arithmetic is faster than floating-point arithmetic since integer instructions are faster so I would ask about the second point put by Adam that mathematical functions are slow with fixed-point numbers. Can you please elaborate on that?

Thanks
YC