TEST
Usage: TEST dest,src Modifies flags: CF OF PF SF ZF (AF undefined)
Performs a logical AND of the two operands updating the flags register without saving the result.
Test Bits (notional bitwise AND)
TEST r/m8,reg8 ; 84 /r [8086]
TEST r/m16,reg16 ; o16 85 /r [8086]
TEST r/m32,reg32 ; o32 85 /r [386]
TEST r/m8,imm8 ; F6 /0 ib [8086]
TEST r/m16,imm16 ; o16 F7 /0 iw [8086]
TEST r/m32,imm32 ; o32 F7 /0 id [386]
TEST AL,imm8 ; A8 ib [8086]
TEST AX,imm16 ; o16 A9 iw [8086]
TEST EAX,imm32 ; o32 A9 id [386]
TEST performs a `mental' bitwise AND of its two operands, and affects the flags as if the operation had taken place, but does not store the result of the operation anywhere.
EXAMPLE:
Test eax ecx