This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: [PATCH 3/3] aarch64: Hoist ZVA check out of the memset function
- From: Siddhesh Poyarekar <siddhesh at sourceware dot org>
- To: Andrew Pinski <pinskia at gmail dot com>
- Cc: GNU C Library <libc-alpha at sourceware dot org>, Wilco Dijkstra <Wilco dot Dijkstra at arm dot com>, Szabolcs Nagy <szabolcs dot nagy at arm dot com>
- Date: Thu, 9 Nov 2017 11:14:18 +0530
- Subject: Re: [PATCH 3/3] aarch64: Hoist ZVA check out of the memset function
- Authentication-results: sourceware.org; auth=none
- References: <1510204408-1739-1-git-send-email-siddhesh@sourceware.org> <1510204408-1739-4-git-send-email-siddhesh@sourceware.org> <CA+=Sn1=MCd=JsNZwaHkRJ2j-kgKWKkxHdSskuSfi4dLd=2N96Q@mail.gmail.com>
- Reply-to: siddhesh at sourceware dot org
On Thursday 09 November 2017 10:59 AM, Andrew Pinski wrote:
> I don't like this at all for the increase file size for the not so
> significant gain on real platforms. I think we should declare falkor
> micro-arch is broken and move on.
Are you sure this doesn't give any gains for thunderx for the sizes I
mentioned (256B - ~1K)? I see significant gains on mustang too and it
is obvious to see why; it is 3 instructions and a branch less in a hot
path and that should be significant regardless of the MRS cost.
If you don't see any gain then I don't mind posting this as a
falkor-specific change. If you change your mind in future we can always
change the IFUNC condition.
Siddhesh