From: "Eric Bénard" <eric@eukrea.com>
To: openembedded-devel@lists.openembedded.org
Subject: Re: [PATCH/RFC] qt4-embedded: tune QT_ARCH for armv6
Date: Thu, 04 Nov 2010 20:14:04 +0100 [thread overview]
Message-ID: <4CD305FC.7070305@eukrea.com> (raw)
In-Reply-To: <4CD2FAF0.4080905@freyther.de>
Hi,
Le 04/11/2010 19:26, Holger Freyther a écrit :
> On 11/04/2010 10:52 AM, Eric Bénard wrote:
>> this is a RFC, I think it can also be used on qt 4.6.x and on armv7.
>> Setting QT_ARCH to armv6 enable some asm optimized functions in QT.
>
> Do you know the consequences of this change? E.g. in the painting
> engine unaligned memory access will be allowed. I am not sure that Nokia has
> ever benchmarked what is faster (aligned/unaligned) access. So it would be
> very interesting to know the perf difference. E.g. use qttracereply to measure it.
>
> Phil do you happen to know why unaligned access got allowed starting from
> armv6? How fast will it be?
>
in the painting engine, from what I saw in the .h, the asm optimisations are
only enabled when using ARM RCVT compiler and not when using gcc but I have
not checked everywhere in the code so I'm not sure of this.
Eric
next prev parent reply other threads:[~2010-11-04 19:14 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-04 9:52 [PATCH/RFC] qt4-embedded: tune QT_ARCH for armv6 Eric Bénard
2010-11-04 18:05 ` Khem Raj
2010-11-04 18:26 ` Holger Freyther
2010-11-04 19:14 ` Eric Bénard [this message]
2010-11-05 9:32 ` Holger Freyther
2010-11-05 9:42 ` Eric Bénard
2010-11-05 10:21 ` Holger Freyther
2010-11-05 10:41 ` Eric Bénard
2010-11-07 19:42 ` Eric Bénard
2010-11-04 20:27 ` Khem Raj
2010-11-04 21:05 ` Koen Kooi
2010-11-05 11:21 ` Phil Blundell
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