JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech III COMPILER DESIGN Previous Question Paper (July - 2023 - R16)

A finite automaton is a mathematical model of computation consisting of a finite set of states and a set of transitions from state to state that occur on input symbols. It is defined by a 5-tuple (Q, Σ, δ, q₀, F), where Q is a finite set of states, Σ is a finite set of input symbols (alphabet), δ is the transition function mapping (Q × Σ) to Q, q₀ is the start state, and F is the set of final or accepting states.

In compiler design, a phase represents a logically distinct stage of the compilation process that performs a specific task, such as lexical analysis, syntax analysis, or code generation. A pass refers to a single traversal of the entire source program or its intermediate representation by the compiler to perform one or more phases.

Key differences include:

• Multiple phases can be combined into a single pass to improve efficiency by reducing the number of times the compiler reads and writes to memory or disk.
• A phase is defined by its functional role in the translation process, whereas a pass is defined by the physical traversal of the code structure.
• Compilers are often designed to minimize the number of passes to reduce compilation time, even if the process involves several distinct logical phases.