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From: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
To: 'GNU C Library' <libc-alpha@sourceware.org>
Cc: nd <nd@arm.com>, Richard Earnshaw <Richard.Earnshaw@arm.com>,
	"Marcus Shawcroft" <Marcus.Shawcroft@arm.com>
Subject: Re: [PATCH][AArch64] Optimized memset
Date: Fri, 15 Apr 2016 12:40:00 -0000	[thread overview]
Message-ID: <AM3PR08MB0088C89624B01DFA6E30154083680@AM3PR08MB0088.eurprd08.prod.outlook.com> (raw)
In-Reply-To: <AM3PR08MB0088F02B88A2C6614843F2A383EE0@AM3PR08MB0088.eurprd08.prod.outlook.com>

ping

________________________________________
From: Wilco Dijkstra
Sent: 15 December 2015 16:39
To: 'GNU C Library'
Cc: nd
Subject: Re: [PATCH][AArch64] Optimized memset

ping

-----Original Message-----
From: Wilco Dijkstra [mailto:wdijkstr@arm.com]
Sent: 31 July 2015 16:02
To: 'GNU C Library'
Subject: [PATCH][AArch64] Optimized memset

This is an optimized memset for AArch64. Memset is split into 4 main cases: small sets of up to 16 bytes, medium of 16..96 bytes which are fully unrolled. Large memsets of more than 96 bytes align the destination and use an unrolled loop processing 64 bytes per iteration. Memsets of zero of more than 256 use the dc zva instruction, and there are faster versions for the common ZVA sizes 64 or 128. STP of Q registers is used to reduce codesize without loss of performance.

Speedup on test-memset is 1% on Cortex-A57 and 8% on Cortex-A53. On a random test with varying sizes and alignment the new version is 50% faster.

OK for commit?

ChangeLog:
2015-07-31  Wilco Dijkstra  <wdijkstr@arm.com>

        * sysdeps/aarch64/memset.S (__memset):
        Rewrite of optimized memset.

  reply	other threads:[~2016-04-15 12:40 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-15 16:39 Wilco Dijkstra
2016-04-15 12:40 ` Wilco Dijkstra [this message]
2016-04-20 21:10 ` Adhemerval Zanella
2016-05-12 13:58 ` Wilco Dijkstra
2016-05-12 15:32   ` Marcus Shawcroft
  -- strict thread matches above, loose matches on Subject: below --
2015-09-25 13:24 Wilco Dijkstra
2015-07-31 15:02 Wilco Dijkstra
2015-08-11 12:23 ` Ondřej Bílka
2015-08-11 13:02   ` Wilco Dijkstra
2015-08-11 13:43     ` Ondřej Bílka
2015-09-25 14:55 ` Marcus Shawcroft
2015-09-30 12:58 ` Ondřej Bílka
2015-10-01 14:38   ` Wilco Dijkstra

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