This is the mail archive of the libc-alpha@sources.redhat.com mailing list for the glibc project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]

Re: K6-II+, persistent strange test results of glibc-2.2.3


Byeong-ryeol Kim <jinbo21@hananet.net> writes:

> On 28 Apr 2001, Ulrich Drepper wrote:
> 
> > Byeong-ryeol Kim <jinbo21@hananet.net> writes:
> >
> > >  is:         -2.48292386531829833984e-01  -0x1.fc80b800000000000000p-3
> > >  should be:  -2.51362651586532592773e-01  -0x1.01653600000000000000p-2
> > >  difference:  3.07026505470275878906e-03   0x1.926d0000000000000000p-9
> > >  ulp       :  103021.0000
> > >  max.ulp   :  1.0000
> > > Maximal error of `yn'
> > >  is      :  103021.0000 ulp
> > >  accepted:  3.0000 ulp
> >
> > This normally would suggest that the compiler is broken and you should
> > use a better one.
> ....
> 
> I'll try to test with latest gcc 3.1 pre-release, later.
> 
> > If you say that running the same binary produces different results
> > (and since this is not the case anywhere else) it's either a kernel or
> > a CPU problem.  AMD's FPU is lousy and I wouldn't be surprised at all.
> ...
> If these problems were related with kernel, which version of kernel
> would be adequate for glibc-2.2.3?
> 
> Yes, I know, AMD CPUs prior to Athlons have deficiency in FPU-intensive
> work, and I admit my CPU has serious problem, prepared to give up this
> CPU.

Please run the same binary (with the same libm and libc) on another
machine to check whether the CPU or the compiler is broken.

> But, why problems I mentioned in previous mail appear these
> days(2.2.3preX era), are newly added math functions revealing the
> workarounded CPU problems explicitly?
> If those were due to the deficiency of FPU of AMD CPUs, is this
> statement interpretable that AMD CPUs(though not all) are not adequate
> for FPU-intensive work or development platform of FPU-intensive programs?
> If so, How about Athlon or Duron family?

I don't have problem with the gcc 3.0 branch on athlons.

Andreas
-- 
 Andreas Jaeger
  SuSE Labs aj@suse.de
   private aj@arthur.inka.de
    http://www.suse.de/~aj


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]