64 bits. This applies to near returns, not far returns; the default operation size of far returns is 32 bits.</p>
<h2>Operation</h2>
<pre>(* Near return *)
IF instruction = near return
    THEN;
         IF OperandSize = 32
              THEN
                    IF top 4 bytes of stack not within stack limits
                         THEN #SS(0); FI;
                    EIP ← Pop();
              ELSE
                    IF OperandSize = 64
                         THEN
                              IF to