Was ist falsch an meinem MIPS-Code (Arrays)?

Question

Nun, ich habe

# j = 0 
# x = a[j+k] 
# a[j+k] = a[j] 
# repeat n-1 times 
# j = (j+k) mod n 
# m = (j+k) mod n 
# y = a[m] 
# a[m] = x 
# x = y 
# end repeat 

auf MIPS-Code zu konvertieren. Bisher habe ich mir das ausgedacht, aber es gibt falsche Ausgaben aus. Irgendeine Hilfe?

  .data 
     .align 2 
head1: .asciiz "\n\nThis program reads a list of integers into an array, and then" 
head2: .asciiz "\nshifts the array to the right with wrap around." 
head3: .asciiz "\nThe list is terminated by a negative integer." 
prompt1: .asciiz "\nEnter the shift amount first: " 
prompt2: .asciiz "\nEnter array numbers (negative to end)" 
newline: .asciiz "\n" 
     .text 
     .globl main 
main:  
# print the prompt messages  See appendix B of P&H or chapter 4 of Britton 
     li $v0, 4   # $v0 = print_string system call code 
     la $a0, head1  # $a0 = address of first prompt 
     syscall    # print first prompt 
     li $v0, 4   # $v0 = print_string system call code 
     la $a0, head2  # $a0 = address of second prompt 
     syscall    # print second prompt 
     li $v0, 4   # $v0 = print_string system call code 
     la $a0, head3  # $a0 = address of third prompt 
     syscall    # print third prompt 
# Main program - calls read, rearrange and print functions 
     li $v0, 4   # $v0 = print_string system call code 
     la $a0, prompt1  # $a0 = address of fourth prompt 
     syscall    # print fourth prompt 
     li $v0, 5   # $v0 = read_int system call code 
     syscall    # read an integer - n 
     move $a2, $v0   # $a2 = separation point for rearranging array 
     li $v0, 4   # $v0 = print_string system call code 
     la $a0, prompt2  # $a0 = address of fifth prompt 
     syscall    # print fifth prompt 
     li $a0, 0x10000000 # $a0 = base address of array = 10000000 (hex)   
     jal reada   # read numbers into array 
     move $a1, $v0   # $a1 = number of ints read - size of array 
     jal shift   # shift the array to the right 
     jal printa   # print numbers from array to screen 
# Call system exit 
     li $v0, 10   # $v0 = exit system call code 
     syscall    # halt program execution 

# Algorithm for reading numbers into an array 
reada: move $t0, $a0   # $t0 = base address of array 
     move $t1, $zero  # $t1 = counter = 0 
read: li $v0, 5   # $v0 = read_int system call code 
     syscall    # read an integer - n 
     slt $t2, $v0, $zero # if n < 0 then stop reading 
     bne $t2, $zero, exit # exit procedure and return to caller 
     sw $v0, 0($t0)  # a[i] = n 
     addi $t1, $t1, 1  # i = i + 1 
     addi $t0, $t0, 4  # $t0 = address of a[i + 1] 
     j read    # go back up and read another integer 
exit: move $v0, $t1   # return number of integers read into array 
     jr $ra    # return to calling routine 

# Algorithm for printing numbers from an array 
printa: move $t0, $a0   # $t0 = base address of array 
     move $t1, $zero  # $t1 = counter = 0 
print: beq $t1, $a1, exitp # if (array index = array size), then exit 
     lw $t2, 0($t0)  # $t2 = a[i] 
     li $v0, 4   # $v0 = print_string system call code 
     la $a0, newline  # $a0 = address of newline character 
     syscall    # print new line 
     li $v0, 1   # $v0 = print_int system call code 
     move $a0, $t2   # $a0 = a[i] 
     syscall    # print a[i] 
     addi $t1, $t1, 1  # i = i + 1 
      addi $t0, $t0, 4  # $t0 = address of a[i + 1] 
     j print   # go back up and print another integer 
exitp: li $v0, 4   # $v0 = print_string system call code 
     la $a0, newline  # $a0 = address of newline character 
     syscall    # print new line 
     jr $ra 

# Algorithm for rearranging array 

# j = 0 
# x = a[j+k] 
# a[j+k] = a[j] 
# repeat n-1 times 
# j = (j+k) mod n 
# m = (j+k) mod n 
# y = a[m] 
# a[m] = x 
# x = y 
# end repeat 

# Register usage 
# $a0 = base address of array 
# $a1 = n, size of array 
# $a2 = k, the shift amount 


shift: li $t3, 0   #j = 0 
      lw $t3, 0($a0)  #load the value of $a0 in to j 
      add $t3, $t3, $a2 # j = j+k 
      sw $t3, 4($a0)  # store the new value of j in to $a0 

repeat: beq $a1, $zero, end 
      sub $a1, $a1, 1  #n = n-1 
      add $t4, $t3, $a2 #j+k 
      div $t4, $a1   #divide (j+k) by n 
      mfhi $t5   

      move $t5, $t3  #j = (j+k) mod n 

      add $t4, $t5, $a2 #j+k 
      div $t4, $a1   #divide (j+k) by n 
      mfhi $t5    #move rem into t2 
      move $t5, $t3  #m = (j+k) mod n 
      sw $t3, 4($a0) 
      jr $ra 
      lw $t3, 0($a0) 
      b repeat 

end:  

Answer 1

Ihr lw $ t3 nach jr $ ra wird nie herauskommen.