TD4/mips3.asm

   1 .data
   2 input:                 .space  50
   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:                .asciiz " est"
   7 msg_is_not:            .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, 50
  25     syscall
  26     jr  $ra
  27
  28 clean_and_length_word:
  29     la   $s4, ($zero)   # word length
  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     sb   $0, 0($s0)     # replace newline with 0
  40     la   $a2, ($s4)
  41     jr   $ra
  42
  43 isPalindrome:
  44     # Check base case
  45     slti $t0, $a2, 2
  46     bne  $t0, $zero, returnTrue
  47
  48     # Make sure first and last are equal
  49     lb   $t0, 0($a0)
  50     addi $t1, $a2, -1
  51     add  $t1, $t1, $a0
  52     lb   $t1, 0($t1)
  53     bne  $t0, $t1, returnFalse
  54
  55     # Shift pointer, length, recurse
  56     addi $a2, $a2, -2
  57     addi $a0, $a0, 1
  58     j    isPalindrome
  59
  60 returnFalse:
  61     addi $v0, $zero, 0
  62     addi $sp, $sp, -4
  63     sw   $ra, 0($sp)
  64     jal  display_not_palindrome
  65     lw   $ra, 0($sp)
  66     addi $sp, $sp, 4
  67     jr   $ra
  68
  69 returnTrue:
  70     addi $v0, $zero, 1
  71     addi $sp, $sp, -4
  72     sw   $ra, 0($sp)
  73     jal  display_palindrome
  74     lw   $ra, 0($sp)
  75     addi $sp, $sp, 4
  76     jr   $ra
  77
  78 display_palindrome:
  79     la   $a0, msg_palindrome_part_1
  80     li   $v0, 4
  81     syscall
  82     la   $a0, input
  83     li   $v0, 4
  84     syscall
  85     la   $a0, msg_is
  86     li   $v0, 4
  87     syscall
  88     la   $a0, msg_palindrome_part_2
  89     li   $v0, 4
  90     syscall
  91     la   $a0, newline
  92     li   $v0, 4
  93     syscall
  94     jr   $ra
  95
  96 display_not_palindrome:
  97     la   $a0, msg_palindrome_part_1
  98     li   $v0, 4
  99     syscall
 100     la   $a0, input
 101     li   $v0, 4
 102     syscall
 103     la   $a0, msg_is_not
 104     li   $v0, 4
 105     syscall
 106     la   $a0, msg_palindrome_part_2
 107     li   $v0, 4
 108     syscall
 109     la   $a0, newline
 110     li   $v0, 4
 111     syscall
 112     jr   $ra