[LLVMdev] [PowerPC] ABI questions

[Ulrich Weigand]

Jonas Maebe <jonas.maebe at elis.ugent.be> wrote on 01.08.2014 15:19:29:

> There's one small difference between the two: with the 64 bit ELFv1/
> SVR4 ABI, tail padding for structs passed by value is only performed
> in case the struct is larger than 8 bytes, while for AIX 64 bit it's
> always done. As an aside, on Darwin/ppc64 it's done if the
> aggregate's size is not in [1,2,4].

Ah, right, that's still a special case on AIX.

> For an example, look at the assembly code for the program below. I
> don't have the setup to compile for Linux/AIX PPC64 with clang, so I
> don't know what LLVM does right now (I performed the tests with gcc).

Well, LLVM follows the Linux variant.  I don't think we really
support AIX in LLVM anyway at this point ...

Bye,
Ulrich