如何在 RISC-V 程序集中使用数组

Question

I'm learning RISC-V assembly and i need to use array for an exercise that i'm solving; the problem is that the simulator that i'm using( RARS ) gave me an error:
Error in /home/username/file_name line 8: Runtime exception at 0x00400010: address out of range 0x000003e8.

This is the code i wrote so far:

.data
arr: .word 1000
e0: .word 5

.text
lw t1, arr # load arr into t1
lw t2, e0 # Load e0 value into t2
sw t2, 0(t1) # save t2 value into arr[0]

What i'm doing wrong?

Answer 1

The instruction sw t2, 0(t1) stores the content of the register t2 into the memory address provided by the register t1 . However, t1 does not contain the address that corresponds to the label arr – the address where the value 1000 is stored – because t1 was initialized by the instruction lw t1, arr , and this loads the content of the address corresponding to arr into t1 , ie, it loads the value 1000 into t1 .

Instead, replace lw t1, arr by la t1, arr , which does load into t1 the address that arr is representing.