From: Rich Felker <dalias@libc.org>
To: Rob Landley <rob@landley.net>
Cc: "j-core@j-core.org" <j-core@j-core.org>, musl@lists.openwall.com
Subject: Re: Re: [J-core] Aligned copies and cacheline conflicts?
Date: Wed, 14 Sep 2016 22:36:45 -0400 [thread overview]
Message-ID: <20160915023644.GD15995@brightrain.aerifal.cx> (raw)
In-Reply-To: <8498eaa7-f263-efc8-a59c-d601e84af2db@landley.net>
On Wed, Sep 14, 2016 at 07:58:52PM -0500, Rob Landley wrote:
> On 09/14/2016 07:34 PM, Rich Felker wrote:
> > I could put a fork of memcpy.c in sh/memcpy.c and work on it there and
> > only merge it back to the shared one if others test it on other archs
> > and find it beneficial (or at least not harmful).
>
> Both musl and the kernel need it. And yes at the moment it seems
> architecture-specific, but it's a _big_ performance difference...
I actually think it's justifiable to have in the generic C memcpy,
from a standpoint that the generic C shouldn't assume an N-way (N>1,
i.e. not direct mapped) associative cache. Just need to make sure
changing it doesn't make gcc do something utterly idiotic for other
archs, I guess. I'll take a look at this.
Rich
next prev parent reply other threads:[~2016-09-15 2:36 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <0c256cb1-d0fa-9a5a-3976-b7ef545c1827@landley.net>
2016-09-15 0:34 ` Rich Felker
2016-09-15 0:58 ` Rob Landley
2016-09-15 2:36 ` Rich Felker [this message]
2016-09-16 22:16 ` Rich Felker
2016-09-17 1:40 ` Rob Landley
2016-09-17 2:17 ` Rich Felker
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