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Re: [PATCH,i386] cpuid function for prefetchw


On Mon, Aug 13, 2012 at 2:10 PM, Jakub Jelinek <jakub@redhat.com> wrote:

>> > To get the prefetchw cpuid flag, cpuid
>> > function 0x80000001 needs to be called.
>> > Previous to patch, function 0x7 is called.
>> >
>> > Bootstrapping and "make -k check" passes without failures.
>> > Ok for trunk?
>>
>> IMHO you move it to a wrong spot, ecx bits of CPUID 0x80000001 are tested
>> earlier.
>>
>> So I think you want this instead (bootstrap/regtest in progress):
>>
>> 2012-08-13  Ganesh Gopalasubramanian  <Ganesh.Gopalasubramanian@amd.com>
>>           Jakub Jelinek  <jakub@redhat.com>
>>
>>       PR driver/54210
>>       * config/i386/driver-i386.c (host_detect_local_cpu): Test bit_PRFCHW
>>       bit of CPUID 0x80000001 %ecx instead of CPUID 7 %ecx.
>>       * config/i386/cpuid.h (bits_PRFCHW): Move definition to CPUID
>>       0x80000001 %ecx flags.
>
> Now bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

OK, but I didn't find PRFCHW in the cpuid documentation to confirm the change.

Thanks,
Uros.


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