From: "Dr. Philipp Tomsich" <philipp.tomsich@theobroma-systems.com>
To: James Greenhalgh <james.greenhalgh@arm.com>
Cc: GCC Patches <gcc-patches@gcc.gnu.org>,
nd@arm.com, Marcus Shawcroft <marcus.shawcroft@arm.com>,
richard.earnshaw@arm.com, "Kumar,
Venkataramanan" <Venkataramanan.Kumar@amd.com>,
Andrew Pinski <pinskia@gmail.com>,
Kyrylo.Tkachov@arm.com, Evandro Menezes <e.menezes@samsung.com>,
Benedikt Huber <benedikt.huber@theobroma-systems.com>
Subject: Re: [AArch64] Remove AARCH64_EXTRA_TUNE_RECIP_SQRT from Cortex-A57 tuning
Date: Mon, 11 Jan 2016 13:31:00 -0000 [thread overview]
Message-ID: <14364F53-691F-463E-9AA2-2EAF0C4EAB55@theobroma-systems.com> (raw)
In-Reply-To: <1452513883-25826-1-git-send-email-james.greenhalgh@arm.com>
James,
ok from our side—good to see that this also benefits the A57.
Best,
Philipp.
> On 11 Jan 2016, at 13:04, James Greenhalgh <james.greenhalgh@arm.com> wrote:
>
>
> Hi,
>
> I've seen a couple of large performance issues caused by expanding
> the high-precision reciprocal square root for Cortex-A57, so I'd like
> to turn it off by default.
>
> This is good for art (~2%) from Spec2000, bad (~3.5%) for fma3d from
> Spec2000, good (~5.5%) for gromcas from Spec2006, and very good (>10%) for
> some private microbenchmark kernels which stress the divide/sqrt/multiply
> units. It therefore seems to me to be the correct choice to make across
> a number of workloads.
>
> Bootstrapped and tested on aarch64-none-linux-gnu with no issues.
>
> OK?
>
> Thanks,
> James
>
> ---
> 2015-12-11 James Greenhalgh <james.greenhalgh@arm.com>
>
> * config/aarch64/aarch64.c (cortexa57_tunings): Remove
> AARCH64_EXTRA_TUNE_RECIP_SQRT.
>
> <0001-AArch64-Remove-AARCH64_EXTRA_TUNE_RECIP_SQRT-from-Co.patch>
next prev parent reply other threads:[~2016-01-11 13:31 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-11 11:53 [Patch AArch64] Use software sqrt expansion always for -mlow-precision-recip-sqrt James Greenhalgh
2016-01-11 12:05 ` [AArch64] Remove AARCH64_EXTRA_TUNE_RECIP_SQRT from Cortex-A57 tuning James Greenhalgh
2016-01-11 13:31 ` Dr. Philipp Tomsich [this message]
2016-01-25 11:20 ` James Greenhalgh
2016-02-01 14:00 ` James Greenhalgh
2016-02-08 10:57 ` James Greenhalgh
2016-02-15 10:50 ` James Greenhalgh
2016-02-15 17:25 ` Evandro Menezes
2016-02-16 10:28 ` James Greenhalgh
2016-02-16 20:46 ` Evandro Menezes
2016-02-16 8:49 ` Marcus Shawcroft
2016-01-11 22:58 ` [Patch AArch64] Use software sqrt expansion always for -mlow-precision-recip-sqrt Evandro Menezes
2016-01-12 11:32 ` James Greenhalgh
2016-01-12 11:44 ` Kyrill Tkachov
2016-01-12 5:53 ` Kumar, Venkataramanan
2016-01-12 11:48 ` James Greenhalgh
2016-01-25 11:21 ` James Greenhalgh
2016-02-01 13:59 ` James Greenhalgh
2016-02-08 10:57 ` James Greenhalgh
2016-02-15 10:48 ` James Greenhalgh
2016-02-16 8:40 ` Marcus Shawcroft
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