[llvm-dev] Matthias` suggestion for "test-suite" tests that are broken at "-Ofast" and are difficult to "repair"

[Hal Finkel via llvm-dev]

----- Original Message -----
> From: "Abe Skolnik" <a.skolnik at samsung.com>
> To: "Matthias Braun" <mbraun at apple.com>
> Cc: "Hal Finkel" <hfinkel at anl.gov>, "Renato Golin" <renato.golin at linaro.org>, "llvm-dev" <llvm-dev at lists.llvm.org>
> Sent: Wednesday, October 12, 2016 11:00:39 AM
> Subject: Matthias` suggestion for "test-suite" tests that are broken at "-Ofast" and are difficult to "repair"
> 
> On 10/11/2016 at 4:15 PM, Matthias Braun wrote:
> 
> > I don't find it surprising that some applications do not work
> > properly with -ffast-math and I think we
> > have to accept that fact.  I think it is valid to skip those tests
> > in the test-suite when a fast math
> > flag combination is used (after making sure there is no easy way to
> > make the test more robust).
> 
> > I would add a "TEST_SUITE_FAST_MATH" variable in the cmake build
> > (possibly scanning CFLAGS for -ffast-math/-Ofast
> >  to determine the default value) and then adding if(NOT
> >  TEST_SUITE_FAST_MATH) ... endif()
> around the benchmark.
> 
> 
> 
> I accept Matthias` proposal, and I propose that the above be used for
> wherever "really fixing"
> the FP problems with a test is beyond a reasonable effort+time level.
>  This email is to check
> acceptance [or lack thereof] of the above.

This makes sense to me. I think we should set this up so that the tests are enabled by default, and then we specifically disable those tests for which we've determined that is the best practical solution.

 -Hal

>
> Regards,
> 
> Abe
> 

-- 
Hal Finkel
Lead, Compiler Technology and Programming Languages
Leadership Computing Facility
Argonne National Laboratory