Run S+isync+sync in model, using ppcmem
PPC S+isync+sync "ISyncdWW Rfe SyncdRW Wse" Cycle=Rfe SyncdRW Wse ISyncdWW { 0:r2=x; 0:r4=y; 1:r2=y; 1:r4=x; } P0 | P1 ; li r1,2 | lwz r1,0(r2) ; stw r1,0(r2) | sync ; isync | li r3,1 ; li r3,1 | stw r3,0(r4) ; stw r3,0(r4) | ; exists (x=2 /\ 1:r1=1)