1. Consider the following code segment for a loop: int a = 3, b = 4;
int x;
if (x is a multiplication of 3) <-- branch b increment a <-- b1 taken else <-- b1 not taken increment b
Assume that the following list of 10 values of x is processed by 10 iterations of this code: 7, 6, 10, 11, 9, 5, 3, 13, 2, 17
Assume that a two-bit branch prediction scheme is used. For each iteration of the loop, show
the prediction and state of the two-bit branch predictor (the predicted direction) and the actual
branch direction of the b1 branch instructions. The first iteration has been filled in already.
1 = Taken, 0 = Not Taken. 00 = Strongly Not Taken (Initial state of 2-bit predictor), 01: weakly NT, 10: Strongly
Taken, 11: weakly Taken.
What is the misprediction rate for branch b1?
Iteration 1 2 3 4 5 6 7 8 9 10
b1 (prediction /actual)
00 / /

2. Important topics Cache addressing; LRU replacement policy; AMAT
Defining number of bits needed for PO, VPN, PFN in single/multi-level page tables.
Pipeline design; Understanding data/control dependency; being able to draw the space-time diagram with and without forwarding…
Single-bit/double-bit branch predictors