Re: [PATCH] don't generate long nops on i686 (only when -march=[intel])

[Quentin Neill <quentin dot neill dot gnu at gmail dot com>]

On Tue, Jul 13, 2010 at 8:33 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Tue, Jul 13, 2010 at 5:59 AM, Kyle McMartin <kyle@mcmartin.ca> wrote:
>> From: Kyle McMartin <kyle@redhat.com>
>>
>> Hi,
>>
>> In Fedora, glibc started building itself with -march=i686 flags to
>> binutils as an "optimization." This exposes issues on the Geode, which
>> is i686, but for long nops, since they are apparently not an architected
>> part of the i686 ISA.
>>
>> Clarify this by only enabling long nops if we're generating 64-bit code
>> (as far as I can tell, all x86_64 cpus support this) or explicitly
>> generating code for the pentiumpro and above.
>>
>> Using this patch prevents people from overambitiously optimizing and
>> breaking the Geode.
>>
>> Signed-off-by: Kyle McMartin <kyle@redhat.com>
>
> There is no ChangeLog. Please add CpuNop to i386-opc.h and use it
> to determine when to generate nops.
>
> Thanks.

Kyle, I was working on a similar patch.  Here it is for previewing.

It has a ChangeLog entry but without test cases.  I will post with the
test cases as soon as I get a clean "make check" .

-- 
Quentin Neill

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