Re: fcmove on Alpha not qualified with /su when compiling -mieee - is that correct ?

[Richard Henderson <rth at cygnus dot com>]

On Mon, Jul 03, 2000 at 09:16:26PM +0200, Toon Moene wrote:
> Hmmmm, fascinating - let's see if I can compile my own kernel ;-)

Or perhaps try the errata update kernel from Red Hat 6.2, which
I believe to be 2.2.16 based.

> BTW, so what you're saying is:  It is immaterial whether you specify
> -mieee w.r.t. denormals.  That's interesting, because I managed to
> "cure" several fpe's in our code by just compiling it with -mieee 1). 
> Perhaps that was just a fortuitous side-effect.

No, that's not what I'm saying.  I'm saying that it's immaterial
to the slow speed of the program whether you specify -mieee,
since the processor is going to trap either way.

However, -mieee code should be handled by the kernel's software
floating-point implementation, and the program should see SIGFPE
iff such an exception is warrented by IEEE rules (SNaN or whatever,
modulo the current IEEE exception mask).

> 1) Aside from the fact that I repaired a number of utterly
> non-physical assumptions, like a water vapor saturation pressure
> table starting from 13 K ...

Heh.

Interesting that someone would decide to start the table at 13 K rather
than 0 K.  I mean, if you're not actually thinking about the realities
of water to begin with, why would you think about 13 K rather than have
the table be "complete"?


r~