[U-Boot] [PATCH] ARM: Add comments why -msoft-float is used.

[Wolfgang Denk <wd@denx.de>]

Dear Alexander Holler,

In message <4D60E16E.1060406@ahsoftware.de> you wrote:
>
> I don't know how other the compiler behaves for other architectures and 
> if those are having the need to save fp-contexts for irqs.

I thought I had explained this again in recent postings, not to
mention the times I did that before; you probably can find this in the
archives.

> # -msoft-float forces the compiler to avoid any fp-related instructions 
> for optimizations.
> 
> Would that be better?

No, not at all, because the only additional information about what
-msoft-float does (not using FP instructions) in the "for
optimizations" part - but that does not help much if you don;t have
the background we discussed here again.

So if you want to document this, then please provide a more complete
explanation about the reasons for using -msoft-float, summarizing the
recent discussion.

Keep in mind that it does not only apply to ARM Makefiles, but to all
other architectures as well. And instead of adding it to all ~30
affected files (which also gives no guarantee that it will be
documented in any newly created config.mk files), please add it to
some central doc file - either to the README, or feel free to create
a doc/README.toolchain or similar that can then also be used to
document things like linker options, information about known issues,
etc.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Remember, an int is not always 16 bits. I'm  not  sure,  but  if  the
80386  is one step closer to Intel's slugfest with the CPU curve that
is aymptotically approaching a real machine, perhaps an int has  been
implemented as 32 bits by some Unix vendors...?       - Derek Terveer