PPC hh2 (BasicHHTwo) { x=0 ; y=0; 0:r4=x ; 0:r5=y; 1:r4=x ; 1:r5=y; 0:r1=1 ; 0:r2=2 ; 1:r1=1; 2:r5=y ; 2:r2=2 ; } P0 | P1 |P2 ; stw r2,0(r4) | lwz r2,0(r5) |stw r2,0(r5) ; sync | sync | ; stw r1,0(r5) | stw r1,0(r4) | ; locations [1:r2; x; y;] exists (1:r2=2 /\ x=2 /\ y=2)