assemblyx86intelopcodemnemonics

What is the JCC instruction in x86

I only know instructions like je, jnl, etc., in x86 AT&T syntax.

What does jcc actually mean? All jump instructions?

Solution

  • cc stands for condition code.

    Jcc is not a single instruction, it just describes the jump mnemonics that check the condition code before jumping.

    JNE for instance, checks the condition code before jumping.

    The typical case is to do a comparison (which sets the CC) and then use one of the jump mnemonics afterwards.

    The condition code can also be set with instructions like AND, OR, XOR, addition, subtraction (or CMP, of course).