[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Date: Fri, 13 Feb 2015 17:38:45 +0100
From: Denys Vlasenko <vda.linux@...glemail.com>
To: musl <musl@...ts.openwall.com>
Subject: Re: [PATCH 1/2] x86_64/memset: avoid multiply insn if possible
On Fri, Feb 13, 2015 at 8:24 AM, Rich Felker <dalias@...c.org> wrote:
> On Thu, Feb 12, 2015 at 09:36:26PM +0100, Denys Vlasenko wrote:
> In practice it performs quite well. x86's are good at this. The
> generic C code in memset.c does not do any overlapping writes of
> different sizes for the short buffer code path -- all writes there are
> single-byte, and multiple-write only happens for some of the inner
> bytes depending on the value of n.
Measurements agree: I was not able to make it faster by doing it
differently.
I did find it possible to extend your trick to be usable for up to 30
byte blocks.
Sending the patch...
Powered by blists - more mailing lists
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
