Test m4ds

PPC m4ds (PPCMFourDepSync)
{
0:r5=x;
1:r5=x; 1:r6=y;
2:r5=x; 2:r6=y;
0:r1=1;
2:r1=1;
}
P0          |P1           |P2          ;
stw r1,0(r5)|lwz r1,0(r5) |stw r1,0(r6);
            |xor r9,r1,r1 |sync        ;
            |lwzx r2,r9,r6|lwz r3,0(r5);
exists (1:r1=1 /\  1:r2=0 /\ 2:r3=0)