AArch64 CAS+data2 { z=1; 0:X1=x; 0:X3=y; 1:X1=x; 1:X3=y; 1:X8=z; } P0 | P1 ; NOP | LDR W0,[X1] ; NOP | MOV W5,W0 ; MOV W0,#1 | CAS W0,W6,[X8] ; STR W0,[X3] | LDR W0,[X8] ; STLR W0,[X1] | EOR W0,W0,W0 ; NOP | LDR W4,[X3,W0,SXTW] ; Observed 1:X5=1; 1:X4=0;