ChallengesRISC-V

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All challengesRISC-VIntermediate25 min0 submissions

RISC-V challenge

Call a multiply function

Return 6 × 7 through a0 and print 42.

Complete multiply without changing main's call site. Follow the RV32 ABI: arguments and the return value use a0/a1 and ret returns through ra.

Learning goals

Call with JAL
Return through RA
Use the RV32M multiply instruction

Tests

Program exits cleanly
t0 preserves the returned 42
Terminal prints 42
Solution calls with JAL
Solution uses MUL
1 hidden grading test

Hints

riscv-call-product.sRISC-V source

.text
.globl main
main:
  li a0, 6
  li a1, 7
  jal ra, multiply
  mv t0, a0
  li a7, 1
  ecall
  li a7, 10
  ecall

multiply:
  # TODO: return a0 * a1 in a0
  ret

Run the visible tests or submit when you are ready.