MCQ2 marks
Consider the control flow graph given below.
Which one of the following options is the set of live variables at the exit point of each basic block?
Single correct
MCQ2 marks
Consider the following ANSI C code segment:
z = x + 3 + y->f1 + y->f2;
for (i = 0; i < 200; i = i + 2){
if (z > i) {
p = p + x + 3;
q = q + y->f1;
} else {
p = p + y->f2;
q = q + x + 3;
}
}y points to a struct (allocated on the heap) containing two fields f1 and f2, and the local variables x, y, z, p, q, and i are allotted registers. Common sub-expression elimination (CSE) optimization is applied on the code. The number of addition and dereference operations (of the form y->f1 or y->f2) in the optimized code, respectively, are:Single correct
Answer key coming soon
MCQ2 marks
For a statement in a program, in the context of liveness analysis, the following sets are defined:
: the set of variables used in
: the set of variables that are live at the entry of
: the set of variables that are live at the exit of
Consider a basic block that consists of two statements, followed by .
Which one of the following statements is correct?
Single correct
Answer key coming soon
MCQ2 marks
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)Single correct
MCQ2 marks
Consider the basic block given below.
a = b + c
c = a + d
d = b + c
e = d - b
a = e + bSingle correct
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