PPC IRIW+syncs Orig=Rfe SyncdRR Fre Rfe SyncdRR Fre { 0:r2=x; 1:r2=x; 1:r4=y; 2:r2=y; 3:r2=y; 3:r4=x; } P0 | P1 | P2 | P3 ; li r1,1 | lwz r1,0(r2) | li r1,1 | lwz r1,0(r2) ; stw r1,0(r2) | sync | stw r1,0(r2) | sync ; | lwz r3,0(r4) | | lwz r3,0(r4) ; exists (1:r1=1 /\ 1:r3=0 /\ 3:r1=1 /\ 3:r3=0)