Re: [PATCH rs6000] Fix up BMI/BMI2 intrinsic DG tests

[Steven Munroe <munroesj at linux dot vnet dot ibm dot com>]

On Wed, 2017-07-19 at 12:45 -0500, Segher Boessenkool wrote:
> On Tue, Jul 18, 2017 at 05:10:42PM -0500, Steven Munroe wrote:
> > On Tue, 2017-07-18 at 16:54 -0500, Segher Boessenkool wrote:
> > > On Mon, Jul 17, 2017 at 01:28:20PM -0500, Steven Munroe wrote:
> > > > After a resent GCC change the previously submitted BMI/BMI2 intrinsic
> > > > test started to fail with the following warning/error.
> > > > 
> > > > ppc_cpu_supports_hw_available122373.c: In function 'main':
> > > > ppc_cpu_supports_hw_available122373.c:9:10: warning:
> > > > __builtin_cpu_supports need
> > > > s GLIBC (2.23 and newer) that exports hardware capability bits
> > > > 
> > > > The does not occur on systems with the newer (2.23) GLIBC but is common
> > > > on older (stable) distos.
> > > > 
> > > > As this is coming from the bmi-check.h and bmi2-check.h includes (and
> > > > not the tests directly) it seems simpler to simply skip the test unless
> > > > __BUILTIN_CPU_SUPPORTS__ is defined.
> > > 
> > > So this will skip on most current systems; is there no reasonable
> > > way around that?
> > > 
> > The work around would be to add an #else leg where we obtain the address
> > of the auxv then scan for the AT_PLATFOM, AT_HWCAP, and AT_HWCAP2
> > entries. Then perform the required string compares and / or bit tests.
> 
> Yeah let's not do that.  We'll just have to live with less test
> coverage by random testers, for now.  It's no different from any other
> new feature in that regard.
> 
So proceed with check in ?