# Compiler Quiz 2 (III Cse C)

30 Questions | Total Attempts: 179  Settings  • 1.
• A.

• B.

• C.

No unary operators

• D.

None of the mentioned

• 2.
An intermediate code form is
• A.

Post-fix Notation

• B.

Syntax Trees

• C.

• D.

All of the mentioned

• 3.
The graph that shows basic blocks and their successor relationship is called
• A.

Dag

• B.

Flow Graph

• C.

Control Graph

• D.

Hamilton Graph

• 4.
Some code optimizations are carried out on the intermediate code because
• A.

They enhance the portability of the compiler to other target processors

• B.

Program analysis is more accurate on intermediate code than on machine code

• C.

The information from dataflow analysis cannot otherwise be used for optimization

• D.

The information from the front end cannot otherwise be used for optimization

• 5.
Consider the following C code segment. for (i = 0, i { for (j=0; j { if (i%2) { x += (4*j + 5*i); y += (7 + 4*j); }} } Which one of the following is false?
• A.

The code contains loop invariant computation

• B.

There is scope of common sub-expression elimination in this code

• C.

There is scope of strength reduction in this code

• D.

There is scope of dead code elimination in this code

• 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

• 7.
Consider the following code segment.   x = u - t; y = x * v; x = y + w; y = t - z; y = x * y; The minimum number of total variables required to convert the above code segment to static single assignment form is
• A.

6

• B.

8

• C.

9

• D.

10

• 8.
Consider the following source code :   c = a + b d = c c = c – e a = d – e b = b * e b = d/b Which of the following is correct optimization of given code?
• A.

c = a + b    t = b * e    a = d – e    b = d/t    c = a

• B.

c = a + b       d = c       c = c – e       a = d – e       b = d/b

• C.

d = c      c = c – e      a = d – e      b = b * e      b = d/b

• D.

None of the above

• 9.
Peephole optimization is form of
• A.

Loop optimization

• B.

Local optimization

• C.

Constant folding

• D.

Data flow analysis

• 10.
In compiler terminology reduction in strength means
• A.

Replacing run time computation by compile time computation

• B.

Removing common subexpression

• C.

Removing loop invariant computation

• D.

Replacing a costly operation by a relatively cheaper one

• 11.
Substitution of values for names (whose values are constants) is done in
• A.

Local optimization

• B.

Loop optimization

• C.

Constant folding

• D.

Strength reduction

• 12.
The method which merges the bodies of two loops is
• A.

Loop rolling

• B.

Loop Jamming

• C.

Constant folding

• D.

None of these

• 13.
Syntax directed translation scheme is desirable because
• A.

It is based on the syntax

• B.

Its description is independent of any implementation

• C.

It is easy to modify

• D.

All of these

• 14.
The optimization technique which is typically applied on loops is
• A.

Removal of invariant computation

• B.

Peephole optimization

• C.

Constant folding

• D.

All of these

• 15.
The graph that shows basic blocks and their successor relationship is called
• A.

DAG

• B.

Flow graph

• C.

Control graph

• D.

Hamiltonian graph

• 16.
An intermediate code form is
• A.

Postfix notation

• B.

Syntax trees

• C.

• D.

All of these

• 17.
Input to code generator
• A.

Source code

• B.

Intermediate code

• C.

Target code

• D.

All of the above

• 18.
The identification of common sub-expression and replacement of run-time computations by compile-time computations is
• A.

Local optimization

• B.

Loop optimization

• C.

Constant folding

• D.

Data flow analysis

• 19.
Local and loop optimization in turn provide motivation for
• A.

Data flow analysis

• B.

Constant folding

• C.

Peep hole optimization

• D.

DFA and constant folding

• 20.
An optimizing compiler
• A.

Is optimized to occupy less space

• B.

Is optimized to take less time for execution

• C.

Optimizes the code

• D.

All of the above

• 21.
A basic block can be analyzed by
• A.

DAG

• B.

A flow graph

• C.

A graph with cycles

• D.

None of the above

• 22.
A pictorial representation of the value computed by each statement in the basic block is
• A.

Tree

• B.

DAG

• C.

Graph

• D.

None of the above

• 23.
Boolean expressions have following purposes
• A.

Computing logical values

• B.

Used as conditional expressions

• C.

Both a &b

• D.

None of the above

• 24.
__________can be used to generate code for Boolean expressions and flow of-control statements in one pass.
• A.

Backpatching

• B.

Code-generator

• C.

Parser

• D.

Static checker

• 25.
Principal methods of representing the value of boolean expression
• A.

Encoding true & false numerically

• B.

To evaluate boolean expression analogously to an arithmetic expression

• C.

Implementing boolean expression by flow of control

• D.

All of the above Back to top