From: Paul Zimmermann <Paul.Zimmermann@inria.fr>
To: "H.J. Lu" <hjl.tools@gmail.com>
Cc: libc-alpha@sourceware.org
Subject: Re: [PATCH] x86_64: Add log1p with FMA
Date: Mon, 21 Aug 2023 14:31:58 +0200 [thread overview]
Message-ID: <p9u0v8d81sqp.fsf@coriandre.loria.fr> (raw)
In-Reply-To: <20230817164229.512321-1-hjl.tools@gmail.com> (libc-alpha@sourceware.org)
Hi H.J.
> On Skylake, it changes log1p bench performance by:
>
> Before After Improvement
> max 63.349 58.347 8%
> min 4.448 5.651 -30%
> mean 12.0674 10.336 14%
the largest known error decreases from 0.903 ulp:
log1p 0 -1 -0x1.2c10396268852p-2 [1] [0.903] 0.902709 0.9027087876691803
to 0.899 ulp:
log1p 0 -1 -0x1.2bf183e0344b2p-2 [1] [0.899] 0.898172 0.8981716806917975
LGTM.
Paul
PS: the largest error for asinh is unchanged:
asinh 0 -1 -0x1.02657ff36d5f3p-2 [2] [1.92] 1.91356 1.913551236624182
and for atanh it seems to improve.
prev parent reply other threads:[~2023-08-21 12:32 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-17 16:42 H.J. Lu
2023-08-21 12:31 ` Paul Zimmermann [this message]
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