Test RDWI

Run RDWI in model, using ppcmem

PPC RDWI
"is RR to same location in ppo?, intervening internal write variation"
{
1:r6=x; 1:r7=y; 1:r8=z;
0:r7=y; 0:r8=z;
}
P0           |P1            ;
li r1,1      |lwz r1,0(r7)  ;
stw r1,0(r8) |xor r9,r1,r1  ;
sync         |lwzx r3,r9,r6 ;
li r2,2      |li r11,1      ;
stw r2,0(r7) |stw r11,0(r6) ;
             |lwz r4,0(r6)  ;
             |xor r10,r4,r4 ;
             |lwzx r2,r10,r8;

exists (1:r1=2 /\ 1:r2=0 /\ 1:r3=0 /\ 1:r4=1)