Test dd2

PPC dd2 (DDTwo)
"Double test, load;sync;store || load;sync;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 ;
            |            |sync       |sync        ;
            |            |stw r1,0,r4|stw r1,0,r5 ;

locations [x;y;]
~exists (2:r2=1 /\ 3:r2=1)