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From: Jakub Jelinek <jakub@redhat.com>
To: Pranav Kant <prka@google.com>
Cc: Jonathan Wakely <jwakely@redhat.com>,
	Stephan Bergmann <sbergman@redhat.com>,
	libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org
Subject: Re: [committed] libstdc++: Define std::numeric_limits<_FloatNN> before C++23
Date: Wed, 4 Oct 2023 18:57:13 +0200	[thread overview]
Message-ID: <ZR2ZaXksYJfqBWvp@tucnak> (raw)
In-Reply-To: <CAPvNhsKd15j0ydAotea1H4ZtQHM=Hni+mJ6Mi6X4HDnHi7mPtw@mail.gmail.com>

On Wed, Oct 04, 2023 at 09:47:34AM -0700, Pranav Kant wrote:
> Thanks for bringing this to my attention. I am working on a fix. Will keep
> this thread posted.
> 
> Clang *does* define this macro only when float128 type is available. But
> the problem seems to be that clang doesn't define _Float128 alias type
> which is what's being used here. It only defines __float128 type. Should be
> easy to fix.

_Float128 (and other _FloatNN types) are standard C23 and C++23 types,
they certainly can't be simple aliases to __float128 or other similar types.
In C++ they mangle differently, have significantly different behavior in
lots of different language details.
So, you need to implement the https://wg21.link/P1467R9 paper, rather than
doing quick hacks.

	Jakub


  reply	other threads:[~2023-10-04 16:57 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-17 20:32 Jonathan Wakely
2023-10-04 15:54 ` Stephan Bergmann
2023-10-04 15:56   ` Jonathan Wakely
2023-10-04 16:47     ` Pranav Kant
2023-10-04 16:57       ` Jakub Jelinek [this message]
2023-10-04 17:00         ` Pranav Kant
2023-10-04 18:21           ` Pranav Kant

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