[PATCH] Don't assume MEM_SIZE is always set in rs6000 adjacent_mem_locations (PR target/34225)

[David Edelsohn]

>>>>> Jakub Jelinek writes:

Jakub> Well, stack_tie is presented as real instruction, the only thing the ppc
Jakub> backend can see on it exceptional is zero length.  
Jakub> That said, rs6000_variable_issue and the various is_*_insn probably
Jakub> should special case stack_tie, in most cases handle it the same way
Jakub> as USE or CLOBBER.  But it is not a correctness issue, but just something
Jakub> to get better scheduling.

	Okay, go ahead with your patch.  I will figure out how to follow
up with code to ignore stack_tie for scheduling purposes as an
enhancement.

Thanks, David