From: Phil Blundell <philb@gnu.org>
To: Khem Raj <raj.khem@gmail.com>
Cc: Koen Kooi <koen@dominion.thruhere.net>,
openembedded-core@lists.openembedded.org
Subject: Re: ARM-tuning -- was qemuarm: should it really have TUNE_ARCH armv5te?
Date: Tue, 11 Sep 2012 19:53:02 +0100 [thread overview]
Message-ID: <1347389582.29443.52.camel@x121e.pbcl.net> (raw)
In-Reply-To: <CAMKF1spX7cpvrb=zLOxi+qFaYhW2fpccOdFQ1-=-LVgv1gETKg@mail.gmail.com>
On Tue, 2012-09-11 at 11:40 -0700, Khem Raj wrote:
> On Tue, Sep 11, 2012 at 9:13 AM, Koen Kooi <koen@dominion.thruhere.net> wrote:
> > From a gcc point of view both are the same ISA, but using xscale will take in account the absurdly long pipeline on that SoC.
>
> Not really, when you tune for XScale it will use ldrd/strd and pld if possible
Are you sure? As far as I remember, the only effects of -mtune=xscale
are to alter some minor pipeline-related tradeoffs in code generation.
In particular, LDM is especially slow on xscale so it is usually best
avoided unless loading very large numbers of registers.
I can't think of any reason why pld would be any more beneficial on
xscale than generic v5TE, and I don't think gcc does anything special
with it in that regard.
p.
next prev parent reply other threads:[~2012-09-11 19:07 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-11 13:01 qemuarm: should it really have TUNE_ARCH armv5te? Martin Jansa
2012-09-11 13:48 ` Martin Jansa
2012-09-11 15:51 ` ARM-tuning -- was " Mark Hatle
2012-09-11 15:59 ` Martin Jansa
2012-09-11 16:09 ` Mark Hatle
2012-09-11 16:22 ` Martin Jansa
2012-09-11 16:13 ` Koen Kooi
2012-09-11 18:40 ` Khem Raj
2012-09-11 18:53 ` Phil Blundell [this message]
2012-09-11 19:58 ` Khem Raj
2012-09-11 16:46 ` Phil Blundell
2012-09-11 16:53 ` Martin Jansa
2012-09-11 17:14 ` Phil Blundell
2012-09-11 17:21 ` Martin Jansa
2012-09-11 17:35 ` Martin Jansa
2012-09-11 17:37 ` Phil Blundell
2012-09-11 17:43 ` Martin Jansa
2012-09-11 18:00 ` Mark Hatle
2012-09-12 14:33 ` Richard Purdie
2012-09-13 6:20 ` Martin Jansa
2012-09-13 10:42 ` Richard Purdie
2012-09-13 12:14 ` Martin Jansa
2012-09-13 12:58 ` Richard Purdie
2012-09-15 7:01 ` Martin Jansa
2012-09-21 15:52 ` Martin Jansa
2012-09-22 11:48 ` Richard Purdie
2012-09-13 16:47 ` Mark Hatle
2012-09-13 17:02 ` Phil Blundell
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