From: Andrew Haley <aph@redhat.com>
To: Kyrill Tkachov <kyrylo.tkachov@foss.arm.com>,
"Kay F. Jahnke" <kfjahnke@gmail.com>,
"gcc@gcc.gnu.org" <gcc@gcc.gnu.org>
Subject: Re: autovectorization in gcc
Date: Wed, 09 Jan 2019 09:50:00 -0000 [thread overview]
Message-ID: <2721bb39-ee4b-0202-d81d-e0b36d2059fa@redhat.com> (raw)
In-Reply-To: <5C35C2C2.1050106@foss.arm.com>
On 1/9/19 9:45 AM, Kyrill Tkachov wrote:
> Hi Kay,
>
> On 09/01/19 08:29, Kay F. Jahnke wrote:
>> Hi there!
>>
>> I am developing software which tries to deliberately exploit the
>> compiler's autovectorization facilities by feeding data in
>> autovectorization-friendly loops. I'm currently using both g++ and
>> clang++ to see how well this approach works. Using simple arithmetic, I
>> often get good results. To widen the scope of my work, I was looking for
>> documentation on which constructs would be recognized by the
>> autovectorization stage, and found
>>
>> https://www.gnu.org/software/gcc/projects/tree-ssa/vectorization.html
>>
>
> Yeah, that page hasn't been updated in ages AFAIK.
>
>> By the looks of it, this document has not seen any changes for several
>> years. Has development on the autovectorization stage stopped, or is
>> there simply no documentation?
>>
>
> There's plenty of work being done on auto-vectorisation in GCC.
> Auto-vectorisation is a performance optimisation and as such is not really
> a user-visible feature that absolutely requires user documentation.
I don't agree. Sometimes vectorization is critical. It would be nice
to have a warning which would fire if vectorization failed. That would
surely help the OP.
--
Andrew Haley
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671
next prev parent reply other threads:[~2019-01-09 9:50 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-09 8:29 Kay F. Jahnke
2019-01-09 9:46 ` Kyrill Tkachov
2019-01-09 9:50 ` Andrew Haley [this message]
2019-01-09 9:56 ` Jonathan Wakely
2019-01-09 16:10 ` David Malcolm
2019-01-09 16:25 ` Jakub Jelinek
2019-01-10 8:19 ` Richard Biener
2019-01-10 11:11 ` Szabolcs Nagy
2019-01-09 16:26 ` David Malcolm
2019-01-09 10:47 ` Ramana Radhakrishnan
2019-01-10 9:24 ` Kay F. Jahnke
2019-01-10 11:18 ` Jonathan Wakely
2019-08-18 10:59 ` [wwwdocs PATCH] for " Gerald Pfeifer
2019-01-09 10:56 ` Kay F. Jahnke
2019-01-09 11:03 ` Jakub Jelinek
2019-01-09 11:21 ` Jakub Jelinek
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