How do we test the IBM ieee754 math library?

[H . J . Lu]

On Sun, Nov 25, 2001 at 08:46:45AM -0500, Stephen L Moshier wrote:
> 
> > Have you compared the IBM libm on x86 against the asm version on x86?
> > How are the results of "make check" in glibc?
> 
> What I checked, more specifically, was IBM libm functions running with the
> x86 coprocessor set to double precision.  Now I see that using the
> default linux fpu setting of 80-bit long double mode, the IBM routines
> totally fall to pieces.
> 
> 
> On x86 linux, make check doesn't run very far without coaxing.
> It reports things like
>     atest-exp.out:
>     131049 failures; 0 errors; error rate 0.00%
>     maximum error:   0b7f0f5245eea089d210d002d3fb98d57
>     error in exp(1): 00000000000000000000000cbffc1f5e9
> 
> This may not be worthwhile trying to fix except to ask what
> computer these programs were developed on or what computers they have
> actually been tested on.  Evidently the code is intolerant of IEEE
> flaws so there are going to be various systems on which it dosn't work
> properly.

That is what I have seeen. FWIW, the IBM libm functions don't work too
well on mips either. I thought it was faster and easier to fix them on
x86 than on a slow mips machine.



H.J.