MCQOPTIONS
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MCQOPTIONS
This section includes 13 Mcqs, each offering curated multiple-choice questions to sharpen your Compilers knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
In the context of compilers, which of the following is/are NOT an intermediate representation of the source program? |
| A. | Control Flow Graph (CFG) |
| B. | Symbol table |
| C. | Three address code |
| D. | A bstract Syntax Tree (AST) |
| Answer» C. Three address code | |
| 2. |
Match the following according to input (from the left column) to the compiler phase (in the right column) that processes it:(P)Syntax tree(i)Code generator(Q)Character steam(ii)Syntax analyzer(R)Intermediate representation(iii)Semantic analyser(S)Token stream(iv)Lexical analyzer |
| A. | P → (ii), Q → (iii), R → (iv), S → (i) |
| B. | P → (ii), Q → (i), R → (iii), S → (iv) |
| C. | P → (iii), Q → (iv), R → (i), S → (ii) |
| D. | P → (i), Q → (iv), R → (ii), S → (iii) |
| Answer» D. P → (i), Q → (iv), R → (ii), S → (iii) | |
| 3. |
Consider the basic block given below.a = b + cc = a + dd = b + ce = d - ba = e + bThe minimum number of nodes and edges present in the DAG representation of the above basic block respectively are |
| A. | 6 and 6 |
| B. | 8 and 10 |
| C. | 9 and 12 |
| D. | 4 and 4 |
| Answer» B. 8 and 10 | |
| 4. |
Consider the intermediate code given below.1) i = 12) j = 13) t1 = 5 ∗ i4) t2 = t1 + j5) t3 = 4 ∗ t26) t4 = t37) a[t4] = - 18) j = j + 19) if j < = 5 goto (3)10) i = i + 111) 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 |
| Answer» C. 5 and 5 | |
| 5. |
Generation of intermediate code based on an abstract machine model is useful in compilers because: |
| A. | Syntax translations are easier for intermediate code generation |
| B. | It is difficult to generate executable code from high level language program. |
| C. | It enhances the portability of the compiler system program |
| D. | It makes implementation of lexical and syntax analysis easier |
| Answer» D. It makes implementation of lexical and syntax analysis easier | |
| 6. |
A variable x is said to be live at a statement Si in a program if the following three conditions hold simultaneously:i. There exists a statement Sj that uses xii. There is a path from Si to Sj in the flow graph corresponding to the programiii. The path has no intervening assignment to x including at Si and SjThe 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 |
| Answer» D. q, v | |
| 7. |
Consider the following intermediate program in three address code:p = a – bq = p * cp = u * vq = p + qWhich one of the following corresponds to a static single assignment form of the above code? |
| A. | p1 = a - bq1 = p1 * cp1 = u * vq1 = p1 + q1 |
| B. | p3 = a – bq4 = p3 * cp4 = u * vq5 = p4 + q4 |
| C. | p1 = a – bq1 = p2 * cp3 = u * vq2 = p4 + q3 |
| D. | p1 = a – bq1 = p * cp2 = u * vq2 = p + q |
| Answer» C. p1 = a – bq1 = p2 * cp3 = u * vq2 = p4 + q3 | |
| 8. |
Which of these does not belong to CFG? |
| A. | Terminal Symbol |
| B. | Non terminal Symbol |
| C. | Start symbol |
| D. | End Symbol |
| Answer» E. | |
| 9. |
A CFG is closed under |
| A. | Union |
| B. | Kleene star |
| C. | Concatenation |
| D. | None of the mentioned |
| Answer» E. | |
| 10. |
A regular Grammar is a |
| A. | CFG |
| B. | Non CFG |
| C. | English Grammar |
| D. | None of the mentioned |
| Answer» B. Non CFG | |
| 11. |
Push down automata accepts which language |
| A. | Context sensitive language |
| B. | Context free language |
| C. | Recursive language |
| D. | None of the mentioned |
| Answer» C. Recursive language | |
| 12. |
The context free grammar S ‚Üí SS | 0S1 | 1S0 | …õ generates$ |
| A. | Equal number of 0’s and 1’s |
| B. | Unequal number of 0’s and 1’s |
| C. | Number of 0’s followed by any number of 1’s |
| D. | None of the mentioned |
| Answer» B. Unequal number of 0‚Äö√Ñ√∂‚àö√ë‚àö¬•s and 1‚Äö√Ñ√∂‚àö√ë‚àö¬•s | |
| 13. |
The context free grammar S ‚Üí A111|S1, A ‚Üí A0 | 00 is equivalent to$ |
| A. | {0ⁿ1ᵐ | n=2, m=3} |
| B. | {0ⁿ1ᵐ | n=1, m=5} |
| C. | {0ⁿ1ᵐ | n should be greater than two and m should be greater than four} |
| D. | None of these |
| Answer» B. {0‚Äö√Ñ√∂‚àö√ñ‚àö‚àè1¬¨‚à묨¬µ‚àö‚Ñ¢ | n=1, m=5} | |