The Art of Assembly Language, 2nd Edition

7.4 The Conditional Jump Instructions

Although the jmp instruction provides transfer of control, it is inconvenient to use when making decisions such as those you'll need to implement statements like if and while. The 80x86's conditional jump instructions handle this task.

The conditional jumps test one or more CPU flags to see if they match some particular pattern. If the flag settings match the condition, the conditional jump instruction transfers control to the target location. If the match fails, the CPU ignores the conditional jump and execution continues with the instruction following the conditional jump. Some conditional jump instructions simply test the setting of the sign, carry, overflow, and zero flags. For example, after the execution ...