HP Vectra XU5 Reference Manual page 20

Dynamic Branch Prediction
The Pentium processor uses dynamic branch prediction. To dynamically predict instruction
branches, the processor uses two prefetch buffers. One buffer is used to prefetch code in a
linear way and one to prefetch code depending upon the contents of the Branch Target
Buffer (BTB). The BTB is a small cache that keeps a record of the last instruction and
address used. It uses this information to predict the way that the instruction will branch, the
next time it is used. When it has made a correct prediction the branch is executed without
delay, enhancing performance.
Vectra XU Technical Reference System Overview 20