Subject: Re: [PATCH 1/2] powerpc/math-emu: remove the dead code in math.c

From: Benjamin Herrenschmidt <[email-masked]>
Date: Wed, 10 Jul 2013 13:48:08 +1000

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.