x86 EFLAGS

EFLAGS table

Bit	Type /val.	Name	Abbreviation
1	S	Carry Flag	CF
2	0	Always clear	rsvd_2
3	S	Parity Flag	PF
4	1	Always set	rsvd_4
5	S	Auxiliary Carry Flag	AF
6	1	Always set	rsvd_6
7	S	Zero Flag	ZF
8	S	Sign Flag	SF
9	X	Trap Flag	TF
10	X	Interrupt Enable Flag	IF
11	C	Direction Flag	DF
12	S	Overflow Flag	OF
13	X	I/O Privilege Level	IOPL
14	X	Nested Task	NT
15	0	Always clear	rsvd_15
16	X	Resume Flag	RF
17	X	Virtual-8086 Mode	VM
18	X	Alignment Check / Access Control	AC
19	X	Virtual Interrupt Flag	VIF
20	X	Virtual Interrupt Pending	VIP
21	X	ID Flag	ID

C macro constants

#define X86_EFLAGS_CF             0 /* Carry Flag [S]                       */
#define X86_EFLAGS_rsvd_2         1 /* Always clear [0]                     */
#define X86_EFLAGS_PF             2 /* Parity Flag [S]                      */
#define X86_EFLAGS_rsvd_4         3 /* Always set [1]                       */
#define X86_EFLAGS_AF             4 /* Auxiliary Carry Flag [S]             */
#define X86_EFLAGS_rsvd_6         5 /* Always set [1]                       */
#define X86_EFLAGS_ZF             6 /* Zero Flag [S]                        */
#define X86_EFLAGS_SF             7 /* Sign Flag [S]                        */
#define X86_EFLAGS_TF             8 /* Trap Flag [X]                        */
#define X86_EFLAGS_IF             9 /* Interrupt Enable Flag [X]            */
#define X86_EFLAGS_DF            10 /* Direction Flag [C]                   */
#define X86_EFLAGS_OF            11 /* Overflow Flag [S]                    */
#define X86_EFLAGS_IOPL          12 /* I/O Privilege Level [X]              */
#define X86_EFLAGS_IOPL_LO       12 /* I/O Privilege Level low bit. [X]     */
#define X86_EFLAGS_IOPL_HI       13 /* I/O Privilege Level high bit. [X]    */
#define X86_EFLAGS_NT            14 /* Nested Task [X]                      */
#define X86_EFLAGS_rsvd_15       15 /* Always clear [0]                     */
#define X86_EFLAGS_RF            16 /* Resume Flag [X]                      */
#define X86_EFLAGS_VM            17 /* Virtual-8086 Mode [X]                */
#define X86_EFLAGS_AC            18 /* Alignment Check / Access Control [X] */
#define X86_EFLAGS_VIF           19 /* Virtual Interrupt Flag [X]           */
#define X86_EFLAGS_VIP           20 /* Virtual Interrupt Pending [X]        */
#define X86_EFLAGS_ID            21 /* ID Flag [X]                          */