Test b3

PPC b3 (BasicThree)
"Simple sync test, light barrier and load load dependancy"
{0:r6=1; 0:r4=x; 0:r5=y; 1:r4=x; 1:r5=y; x=0; y=0;}

P0              | P1             ;
 stw r6,0,r4    | lwz r1,0,r5    ;
 lwsync         | xor r3,r1,r1   ;
 stw r6,0,r5    | lwzx r2,r3,r4  ;


exists (1:r1=1 /\ 1:r2=0)