PR79286, ira combine_and_move_insns in loops

[Alan Modra]

On Thu, Feb 23, 2017 at 12:46:17AM -0700, Jeff Law wrote:
> And thus we keep the equivalence.  Ultimately may_trap_p considers a PIC
> memory reference as non-trapping.

Which is obviously a bug, because this access is segfaulting..
Not that I want to poke at the bug.  :)

> I really wonder if we should just drop the may_trap_p test and always do the
> domination check.

Yeah, seems reasonable to me.

-- 
Alan Modra
Australia Development Lab, IBM