On Thu, 16 Feb 2012, Andrew Haley wrote: > On 02/16/2012 02:42 PM, Vincent Lefevre wrote: > > On 2012-02-15 15:18:45 +0000, Andrew Haley wrote: > > > > On 02/15/2012 09:30 AM, Vincent Lefevre wrote: > > > > > > >> But to be absolutely clear, glibc's libm doesn't have a problem > > > > > > > >> meeting C99, AFAIK. > > > > > > That's not quite correct. It is completely broken in directed > > > > > > rounding modes (up to crashes). > > > > > > > > Eh? C99 doesn't require directed rounding modes. I'll grant you, > > > > if they are provided they shouldn't crash. :-) > > C99 doesn't require directed rounding modes, but as long as they > > are claimed to be supported by<fenv.h>, they should work: > > Ah, I see. So, we could bring gcc+glibc into compliance by not > defining the rounding mode macros.
I don't think that's a good approach; I think we should fix the GCC bugs with -frounding-math etc. (and implement the standard pragmas). It's just that completing the support for exceptions and rounding modes will involve a fair amount of work and user demand seems limited, so it hasn't been done yet. -- Joseph S. Myers jos...@codesourcery.com
