How to read the flags registers in x86 processor [duplicate]

Question

Are there any assembly instructions to let us directly read or write the overflow flag in Intel's 80386 16-bit Flags register ? If not, what pseudo code should we use?

Answer 1

To read only the overflow flag:

SETO AL
; AL now contains 1 if the overflow flag was set, and 0 if it wasn't

To invert the overflow flag:

PUSHF
POP    AX
XOR    AX,800h  ; The overflow flag is in bit 11
PUSH   AX
POPF