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

[Renato Golin via llvm-dev]

On 12 October 2016 at 17:09, Hal Finkel <hfinkel at anl.gov> wrote:
>> 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.

With -ffast-math, all bets are off, and it makes no sense to check
against good values, I agree.

But the benchmarking mode could be run with -ffast-math, and you'd
still want to make sure it works to some level. I mean, we run SPEC
with -ffast-math and it's not that bad, so it should be doable.

But from a test point of view, what sense does it make to run with
-ffast-math if you'll discard all "problematic" FP tests? Why run the
tests at all in that config if they're not meaningful?

I'm not against marking them off for fast-math, I'm just honestly
trying to understand what the point of it is... simply put: "what is
the meaning of saying all integer and some non-previously-failing FP
tests `pass` with -ffast-math"?

cheers,
--renato