Re: ARM inline assembly usage in Linux kernel

[Renato Golin <renato.golin@linaro.org>]

On 20 February 2014 12:59, Ramana Radhakrishnan
<ramana.gcc@googlemail.com> wrote:
> It's not really because GAS supports it, but there exists a large body
> of code out there which uses inline assembler with pre-UAL syntax. I'm
> not sure people will appreciate a blanket break in one version of the
> toolchain and especially when people could quite easily mix and match
> between compiler versions and binutils versions.

Hi Ramana,

I agree, I didn't mean it was GAS' fault.


> Before anything else the compiler needs to be fixed and there are some
> corner cases to deal with build attributes especially for Thumb1 in
> the assembler before we can starting thinking about deprecating
> pre-UAL syntax.

Absolutely. But there needs to be an interest in the GNU community to
drive these changes forward. In LLVM we're very much pro-UAL and it
took us quite a lot of convincing to support pre-UAL syntax in the
*parser only*, but we'll never generate it ourselves. Everything we
generate is (or should be) UAL.


> It may be of
> interest for 4.9 + 1 = (4.10 /5.0) in GCC and the next binutils
> revision.

If people are really interested, I can start the ball rolling in the
binutils list.


> Adding the warning by default to GAS is just part of the solution.

It'll only be the second step, yes, with the first one being to fix
the remaining ugly bugs. There will be many more...

cheers,
--renato