Re: [PATCH] powerpc:GCC(<10) doesn't allow -mlong-double-64 after -mabi=ieeelongdouble

[MAHESH BODAPATI <bmahi496@linux.ibm.com>]

On 16/05/23 12:56 am, Florian Weimer wrote:
> * MAHESH BODAPATI:
>
>> On 15/05/23 6:39 pm, Florian Weimer wrote:
>>> * MAHESH BODAPATI via Libc-alpha:
>>>
>>>> From: Mahesh Bodapati <mahesh.bodapati@ibm.com>
>>>>
>>>> Removed -mabi=ieeelongdouble on failing tests. It resolves the error.
>>>> error: ‘-mabi=ieeelongdouble’ requires ‘-mlong-double-128’
>>> I think this is only need if GCC defaults to -mabi=ieeelongdouble, and
>>> GCC 10 is not ready for that for different reasons?
>> Yes,these tests are under "sysdeps/ieee754/ldbl-opt" and ieee754
>> defaults to -mabi=ieeelongdouble and the
>>
>> CFLAGS were appended with -mlong-double-64 in commit
>> dee2bea048b688b643a9a ,but powerpc gcc (<10)
>>
>> doesn't support mabi=ieeelongdouble with -mlong-double-64.the support
>> has been addedin gcc 12.1 and
>>
>> it has been back-ported till gcc 10 so we are filtering out the
>> -mabi=ieelongdouble to make it work
> I think if you backport this stuff to GCC 10, you should also pick up
> the commit that fixed GCC.  I believe its commit cb16bc3b5f34733ef9bb
> ("rs6000: Allow -mlong-double-64 after -mabi={ibm,ieee}longdouble
> [PR104208, P R87496]").

Yes,that's the commit. we planned to switch the flags with respect to 
GCC version but I don't see a existing mechanism for switching the 
CFLAGS based on the target and GCC version so

we are filtering out the flag "-mabi=ieeelongdouble" to make it work on 
all the PowerPC GCC versions.

>
> Thanks,
> Florian
>