[cfe-dev] [RFC][ARM] -Oz implies -mthumb

[Bruce Hoult via cfe-dev]

I've never tried -mcpu=cortex-xyz but I know -march=armv7 defaults to Thumb

OK, I just checked, and -mcpu=cortex-{m3,m4,m7,a7,a9,a15,a53} gives Thumb
at -O1, -O1, -Os on the following gcc:

arm-linux-gnueabihf-gcc (Ubuntu/Linaro 7.3.0-27ubuntu1~18.04) 7.3.0

cortex-m0 fails because it doesn't do hard float. I don't have an eabi
compiler around.


On Thu, Nov 15, 2018 at 4:14 AM, Tim Northover via cfe-dev <
cfe-dev at lists.llvm.org> wrote:

> Hi Sjoerd,
>
> On Thu, 15 Nov 2018 at 11:49, Sjoerd Meijer via cfe-dev
> <cfe-dev at lists.llvm.org> wrote:
> > does not really give minimum code size because -mthumb is not enabled.
> This looks like a sub-optimal user experience to me, and also, it is
> inconsistent with GCC's behaviour.
>
> Which version? None of the GCCs on Godbolt exhibit the kind of
> switching you're describing as far as I can tell.
>
> Cheers.
>
> Tim.
> _______________________________________________
> cfe-dev mailing list
> cfe-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/cfe-dev/attachments/20181115/17708337/attachment.html>