Operation

IF AddressSize = 16
THEN use CX for CountReg;
ELSE (* AddressSize = 32 *) use ECX for CountReg;
FI;
WHILE CountReg <> 0
DO
service pending interrupts (if any);
perform primitive string instruction;
CountReg CountReg -1;
IF primitive operation is CMPSB, CMPSW, CMPSD, SCASB,
SCASW, or SCASD
THEN
IF (instruction is REP/REPE/REPZ) AND (ZF=0)
THEN exit WHILE loop
ELSE
IF (instruction if REPNZ or REPNE) AND (ZF=1)
THEN exit WHILE loop;
FI;
FI;
FO;
OD;

[Back: Description]
[Next: Flags Affected]