In the x86 assembly language, the TEST instruction performs a bitwise AND on two operands. The flags SF, ZF, PF are modified while the result of the AND is discarded.
; Conditional Jump
test cl, cl ; set ZF to 1 if cl == 0
je 0x804f430 ; jump if ZF ==1 ; or
test eax, eax ; set SF to 1 if eax < 0 (negative)
js error ; jump if SF == 1