PPC non-treelike-coherence "Non-treelike coherence" { 0:r2=x; 1:r2=x; 2:r2=x; 3:r2=x; 4:r2=x; } P0 | P1 | P2 | P3 | P4 ; li r1,1 | lwz r1,0(r2) | li r1,2 | lwz r1,0(r2) | li r1,3 ; stw r1,0(r2) | xor r3,r1,r1 | stw r1,0(r2) | xor r3,r1,r1 | stw r1,0(r2) ; | lwzx r4,r3,r2 | | lwzx r4,r3,r2 | ; Observed 1:r1=2; 1:r4=3; 3:r1=0; 3:r4=1; x=1; and 1:r1=3; 1:r4=1; 3:r1=0; 3:r4=2; x=2; and 1:r1=1; 1:r4=3; 3:r1=0; 3:r4=2; x=2; and 1:r1=0; 1:r4=3; 3:r1=1; 3:r4=2; x=3;