Negative flag
In a computer processor the negative flag or sign flag is a single bit in a system status register used to indicate whether the result of the last mathematical operation produced a value in which the most significant bit was set. In a two's complement interpretation of the result, the negative flag is set if the result was negative.
For example, in an 8-bit signed number system, -37 will be represented as 1101 1011 in binary, while +37 will be represented as 0010 0101.
The negative flag is set according to the result in the x86 series processors by the following instructions :
