1
GATE CSE 2021 Set 2
MCQ (Single Correct Answer)
+2
-0.66

For a statement S in a program, in the context of liveness analysis, the following sets are defined:

USE(S): the set of variables used in S

IN(S): the set of variables that are live at the entry of S

OUT(S): the set of variables that are live at the exit of S

Consider a basic block that consists of two statements, S1 followed by S2.

Which one of the following statements is correct?

A
OUT(S1) = USE(S1) ∪ IN(S2)
B
OUT(S1) = IN(S2)
C
OUT(S1) = IN(S1) ∪ USE(S1)
D
OUT(S1) = IN(S2) ∪ USE(S2)
2
GATE CSE 2015 Set 1
MCQ (Single Correct Answer)
+2
-0.6
A variable x is said to be live at a statement $${S_i}$$ in a programif the following three conditions hold simultaneously:

i. There exists a statement $${S_j}$$ that uses x
ii. There is a path from $${S_i}$$ to $${S_j}$$ in the flow graph corresponding to the program
iii. The path has no intervening assignment to x including at $${S_i}$$ and $${S_j}$$

GATE CSE 2015 Set 1 Compiler Design - Code Generation and Optimization Question 11 English

The variables which are live both at the statement in basic block 2 and at the statement in basic block 3 of the above control flow graph are

A
p, s, u
B
r, s, u
C
r, u
D
q, v
3
GATE CSE 2015 Set 1
Numerical
+2
-0
The least number of temporary variables required to create a three-address code in static single assignment form for the expression $$q + r / 3 + s - t * 5 + u * v/w$$ is _______________.
Your input ____
4
GATE CSE 2015 Set 2
MCQ (Single Correct Answer)
+2
-0.6
Consider the intermediate code given below.
(1)  i = 1
(2)  j = 1
(3)  t1 = 5 ∗ i
(4)  t2 = t1 + j
(5)  t3 = 4 ∗ t2
(6)  t4 = t3
(7)  a[t4] = -1
(8)  j = j + 1
(9)  if j<=5 goto (3)
(10) i=i+1
(11) if i<5 goto (2)

The number of nodes and edges in the control-flow-graph constructed for the above code, respectively, are

A
5 and 7
B
6 and 7
C
5 and 5
D
7 and 8
GATE CSE Subjects
Software Engineering
Web Technologies
EXAM MAP