Register Allocation and Assignment MCQs January 8, 2026December 14, 2024 by u930973931_answers 15 min Score: 0 Attempted: 0/15 Subscribe 1. What is the main goal of register allocation in code generation? (A) To minimize the number of instructions (B) To assign variables to machine registers efficiently (C) To optimize the high-level language code (D) To detect runtime errors 2. Which of the following is a common technique used for register allocation? (A) Syntax analysis (B) Linear scan (C) Code optimization (D) Loop unrolling 3. Which of the following factors affects the register allocation process? (A) The number of instructions in the intermediate code (B) The syntax of the high-level language (C) The number of available registers in the target machine (D) The type of compiler being used 4. What does “register spilling” refer to in register allocation? (A) Storing values in registers that are not needed (B) Moving data from registers to memory when there are not enough registers (C) Removing unnecessary instructions (D) Allocating more registers than required 5. What is the primary task of a register allocator in a compiler? (A) Assign values to specific memory locations (B) Ensure that variables are only accessed through registers (C) Allocate variables to CPU registers and manage their lifetimes (D) Generate machine-specific assembly code 6. Which of the following is a common approach to register assignment? (A) Syntax tree traversal (B) Graph coloring (C) Loop invariant code motion (D) Constant folding 7. What is a “live range” in the context of register allocation? (A) The amount of time a variable is used in the program (B) The number of instructions a variable is involved in (C) The maximum number of registers available (D) The period during which a variable is stored in a register 8. Why is register allocation important in compiler design? (A) To optimize the execution of a program by minimizing memory access (B) To ensure that the program adheres to the target language’s syntax (C) To detect errors in the code (D) To generate intermediate code efficiently 9. Which of the following is an example of a situation where register spilling occurs? (A) When the number of registers available exceeds the number of variables (B) When multiple variables need to be assigned to the same register (C) When the number of live variables exceeds the number of available registers (D) When a variable is not used during the execution of the program 10. In a graph coloring approach to register allocation, what does each node represent? (A) An instruction in the intermediate code (B) A memory address (C) A variable or a register (D) A function call 11. What is the purpose of interference graphs in register allocation? (A) To represent the relationships between variables that cannot share the same register (B) To track the locations of variables in memory (C) To optimize instruction selection (D) To optimize code execution time 12. Which of the following is a disadvantage of register spilling? (A) It reduces the number of registers available (B) It increases the execution time due to memory accesses (C) It simplifies the code generation phase (D) It improves the program’s memory access speed 13. Which of the following is an example of a register allocation algorithm? (A) Mark-and-sweep algorithm (B) The Chaitin-Briggs algorithm (C) Dynamic programming algorithm (D) Depth-first search algorithm 14. What is the impact of a poor register allocation strategy? (A) The program will use more memory and experience slower execution (B) The program will have improved performance (C) The code will be simpler and easier to understand (D) The program will have fewer errors 15. What does “coalescing” mean in the context of register assignment? (A) Removing unnecessary registers from the code (B) Splitting variables into multiple registers to reduce spilling (C) Assigning variables to registers that are not live (D) Combining variables into fewer registers to optimize register usage