branch prediction

1 definition found

branch prediction - Free On-line Dictionary of Computing (26 May 2007) :

  branch prediction
  
     <processor, algorithm> A technique used in some processors
     with instruction prefetch to guess whether a conditional branch
      will be taken or not and prefetch code from the
     appropriate location.
  
     When a branch instruction is executed, its address and that of
     the next instruction executed (the chosen destination of the
     branch) are stored in the Branch Target Buffer.  This
     information is used to predict which way the instruction will
     branch the next time it is executed so that instruction
     prefetch can continue.  When the prediction is correct (and it
     is over 90% of the time), executing a branch does not cause a
     pipeline break.
  
     Some later CPUs simply prefetch both paths instead of trying
     to predict which way the branch will go.
  
     An extension of the idea of branch prediction is speculative execution
     .
  
     (1998-03-14)