From: Siddhesh Poyarekar <siddhesh@gotplt.org>
To: Feng Xue <fxue@os.amperecomputing.com>,
"libc-alpha@sourceware.org" <libc-alpha@sourceware.org>
Subject: Re: [PATCH 1/3] aarch64: Optimized memset specific to AmpereComputing emag
Date: Thu, 20 Dec 2018 09:24:00 -0000 [thread overview]
Message-ID: <19165708-8073-ac98-cdc5-a6bcaa142097@gotplt.org> (raw)
In-Reply-To: <BL0PR01MB4593104C25CE1A807F2F6FA7F7BD0@BL0PR01MB4593.prod.exchangelabs.com>
On 18/12/18 3:33 PM, Feng Xue wrote:
> This version uses general register based memory store instead of
> vector register based, for the former is faster than the latter
> in emag.
Barring a couple of instances that show a 5%+ difference from
__memset_generic (which also seems sporadic, maybe due to noise?),
everything else seems to be in the 1-2% range. Is that a significant
enough difference to warrant a new variant?
It may not be worth adding another variant for a mere 1-2% overall gain
for string routines but maybe I've misread the results and you have a
better justification for this. Please let me know if you do.
This is not a strong opposition though; if Szabolcs, Wilco, etc. don't
mind maintaining another variant (by calling it zva64_nosimd) despite
the seemingly low relative performance gain then I won't stand in the way.
Siddhesh
next prev parent reply other threads:[~2018-12-20 9:15 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-18 10:06 Feng Xue
2018-12-19 15:41 ` Szabolcs Nagy
2018-12-20 11:19 ` Siddhesh Poyarekar
2018-12-20 9:24 ` Siddhesh Poyarekar [this message]
2018-12-20 9:29 ` Siddhesh Poyarekar
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