Christophe Leroy <[email protected]> writes:
> cpu-as-y is there to force assembler building options.
> But there is no need for that. Gcc is passed the necessary
> options and it automatically pass the appropriate option to
> GAS.
>
> GCC is given -maltivec when relevant, so no need
> for -Wa,-maltivec in addition
>
> And -Wa,-many is wrong as it will hide innapropriate
> instructions. Better to detect them and handle them on a
> case by case basis.
> -Wa,-many was added by commit 960e30029863 ("powerpc/Makefile:
> Fix PPC_BOOK3S_64 ASFLAGS") in order to fix an issue with
> clang and the passed -Wa,-mpower4 option. But we have now
> removed it expecting the compiler to automatically pass the
> proper options and instructions based on -mcpu=power4
I wanted to apply this one, but it caused a lot of breakage for big
endian Book3S-64 builds - where we build for power4 but have lots of
code that uses >= power5 instructions.
I'll try and get those all fixed and pick this up for the next merge
window.
cheers
Le 20/02/2023 à 07:00, Michael Ellerman a écrit :
> Christophe Leroy <[email protected]> writes:
>> cpu-as-y is there to force assembler building options.
>> But there is no need for that. Gcc is passed the necessary
>> options and it automatically pass the appropriate option to
>> GAS.
>>
>> GCC is given -maltivec when relevant, so no need
>> for -Wa,-maltivec in addition
>>
>> And -Wa,-many is wrong as it will hide innapropriate
>> instructions. Better to detect them and handle them on a
>> case by case basis.
>> -Wa,-many was added by commit 960e30029863 ("powerpc/Makefile:
>> Fix PPC_BOOK3S_64 ASFLAGS") in order to fix an issue with
>> clang and the passed -Wa,-mpower4 option. But we have now
>> removed it expecting the compiler to automatically pass the
>> proper options and instructions based on -mcpu=power4
>
> I wanted to apply this one, but it caused a lot of breakage for big
> endian Book3S-64 builds - where we build for power4 but have lots of
> code that uses >= power5 instructions.
>
> I'll try and get those all fixed and pick this up for the next merge
> window.
>
ping ?
Christophe Leroy <[email protected]> writes:
> Le 20/02/2023 à 07:00, Michael Ellerman a écrit :
>> Christophe Leroy <[email protected]> writes:
>>> cpu-as-y is there to force assembler building options.
>>> But there is no need for that. Gcc is passed the necessary
>>> options and it automatically pass the appropriate option to
>>> GAS.
>>>
>>> GCC is given -maltivec when relevant, so no need
>>> for -Wa,-maltivec in addition
>>>
>>> And -Wa,-many is wrong as it will hide innapropriate
>>> instructions. Better to detect them and handle them on a
>>> case by case basis.
>>> -Wa,-many was added by commit 960e30029863 ("powerpc/Makefile:
>>> Fix PPC_BOOK3S_64 ASFLAGS") in order to fix an issue with
>>> clang and the passed -Wa,-mpower4 option. But we have now
>>> removed it expecting the compiler to automatically pass the
>>> proper options and instructions based on -mcpu=power4
>>
>> I wanted to apply this one, but it caused a lot of breakage for big
>> endian Book3S-64 builds - where we build for power4 but have lots of
>> code that uses >= power5 instructions.
>>
>> I'll try and get those all fixed and pick this up for the next merge
>> window.
>
> ping ?
Brutal :)
There's still a few issues, I have patches for most of them I think.
Will post this week.
cheers