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From: "hp at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/94600] Ignored volatile specifier on loop unrolling and bitfield misoptimization
Date: Wed, 15 Apr 2020 22:45:49 +0000	[thread overview]
Message-ID: <bug-94600-4-jmewuCBNEW@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-94600-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94600

--- Comment #8 from Hans-Peter Nilsson <hp at gcc dot gnu.org> ---
(In reply to joseph@codesourcery.com from comment #7)
> The Arm AAPCS has detailed rules for operations on individual volatile 
> bit-fields, but not for this case where the whole struct is volatile and 
> the operation is on the whole struct.  I think you can consider this issue 
> in general as quality-of-implementation.

Can we extrapolate this statement to the language level, that this is
implementation- or port-specific?

I'm curious to see how those reads from volatile LHS can be justified from a
correctness point of view, in the context of this being an aggregate
assignment.

  parent reply	other threads:[~2020-04-15 22:45 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-14 23:27 [Bug middle-end/94600] New: " hp at gcc dot gnu.org
2020-04-14 23:32 ` [Bug middle-end/94600] " hp at gcc dot gnu.org
2020-04-14 23:36 ` hp at gcc dot gnu.org
2020-04-15  6:46 ` rguenth at gcc dot gnu.org
2020-04-15  7:05 ` rguenth at gcc dot gnu.org
2020-04-15  7:06 ` rguenth at gcc dot gnu.org
2020-04-15  7:07 ` rguenth at gcc dot gnu.org
2020-04-15 22:33 ` joseph at codesourcery dot com
2020-04-15 22:45 ` hp at gcc dot gnu.org [this message]
2020-07-13  6:09 ` cvs-commit at gcc dot gnu.org
2020-07-13  6:30 ` cvs-commit at gcc dot gnu.org
2020-08-13  3:13 ` cvs-commit at gcc dot gnu.org
2020-12-04 19:29 ` cvs-commit at gcc dot gnu.org
2020-12-04 19:37 ` cvs-commit at gcc dot gnu.org
2021-12-21  2:46 ` hp at gcc dot gnu.org

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