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Consider the following two sets of LR(1) items of an LR(1) grammar. X -> c.X, c/d X -> .cX, c/d X -> .d, c/d X -> c.X, $ X -> .cX, $ X -> .d, $ Which of the following statements related to merging of the two sets in thecorresponding LALR parser is/are FALSE? 1) Cannot be merged since look aheads are different. 2) Can be merged but will result in S-R conflict. 3) Can be merged but will result in R-R conflict. 4) Cannot be merged since goto on c will lead to two different sets.


A) 1 only
B) 2 only
C) 1 and 4 only
D) 1, 2, 3, and 4

E) C) and D)
F) A) and C)

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Which of the following statements are TRUE? I. There exist parsing algorithms for some programming languages whose complexities are less than O( n3) . II. A programming language which allows recursion can be implemented with static storage allocation. III. No L-attributed definition can be evaluated in the framework of bottom-up parsing. IV. Code improving transformations can be performed at both source language and intermediate code level.


A) I and II
B) I and IV
C) III and IV
D) I, III and IV

E) A) and D)
F) C) and D)

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B

Consider the grammar S ? (S) | a Let the number of states in SLR(1) , LR(1) and LALR(1) parsers for the grammar be n1, n2 and n3 respectively. The following relationship holds good


A) n1 < n2 < n3
B) n1 = n3 < n2
C) n1 = n2 = n3
D) n1 ? n3 ? n2

E) All of the above
F) B) and C)

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Consider the following two statements: P: Every regular grammar is LL(1) Q: Every regular set has a LR(1) grammar Which of the following is TRUE?


A) Both P and Q are true
B) P is true and Q is false
C) P is false and Q is true
D) Both P and Q are false

E) B) and D)
F) B) and C)

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The lexical analysis for a modern computer language such as Java needs the power of which one of the following machine models in a necessary and sufficient sense?


A) Finite state automata
B) Deterministic pushdown automata
C) Non-Deterministic pushdown automata
D) Turing Machine

E) A) and B)
F) A) and C)

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Which one of the following statements is FALSE?


A) Context-free grammar can be used to specify both lexical and syntax rules.
B) Type checking is done before parsing.
C) High-level language programs can be translated to different Intermediate Representations.
D) Arguments to a function can be passed using the program stack.

E) None of the above
F) B) and C)

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B

Consider the grammar defined by the following production rules, with twooperators ? and + S --> T * P T --> U | T * U P --> Q + P | Q Q --> Id U --> Id Which one of the following is TRUE?


A) + is left associative, while ? is right associative
B) + is right associative, while ? is left associative
C) Both + and ? are right associative
D) Both + and ? are left associative

E) A) and D)
F) All of the above

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The grammar S ? aSa | bS | c is


A) LL(1) but not LR(1)
B) LR(1) but not LR(1)
C) Both LL(1) and LR(1)
D) Neither LL(1) nor LR(1)

E) C) and D)
F) None of the above

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Which of the following describes a handle (as applicable to LR-parsing) appropriately?


A) It is the position in a sentential form where the next shift or reduce operation will occur
B) It is non-terminal whose production will be used for reduction in the next step
C) It is a production that may be used for reduction in a future step along with a position in the sentential form where the next shift or reduce operation will occur
D) It is the production p that will be used for reduction in the next step along with a position in the sentential form where the right hand side of the production may be found

E) B) and C)
F) B) and D)

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Consider the following grammar. S -> S * E S -> E E -> F + E E -> F F -> id Consider the following LR(0) items corresponding to the grammar above. (i) S -> S * .E (ii) E -> F. + E (iii) E -> F + .E Given the items above, which two of them will appear in the same set in the canonicalsets-of-items for the grammar?


A) (i) and (ii)
B) (ii) and (iii)
C) (i) and (iii)
D) None of the above

E) B) and C)
F) All of the above

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Consider the following statements related to compiler construction : I. Lexical Analysis is specified by context-free grammars and implemented by pushdown automata. II. Syntax Analysis is specified by regular expressions and implemented by finite-state machine. Which of the above statement(s) is/are correct?


A) Only I
B) Only II
C) Both I and II
D) Neither I nor II

E) A) and C)
F) All of the above

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D

In compiler optimization, operator strength reduction uses mathematical identities to replace slow math operations with faster operations. Which of the following code replacements is an illustration of operator strength reduction?


A) Replace P + P by 2 * P or Replace 3 + 4 by 7.
B) Replace P * 32 by P < < 5
C) Replace P * 0 by 0
D) Replace (P < <4) - P by P * 15

E) None of the above
F) A) and C)

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The number of tokens in the following C statement is printf("i=%d, &i=%x", i&i) ;


A) 13
B) 6
C) 10
D) 9

E) B) and D)
F) A) and C)

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Consider the following statements: (I) The output of a lexical analyzer is groups of characters. (II) Total number of tokens in printf("i=%d, &i=%x", i, &i) ; are 11. (III) Symbol table can be implementation by using array and hash table but not tree. Which of the following statement(s) is/are correct?


A) Only (I)
B) Only (II) and (III)
C) All (I) , (II) , and (III)
D) None of these

E) C) and D)
F) All of the above

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Which of the following statement(s) regarding a linker software is/are true? I. A function of a linker is to combine several object modules into a single load module. II. A function of a linker is to replace absolute references in an object module by symbolic references to locations in other modules.


A) Only I
B) Only II
C) Both I and II
D) Neither I nor II

E) B) and C)
F) C) and D)

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Consider the following translation scheme. S ? ER R ? *E{print("*") ;}R | ? E? F + E {print("+") ;} | F F ? (S) | id {print(id.value) ;} Here id is a token that represents an integer and id.value represents the corresponding integer value. For an input '2 * 3 + 4', this translation scheme prints


A) 2 * 3 + 4
B) 2 * +3 4
C) 2 3 * 4 +
D) 2 3 4+*

E) A) and D)
F) A) and C)

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The grammar A ? AA | (A) | ? is not suitable for predictive-parsing because the grammar is


A) ambiguous
B) left-recursive
C) right-recursive
D) an operator-grammar

E) C) and D)
F) B) and D)

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From the given data below : a b b a a b b a a b which one of the following is not a word in the dictionary created by LZ-coding (the initial words are a, b) ?


A) a b
B) b b
C) b a
D) b a a b

E) A) and B)
F) A) and C)

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An LALR(1) parser for a grammar G can have shift-reduce (S-R) conflicts if and only if


A) the SLR(1) parser for G has S-R conflicts
B) the LR(1) parser for G has S-R conflicts
C) the LR(0) parser for G has S-R conflicts
D) the LALR(1) parser for G has reduce-reduce conflicts

E) A) and B)
F) None of the above

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In a compiler, keywords of a language are recognized during


A) parsing of the program
B) the code generation
C) the lexical analysis of the program
D) dataflow analysis

E) B) and D)
F) B) and C)

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