From: Pedro Alves <pedro@palves.net>
To: Andrew Burgess <aburgess@redhat.com>,
Lancelot SIX <lsix@lancelotsix.com>
Cc: gdb-patches@sourceware.org
Subject: Re: [PATCH 4/5] sim/erc32: avoid dereferencing type-punned pointer warnings
Date: Thu, 13 Oct 2022 11:49:43 +0100 [thread overview]
Message-ID: <1205589e-d898-1373-2f53-d44fd5555938@palves.net> (raw)
In-Reply-To: <87czawau5m.fsf@redhat.com>
Hi,
On 2022-10-13 11:35 a.m., Andrew Burgess wrote:
> Lancelot SIX <lsix@lancelotsix.com> writes:
>>
>> Another well defined (at least to my knowledge) solution to this problem
>> is memcpy. You could do something like:
>>
>> memcpy (&sregt->fs[rd], ddata, sizeof (float32));
>>
>> I tend to find this more straightforward than the type punning version,
>> but I would be happy with either.
Yes, memcpy is fine too.
> Pedro, Lancelot, thanks for taking the time to give really useful
> feedback.
>
> In the end I went with the memcpy approach. I ran a few tests with GCC,
> Clang, and ICC, and in each case the code generated at -O0 was either
> identical, or pretty much identical when using memcpy vs using a union.
> When switching to -O2 the code was identical in all cases I checked.
>
> Thoughts?
LGTM.
Pedro Alves
next prev parent reply other threads:[~2022-10-13 10:49 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-12 12:38 [PATCH 0/5] Silence some build warnings in various simulators Andrew Burgess
2022-10-12 12:38 ` [PATCH 1/5] sim/cgen: mask uninitialized variable warning in cgen-run.c Andrew Burgess
2022-10-23 12:30 ` Mike Frysinger
2022-10-24 15:57 ` Andrew Burgess
2022-10-24 15:59 ` Mike Frysinger
2022-10-27 15:53 ` Andrew Burgess
2022-10-12 12:38 ` [PATCH 2/5] sim/ppc: fix warnings related to printf format strings Andrew Burgess
2022-10-12 12:46 ` Tsukasa OI
2022-10-12 13:50 ` Andrew Burgess
2022-10-23 12:20 ` Mike Frysinger
2022-10-24 15:41 ` Andrew Burgess
2022-10-12 12:38 ` [PATCH 3/5] sim/ppc: mark device_error function as ATTRIBUTE_NORETURN Andrew Burgess
2022-10-12 12:38 ` [PATCH 4/5] sim/erc32: avoid dereferencing type-punned pointer warnings Andrew Burgess
2022-10-12 14:11 ` Pedro Alves
2022-10-12 17:02 ` Lancelot SIX
2022-10-13 10:35 ` Andrew Burgess
2022-10-13 10:49 ` Pedro Alves [this message]
2022-10-23 12:34 ` Mike Frysinger
2022-10-24 15:42 ` Andrew Burgess
2022-10-12 12:38 ` [PATCH 5/5] sim/iq2000: silence pointer-sign warnings Andrew Burgess
2022-10-23 12:32 ` Mike Frysinger
2022-10-24 15:45 ` Andrew Burgess
2022-10-26 8:51 ` Mike Frysinger
2022-10-14 17:50 ` [PATCH 0/5] Silence some build warnings in various simulators Tom Tromey
2022-10-19 13:34 ` Andrew Burgess
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