[Pkg-opencl-devel] Bug#888062: pocl: FTBFS on arm64: test_fabs and test_shuffle_{char, ..., float} fail

[Punit Agrawal]

On Wed, Jan 31, 2018 at 12:46 AM, Andreas Beckmann <anbe at debian.org> wrote:
> On 2018-01-31 01:16, Punit Agrawal wrote:
>>>   7/121 Test  #22: kernel/test_shuffle_char ............................................................***Failed  Required regular expression found.Regex=[OK
>
>> The attached patch (on top of the package repository) fixes it for me.
>
> Thanks.
>
>> While investigating this failure, I noticed an unrelated issue with
>> the debian build for arm64 - instead of choosing a generic armv8 as
>> the target cpu, the rules file chooses to build with cortex-a53 (value
>> picked from debian/supported-arch). Just thought I'd mention it.
>
> Thanks. Do the shuffle tests still succeed for armv8?

All the tests (except for test_fabs) passed when LLVM_ARCH was set to
"generic" on arm64. I did this by modifying debian/supported_archs.

> It's damned hard to find the generic default -march= setting from llvm
> for each architecture - we have to set it explicitly for pocl, otherwise
> it will internally use the equivalent of -march=native.

I am not familiar with llvm configuration so could be misunderstanding
but I was just worried that choosing "cortex-a53" might assume
micro-architectural features that may not be present on other ARMv8
implementations. It's not so bad if the value is used as a hint to
choose optimised code sequences.

Punit