TD4/mips3.asm

   1 .data
   2 input:                 .space  20
   3 input_string:          .asciiz "Saisir un mot ? "
   4 msg_palindrome_part_1: .asciiz "Le mot "
   5 msg_palindrome_part_2: .asciiz " un palindrome"
   6 msg_is_palindrome:     .asciiz "est"
   7 msg_is_not_palindrome: .asciiz "n'est pas"
   8 newline:               .asciiz "\n"
   9
  10 .text
  11 main:
  12     jal input_word
  13     jal clean_and_length_word
  14     jal isPalindrome
  15     li  $v0, 10
  16     syscall
  17
  18 input_word:
  19     la  $a0, input_string
  20     li  $v0, 4
  21     syscall
  22     li  $v0, 8
  23     la  $a0, input
  24     li  $a1, 20
  25     syscall
  26     jr  $ra
  27
  28 clean_and_length_word:
  29     la   $s4, ($zero)
  30     la   $s0, input     # $s0 contains base address of the string buffer
  31     addi $s3, $0, '\n'  # $s3 = '\n'
  32 loop1:
  33     lb   $s1, 0($s0)    # load character into $s1
  34     beq  $s1, $s3, end1 # break if byte is newline
  35     addi $s0, $s0, 1    # increment buffer address
  36     addi $s4, $s4, 1
  37     j    loop1
  38 end1:
  39     la   $a2, ($s4)
  40     jr   $ra
  41
  42 isPalindrome:
  43     # Check base case
  44     slti $t0, $a2, 2
  45     bne  $t0, $zero, returnTrue
  46
  47     # Make sure first and last are equal
  48     lb   $t0, 0($a0)
  49     addi $t1, $a2, -1
  50     add  $t1, $t1, $a0
  51     lb   $t1, 0($t1)
  52     bne  $t0, $t1, returnFalse
  53
  54     # Shift pointer, length, recurse
  55     addi $a2, $a2, -2
  56     addi $a0, $a0, 1
  57     j    isPalindrome
  58
  59 returnFalse:
  60     addi $v0, $zero, 0
  61     addi $sp, $sp, -4
  62     sw   $ra, 0($sp)
  63     jal  display_not_palindrome
  64     lw   $ra, 0($sp)
  65     addi $sp, $sp, 4
  66     jr   $ra
  67
  68 returnTrue:
  69     addi $v0, $zero, 1
  70     addi $sp, $sp, -4
  71     sw   $ra, 0($sp)
  72     jal  display_palindrome
  73     lw   $ra, 0($sp)
  74     addi $sp, $sp, 4
  75     jr   $ra
  76
  77 display_palindrome:
  78     la   $a0, msg_palindrome_part_1
  79     li   $v0, 4
  80     syscall
  81     la   $a0, input
  82     li   $v0, 4
  83     syscall
  84     la   $a0, msg_is_palindrome
  85     li   $v0, 4
  86     syscall
  87     la   $a0, msg_palindrome_part_2
  88     li   $v0, 4
  89     syscall
  90     la   $a0, newline
  91     li   $v0, 4
  92     syscall
  93     jr   $ra
  94
  95 display_not_palindrome:
  96     la   $a0, msg_palindrome_part_1
  97     li   $v0, 4
  98     syscall
  99     la   $a0, input
 100     li   $v0, 4
 101     syscall
 102     la   $a0, msg_is_not_palindrome
 103     li   $v0, 4
 104     syscall
 105     la   $a0, msg_palindrome_part_2
 106     li   $v0, 4
 107     syscall
 108     la   $a0, newline
 109     li   $v0, 4
 110     syscall
 111     jr   $ra