From: Albert ARIBAUD <albert.u.boot@aribaud.net>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH v2] arm: Switch to -mno-unaligned-access when supported by the compiler
Date: Mon, 10 Feb 2014 17:12:24 +0100 [thread overview]
Message-ID: <20140210171224.477e2906@lilith> (raw)
In-Reply-To: <yw1xeh3batjq.fsf@unicorn.mansr.com>
Hi M?ns,
On Mon, 10 Feb 2014 15:14:49 +0000, M?ns Rullg?rd <mans@mansr.com>
wrote:
> Albert ARIBAUD <albert.u.boot@aribaud.net> writes:
>
> > Hi Tom,
> >
> > On Mon, 10 Feb 2014 08:21:39 -0500, Tom Rini <trini@ti.com> wrote:
> >
> >> On Mon, Feb 10, 2014 at 10:24:47AM +0100, Albert ARIBAUD wrote:
> >> > Hi Tom,
> >> >
> >> > On Tue, 4 Feb 2014 12:05:33 -0500, Tom Rini <trini@ti.com> wrote:
> >> >
> >> > > When we tell the compiler to optimize for ARMv7 it assumes a default of
> >> > > unaligned accesses being supported at the hardware level and can make
> >> > > use of this to perform what it deems as an optimization in any case,
> >> > > including allowing for data to become unaligned. We explicitly disallow
> >> > > this hardware feature so we must tell the compiler.
> >> > >
> >> > > Cc: Albert ARIBAUD <albert.u.boot@aribaud.net>
> >> > > Cc: Mans Rullgard <mans@mansr.com>
> >> > > Signed-off-by: Tom Rini <trini@ti.com>
> >> >
> >> > NAK -- the discrepancy between the compiler being told to allow native
> >> > unaligned accesses while at the same time telling the hardware to trap
> >> > them is conscious and voluntary. It was chosen to help detect unaligned
> >> > accesses which are rarely necessary and can be explicitly performed by
> >> > software on a case by case basis.
> >> >
> >> > If and when a specific file requires unaligned access which cannot be
> >> > made by some other mean than enabling -mno-unaligned-access, then this
> >> > file should have it added, not the whole of U-Boot.
> >>
> >> Right, I recall the discussion, and we chose wrong.
> >
> > I am quite prepared to discuss whether we chose wrong or right, and
> > to change my mind when the conditions are right, but I'll need more than
> > such a short and simple statement. :)
>
> I already gave you a detailed explanation some months ago. You refused
> to read it.
I can hardly have "refused to read" a message which I *answered*, laid
out how I thought the issue should be solved... and got no answer after
this.
Now, are we going to discuss the technical issue or is this going to go
debian-TC -- which I wouldn't see the point of.
Amicalement,
--
Albert.
next prev parent reply other threads:[~2014-02-10 16:12 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-04 17:05 [U-Boot] [PATCH v2] arm: Switch to -mno-unaligned-access when supported by the compiler Tom Rini
2014-02-04 17:35 ` Måns Rullgård
2014-02-10 9:24 ` Albert ARIBAUD
2014-02-10 13:21 ` Tom Rini
2014-02-10 14:57 ` Albert ARIBAUD
2014-02-10 15:14 ` Måns Rullgård
2014-02-10 15:40 ` Måns Rullgård
2014-02-10 16:12 ` Albert ARIBAUD [this message]
2014-02-10 16:21 ` Måns Rullgård
2014-02-10 16:24 ` Tom Rini
2014-02-10 17:26 ` Albert ARIBAUD
2014-02-10 18:54 ` Wolfgang Denk
2014-02-10 21:26 ` Tom Rini
2014-02-10 22:17 ` Wolfgang Denk
2014-02-10 22:28 ` Tom Rini
2014-02-11 8:19 ` Wolfgang Denk
2014-02-11 12:37 ` Måns Rullgård
2014-02-11 14:43 ` Wolfgang Denk
2014-02-11 15:33 ` Måns Rullgård
2014-02-11 16:37 ` Albert ARIBAUD
2014-02-11 16:44 ` Måns Rullgård
2014-02-11 17:11 ` Albert ARIBAUD
2014-02-11 17:21 ` Albert ARIBAUD
2014-02-12 14:35 ` Tom Rini
2014-02-12 16:19 ` Albert ARIBAUD
2014-02-17 15:45 ` Tom Rini
2014-02-17 15:55 ` Albert ARIBAUD
2014-02-11 18:18 ` Wolfgang Denk
2014-02-11 18:21 ` Måns Rullgård
2014-02-11 8:44 ` Albert ARIBAUD
2014-02-12 14:25 ` Tom Rini
2014-02-12 15:51 ` Wolfgang Denk
2014-02-10 15:21 ` Tom Rini
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