delay slot

from The Free On-line Dictionary of Computing (8 July 2008)
delayed control-transfer
annulled branch
branch delay slot
delay instruction
delay slot

   <SPARC, programming> A technique used on the {SPARC} to reduce
   the effect of {pipeline breaks} by executing the instruction
   after a branch instruction (the "delay instruction" in the
   "delay slot").  If there is no useful instruction which can be
   placed in the delay slot then the "annul bit" on the control
   transfer instruction can be set, preventing execution of the
   delay instruction (unless the control transfer is conditional
   and is taken).

   Annulled branches are indicated in SPARC assembler language by
   appending ",A" to the {operation code}.  For example,

    LOOP: ...
    CMP    %L0,10
    BLE,A   LOOP
    ADD     %L2, %L3, #L4

   If the delay instruction is also a control transfer
   instruction then it gets more complicated.  Both control
   transfer instructions are executed (but not the following
   instruction) and, assuming they are both taken, control is
   transferred briefly to the destination of the first and then
   immediately to the destination of the second.

   (2001-06-26)