Folding a constant into the instruction
When you add a small constant, the compiler doesn't load it into a register first — it uses the immediate form addi rD, rA, imm:
addi r3, r3, 1 ; r3 = r3 + 1
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Immediates are signed 16-bit, so the same addi handles subtraction of a constant too (x - 5 → addi r3, r3, -5). No separate instruction needed.
Your task
Write increment, returning x + 1.