[llvm-dev] LLVM mtriple for aarch64-win32-msvc ?

[Saleem Abdulrasool via llvm-dev]

Yeah, Windows 10 is a pure thumb2 environment.  Although it is possible to
execute ARM mode code, any context switch into kernel space can cause
problems (they do not guarantee that you will be in ARM mode when you come
back).  For that reason, we simply force everything is generated in thumb
mode only.  When using clang, we allow the user to specify
`armv7-unknown-windows-msvc` as the triple and map that to
`thumbv7-unknown-windows-msvc`.

On Sat, Sep 16, 2017 at 8:36 AM, Tim Northover via llvm-dev <
llvm-dev at lists.llvm.org> wrote:

> On 16 September 2017 at 04:00, Chris Lovett via llvm-dev
> <llvm-dev at lists.llvm.org> wrote:
> > So using armv7-win32-msvc  is getting me a bit closer, but what CPU,
> > raspberry pi 3 is running a Cortext-A53, but when I specify that in -mcpu
> > argument I get this error:
> >
> >> llc.exe test.bc -o test.obj -filetype=obj -O3 -mtriple=armv7-win32-msvc
> >> -mcpu=cortex-a53 -relocation-model=pic
> >> llc.exe failed: LLVM ERROR: CPU: 'cortex-a53' does not support ARM mode
> >> execution!
>
> I think I remember from discussions with Saleem that Windows only
> supports code running in Thumb mode, so using "thumbv7" at the start
> of the triple is probably a lot more likely to work.
>
> That said, I have no idea why it's complaining about the Cortex-A53
> CPU, that definitely supports ARM mode. It put it down to gremlins
> producing random, non-helpful messages.
>
> Cheers.
>
> Tim.
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>



-- 
Saleem Abdulrasool
compnerd (at) compnerd (dot) org
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20170916/f1dfce3e/attachment.html>