19 07 2021 E TS Santambrogio

Page 1

Dipartimento di Elettronica e Informazione Politecnico di Milano 20133 Milano (Italia) Piazza Leonardo da Vinci, 32 Tel. (+39) 02-2399.3400 Fax (+39) 02-2399.3411 Advanced Computer Architecture July 19, 2021 Prof. Marco Santambrogio Name Last Name Code Name (Codice Persona) WRITE YOUR NAME and CODE NAME. Pick 2 out of th 3 problems, DO NOT DO ALL THE 3! Questions (20%) Problem 1 (40%) Problem 2 (40%) Problem 3 (40%) Total (100%) Question 1 An Embarrassingly Parallel Algorithms is always gaining benefits by an increment in the number of cores provided by the underlying architecture. Note, in parallel programming, an embarrassingly parallel algorithm is one that requires no communication or dependency between the processes. (True/False) Answer (Effectively support your answer) Question 2 Theoretically, an unlimited number of issues will be the best option to achieve the highest performance (True/False) Answer (Effectively support your answer) Question 3 Which type of hazards can be caused by the name dependences? Answer 1: WAR Answer 2: RAR Answer 3: WAW Answer 4: RAW Answer (list all the correct answer(s) and explain why) Question 4 In a 5-stage pipeline MIPS architecture, it is possible to forward a data twice from stage-i to stage-j. As an example, given the following code: I1 ADDD F2, F4, F6 I2 ADDD F4, F2, F26 I1 ADDD F6, F2, F4 F2 will be forwarder from I1 to both I2 and I3 by using the EX->EX forwarding path (True/False) Answer (Effectively support your answer)