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From: "sgk at troutmask dot apl.washington.edu" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug fortran/107753] gfortran returns NaN in complex divisions (x+x*I)/(x+x*I) and (x+x*I)/(x-x*I)
Date: Sat, 19 Nov 2022 00:25:28 +0000 [thread overview]
Message-ID: <bug-107753-4-UY3PzHgM0w@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-107753-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107753
--- Comment #9 from Steve Kargl <sgk at troutmask dot apl.washington.edu> ---
On Fri, Nov 18, 2022 at 11:24:29PM +0000, sgk at troutmask dot
apl.washington.edu wrote:
>
> Does anyone know what is meant by "Fortran rules"? F66 does not
> have any particular algorithm specified. I'll look at F77 shortly.
>
Well, I hunted down the origins of -fcx-fortran-rules.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=29549
So, it appears to be an optimization, where Smith's algorithm
will fail for extreme values of the real and imaginary parts
of the complex number.
next prev parent reply other threads:[~2022-11-19 0:25 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-18 19:32 [Bug fortran/107753] New: " weslley.pereira at ucdenver dot edu
2022-11-18 19:50 ` [Bug fortran/107753] " anlauf at gcc dot gnu.org
2022-11-18 20:50 ` kargl at gcc dot gnu.org
2022-11-18 21:26 ` anlauf at gcc dot gnu.org
2022-11-18 22:05 ` kargl at gcc dot gnu.org
2022-11-18 23:24 ` sgk at troutmask dot apl.washington.edu
2022-11-18 23:32 ` sgk at troutmask dot apl.washington.edu
2022-11-18 23:45 ` weslley.pereira at ucdenver dot edu
2022-11-18 23:47 ` weslley.pereira at ucdenver dot edu
2022-11-19 0:25 ` sgk at troutmask dot apl.washington.edu [this message]
2022-11-19 19:11 ` kargl at gcc dot gnu.org
2022-11-19 20:14 ` anlauf at gcc dot gnu.org
2022-11-20 0:54 ` sgk at troutmask dot apl.washington.edu
2022-12-07 21:16 ` anlauf at gcc dot gnu.org
2022-12-07 21:50 ` kargl at gcc dot gnu.org
2022-12-07 22:31 ` anlauf at gcc dot gnu.org
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