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From: Paul Zimmermann <Paul.Zimmermann@inria.fr>
To: Jeff Johnston <jjohnstn@redhat.com>
Cc: keithp@keithp.com, newlib@sourceware.org
Subject: Re: regression in tgamma?
Date: Fri, 18 Dec 2020 09:37:35 +0100	[thread overview]
Message-ID: <mwmtyb33xs.fsf@tomate.loria.fr> (raw)
In-Reply-To: <CAOox84uKYDq7huWPwFFz7jZpJpUR1dJdfQipv-tr1RU6YzxESg@mail.gmail.com> (message from Jeff Johnston on Thu, 17 Dec 2020 16:28:12 -0500)

       Hi again,

I have checked both tgammaf and tgamma with commit b2f3d59 (on x86_64).

tgammaf (exhaustive test of all the 2^32 inputs) no longer has the issue
of tgammaf(-0) = +inf instead of -inf, and similarly for -2^-128 <= x < 0.
The larger ulp error is 239 ulps as in 3.3.0 (for x=-0x1.01743cp+5).

For tgamma, by random testing I get the same maximal error as before:
2244.45 ulps for x=-0x1.53f198fe3b278p+7.

Thus the regression we had in 4.0.0 has gone.

Thanks Jeff,
Paul

  parent reply	other threads:[~2020-12-18  8:37 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-16 13:48 Paul Zimmermann
2020-12-16 20:31 ` Jeff Johnston
2020-12-17  7:29   ` Paul Zimmermann
2020-12-17 16:13     ` Keith Packard
2020-12-17 18:27       ` Jeff Johnston
2020-12-17 19:16         ` Keith Packard
2020-12-17 21:28           ` Jeff Johnston
2020-12-18  6:36             ` Paul Zimmermann
2020-12-18  8:42               ` Corinna Vinschen
2020-12-18  8:54                 ` Paul Zimmermann
2020-12-18  9:07                   ` Corinna Vinschen
2020-12-18 17:42                     ` Jeff Johnston
2020-12-18  8:37             ` Paul Zimmermann [this message]
  -- strict thread matches above, loose matches on Subject: below --
2020-12-15 13:35 Paul Zimmermann
2020-12-15 17:11 ` Jeff Johnston
2020-12-16  6:36   ` Paul Zimmermann

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