Re: [musl] musl how to use hard float with aarch64-none-elf-gcc

[Rich Felker <dalias@libc.org>]

On Wed, Feb 16, 2022 at 12:59:13PM +0100, SIMONE MIONE wrote:
> Thank you all for your reply.
> I meant when I add musl's lib*.a into my makefile, the compiler complains
> about "undefined reference to __addtf3" (and others). Isn't that
> soft-float? Or emulation float?

It's the implementation of long double which is IEEE quad in the
aarch64 ABI.

> My supervisor told me "we already have float implementation so we don't
> need those functions". So I was wondering if I need to disable it in some
> way.

No, you need them because there is no fpu implementation of quad.


> Il giorno mer 16 feb 2022 alle ore 12:32 Jeffrey Walton <noloader@gmail.com>
> ha scritto:
> 
> > On Wed, Feb 16, 2022 at 6:29 AM Szabolcs Nagy <nsz@port70.net> wrote:
> > >
> > > * Jeffrey Walton <noloader@gmail.com> [2022-02-16 05:24:48 -0500]:
> > > > On Wed, Feb 16, 2022 at 4:51 AM SIMONE MIONE <
> > 205212@studenti.unimore.it> wrote:
> > > > >
> > > > > I am trying to integrate musl in a baremetal environment. I already
> > have float support but I can't manage to disable soft-float by musl.
> > > > >
> > > > > I configure with:
> > > > > ./configure --target=aarch64-none-elf --enable-debug --disable-shared
> > > > > And simple compile with:
> > > > > make
> > > > >
> > > > > Does anyone know how to use hardfloat instead of soft float? Is
> > there any option or flag? Thank you
> > > >
> > > > The GCC options for hard-floats are -mfpu=neon -mfloat-abi=hard. In
> > > > later versions of GCC, you can also use -mfpu=auto (sometimes).
> > >
> > > that's for 32bit arm
> > >
> > > there is no soft float abi for aarch64, so i'm not sure what's going on.
> >
> > Oh, you're right My bad. I did not notice it was Aarch64.
> >
> > Jeff
> >