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Re: [PATCH] [RFC] Change SET_RESTORE_ROUND to just set the roundingmode

On Thu, 14 Mar 2013, Adhemerval Zanella wrote:

> Hi Joseph,
> I have opened bug BZ#15268. I couldn't find a easy way to add a testcase in the
> existing math mainly because although the exp call underflow, the result is
> not inexact and the underflow mask is set on test-* cases to not trap. I open
> to suggestion on how to add a testcase or if is really need to add one.

The final exp result certainly isn't exact.  There may be two separate 
bugs here: missing underflow exceptions when the internal computation that 
underflows is exact although the final result isn't, and missing underflow 
exceptions in both cases on powerpc.

Maybe you can find an input that *does* raise the underflow flag on other 
architectures, because the internal calculation is inexact, but does not 
do so on powerpc, and use that in the testcase in  Then 
file a separate bug for the case where the internal calculation is exact 
so the underflow flag doesn't get raised (in the absence of trapping on 
underflow) on any architecture?

Joseph S. Myers

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