CD VIVA

The number of tokens in the following C statement is

printf("i = %d, &i = %x", i, &i);

• 3

• 26

• 10

• 21

In a compiler, keywords of a language are recognized during

• parsing of the program

• the code generation

• the lexical analysis of the program

• dataflow analysis

Which one of the following statements is FALSE?

• Context-free grammar can be used to specify both lexical and syntax rules.

• Type checking is done before parsing

• High-level language programs can be translated to different Intermediate Representations.

• Arguments to a function can be passed using the program stack.

What is the maximum number of reduce moves that can be taken by a bottom-up parser for a grammar with no epsilon- and unit-production (i.e., of type A -> є and A -> a) to parse a string with n tokens?

• n/2

• n-1

• 2n-1

• 2ⁿ

The grammar S → aSa | bS | c is

• LL(1) but not LR(1)

• LR(1)but not LR(1)

• Both LL(1)and LR(1)

• Neither LL(1)nor LR(1)

Match all items in Group 1 with correct options from those given in Group 2.

Group 1 Group 2

P. Regular expression 1. Syntax analysis

Q. Pushdown automata 2. Code generation

R. Dataflow analysis 3. Lexical analysis

S. Register allocation 4. Code optimization

• P-4. Q-1, R-2, S-3

• P-3, Q-1, R-4, S-2

• P-3, Q-4, R-1, S-2

• P-2, Q-1, R-4, S-3

Which one of the following is a top-down parser?

• Recursive descent parser.

• Operator precedence parser.

• An LR(k) parser

• An LALR(k) parser

One of the purposes of using intermediate code in compilers is to

• make parsing and semantic analysis simple

• improve error recovery and error reporting

• increase the chances of reusing the machine-independent code optimizer in other compilers.

• improve the register allocation

Consider the following C code segment.

for (i = 0, i<n; i++)

{

for (j=0; j<n; j++)

{

if (i%2)

{

x += (4*j + 5*i);

y += (7 + 4*j);

}

}

}

• The code contains loop invariant computation

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

• There is scope of strength reduction in this code

• There is scope of dead code elimination in this code

In a resident- OS computer, which of the following system software must reside in the main memory under all situations?

• Assembler

• Linker

• Loader

• Compiler