1. What is the primary function of a Just-in-Time (JIT) compiler?
A) To compile the entire program at once before execution
B) To optimize the code at runtime, converting intermediate code into machine code
C) To generate machine code before the program starts
D) To interpret the code without compiling it
Answer: B) To optimize the code at runtime, converting intermediate code into machine code
2. Which of the following is an advantage of JIT compilation?
A) Faster initial startup time
B) Better runtime performance through optimization
C) The program is fully compiled before execution
D) Less memory usage compared to ahead-of-time compilation
Answer: B) Better runtime performance through optimization
3. Which of the following is a disadvantage of Just-in-Time (JIT) compilation?
A) Increased memory usage during program execution
B) Faster execution time for every program
C) Reduced startup time
D) Compilation of code during the startup phase of a program
Answer: A) Increased memory usage during program execution
4. What is the main purpose of Hot Spot detection in JIT compilation?
A) To identify parts of the code that are least executed
B) To dynamically allocate memory based on program usage
C) To identify the most frequently executed code sections for optimization
D) To reduce the size of the code for faster execution
Answer: C) To identify the most frequently executed code sections for optimization
5. In which scenario is JIT compilation most beneficial?
A) When compiling simple, one-time programs with no optimizations needed
B) For programs that require rapid execution with no runtime optimizations
C) For programs with complex runtime behavior and frequently called functions
D) For applications where performance is not critical
Answer: C) For programs with complex runtime behavior and frequently called functions
6. Which of the following is true about JIT compilation in the context of managed code (e.g., Java, .NET)?
A) JIT compilation is used to execute code without any machine-specific optimizations
B) The code is compiled to an intermediate bytecode format that runs on a virtual machine
C) The compiler generates the final machine code before the program runs
D) JIT compilers perform compilation on hardware instead of software
Answer: B) The code is compiled to an intermediate bytecode format that runs on a virtual machine
7. Which of the following is NOT typically an optimization performed by a JIT compiler?
A) Inlining frequently used functions
B) Loop unrolling
C) Dead code elimination
D) Ahead-of-time compilation for the entire program
Answer: D) Ahead-of-time compilation for the entire program
8. What is the difference between JIT compilation and Ahead-of-Time (AOT) compilation?
A) JIT compilation happens during execution, while AOT compilation happens before execution
B) JIT compilation happens only in low-level programming languages
C) AOT compiles code at runtime, while JIT compiles code before execution
D) JIT and AOT are the same, just named differently
Answer: A) JIT compilation happens during execution, while AOT compilation happens before execution
9. Which of the following does JIT compilation rely on to generate optimized machine code during execution?
A) Profiling the execution to identify performance bottlenecks
B) Static analysis of the source code before execution
C) Generating code for all branches of the program
D) Using a precompiled lookup table
Answer: A) Profiling the execution to identify performance bottlenecks
10. Which of the following languages typically uses JIT compilation for performance optimization?
A) C
B) Java
C) Assembly
D) C++
Answer: B) Java
11. What is the role of runtime profiling in JIT compilation?
A) To check syntax errors during execution
B) To track the execution flow of the program and guide the compiler in optimization
C) To optimize memory usage only
D) To compile the entire code before execution
Answer: B) To track the execution flow of the program and guide the compiler in optimization
12. Which of the following JIT compilation techniques aims to improve performance by reducing the number of method calls during program execution?
A) Method inlining
B) Code hoisting
C) Loop fusion
D) Code motion
Answer: A) Method inlining
13. Which of the following JIT compiler optimizations can improve cache performance?
A) Loop unrolling
B) Function inlining
C) Code caching
D) Code garbage collection
Answer: C) Code caching
14. Which of the following describes a cold spot in JIT compilation?
A) A section of code that is frequently executed and optimized
B) A section of code that is rarely executed and thus not worth optimizing
C) A section of code that is executed with a high frequency but is not optimized
D) A section of code that causes compilation errors
Answer: B) A section of code that is rarely executed and thus not worth optimizing
15. Which of the following is an example of a JIT compilation challenge?
A) Excessive memory usage for storing optimized machine code
B) Lack of intermediate code representation
C) Optimizing code during the program’s startup phase
D) Generating code before execution
Answer: A) Excessive memory usage for storing optimized machine code