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From: Thomas Koenig <tkoenig@netcologne.de>
To: Richard Biener <richard.guenther@gmail.com>,
	"fortran@gcc.gnu.org" <fortran@gcc.gnu.org>,
	gcc-patches <gcc-patches@gcc.gnu.org>
Subject: Re: [patch, fortran] Fix common subexpression elimination with IEEE rounding (PR108329)
Date: Sun, 8 Jan 2023 17:21:29 +0100	[thread overview]
Message-ID: <a13d9941-c8f2-8b92-c47e-85709581cf87@netcologne.de> (raw)
In-Reply-To: <79BE0629-246D-4EB8-A68F-4D9FEA6B013E@gmail.com>

Hi Richard,

>> Am 08.01.2023 um 14:31 schrieb Paul Richard Thomas via Fortran <fortran@gcc.gnu.org>:
>>
>> Hi Thomas,
>>
>> Following your off-line explanation that the seemingly empty looking
>> assembly line forces an effective reload from memory, all is now clear.
> 
> It’s not a full fix (for register vars) and it’s ‚superior‘ to the call itself only because asm handling is implemented in a rather stupid way in the Alias oracle.  So I don’t think this is a „fix“ at all.

There are no register variables in Fortran, this is Fortran FE only,
and it is a fix in the sense that correct code is no longer miscompiled.

There's a FIXME in the code pointing to the relevant PR precisely
because I think that this is less than elegant (as do you, obviously).
Do you have other suggestions how to implement this?  If PR 34678
is solved, this would probably provide a mechanism that we could
simply re-use.

Best regards

	Thomas

  reply	other threads:[~2023-01-08 16:21 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-07 15:46 Thomas Koenig
2023-01-08 13:31 ` Paul Richard Thomas
2023-01-08 15:53   ` Richard Biener
2023-01-08 16:21     ` Thomas Koenig [this message]
2023-01-09 12:59       ` Richard Biener
2023-01-09 15:27         ` Thomas Koenig

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