This is the mail archive of the
mailing list for the binutils project.
Re: 32-bit PowerPC sdata linker problem
- From: Alan Modra <amodra at gmail dot com>
- To: Sebastian Huber <sebastian dot huber at embedded-brains dot de>
- Cc: binutils at sourceware dot org
- Date: Fri, 6 Jun 2014 21:45:31 +0930
- Subject: Re: 32-bit PowerPC sdata linker problem
- Authentication-results: sourceware.org; auth=none
- References: <53918356 dot 3040102 at embedded-brains dot de> <20140606105420 dot GH5592 at bubble dot grove dot modra dot org> <5391A4BF dot 2030308 at embedded-brains dot de> <5391A6A4 dot 6050708 at embedded-brains dot de>
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
> 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.
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
so what the linker is now doing is extending this behaviour to link
Australia Development Lab, IBM