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From: Ravi Kerur <rkerur@gmail.com>
To: Stephen Hemminger <stephen@networkplumber.org>
Cc: "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH] Clean up rte_memcpy.h file
Date: Wed, 15 Apr 2015 14:04:58 -0700	[thread overview]
Message-ID: <CAFb4SLBO0=mxDDTnR=vk3Vp+1J+h8QcOJ_PbVdH58CYWDT6aKw@mail.gmail.com> (raw)
In-Reply-To: <20150414195348.7fe30c3f@urahara>

On Tue, Apr 14, 2015 at 7:53 PM, Stephen Hemminger <
stephen@networkplumber.org> wrote:

> On Tue, 14 Apr 2015 14:31:53 -0700
> Ravi Kerur <rkerur@gmail.com> wrote:
>
> > +
> > +     for (i = 0; i < 2; i++)
> > +             rte_mov32(dst + i * 32, src + i * 32);
> >  }
> Unless you force compiler to unroll the loop, it will be slower.
>

I had done following things

1. Use sample code from Intel to make sure CPU supports those instructions.
2. Check generated code with and without loop using (gcc -O3 -m64 -S), gcc
version is 4.8.2
No difference in code generated between "loop" and "no-loop". At least I
was expecting difference in the code.

3. Run "make test" and compare "memcpy perf" results.

  reply	other threads:[~2015-04-15 21:04 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-14 21:30 [dpdk-dev] [PATCH] Cleanup rte_memcpy.h Ravi Kerur
2015-04-14 21:31 ` [dpdk-dev] [PATCH] Clean up rte_memcpy.h file Ravi Kerur
2015-04-15  2:53   ` Stephen Hemminger
2015-04-15 21:04     ` Ravi Kerur [this message]
2015-04-15  6:32   ` Pawel Wodkowski
2015-04-15 21:00     ` Ravi Kerur

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