Lesson 9--Liveness Analysis

Question 1

in[I]

Answer 1

Live variables at program point before I.

Question 2

out[I]

Answer 2

Live variables at program point after I

Question 3

in[B]

Answer 3

Live variables at the beginning of B

Question 4

out[B]

Answer 4

Live variables at the end of B

Question 5

Uses of I

Answer 5

All variables that I uses are live before I

Question 6

Defs of I

Answer 6

All variables live after I are also live before I, unless I writes to them.

Question 7

Liveness mathematically

Answer 7

in[I] = ( out[I] - def[I] ) U use[I]
out[B] = U in[B']