Test safe507

PPC safe507
"SyncdWW Rfe SyncsRW Rfe DpdR Fri Rfe SyncdRR Fre"
Cycle=SyncdWW Rfe SyncsRW Rfe DpdR Fri Rfe SyncdRR Fre
Relax=
Safe=Fri Fre DpdR ACSyncdRR BCSyncsRW BCSyncdWW
{
0:r2=x;
1:r2=x; 1:r5=y;
2:r2=y; 2:r4=z;
3:r2=z; 3:r4=x;
}
 P0           | P1            | P2           | P3           ;
 lwz r1,0(r2) | lwz r1,0(r2)  | lwz r1,0(r2) | li r1,1      ;
 sync         | xor r3,r1,r1  | sync         | stw r1,0(r2) ;
 li r3,2      | lwzx r4,r3,r5 | lwz r3,0(r4) | sync         ;
 stw r3,0(r2) | li r6,1       |              | li r3,1      ;
              | stw r6,0(r5)  |              | stw r3,0(r4) ;
exists
(x=2 /\ 0:r1=1 /\ 1:r1=2 /\ 1:r4=0 /\ 2:r1=1 /\ 2:r3=0)