Error: selected processor does not support ARM mode `ldralt r5,[r0],#4'

[Matthew Gretton-Dann]

On 12 September 2012 00:22, Khem Raj <raj.khem@gmail.com> wrote:
> Hi Matthew
>
> There is a regression that I am seeing on trunk and also 2.23 branch
>
> testcase
>
> /tmp/as.s
>
> ldralt r5,[r1],#4
>
> $ ./gas/as-new -march=armv5te /tmp/a.s
> /tmp/a.s: Assembler messages:
> /tmp/a.s:1: Error: selected processor does not support ARM mode `ldralt r5,[r1],#4'

Yes - I agree that's a regression.  Can you please raise the issue in BugZilla?

The problem is that
   ldralt is <LDRA><LT> (in unified syntax ARMv8-A and above) and
<LDR><AL><T> (in divided syntax).

I think this may be the only instruction this applies to - but I will
go away and have a think.

There are a couple of user-source workarounds:

 * Use unified syntax - so ldrtal instead of ldralt.
 * Don't use 'al' -so ldrt and not ldralt.

The binutils fix however is going to take some thinking about, and I
need to discuss with a maintainer what the most acceptable way forward
is.  Please don't expect anything before the end of the week.

Thanks,

Matt

-- 
Matthew Gretton-Dann
Linaro Toolchain Working Group
matthew.gretton-dann@linaro.org