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Re: [PATCH] Update sparc ULPs.


On Sun, 18 Nov 2012, David Miller wrote:

> I've done some investigation meanwhile and we end up down in
> atanl(), via atan2l().
> 
> atan2l: x[-2.083218e+306L] y[1.755781e+174L]
> 
> atanl: x[-7.672687e+306L]
> 
> And the atanl() is what generates the spurious underflow.

I don't know if this is an "atan of large argument" issue, but I see we 
don't have any direct tests in the testsuite for atan / atan2 of large 
finite arguments at all.  Maybe we should have tests of atan (+/- 
max_value) and atan2 (+/- max_value, +/-min_value) - expected results all 
being +/- M_PI_2l.  And for that matter, atan2 (+/- min_value, max_value), 
expected results +/- M_PIl, to verify that that doesn't produce any 
spurious underflows either (as it would for a naive conversion from atan2 
to atan).

-- 
Joseph S. Myers
joseph@codesourcery.com


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