Re: [rfc] nopl should not be output on -mtune=i686

[Jan Kratochvil <jan dot kratochvil at redhat dot com>]

On Tue, 08 Feb 2011 18:23:35 +0100, H.J. Lu wrote:
> On Tue, Feb 8, 2011 at 9:10 AM, Jan Kratochvil
> <jan.kratochvil@redhat.com> wrote:
> > Current binutils HEAD:
> > -march | -mtune Â| nopl used? Â| after the attached patch: nopl used?
> > Â-  Â|  -   |  Âno    | no
> > Âi686 Â| -/i686 Â|  Âno    | no
> > Â- Â Â| Â i686 Â| Â yes = BUG | no
> > Âcore2 | -/core2 |  yes    | yes
> > Â- Â Â| Â core2 | Â yes = BUG | no
> >
> > => Currently suppressing -march now produces more advanced code output, this
> > Â does not seem correct to me.
> 
> By default, x86 assembler assumes that the target processor accepts
> any instructions.  You can restrict ISA sets by -march and .arch directive.

Aha, in such case the system build should use some specific -march anyway and
not just to disable `nopl'.

Andreas Schwab has reopened now this one, it should be NOTABUG:
http://sourceware.org/bugzilla/show_bug.cgi?id=6957


> > The flag `+nop' (such as `-march=i686+nop') does not work for me as expected
> > with HEAD and neither works with the patched code.
> 
> Please file a bug report.

I see your fix, thanks.


Thanks,
Jan