(mips64) lw和sw不向寄存器增值

Question

我是mips的新手，对于一个家庭作业项目，我们必须将C代码转换为mips64汇编，并在winmips64中运行它。C代码是这样的：

void fir(int X[], int H[], int Y[], int n, int m)
{
    int i, j;
    int y0;

    for (j=0; j<m; j++){
        y0=0;
        for (i=0; i<n; i++){
            y0+=X[i+j]*H[i];
        }
        Y[j]=y0;
    }
}

我遇到问题的代码行是y0+=X[i+j]*H[i]和Y[j]=y0，这是我尝试这样做的方法：

for2:
    beq r7,r3, afterfor2                        # for(i=0, i<n, i++)

    #making X[i+j]
    dadd r8,r5,r7                               # i+j stored in r8
    dmul r9,r8,r18                              #(i+j)*8 to find address stored in r8r9
    lw r10, r9(r0)                               #load x[i+j] to r10

    #making H[i]
    dmul r11,r18,r7                             # 8*i
    lw r12,r11(r1)                              #load h[i] to r12

    dmul r13,r10,r12                            #x[i+j] * h[i]
    dadd r6,r6,r13                              #y0 = y0 + x[i+j]*h[i]
    daddi r7,r7,1                               # i++
    j for2                                      # repeat loop

afterfor2: 
        
    dmul r14,r5,r18                             #8*j stored to r14
    sw r6, r14(r2)                              #Y[j] = y0
    daddi r5,r5,1                               #j++
    
    j for1                                      #go back to start of loop for1

更具体地说，这些行是因为没有值被添加到寄存器r10,r6和r12

lw r10, r9(r0)                               #load x[i+j] to r10
lw r12,r11(r1)                               #load h[i] to r12
sw r6, r14(r2)                               #Y[j] = y0

winmips64文档提到，我需要使用立即数来存储/加载数组，但是如果我不知道立即数，而值是基于索引的相加和乘法，我该如何做呢？它们不是必须存储在寄存器中吗？

提前感谢您的帮助

编辑:代码总数

.data                                           #data segment
    X: .word 1,1,1,2,2,3,4,2,1,1,2,3,2,4,8,1    #X[]
    H: .word 1,5,1,4,2,1,1,1                    #H[]
    Y: .space 64                                #n*8 = 8*8 = 64 bytes reserved for the y0 results = R2

    n: .word 8                                  #n = 8
    m: .word 8                                  #m = 8

   

.text
fir:                                            #void fir
    
    ori r15, r0, X                             #address of X[]
    ori r1, r0, H                              #address of H[]
    ori r2, r0, Y                              #address of Y[]

    daddi r3,r3,8                               # n = r3 = 8
    daddi r4,r4,8                               # m = r4 = 8

    dadd r5,r0,r0                              #set j counter to 0
    daddi r18,r0,8                                  

    j for1                                      #go to for1 loop

for1:   
    beq r5,r4,exit                              #when j is equal to m loop stops and goes to the exit function
    dadd r6,r0,r0                               #y0 = r6 = 0
    dadd r7,r0,r0                               #set i counter to 0 for every loop

    bne r5,r4,for2                              #go to the nested loop for2

for2:
    beq r7,r3, afterfor2                        # for(i=0, i<n, i++)

    #making X[i+j]
    dadd r8,r5,r7                               #i+j stored in r8
    dmul r9,r8,r18                              #(i+j)*8 to find address stored in r9
    daddu r9,r9,r15
    ld r10,(r9)                                 #load x[i+j] to r10

    #making H[i]
    dmul r11,r18,r7                             #8*i
    daddu r11,r11,r1                            #adding 8*i to the base address
    ld r12,(r11)                                #load h[i] to r12

    dmul r13,r10,r12                            #x[i+j] * h[i]
    dadd r6,r6,r13                              #y0 = y0 + x[i+j]*h[i]
    daddi r7,r7,1                               # i++
    j for2                                      # repeat loop

afterfor2: 
        
    dmul r14,r5,r18                             #8*j stored to r14
    daddu r14,r14,r2
    sd r6,(r14)                                 #Y[j] = y0
    daddi r5,r5,1                               #j++
    
    j for1                                      #go back to start of loop for1


exit:
    halt                                        #exit program

Answer 1

没有像register(register)这样的寻址模式。您必须先将这两个寄存器相加。

例如，执行以下操作，而不是lw r12,r11(r1)：

daddu r11,r11,r1
lw r12,(r11)

请注意，在lw r10, r9(r0)的情况下，您可以简单地将其替换为lw r10, (r9)，因为r0的值被硬连接为0。