edited by
325 views

1 Answer

2 votes
2 votes

A variable is live at a particular point in the program if its value at that point will be used in the future (dead, otherwise).

Apply this definition,

In block 1, variables a,c,d are present, here the value which each of the variables among a,c,d will have, if that same value is used in further operation then those variables are live. Note that the same value which is initialized in the present block must be used in further blocks. If you notice this then rest is easy. So, option D is the correct answer. 

Reference: https://www.cs.columbia.edu/~suman/secure_sw_devel/Basic_Program_Analysis_DF.pdf

Related questions

0 votes
0 votes
2 answers
2
balraj_allam asked Jan 27, 2019
2,227 views
b = b + cd = b + db = b – de = d + bThe minimum number of nodes and edges present in the DAG representation of above basic block respectively are ?4 and 55 and 46 and 6...
2 votes
2 votes
0 answers
4