Nios II Assembly, https://cpulator.01xz.net/?sys=nios-de10-lite :

Suppose we have the following body of a function foo: / [function prologue here] add mov slli r12, r6, 4 mul r2, r4, r5 r6, r4 r16, r2, r12 sub r18, r2, r12 r2, r16, r18 add According to the Nios ABI, which registers must it save to the stack in the function prologue? Select all that apply: r2 Ir6 r12 r16 r17 r18 If this function also called another function before the sub instruction, which additional register(s) would we have to save to the stack? r2 r4 r12 r16 r17 r18 Isp ra