From: Siddhesh Poyarekar <siddhesh@gotplt.org>
To: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
Cc: 'GNU C Library' <libc-alpha@sourceware.org>
Subject: Re: [RFC]: Removing old Falkor ifuncs
Date: Fri, 9 Dec 2022 10:24:21 -0500 [thread overview]
Message-ID: <8862bd85-24ef-42d7-e48a-acdb7ada73c9@gotplt.org> (raw)
In-Reply-To: <PAWPR08MB89827DE1AB6A85BECBD03488831C9@PAWPR08MB8982.eurprd08.prod.outlook.com>
On 2022-12-09 10:14, Wilco Dijkstra wrote:
> Do we need the ifuncs for Falkor? The SIMD memcpy is now the default
> generic memcpy and that is quite similar to the Falkor one, so it seems
> time to remove the Falkor variants. Since you are the original author,
> what do you think?
The key differentiator in memcpy/memmove at that time was the register
number usage since that affected how the hardware prefetcher performed.
Changing that might affect performance on falkor, although I don't
exactly remember by how much.
The other key differentiator is in memset, where reading dczid_el0 was
expensive on falkor, so the value is hard coded to avoid reading it
everytime.
Sid
next prev parent reply other threads:[~2022-12-09 15:24 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-09 15:14 Wilco Dijkstra
2022-12-09 15:24 ` Siddhesh Poyarekar [this message]
2022-12-09 18:00 ` Wilco Dijkstra
2022-12-21 17:27 ` Wilco Dijkstra
2022-12-21 23:38 ` Siddhesh Poyarekar
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