From: Marc Glisse <marc.glisse@inria.fr>
To: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>
Cc: Gcc Patch List <gcc-patches@gcc.gnu.org>,
Martin Sebor <msebor@gmail.com>,
Richard Biener <richard.guenther@gmail.com>
Subject: Re: [PATCH] handle bzero/bcopy in DSE and aliasing (PR 80933, 80934)
Date: Wed, 07 Jun 2017 20:01:00 -0000 [thread overview]
Message-ID: <alpine.DEB.2.20.1706072155550.1988@stedding.saclay.inria.fr> (raw)
In-Reply-To: <656E3329-B549-490D-A87F-7421D424E781@gmail.com>
On Wed, 7 Jun 2017, Bernhard Reutner-Fischer wrote:
> On 7 June 2017 16:46:53 CEST, Martin Sebor <msebor@gmail.com> wrote:
>> On 06/07/2017 02:23 AM, Richard Biener wrote:
>>> On Wed, Jun 7, 2017 at 5:26 AM, Martin Sebor <msebor@gmail.com>
>> wrote:
>>>>> Note I'd be _much_ more sympathetic to simply canonicalizing all of
>>>>> bzero and bcopy
>>>>> to memset / memmove and be done with all the above complexity.
>>>>
>>>>
>>>> Attached is an updated patch along these lines. Please let me
>>>> know if it matches your expectations.
>>>
>>> I think you attached the wrong patch.
>>
>> Yes I did, sorry. The correct one is attached.
>
> Under POSIX.1-2008 "optimizing" bzero or bcmp is IMO plain wrong.
>
> It's like optimizing foo() to a random built-in but maybe that's just
> me. If your libc provides a define to a standard function for these
> under a compat knob then fine but otherwise you should fix that.
> *shrug*. Joseph?
The patch optimizes __builtin_bzero, which should be ok. The question
(independent from this patch) is then under what conditions bzero should
be detected as a builtin.
--
Marc Glisse
next prev parent reply other threads:[~2017-06-07 20:01 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-01 20:53 Martin Sebor
2017-06-02 11:12 ` Richard Biener
2017-06-04 15:36 ` Bernhard Reutner-Fischer
2017-06-06 16:54 ` Jeff Law
2017-06-07 3:26 ` Martin Sebor
2017-06-07 8:23 ` Richard Biener
2017-06-07 14:46 ` Martin Sebor
2017-06-07 18:37 ` Bernhard Reutner-Fischer
2017-06-07 20:01 ` Marc Glisse [this message]
2017-06-07 20:12 ` Martin Sebor
2017-06-08 2:33 ` Martin Sebor
2017-06-08 7:51 ` Richard Biener
2017-06-08 16:29 ` Martin Sebor
2017-06-09 12:35 ` Richard Biener
2017-06-09 13:04 ` Jakub Jelinek
2017-06-09 13:36 ` Richard Biener
2017-06-16 20:52 ` Martin Sebor
2017-06-07 20:23 ` Joseph Myers
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