forked from Imagelibrary/rtems
c1072919fa
This reverts commit d9ff8b3e68.
It is not that simple:
https://sourceware.org/ml/binutils/2014-06/msg00062.html
On Fri, Jun 06, 2014 at 01:31:48PM +0200, Sebastian Huber wrote:
> On 2014-06-06 13:23, Sebastian Huber wrote:
> >Ok, so this "cmplwi cr0, rX, ppc_exc_lock_std@sdarel" is illegal,
> >since
> >ppc_exc_lock_std@sdarel is signed and the immediate is unsigned
> >16-bit? The
> >assembler doesn't issue a warning about this.
> >
> >Exists there a way to rescue this cmplwi hack without relaxing the
> >overflow
> >checks?
>
> Hm, sorry, it was surprisingly simple. This works:
>
> "cmplwi cr0, rX, ppc_exc_lock_std@sdarel@l"
>
> I was not aware that you can add several @ in a row.
That is the wrong thing to use here. sdarel@l translates to a VLE
reloc which applies to a split 16-bit field in VLE insns.
You want
cmpwi cr0, rX, ppc_exc_lock_std@sdarel
to properly compare a 16-bit signed number from sym@sdarel.
Note that the assembler does error if you write something like
cmplwi 3,-30000
or
cmpwi 3,40000
so what the linker is now doing is extending this behaviour to link
time.