This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [RFC PATCH, i386]: Remove special PIC related __cpuid definitions from config/i386/cpuid.h


On Thu, Oct 16, 2014 at 11:24 AM, Jakub Jelinek <jakub@redhat.com> wrote:

>> Now that %ebx is also allocatable in PIC modes, we can cleanup
>> config/i386/cpuid considerably. I propose to remove all PIC related
>> specializations of __cpuid and __cpuid_count and protect the
>> compilation with "#if __GNUC__ >= 5".
>>
>> The only drawback would be that non-bootstrapped build with gcc < 5.0
>> will ignore -march=native, but I think this should be acceptable.
>
> I'm worried about that.
> Can't you instead keep the current cpuid.h stuff as is, just add
> && __GNUC__ < 5
> to that, so it treats GCC 5+ PIC as if __PIC__ wasn't defined?
>
> Or, at least use cpuid.h even for older GCC if __PIC__ is not defined
> (or __x86_64__ is defined and not medium/large PIC model)?

Do we really care that much about non-bootstrapped build? I don't see
a compelling reason to keep these definitions, and by moving version
to 5.0, it seems like the right time to cut the questionable
compatibility stuff out.

Uros.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]