MIPS組件 - 數組？

Question

我絕對全新，以彙編語言編程，我試圖實現以下功能（C語言）在MIPS：

int main() 
{ 
    int A[5]; // Empty memory region for 5 elements 
    int B[5] = {1,2,4,8,16}; 
    int i; 

    for(i=0; i<5; i++) { 
    A[i] = B[i] - 1; 
    } 

    i--; 
    while(i >= 0) { 
    A[i]=(A[i]+B[i]) * 2; 
    i--; 
    } 
} 

到目前爲止，我已經是這樣的：

main: 
#Register Map 
#i --> $s0 
#A[0] --> $s1 address of start of A 
#B[0] --> $s2 address of start of B 
#A[i] --> $t0 
#B[i] --> $t1 
#(A[i] + B[i]) --> $t2 
#((A[i] + B[i]) * 2) --> $t3 

    li $s0, 0  #Load immediate value 0 into i 

#Begin for loop: 
#for(i=0; i<5; i++){ A[i] = B[i] - 1; } 

FOR_LOOP: 
    beq  $s1, $t0, END_FOR #Branch if i == 5, go to END_FOR 

    addi $s0, $s0, 1 #Add immediate value 1 to i (i++) 
    j FOR_LOOP   #Jump back to the top to loop again 

END_FOR:    #End for loop 
    addi $s0, $s0, -1 #Add immediate value -1 to i (i--) 

#Begin while loop: 
#while(i >= 0) { A[i] = (A[i] + B[i]) * 2; i--; } 

WHILE_LOOP: 
    blt  $s1, 0, END_WHILE #Branch END_WHILE when !(i > 0) 

    addi $s0, $s0, -1 #Add immediate value -1 to i (i--) 
    j WHILE_LOOP  #Branch back to the while loop 

END_WHILE: 
    sw  $s0, i  #Copy value in register to memory i 
    li  $v0, 10  #Read integer from user, returned in $v0 (10=exit) 

    syscall   #End program 

#Store A, B in memory 
    .data 

A: .word 0:5   #Allocate 20 consecutive bytes for 5-element integer word array A 
B: .word 1, 2, 4, 8, 16 #Integer words stored in 5-element array B 
i: .word 1  #Initial Value 1 

我的主問題是：

1. 我將如何訪問數組的元素，或我從哪裏開始la？

2. 我是否正確地聲明瞭數組？

3. 我的註冊地圖對於正在嘗試完成的內容有意義嗎？

感謝您的任何和所有幫助。

Answer 1

.text 
main: 
    #Register Map 
    #i --> $s0 
    #A[0] --> $s1 address of start of A 
    #B[0] --> $s2 address of start of B 
    #A[i] --> $t0 
    #B[i] --> $t1 
    #(A[i] + B[i]) --> $t3 
    #((A[i] + B[i]) * 2) --> $t3 
    li $s0, 0  #Load immediate value 0 into i 
    li $t4,5  #upper limit 
    la $s1,A  #address of start of A 
    la $s2,B  #address of start of B 

    #Begin for loop: 
    #for(i=0; i<5; i++){ A[i] = B[i] - 1; } 
FOR_LOOP: 
    bge  $s0, $t4, END_FOR #Branch if i >= 5, go to END_FOR 
    lw $t1,($s2)    #$t1=B[i] 
    addi $t1, $t1, -1   #$t1=B[i]-1 
    sw $t1,($s1)    #A[i]=B[i]-1 
    addi $s1, $s1,4   #next element A[i+1] 
    addi $s2, $s2,4   #next element B[i+1] 
    addi $s0, $s0, 1  #Add immediate value 1 to i (i++) 
    j FOR_LOOP    #Jump back to the top to loop again 

END_FOR:      #End for loop 
    addi $s0, $s0, -1  #Add immediate value -1 to i (i--) 
    addi $s1, $s1,-4   #previous element A[i-1] 
    addi $s2, $s2,-4   #previous element B[i-1] 

    #Begin while loop: 
    #while(i >= 0) { A[i] = (A[i] + B[i]) * 2; i--; } 
WHILE_LOOP: 
    blt  $s0, 0, END_WHILE #Branch END_WHILE when (i < 0) 
    lw $t0,($s1)    #$t0=A[i] 
    lw $t1,($s2)    #$t1=B[i] 
    add $t3, $t0,$t1   #$t3=A[i] + B[i] 
    mul $t3, $t3, 2   #$t3=(A[i] + B[i]) * 2 
    sw $t3,($s1)    #A[i] = (A[i] + B[i]) * 2 
    addi $s1, $s1,-4   #previous element A[i-1] 
    addi $s2, $s2,-4   #previous element B[i-1] 
    addi $s0, $s0, -1  #Add immediate value -1 to i (i--) 
    j WHILE_LOOP    #Branch back to the while loop 

END_WHILE: 

PRINT:      #print array A[i] 
    li $s0, 0     #i=0 
    la $s1, A     #$s1=A[0] 
LOOP: 
    bge $s0, $t4, END   # if i >=5 goto END 
    lw $a0, ($s1)    # $a0 = A[i] 
    li $v0, 1   #function print integers   
    syscall 
    la $a0, space    #print separator (1 space) 
    li $v0, 4   #function print strings    
    syscall 
    addi $s1, $s1, 4   #next element A[i+1] 
    addi $s0, $s0, 1   #i++ 
    b LOOP 

END: 
    li $v0, 10    # $v0 (10=exit) 
    syscall     #End program 

#Store A, B in memory 
.data  
A: .word 0:5   #Allocate 20 consecutive bytes for 5-element integer word array A 
B: .word 1, 2, 4, 8, 16 #Integer words stored in 5-element array B 
space: .asciiz " " #space as separator