我正在尝试使用跳转表为我的工作制作菜单。Everyting 对我来说看起来不错,但下面的代码不起作用。在“jr $s0”指令之后,火星给了我一个错误,比如:
Error in : invalid program counter value: 268501840
我知道十进制地址268501840
是 L1 标签的实际地址,而代码应该去那个标签,但那时我犯了这个错误。为什么?
main:
.data
jTable: .word L0,L1,L2,L3,L4,L5,L6,default #jump table definition
msg: .asciiz "\nEnter Your Choice;\n [1] for build,\n [2] for insert,\n [3] for find,\n [4] for findMinMax,\n [5] for delete,\n [6] for print\n [0] for Exit\nYour choice:#"
.text
userInteraction:
li $v0,4 #print string
la $a0,msg #get string address
syscall
li $v0,5 #get a menu option from user(0 to 6)
syscall
move $s0,$v0 #get index in $s0
sll $s0,$s0,2 #$s0=index*4
la $t0,jTable #$t0=base address of the jump table
add $s0,$s0,$t0 #$s0+$t0 = actual address of jump label
**jr $s0** #jump to label
L0: Todo
j finish
L1: Todo
j userInteraction
L2: Todo
j userInteraction
L3: Todo
j userInteraction
L4: Todo
j userInteraction
L5: Todo
j userInteraction
L6: Todo
j userInteraction
default: Todo
j userInteraction
finish:
li $v0,10 #Exit
syscall #Exit