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AArch64 2+2W+poxxs
"PodWWXX WseXX PodWWXX WseXX"
Cycle=WseXX PodWWXX WseXX PodWWXX
Relax=
Safe=PodWW WseXX
Prefetch=0:x=F,0:y=W,1:y=F,1:x=W
Com=Ws Ws
Orig=PodWWXX WseXX PodWWXX WseXX
{ ok=1;
0:X0=x; 0:X4=y; 0:X8=ok;
1:X0=y; 1:X4=x; 1:X8=ok;
}
P0 | P1 ;
MOV W1,#2 | MOV W1,#2 ;
LDXR W2,[X0] | LDXR W2,[X0] ;
STXR W3,W1,[X0] | STXR W3,W1,[X0] ;
CBNZ W3,Fail0 | CBNZ W3,Fail1 ;
MOV W5,#1 | MOV W5,#1 ;
LDXR W6,[X4] | LDXR W6,[X4] ;
STXR W3,W5,[X4] | STXR W3,W5,[X4] ;
CBNZ W3,Fail0 | CBNZ W3,Fail1 ;
B Exit0 | B Exit1 ;
Fail0: | Fail1: ;
MOV W7,#0 | MOV W7,#0 ;
STR W7,[X8] | STR W7,[X8] ;
Exit0: | Exit1: ;
Observed
y=2; x=2; ok=1; 1:X6=0; 1:X2=1; 0:X6=0; 0:X2=1;
and y=2; x=2; ok=0; 1:X6=0; 1:X2=0; 0:X6=0; 0:X2=1;
and y=2; x=2; ok=0; 1:X6=0; 1:X2=1; 0:X6=0; 0:X2=0;
and y=2; x=2; ok=0; 1:X6=0; 1:X2=0; 0:X6=0; 0:X2=0;