Subject: Re: bug#69770: [PATCH] build: strengthen 16 bit float support checks

From: Collin Funk <[email-masked]>
Date: Thu, 14 Mar 2024 08:51:42 -0700

On 3/14/24 7:48 AM, Pádraig Brady wrote:
> For completeness I should add that the above check can be
> overridden if cross-compiling or whatever like:
> 
>   ./configure utils_cv_ieee_16_bit_supported=yes utils_cv_brain_16_bit_supported=yes

Ah, thanks. I wasn't aware of this.

> Interesting.
> Perhaps this is something that could be configured separately
> on the build system, through something like binfmt_misc ?

It has been a while, but IIRC on Debian GNU/Linux:

$ sudo apt install binfmt-support wine-binfmt

would allow you to run QEMU and Windows binaries similar to a normal
program, e.g. './emulated-program' would run QEMU or Wine. I assume
other distributions have similar packages.

I typically used this for CMake cross-compiling instead of setting
CMAKE_CROSSCOMPILING_EMULATOR. Then you could also run test programs
that were built as if they were native programs which was nice.

I'd have to look at Autoconf's sources, but I'd imagine something
similar could be done there. You'd just have to check if binfmt is
supported and that cross-compiled binaries could be run.

Binfmt is Linux specific though right? Allowing the user to pass an
emulator explicitly would be more portable in that case. I am willing
to look into it more if it seems beneficial.

Collin