Use of C99 extra long double math functions after r236148

Steve Kargl sgk at troutmask.apl.washington.edu
Tue May 29 06:10:36 UTC 2012


On Tue, May 29, 2012 at 02:56:13PM +1000, Peter Jeremy wrote:
> On 2012-May-28 15:54:06 -0700, Steve Kargl <sgk at troutmask.apl.washington.edu> wrote:
> 
> There some test code in cephes.  Can you point me to a suitable test
> suite for LD80 and LD128?  The reason for calling it libm is to avoid
> having to hack every consumer to add an additional library.

I can't point you to test code.  When I work on a function,
I write test code.

> >  It took
> >me 3+ years to get sqrtl() into libm, but bde and das (and
> >myself) wanted to make sure the code worked.
> 
> Last time I checked (a couple of years ago), FreeBSD was missing 65
> C99 libm functions.  At 3 years per function, we should have C99
> support available early in the 23rd century - which may be a bit late.

sqrtl() is a bit special in that IEEE 754 requires that
it have no more than 0.5 ULP for all arguments in all
roundng modes.  As to other functions, I've been trying
for 10+ years to get some of these into FreeBSD.  I can
assure you that there has never been a rush of people
volunteering to help or a rush of people willing to fund
the development of the necessary code. 

> 
> On 2012-May-28 22:03:43 -0500, Stephen Montgomery-Smith <stephen at missouri.edu> wrote:
> >1.  By being so picky about being so precise, FreeBSD is behind the time 
> >line in rolling out a usable set of C99 functions.
> 
> And at the current rate, we'll all be long dead before they are
> available.

It seems you've had "a couple of years" to implement one or
more of the missing functions.  Yes, we'll all be dead before
libm is C99 ready because no one, other than bde@, das@ and
myself, has been willing to actually help write the code.  I
know that at least one of those three people has had no time
in the last year or two work on libm. 

-- 
Steve


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