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From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Michael Ellerman <michael@ellerman.id.au>
Cc: linuxppc <linuxppc-dev@lists.ozlabs.org>, Kevin Hao <haokexin@gmail.com>
Subject: Re: [PATCH 1/2] powerpc/math-emu: remove the dead code in math.c
Date: Wed, 10 Jul 2013 13:48:08 +1000	[thread overview]
Message-ID: <1373428088.16720.8.camel@pasglop> (raw)
In-Reply-To: <20130710032533.GA10374@concordia>

On Wed, 2013-07-10 at 13:25 +1000, Michael Ellerman wrote:
> > > Any idea why we have that there? ie. have the config symbols changed
> > > over time or was this always dead code?
> > 
> > No idea. I tried to trace this before submitting the patch. But it has
> > been there since the begin of the git history. So I just assume that it is
> > always dead code. :-)
> 
> Yeah looks like it. Even in the git-huge tree I see it in the initial
> commit.
> 
> You should say that in the commit message though. Otherwise it's not
> clear if you're fixing a recent breakage or not.

This is ancient code that was meant to emulate only load/stores/fmr without
the rest of the emulation. The goal was to be able to boot userspace that
was compiled without -msoft-float to *some* extent (bcs it would potentially
use fp load/stores for things like memcpy) on small CPUs where the kernel
footprint was critical.

It's been obsolete for a while now.

Cheers,
Ben.

  parent reply	other threads:[~2013-07-10  3:49 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-07-10  1:43 [PATCH 0/2] powerpc/math-emu: two minor cleanup patches for math.c Kevin Hao
2013-07-10  1:43 ` [PATCH 1/2] powerpc/math-emu: remove the dead code in math.c Kevin Hao
2013-07-10  2:01   ` Michael Ellerman
2013-07-10  2:23     ` Kevin Hao
2013-07-10  3:25       ` Michael Ellerman
2013-07-10  3:46         ` Kevin Hao
2013-07-10  3:48         ` Benjamin Herrenschmidt [this message]
2013-07-10  1:43 ` [PATCH 2/2] powerpc/math-emu: remove the unneeded check for CONFIG_MATH_EMULATION " Kevin Hao

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