[PATCH 4/9] regrename: Don't rename restores

[Segher Boessenkool]

On Thu, Sep 08, 2016 at 11:51:53AM -0600, Jeff Law wrote:
> On 07/31/2016 07:42 PM, Segher Boessenkool wrote:
> >A restore is supposed to restore some certain register.  Restoring it
> >into some other register will not work.  Don't.
> >
> >2016-06-07  Segher Boessenkool  <segher@kernel.crashing.org>
> >
> >	* regrename.c (build_def_use): Invalidate chains that have a
> >	REG_CFA_RESTORE on some instruction.
> Again, how is this different from a normal epilogue that restores 
> registers which regrename seems to not muck with.

Good question.  Either way, it is always wrong to rename a register we
restore from stack.


Segher