Test SyncWith4+sync

PPC SyncWith4+sync
{
0:r2=a; 0:r5=x; 0:r7=s0;
1:r2=x; 1:r4=y; 1:r7=s2;
2:r2=y; 2:r5=z; 2:r7=s2;
3:r2=z; 3:r4=a; 3:r7=s0;
}
 P0            | P1           | P2            | P3           ;
               |              |               |              ;
 lwz r6,0(r7)  |              | lwz r6,0(r7)  |              ;
 cmpw r6,r6    |              | cmpw r6,r6    |              ;
 bne L0        |              | bne L2        |              ;
L0:            |              |L2:            |              ;
 isync         |              | isync         |              ;
 lwz r1,0(r2)  | li r1,1      | lwz r1,0(r2)  | li r1,1      ;
               | stw r1,0(r2) |               | stw r1,0(r2) ;
 lwz  r4,0(r5) | stw r1,0(r4) | lwz r4,0(r5)  | stw r1,0(r4) ;
               | sync         |               | sync         ;
               | stw r1,0(r7) |               | stw r1,0(r7) ;

~exists
(0:r1=1 /\ 0:r4=0 /\ 0:r6=1 /\ 2:r1=1 /\ 2:r4=0 /\ 2:r6=1 )