Re: [boost] Optimized portable isnan, isfinite, fpclassify etc

From: Markus Schöpflin (markus.schoepflin_at_[hidden])
Date: 2006-12-06 04:33:39

Johan Råde wrote:
> Markus Schöpflin wrote:
> 
>> You can't leave out -ieee as 
>> the Alpha needs some special compiler help for conforming IEEE math 
>> handling, the processor itself is only 'mostly conformant'.
> 
> What happens if you leave out -ieee?

I forgot to add something... from the compiler man page:

-ieee
Support all portable features of the IEEE Standard for Binary
Floating-Point Arithmetic (ANSI/IEEE Standard 754-1985), including the
treatment of denormalized numbers, NaNs, infinities, and the handling
of error cases. This flag also sets the _IEEE_FP macro.  To flush
floating point underflows to zero, add the -underflow_to_zero option.

-underflow_to_zero
When used with the -ieee option, directs the compiler to flush float-
ing point underflows to zero.

Markus