time stamp counter in "make check"

[Carlos O'Donell]

On 7/12/2012 10:58 AM, Dmitrieva Liubov wrote:
> So, my proposal is to change from "rdtsc" instruction to "rdtscp"
> instruction (which is a serializing variant of the RDTSC)  if rdtscp
> is available for target architecture.
> This definitely solves the issue with negatives values.

I see no problem in replacing rdtsc with rdtscp if the target machine
has support for rdtscp.

Note:
I never liked that ./sysdeps/i386/i686/hp-timing.h didn't use CPUID
as a barrier, since IMO it would seem to violate some of the constraints
of the interfaces that are built upon hp-timing.h. I would be happy
to see this changed to use rdtscp or cpuid. Though this is a distinct
patch from what your suggesting.

Cheers,
Carlos.
-- 
Carlos O'Donell
Mentor Graphics / CodeSourcery
carlos_odonell@mentor.com
carlos@codesourcery.com
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