[LLVMdev] RFC: Tail call optimization X86

[Arnold Schwaighofer]

On 5 Oct 2007, at 20:00, Dale Johannesen wrote:

>>> I am not to sure on that. because that would make modules compiled
>>> with the flag on incompatible with ones compiled without the flag  
>>> off
>>> as stack behaviour would mismatch.
>>> It would be no problem to make the behaviour dependent on the -tail-
>>> call-opt flag. i am not sure that this is a good idea?
>>
>> In theory, any function can be marked fastcc. But llvm-gcc c / c++
>> frontend does *not* mark any external functions fastcc.
>
> The user can specify the "fastcall" and "stdcall" attributes, and it
> looks
> to me like llvm-gcc honors that.  Certainly it should.

This would imply one fastcc abi (callee pops args on return) to rule  
them all?
That is only if fastcall translates to llvm fastcc  of course.

regards