[Doing a NOP]                                          [Assembler][/][8086]

This gem shows how you can replace the instruction NOP with "bigger
instructions". Assuming we are in a 16-bit segment we can do the following:

     2-bytes         mov     reg,reg         ; true NOP
     2-bytes         xchg    ax,ax           ; true NOP
     3-bytes         lea     reg,[reg+0]     ; true NOP, use 8-bit displacement

The following versions use 32-bit registers and does not work on any CPU
less than 80386:

     4-bytes         shl     eax,0           ; true NOP
     5-bytes         shrd    eax,eax,0       ; true NOP
     6-bytes         lea     eax,[eax+0]     ; true NOP

                                                  Gem writer: John Eckerdal
                                                   last updated: 1998-03-16
