Test dd3

PPC dd3 (DDThree)
"Double test, load;lwsync;store || load;lwsync;store"
{
 0:r2=2; 0:r4=x;
 1:r2=2; 1:r5=y;
 2:r1=1; 2:r4=x; 2:r5=y;
 3:r1=1; 3:r4=x; 3:r5=y;
}

P0          | P1         | P2        |P3          ;
stw r2,0(r4)|stw r2,0(r5)|lwz r2,0,r5|lwz r2,0,r4 ;
            |            |lwsync     |lwsync      ;
            |            |stw r1,0,r4|stw r1,0,r5 ;

locations [x;y;]
~exists (2:r2=1 /\ 3:r2=1)
(*
  Condition is not very significant [causality more or less -> dd4]
*)
(*
on doko we have:
exists (2:r2=1 /\ 3:r2=2 /\ x=2 /\ y=1)
*)