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From: "kretz at kde dot org" <sourceware-bugzilla@sourceware.org>
To: glibc-bugs@sourceware.org
Subject: [Bug math/27460] hypot(__DBL_DENORM_MIN__, -0.) incorrectly raises FE_INEXACT and FE_UNDERFLOW
Date: Tue, 23 Feb 2021 21:06:29 +0000	[thread overview]
Message-ID: <bug-27460-131-sVPpAFHBXy@http.sourceware.org/bugzilla/> (raw)
In-Reply-To: <bug-27460-131@http.sourceware.org/bugzilla/>

https://sourceware.org/bugzilla/show_bug.cgi?id=27460

--- Comment #6 from Matthias Kretz (Vir) <kretz at kde dot org> ---
F10/9 Whether or when library functions raise an undeserved "underflow"
floating-point exception is unspecified.379) Otherwise, as implied by F.8.6,
the <math.h> functions do not raise spurious floating-point exceptions
(detectable by the user), other than the "inexact" floating-point exception.

Footnote 379) It is intended that undeserved "underflow" and "inexact"
floating-point exceptions are raised only if avoiding them would be too costly.

Additionally I believe F.10.4.3 states otherwise. I.e. hypot(denorm_min, 0) is
equivalent to fabs(denorm_min) and hypot(0, denorm_min) is equivalent to
hypot(denorm_min, 0).

But I'm new to interpreting floating-point exceptions legalese. I was only
trying to verify my hypot SIMD implementation against yours and stumbled over
this inconsistency.

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  parent reply	other threads:[~2021-02-23 21:06 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-23 16:07 [Bug math/27460] New: " kretz at kde dot org
2021-02-23 16:07 ` [Bug math/27460] " kretz at kde dot org
2021-02-23 20:13 ` adhemerval.zanella at linaro dot org
2021-02-23 20:20 ` kretz at kde dot org
2021-02-23 20:37 ` adhemerval.zanella at linaro dot org
2021-02-23 20:46 ` kretz at kde dot org
2021-02-23 20:54 ` joseph at codesourcery dot com
2021-02-23 21:06 ` kretz at kde dot org [this message]
2021-02-24 13:32 ` adhemerval.zanella at linaro dot org
2021-02-24 22:48 ` joseph at codesourcery dot com
2021-04-08  4:38 ` zimmerma+gcc at loria dot fr
2021-04-08 10:34 ` adhemerval.zanella at linaro dot org

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