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Re: [RFC PATCH] aarch64: improve memset
- From: Marcus Shawcroft <marcus dot shawcroft at gmail dot com>
- To: Richard Henderson <rth at twiddle dot net>
- Cc: libc-alpha <libc-alpha at sourceware dot org>
- Date: Tue, 30 Sep 2014 12:03:39 +0100
- Subject: Re: [RFC PATCH] aarch64: improve memset
- Authentication-results: sourceware.org; auth=none
- References: <539BF47F dot 3030907 at twiddle dot net>
On 14 June 2014 08:06, Richard Henderson <firstname.lastname@example.org> wrote:
> The major idea here is to use IFUNC to check the zva line size once, and use
> that to select different entry points. This saves 3 branches during startup,
> and allows significantly more flexibility.
> Also, I've cribbed several of the unaligned store ideas that Ondrej has done
> with the x86 versions.
> I've done some performance testing using cachebench, which suggests that the
> unrolled memset_zva_64 path is 1.5x faster than the current memset at 1024
> bytes and above. The non-zva path appears to be largely unchanged.
OK Thanks /Marcus