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

From: Johan Råde (rade_at_[hidden])
Date: 2006-12-07 08:24:08

Johan Råde wrote:
> Boris Gubenko wrote:
> 
>> As Markus pointed out, it is not the processor itself: one needs to
>> compile -ieee in order to get full support of ANSI/IEEE Standard 754-1985.
>>
>> For your library, compiling with cxx on Tru64 without -ieee makes little
>> sense. Likewise, on AlphaVMS, it should be compiled /float=ieee/ieee=denorm.
>> On iVMS, i.e. VMS on ia64, the full support for IEEE features is on by
>> default.
> 
> It should still be meaningful to use the library without -ieee.
> If there are no infinities and no NaNs,
> then the functions isinf and isnan should always return false.

Let me rephrase that:

The library should produce correct results,
regardless of compiler flags.

Whether the library is useful or not, with certain compiler flags,
is up to the user to decide.

--Johan