Test bf

PPC bf
(* Test for reg arch duplicates that can be observed on hardware *)
{
0:r5=x ; 0:r6=y;
1:r5=x ; 1:r6=y;
}
P0           |  P1          ;
li r1,1      | lwz r2,0(r5) ;
stw r1,0(r6) | mr r1,r2     ;
sync         | lwz r2,0(r6) ;
li r2,1      |              ;
stw r2,0(r5) |              ;

exists (1:r1=0 /\ 1:r2 = 1)