[PATCH] D48580: [AArch64] Support reserving x1-7 registers.

[James Y Knight via Phabricator via llvm-commits]

jyknight added a comment.

In https://reviews.llvm.org/D48580#1168490, @jyknight wrote:

> In https://reviews.llvm.org/D48580#1168470, @manojgupta wrote:
>
> > @efriedma  Maybe not relevant to the patch here but our kernel devs were looking into preserve_all but it does not seem to work for AArch64.
> >
> > $ cat test.c 
> >  void __attribute__((preserve_all)) foo(void *ptr) { }
> >
> > $ clang -c test.c -> compiles for x86_64
> >  $ clang -c -target aarch64-unknown-linux-gnu
> >
> > fatal error: error in backend: Unsupported calling convention.
>
>
> What clang version is that? Works fine for me.


Ugh, nevermind -- I take that back. *Old* clang didn't complain about it, new clang does. Haven't checked, maybe it was ignoring it before or something. :(

Anyhow, IMO, we should make that work, and not do this.


Repository:
  rL LLVM

https://reviews.llvm.org/D48580