Instruction-Level Parallelism and Its Exploitation - Computer Architecture: A Quantitative Approach - page 157

A 2-bit predictor with no global history is simply a (0,2) predictor.
Example
How many bits are in the (0,2) branch predictor with 4K entries? How many
entries are in a (2,2) predictor with the same number of bits?
Answer
The predictor with 4K entries has
How many branch-selected entries are in a (2,2) predictor that has a total of 8K
bits in the prediction buffer? We know that
Hence, the number of prediction entries selected by the branch = 1K.
Figure 3.3 compares the misprediction rates of the earlier (0,2) predictor with 4K entries and
a (2,2) predictor with 1K entries. As you can see, this correlating predictor not only outper-
forms a simple 2-bit predictor with the same total number of state bits, but it also often out-
performs a 2-bit predictor with an unlimited number of entries.