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