Re: [PATCH v2] Aarch64: Add simd exp/expf functions

[Florian Weimer <fweimer at redhat dot com>]

* Szabolcs Nagy:

> On 21/06/2019 11:53, Florian Weimer wrote:
>> * Szabolcs Nagy:
>> 
>>> On 23/05/2019 11:53, Szabolcs Nagy wrote:
>>>> (1) it is not obvious that we can enable libmvec in glibc
>>>> without a toolchain that follows the new ELF abi.
>>>
>>> i was thinking about this and i believe we can add
>>> libmvec abi without toolchain support (e.g. dummy
>>> asm implementation that falls back to scalar code).
>> 
>> To be clear, it's not a dummy implementation, but one with assembler
>> trampolines which adjust the calling convention?
>> 
>> So it will be fully functional, just rather slow?
>
> yes, it's fully functional and call abi conform.
>
> i call it dummy because i would not add vector
> code, just fall back to scalar calls in the asm.
>
> i guess the asm could be a trampoline that calls
> vector c code following the base call convention,
> but we don't have reasonable vector c code yet.
>
> either way we can have abi symbols that follow
> the right call convention using asm with an old
> compiler.

That still sounds reasonable to me. 8-)

Thanks,
Florian