Re: [Gsl-shell-info] 0/0 and nan

[Francesco]

On 09/01/2014 12:14, Lesley De Cruz wrote:
> On 9 January 2014 00:25, elton wang <address@hidden> wrote:
> > In gsl-shell 2.3.1 windows version, why 0/0 == 0/0 returns true?
> > in Lua 5.1,  0/0 == 0/0 returns false.
> > thanks,
> That's because gsl-shell is compiled with the -ffast-math flag, which
> (surprisingly!) disables nans and infs -- ouch.
Thank you Lesley for looking at that. Actually this is not entirely 
surprising to me, the
--fast-math option let you have faster operations by disregarding some 
IEEE754 rules for
floating point operations. Yet I was not really aware of this 
non-conforming behavior.

I'm wondering is I shouldn't turn off the --fast-math option from the 
build flags in gsl shell.
I guess it is better to stick with the standards even if it does means a 
slight decrease in
execution speed.

Francesco