Re: ARM32 configury changes, with no FPU as a default

[Florian Weimer <fweimer@redhat.com>]

* Matthias Klose:

> Starting with GCC 8, the configury allows to encode extra features into the
> architecture string. Debian and Ubuntu's armhf (hard float) architecture is
> configured with
>
>   --with-arch=armv7-a --with-fpu=vfpv3-d16
>
> and now should be configured with
>
>   --with-arch=armv7-a+fp
>
> The --with-fpu configure option is deprecated.  The problem with this approach
> is that there is no default for the fpu setting, while old compilers silently
> pick up the -mfpu from the configured compiler.

FWIW, Fedora uses:

        --with-tune=generic-armv7-a --with-arch=armv7-a \
	--with-float=hard --with-fpu=vfpv3-d16 --with-abi=aapcs-linux \

Not sure how it is impacted by this change.

> This breaks software which explicitly configures things like
> -march=armv7-a, or where the architecture string is embedded in the
> source as an attribute.  So going from one place in the compiler about
> configuring the ABI for a distro arch, this config now moves to some
> dozen places in different packages.  Not the thing I would expect.

I don't know if we have seen such problems in Fedora.  I don't remember
any reports.

Thanks,
Florian