Intel 64 and IA-32 Architectures Software Developers Manual Volume 1, Basic Architecture

Vol. 1 B-1
APPENDIX B
EFLAGS CONDITION CODES
B.1 CONDITION CODES
Table B-1 lists condition codes that can be queried using CMOVcc, FCMOVcc, Jcc, and
SETcc. Condition codes refer to the setting of one or more status flags (CF, OF, SF, ZF,
and PF) in the EFLAGS register. In the table below:
• The “Mnemonic” column provides the suffix (cc) added to the instruction to
specify a test condition.
• “Condition Tested For” describes the targeted condition.
• “Instruction Subcode” provides the opcode suffix added to the main opcode to
specify the test condition.
• “Status Flags Setting” describes the flag setting.
Table B-1. EFLAGS Condition Codes
Mnemonic (cc) Condition Tested For
Instruction
Subcode Status Flags Setting
O Overflow 0000 OF = 1
NO No overflow 0001 OF = 0
B
NAE
Below
Neither above nor equal
0010 CF = 1
NB
AE
Not below
Above or equal
0011 CF = 0
E
Z
Equal
Zero
0100 ZF = 1
NE
NZ
Not equal
Not zero
0101 ZF = 0
BE
NA
Below or equal
Not above
0110 (CF OR ZF) = 1
NBE
A
Neither below nor equal
Above
0111 (CF OR ZF) = 0
S Sign 1000 SF = 1
NS No sign 1001 SF = 0
P
PE
Parity
Parity even
1010 PF = 1