Date: Thu, 21 Apr 2016 22:34:15 +0200
From: Ralf Baechle <ralf@linux-mips.org>
To: "Maciej W. Rozycki" <macro@imgtec.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>, kbuild-all@01.org,
        Paul Burton <paul.burton@imgtec.com>, linux-kernel@vger.kernel.org,
        Philip Li <philip.li@intel.com>
Subject: Re: [kbuild-all] mipsel-linux-gnu-gcc: error: unrecognized command
 line option '-mcompact-branches=optimal'
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 <20160421045129.GB4038@wfg-t540p.sh.intel.com>
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On Thu, Apr 21, 2016 at 08:55:34PM +0100, Maciej W. Rozycki wrote:

> > % mips-linux-gnu-gcc --version
> > mips-linux-gnu-gcc (Debian 5.2.1-16) 5.2.1 20150903
> > Copyright (C) 2015 Free Software Foundation, Inc.
> > 
> > How about temporarily disable that error, until we upgrade to a new
> > gcc version which supports the -mcompact-branches option?
> 
>  I don't think it makes sense as the compiler won't support MIPSr6 code 
> anyway, so first it'll bail out on `-march=mips32r6', and if we go even 
> further and disable that too, then GAS will probably break somewhere on 
> inline asm and GCC will produce code which does not make sense otherwise.

GCC 5.2.0 claims to support mips32r6 and mips64r6.  It's just the option
-mcompact-branches which seem to have been added later only.

  Ralf