[ARM] Fix, add tests for FP16 aapcs.

[Matthew Wahab]

On 10/06/16 15:22, Christophe Lyon wrote:
> On 10 June 2016 at 15:56, Matthew Wahab <matthew.wahab@foss.arm.com> wrote:
>> On 10/06/16 09:32, Christophe Lyon wrote:
>>>
>>> On 9 June 2016 at 17:21, Matthew Wahab <matthew.wahab@foss.arm.com> wrote:
>>>>
>>> It's an improvement, but I'm still seeing a few problems with this patch:
>>> the vfp* tests are still failing in some of the configurations I test,
>>> because
>>> * you force dg-options that contains -mfloat-abi=hard,
>>> * you check effective-target arm_neon_fp16_hw
>>> * but you don't call dg-add-options arm_neon_fp16
>>>
>>
>> I'm not sure why the skip-if is failing, it's intended to skip the test if
>> float-abi={soft,softfp} appears anywhere in the command line. That's needed
>> because, in some configurations, the directives add an -mfloat-abi=softfp
>> after the -mfloat-abi=hard from dg-options, making the test fail.
>>
>> The require-effective-target arm_neon_fp16_hw was intended to select a
>> hard-float target with FP16 support. I don't think that dg-add-options
>> arm_neon_fp16 is right because that could also force soft-fp.
>>
> I'm seeing arm_neon_fp16_hw test passing with -mfpu=neon-fp16 -mfloat-abi=softfp
> but since you don't call dg-add-options arm_neon_fp16, the dg-skip directive
> sees only the -mfloat-abi-hard which comes from dg-options.
> The test fails to link for me with -mfpu=vfp -mfloat-abi=hard -mfp16-format=ieee
> according to my gcc.log
>

I understand now. I still think it would be better to use a list of 
require-effective-targets so I'll try that first and use the arm_neon_fp16 
options if that doesn't work.

Thanks,
Matthew