Bird
0
0

You want to write a recursive ARM assembly function to compute the nth Fibonacci number. Which of these is essential to correctly implement recursion here?

hard📝 Application Q15 of 15
ARM Architecture - Subroutines and Stack
You want to write a recursive ARM assembly function to compute the nth Fibonacci number. Which of these is essential to correctly implement recursion here?
AHandle base cases to stop recursion and save LR on stack before recursive calls
BUse only registers without stack to speed up recursion
CAvoid base cases to allow infinite recursion for all n
DUse unconditional jumps instead of BL for recursive calls
Step-by-Step Solution
Solution:

  1. Step 1: Importance of base cases

    Base cases stop recursion to prevent infinite loops, essential for Fibonacci calculation.

  2. Step 2: Save LR on stack before recursive calls

    Saving LR preserves return addresses during multiple recursive calls, avoiding crashes.

  3. Final Answer:

    Handle base cases to stop recursion and save LR on stack before recursive calls -> Option A

  4. Quick Check:

    Base cases + LR save = correct recursion [OK]
Quick Trick: Always include base cases and save LR in recursion [OK]
Common Mistakes:
  • Skipping base cases causing infinite recursion
  • Not saving LR causing return errors
  • Using jumps instead of BL for calls

Want More Practice?

15+ quiz questions · All difficulty levels · Free

Free Signup - Practice All Questions
More ARM Architecture Quizzes
Bus Architecture - DMA controller on bus - Quiz 14medium Bus Architecture - Bus matrix for multi-master access - Quiz 4medium Control Flow Instructions - Loop implementation in assembly - Quiz 14medium Control Flow Instructions - Why branching controls program execution - Quiz 7medium Exception and Interrupt Model - Why exceptions handle hardware events - Quiz 12easy Exception and Interrupt Model - NVIC (Nested Vectored Interrupt Controller) - Quiz 3easy Exception and Interrupt Model - Exception priority levels - Quiz 4medium Subroutines and Stack - Why subroutines enable modular assembly code - Quiz 11easy Subroutines and Stack - Return value in R0 - Quiz 15hard Subroutines and Stack - Preserving callee-saved registers - Quiz 1easy