On 2021/5/13 7:00, Honnappa Nagarahalli wrote:
> <snip>
>
>>
>> On Wed, May 12, 2021 at 2:01 PM Chengwen Feng
>> <fengcheng...@huawei.com> wrote:
>>>
>>> Currently, the soc_kunpeng930 declares '-march=armv8.2-a+crypto+sve',
>>> but some compiler doesn't recognize the march because it doesn't
>>> support sve.
>>
>> Agree with the problem statement.
>>
>> + @Juraj Linkeš
>>
>>>
>>> This patch adds '-march=armv8.2-a+crypto' before
>>> '-march=armv8.2-a+crypto+sve' so that:
>>> 1. If compiler doesn't support '-march=armv8.2-a+crypto+sve', then it
>>> will fallback supports 'armv8.2-a+crypto'.
>>> 2. If compiler supports '-march=armv8.2-a+crypto+sve', then it will
>>> compile SVE-related code.
>>>
>>> Fixes: 7cf32a22b240 ("config/arm: add Hisilicon kunpeng")
>>>
>>> Signed-off-by: Chengwen Feng <fengcheng...@huawei.com>
>>> ---
>>> config/arm/meson.build | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/config/arm/meson.build b/config/arm/meson.build index
>>> 3f34ec9..fe6c29b 100644
>>> --- a/config/arm/meson.build
>>> +++ b/config/arm/meson.build
>>> @@ -158,7 +158,7 @@ implementer_hisilicon = {
>>> ]
>>> },
>>> '0xd02': {
>>> - 'machine_args': ['-march=armv8.2-a+crypto+sve'],
>>> + 'machine_args': ['-march=armv8.2-a+crypto',
>>> + '-march=armv8.2-a+crypto+sve'],
>>
>> I think, this problem not specific to Kunpeng. I think, in order to have a
>> generic
>> solution, I think, we need to express something like [[armv8.2-a], [crypto],
>> [sve]] or so in the code and any infra code can generate a working
>> combination to avoid duplicating the combination manually in code and have
>> some generic solution for all the platforms.
> I think this approach will be too generic. We have to start with v8.0 (as the
> compiler might not support v8.2-a) and list every feature and check if all
> those features are supported in the compiler. It might be required that some
> features might not perform well in certain applications which requires for
> disabling the features.
>
> I think tweaks like this should be left to the end user.
>
Agree
Fixed in v2 (separate -march='armv8.2-a+crypto+sve' to two tuples, namely:
march_base and march_feature), thanks
>>
>> i.e
>> patch 1: Enable the infrastructure for auto probe based on compiler support.
>> patch 2: Fix existing machines including the Kunpeng.
>>
>>
>>> 'flags': [
>>> ['RTE_MACHINE', '"Kunpeng 930"'],
>>> ['RTE_ARM_FEATURE_ATOMICS', true],
>>> --
>>> 2.8.1
>>>
