Recent questions tagged goclasses-compiler-practice-questions

A lexical analyzer is designed for a new language with the following rules for token generation:$\mathrm{KEYWORD1}: \verb|if|$ $\mathrm{KEYWORD2}: \verb|iff|$ $\mathrm{ID...

Consider the following arammar $G$ :$$\begin{aligned}& S \rightarrow(L) \mid a \\& L \rightarrow L, S \mid S\end{aligned}$$Which of the following statement(s) is/are TRUE...

Consider a Bottom-Up parser for a grammar $G$. During the parsing of an input string $w$, the parser reaches a configuration where the stack contains the prefix $\alpha$ ...

Which of the following statement(s) is/are TRUE regarding Lexical Analysis and Regular Expressions?The number of states in a minimal Deterministic Finite Automaton (DFA) ...

Consider the following Syntax Directed Translation (SDT) scheme where $S$ is the start symbol and $id.\mathrm{val}$ represents the numerical value of an identifier:$$\beg...

A lexical analyzer for a specific language identifies tokens using the following regular expressions:$$\begin{aligned}& L_1: a(a \mid b)^* \\& L_2: a b(a \mid b)^* \\& L_...

Consider the following basic block of intermediate code:1. a = 10 2. b = a + 5 3. c = b * 2 4. a = c - b 5. d = a + bAssuming that only the variable $\verb|d|$ is "live" ...

Consider the following L-attributed Syntax Directed Definition (SDD). $S$ is the start symbol, and S.val is a synthesized attribute. A.inh is an inherited attribute.$S \r...

In the context of Code Optimization, consider the following code segment inside a loop:for (i = 0; i < n; i++) { x = y + z; a[i] = 2 * i + x; }Moving the statemen...

Consider the following syntax-directed translation scheme (SDTS) where $S$ is the start symbol:$$\begin{aligned}& S \rightarrow E\{\text { print }(\text { E.val })\} \\& ...

Consider the following grammar $g$ :$$\begin{gathered}s \rightarrow l=r \mid r \\l \rightarrow * r \mid i d \\r \rightarrow l\end{gathered}$$Which of the following statem...

Consider the following basic block of three-address code:$\mathrm{t 1=a+b}$ $\mathrm{t 2=c* d}$ $\mathrm{t} 3=\mathrm{t} 1+\mathrm{t} 2$ $\mathrm{a=t 3}$ $\mathrm{t 4=c*d...

Consider the following regular expression over the alphabet $\{a, b\}$ used for a lexical analyzer token definition:$$R=(a+b)^*(a a+b b)(a+b)^*$$Which of the following de...

Consider the following SDT scheme used to evaluate an expression. The synthesized attribute $\mathrm{val}$ stores the numerical value.\[\begin{aligned}E &\rightarrow E_1 ...

Consider the following grammar $G$ with terminal set $\Sigma=\{a, b, c, d\}$ and non-terminal set $V=\{S, A, B\}$ :$$\begin{gathered}S \rightarrow a A b \mid b B a \\A \r...

Consider the following sequence of three-address code (TAC) instructions:1. i = 1 2. j = 1 3. t1 = 5 * i 4. t2 = t1 + j 5. a[t2] = 0 6. j = j + 1 7. if j <= 5 goto (3) 8....

Consider the following grammar $G$ with start symbol $S$ :$$\begin{aligned}& S \rightarrow L=R \\& S \rightarrow R \\& L \rightarrow * R \\& L \rightarrow i d . \\& R \ri...

Consider the following basic block of Three-Address Code:1. a = 1 2. b = a + 1 3. c = a + b 4. a = c + b 5. return aA variable is live at a point if its current value wil...

Consider the following Syntax-Directed Translation (SDT) scheme with the grammar rules and actions provided below:$$\begin{aligned}& S \rightarrow S_1 \# T\left\{S . \mat...

Consider the following lexical specification for a scanner:$\mathrm{KEYWORD\_IF: \verb|if|}$ $\mathrm{ID: [a-z][0-9]*}$ $\mathrm{NUM: [0-9]+}$ The scanner follows the Lon...

Consider the following three-address code sequence used for a loop:i = 0 L1: t1 = i * 4 t2 = base + t1 val = load t2 i = i + 1 if i < 100 goto L1Which optimization techni...

An $\mathrm{LR(1)}$ parser is being constructed for a grammar. If a particular state in the corresponding $\mathrm{LR}(1)$ canonical collection contains the item $[A \rig...

In a compiler's optimization phase, a Directed Acyclic Graph (DAG) is often used instead of a standard syntax tree to represent expressions. Consider the expression: $a=(...

Consider a syntax tree for the expression $a+b * c-d / e$. If the expression is evaluated using a post-order traversal of this tree, and the values at the leaves are $a=2...

Consider the expression tree shown below. Each leaf represents a numerical value, which can be chosen from the set $\{-1,1\}$. Over all possible choices of the values at ...

Consider the following basic block consisting of three-address code instructions. Assume that only the variable $\verb|x|$ is "live" at the exit of this basic block.1. a ...

Consider the following C-style code segment:while (a < b) { if (c < d) x = y + z; else x = y - z; }Assume this code is translated into Three-Address Code (TAC) us...

In a compiler's optimization phase, a Directed Acyclic Graph (DAG) is constructed for the following basic block:1. t1 = a + b 2. t2 = c * d 3. t3 = t1 + t2 4. t4 = a + b ...

Consider the following S-attributed SDT scheme used to calculate the value of an expression. The grammar generates simple arithmetic additions and is suitable for an LR p...

Consider the following regular expression over the alphabet $\Sigma=\{a, b\}$ that represents a specific class of tokens in a new programming language:$$r=(a+b)^* a b b$$...