Explore: GATE CS hub · All GATE CS topics · Syllabus & pattern · GATE CS 2026
Answer first
Compiler Design has appeared in 11 of the 11 official GATE CS papers from 2016–2026, with 44 questions in all. It averages 6.1 marks a year, which puts it 11th of 11 technical subjects. The last three papers gave it 7 (2026), 6 (2025), 8 (2024).
The concepts that came back most often are Parsing, Syntax-Directed Translation, Basic Blocks & CFG. Parsing, Syntax-Directed Translation appeared in at least 7 of the 11 years. 30% of the questions are NAT, so you have to work out an exact value with no options to eliminate.
Marks per year
One official set per year (set 1 where GATE CS ran two sessions). Marks are as printed in the official answer key.
| Year | Questions | Marks |
|---|---|---|
| GATE CS 2026 | 5 | 7 |
| GATE CS 2025 | 4 | 6 |
| GATE CS 2024 | 5 | 8 |
| GATE CS 2023 | 5 | 8 |
| GATE CS 2022 | 3 | 4 |
| GATE CS 2021 | 5 | 8 |
| GATE CS 2020 | 3 | 4 |
| GATE CS 2019 | 4 | 6 |
| GATE CS 2018 | 3 | 5 |
| GATE CS 2017 | 4 | 6 |
| GATE CS 2016 | 3 | 5 |
Most-asked concepts
Sorted by how many years a concept appeared in, then by marks.
| Concept | Questions | Marks | Years asked |
|---|---|---|---|
| Parsing | 15 | 20 | 2026, 2025, 2024, 2022, 2021, 2020, 2019, 2018, 2017 |
| Syntax-Directed Translation | 8 | 16 | 2026, 2024, 2023, 2022, 2021, 2020, 2019, 2016 |
| Basic Blocks & CFG | 3 | 6 | 2026, 2025, 2024 |
| Intermediate Code | 3 | 4 | 2021, 2017, 2016 |
| Lexical Analysis | 3 | 4 | 2026, 2023, 2018 |
| Runtime Environment | 3 | 4 | 2023, 2021, 2020 |
| Liveness Analysis | 2 | 3 | 2025, 2023 |
| Operator Precedence | 2 | 3 | 2024, 2016 |
| Compiler Phases | 2 | 2 | 2023, 2018 |
| Code Generation | 1 | 2 | 2017 |
| Grammars | 1 | 2 | 2017 |
| Symbol Table | 1 | 1 | 2025 |
How to practise Compiler Design from these PYQs
- Start with the concepts at the top of the table above. They repeat, so they pay off first.
- Open the official PDF for a year, solve only that year’s Compilers questions against the clock (about 3 minutes a mark), then check the official key listed below.
- Log each miss by concept and type (MCQ, MSQ, NAT). An MSQ with one extra option scores zero, so log those separately.
- Once a concept is clean across two or three years, move on to the next one.
- Then sit a full year paper from the GATE CS hub so the subject drill turns into exam timing.
Questions by year
Each line gives the official question number, marks, type and concept, our one-line summary and the official key. The full question is in the official PDF linked under each year.
GATE CS 2026 (CS1)
- Q.25 · 1 mark · MSQ · Parsing: Ambiguity and derivations of a small grammar (key: A, B, C)
- Q.27 · 1 mark · MSQ · Lexical Analysis: Lexical versus syntax errors in C string declarations (key: C)
- Q.28 · 1 mark · MSQ · Parsing: True statements about LL(1) grammars and parsers (key: C)
- Q.42 · 2 marks · MCQ · Basic Blocks & CFG: Common subexpressions in basic blocks of a flow graph (key: D)
- Q.53 · 2 marks · MSQ · Syntax-Directed Translation: S-attributed vs L-attributed type-declaration SDDs (key: A, B, D)
Paper: official PDF · GATE CS 2026 page
GATE CS 2025 (CS1)
- Q.12 · 1 mark · MCQ · Symbol Table: False statement about the role and implementation of a symbol table (key: C)
- Q.13 · 1 mark · MCQ · Liveness Analysis: Which code optimisation uses live variable analysis (key: B)
- Q.46 · 2 marks · MSQ · Parsing: True statements about computing First and Follow sets (key: A, D)
- Q.52 · 2 marks · NAT · Basic Blocks & CFG: Number of basic blocks in a three-address code sequence (key: 6)
Paper: official PDF · GATE CS 2025 page
GATE CS 2024 (CS1)
- Q.26 · 1 mark · MSQ · Parsing: Which parsers are bottom-up parsers (key: A, D)
- Q.33 · 1 mark · NAT · Operator Precedence: Value of an expression under custom precedence and associativity rules (key: 6)
- Q.37 · 2 marks · MCQ · Syntax-Directed Translation: Value computed by an SDD that converts Roman-numeral strings (key: A)
- Q.38 · 2 marks · MCQ · Parsing: Complete grammar productions so that the grammar is LL(1) (key: A)
- Q.39 · 2 marks · MCQ · Basic Blocks & CFG: Number of basic blocks and edges in a three-address code fragment (key: D)
Paper: official PDF · GATE CS 2024 page
GATE CS 2023
- Q.11 · 1 mark · MCQ · Compiler Phases: Which statements about compiler front-end and back-end phases are correct (key: B)
- Q.19 · 1 mark · MCQ · Lexical Analysis: NFA that recognises an identifier token defined by a regular expression (key: C)
- Q.36 · 2 marks · MCQ · Runtime Environment: Activation tree for a program with nested and recursive calls (key: A)
- Q.37 · 2 marks · MCQ · Liveness Analysis: Live variables at the exit of each basic block in a control flow graph (key: D)
- Q.60 · 2 marks · NAT · Syntax-Directed Translation: Value computed by an SDT that converts a binary fraction string (key: 2.374–2.376)
Paper: official PDF · GATE CS 2023 page
GATE CS 2022
- Q.13 · 1 mark · MCQ · Parsing: True statement about LALR/LR conflicts, symbol tables and compiler phases (key: D)
- Q.29 · 1 mark · NAT · Parsing: Number of LR(0) items in a goto of a closure set (key: 5)
- Q.65 · 2 marks · NAT · Syntax-Directed Translation: Evaluate an expression using translation rules with custom operators (key: 80)
Paper: official PDF · GATE CS 2022 page
GATE CS 2021 (set 1)
- Q.4 · 1 mark · MCQ · Runtime Environment: Procedure calls and returns as traversals of the activation tree (key: C)
- Q.5 · 1 mark · MCQ · Parsing: Statements on SLR(1) grammars and general CFG parsing time (key: C)
- Q.26 · 2 marks · MCQ · Syntax-Directed Translation: Type-checking actions of an SDT for declarations and expressions (key: B)
- Q.31 · 2 marks · MCQ · Parsing: Fill missing entries in an LL(1) parsing table (key: A)
- Q.50 · 2 marks · NAT · Intermediate Code: Number of nodes in the DAG of a basic block (key: 6)
Paper: official PDF · GATE CS 2021 page
GATE CS 2020
- Q.9 · 1 mark · MCQ · Runtime Environment: Statements on symbol tables, heap storage and semantic errors (key: D)
- Q.24 · 1 mark · NAT · Parsing: Reduction steps a bottom-up parser takes for a given string (key: 7)
- Q.33 · 2 marks · MCQ · Syntax-Directed Translation: Which attribute rules are L-attributed (key: B)
Paper: official PDF · GATE CS 2020 page
GATE CS 2019
- Q.3 · 1 mark · MCQ · Parsing: Kind of derivation used by LR parsers (key: D)
- Q.19 · 1 mark · NAT · Parsing: FOLLOW set of a non-terminal in a small grammar (key: 31)
- Q.36 · 2 marks · MCQ · Syntax-Directed Translation: Fill placeholders in inherited-attribute semantic rules (key: A)
- Q.43 · 2 marks · NAT · Parsing: Number of LR(0) items in a GOTO set (key: 5)
Paper: official PDF · GATE CS 2019 page
GATE CS 2018
- Q.8 · 1 mark · MCQ · Compiler Phases: Identify the false statement about compiler phases (key: B)
- Q.37 · 2 marks · MCQ · Lexical Analysis: Token sequence produced by longest-match lexing (key: D)
- Q.38 · 2 marks · MCQ · Parsing: Precedence and associativity implied by a parse tree (key: A)
Paper: official PDF · GATE CS 2018 page
GATE CS 2017 (set 1)
- Q.12 · 1 mark · MCQ · Intermediate Code: Pick the SSA form of a three-address code fragment (key: B)
- Q.17 · 1 mark · MCQ · Parsing: Compute the FOLLOW set of a nonterminal (key: C)
- Q.43 · 2 marks · NAT · Grammars: Number of control flow paths in a program with ten if statements (key: 1024.0)
- Q.52 · 2 marks · NAT · Code Generation: Minimum registers to evaluate an expression without spills (key: 2.0)
Paper: official PDF · GATE CS 2017 page
GATE CS 2016 (set 1)
- Q.19 · 1 mark · NAT · Intermediate Code: Minimum variables to convert code to SSA form (key: 10.0 : 10.0)
- Q.45 · 2 marks · NAT · Operator Precedence: Evaluate an expression with unusual precedence and associativity (key: 9.0 : 9.0)
- Q.46 · 2 marks · MCQ · Syntax-Directed Translation: Output printed by a bottom-up parse using an SDTS (key: C)
Paper: official PDF · GATE CS 2016 page
Other GATE CS subjects
- General Aptitude
- Engineering Mathematics
- Discrete Mathematics
- Digital Logic
- Computer Organization & Architecture
- Programming & Data Structures
- Algorithms
- Theory of Computation
- Operating Systems
- Databases (DBMS)
- Computer Networks
FAQ
How many marks does Compiler Design carry in GATE CS?
Across the official GATE CS papers from 2016–2026 (one set per year), Compiler Design carried 6.1 marks a year on average, from 4 in 2022 to 8 in 2024.
Which Compiler Design topics repeat most in GATE CS?
By the number of years they appeared in: Parsing, Syntax-Directed Translation, Basic Blocks & CFG. The concept table on this page lists every concept with its question count and years.
Are these the official GATE CS Compiler Design questions?
Yes. Each question comes from the official GATE CS question paper for that year, and the key, marks and question type come from the official answer key. Summaries are ours; open the official PDF for the full question.
What question types does Compiler Design use in GATE CS?
Of 44 questions: 25 MCQ, 6 MSQ and 13 NAT. MSQ only appears from 2021 onwards. 23 of the 44 questions carry 2 marks.