[PATCH] Add testcase for expl

[Joseph S. Myers]

On Thu, 6 Feb 2014, Stefan Liebler wrote:

> Hi,
> 
> due to Bug 16447, the function __erfcl
> in sysdeps/ieee754/ldbl-128/s_erfl.c
> calls __ieee754_expl in sysdeps/ieee754/ldbl-128/e_expl.c.
> The value returned by expl is a normalized value, but FE_UNDERFLOW is set on
> S/390. Therefore the testcase shows the problem directly.

"Bug N" comments in auto-libm-test-in are present as justification for 
xfail, missing-* or spurious-* annotations for tests (searching for "bug" 
in the file shows exactly what's marked as expected to fail because of 
known bugs).  Thus, if adding the test on its own (and normally the test 
would be added by the same patch fixing the bug, rather than before the 
fix), there should be a spurious-underflow:ldbl-128 annotation.

-- 
Joseph S. Myers
joseph@codesourcery.com