ArrayFunctionsTest::testDubiousArrayFormulasFODS fails on ppc64le (and s390x)

[Stephan Bergmann]

On 9/1/23 15:41, Dan Horák wrote:
> On Fri, 1 Sep 2023 11:29:23 +0200
> Stephan Bergmann <sbergman at redhat.com> wrote:
[...]
>> would be that the TODO comment makes it then sound like the issues on
>> ppc64le and s390x are also known to be due to -ffp-contract settings,
>> even if you would not verify that.
> 
> I have verified it's indeed caused by -ffp-contract. When set to "off",
> the test passes (checked on ppc64le).

Good to know.  Please add that knowledge to the commit message.

>> So maybe the best thing is to turn this into a x86_64 only conditional,
>> and extend the TODO comment with something like "...on at least aarch64,
>> so lets only execute this on x86-64, where it appears to always work well:"
> 
> yeah, I think using a "positive" list would be better. I could
> possibly prepare a patch, but is there an example where I can see how
> the condition should look like?

For better or worse, we pass or configure.ac's "compiler independent" 
CPUNAME into the compiler via -D$(CPUNAME) (solenv/gbuild/gbuild.mk), so 
something like

> #if defined X86_64

should work for a positive list of just x86_64, regardless of compiler 
(MSVC vs. Clang/GCC).