Test safe538

PPC safe538
"LwSyncdWW Rfe SyncsRW Rfe SyncdRR Fre"
Cycle=LwSyncdWW Rfe SyncsRW Rfe SyncdRR Fre
Relax=
Safe=Fre LwSyncdWW ACSyncsRW ACSyncdRR
{
0:r2=x;
1:r2=x; 1:r4=y;
2:r2=y; 2:r4=x;
}
 P0           | P1           | P2           ;
 lwz r1,0(r2) | lwz r1,0(r2) | li r1,1      ;
 sync         | sync         | stw r1,0(r2) ;
 li r3,2      | lwz r3,0(r4) | lwsync       ;
 stw r3,0(r2) |              | li r3,1      ;
              |              | stw r3,0(r4) ;
Observed
    0:r1=0; 1:r1=2; 1:r3=0; x=2;