[PATCH] D11815: Pass subtarget feature "force-align-stack"

[Akira Hatanaka via cfe-commits]

ahatanak added a comment.

In http://reviews.llvm.org/D11815#238209, @vkalintiris wrote:

> In http://reviews.llvm.org/D11815#237541, @ahatanak wrote:
>
> > In http://reviews.llvm.org/D11815#236368, @vkalintiris wrote:
> >
> > > In http://reviews.llvm.org/D11815#235394, @ahatanak wrote:
> > >
> > > >
> > >
> >
> >
> > The purpose of this patch is to make sure -mstackrealign works when doing LTO
>
>
> Out of curiosity, I was wondering why dynamic stack realignment isn't enough for LTO. I would guess that the alignment of the data types used under SSE might have a smaller alignment than the one required by the ABI.


I'm not sure if I understood your question, but if you are asking why -mstackrealign doesn't work when doing LTO, the reason is much simpler. In order to force stack realignment in the backend, ForceStackAlign has to be set to true, but that doesn't happen because -force-align-stack isn't passed to libLTO (or passed as a plugin option if gold is being used).


http://reviews.llvm.org/D11815