libm-test.inc: Computing ulps near FP_ZERO.

[Carlos O'Donell]

On 04/08/2013 09:38 PM, Brooks Moses wrote:
> Which is to say that there's a more fundamental problem here, because
> there's no clear way to implement what you actually need to do in the
> test harness as it stands.  This test suite is assuming (in, e.g.,
> check_float_internal) that some fixed multiple of ulp(expected) is a
> reasonable measure of the expected error bounds.
> 
> That, in this case, is fundamentally _false_.

I understand your point about this now.

The error in expressing pi is simply an upper bound on the error.

It will generate many ulp error for a precise answer to the question
cos(M_PI_2l).

I think Rich's answer is the only reasonable one, which is to compute
what the exact answer should be.

Cheers,
Carlos.