# Computer Architecture: Quiz
1. Assume the base address of array `A[]` is stored in register `s0`. Describe what the following RISC-V instructions (RV32I) do:
```clike
lw t0, 0(s0)
lw t1, 8(s0)
add t2, t0, t1
sw t2, 4 (s0)
```
2. Inside a procedure the following code is found:
```clike
testproced:
addi sp, sp, -12
sw ra, 0(sp)
sw s0, 4(sp)
sw s1, 8(sp)
...
```
Answer the questions below:
a) what might be a reason be for saving the return address on the stack?
b) why is the stack pointer decremented by 12?
c) show the last 4 lines of this procedure which immediately precede the return from procedure instruction (or jalr instruction):