Program & Compiler Optimization

Question 1

LICM

Answer 1

Loop invariant code motion. A value or part of a value that doesn’t change through out a loop iteration. Can just the column of an array or the row exp a[i] or a[i][j].

Question 2

Name the types of compiler optimization

Answer 2

LICM, function inlining, constant propogation, ..

Question 3

What is a compiler?

Answer 3

It generates code to the program at an intermediary stage similaar to assembly before it is turned into assembly instructions (ISA)

Question 4

What is an optimizing compiler?

Answer 4

It is a compiler that has an additional step before the intermediary stage where it generates and adds additional code to the program to improve performance

Question 5

The equation used to measure performance improvement?

Answer 5

execution time = no. of instruction x CPI x cycle period

Question 6

How to reduce CPI?

Question 7

How to reduce no. of instructions?

Question 8

Program optimizations

Answer 8

Loop unrolling. Using a profiler to find bottlenecks