[LLVMdev] Adding support for explicitly specified TLS models (PR9788)

[Hans Wennborg]

On Thu, Apr 26, 2012 at 01:10, Joerg Sonnenberger
<joerg at britannica.bec.de> wrote:
>> > For ELF, it doesn't make sense to reject one as it can always be
>> > relaxed. An application program shouldn't have to worry about that, it
>> > is just an implementation detail.
>>
>> I'd be fine with that.
>>
>> (Clang should still worry about it though, so it can provide a "the
>> TLS model you selected is not supported by the target, it will fall
>> back to another one" warning.)
>
> There is no point in warning about it. Basically, anything but global
> dynamic a pure performance optimisation.

It was pointed out in #llvm that programs that mix C and assembly to
access thread-local variables would break if the TLS model isn't what
they specify, so I still think there's a case for warning about it.

 - Hans