samples-with-macros/rek-gcd-predef.asm

   1 .model      small
   2 ;recursive version of GCD, predefined input
   3 data segment
   4   strNZD db "        "
   5 data ends
   6 ;#macro-commands-start
   7 ; print a string on screen
   8 print_str macro s
   9     push ax
  10     push dx
  11     mov dx, offset s
  12     mov ah, 09
  13     int 21h
  14     pop dx
  15     pop ax
  16 endm
  17
  18
  19 ; write a single char
  20 print_char macro c
  21     push ax
  22     push dx
  23     mov ah, 02
  24     mov dl, c
  25     int 21h
  26     pop dx
  27     pop ax
  28 endm
  29
  30 ; finish the execution
  31 end_execution macro
  32     mov ax, 4c02h
  33     int 21h
  34 endm
  35
  36 ; Konvertovanje broja u string
  37 inttostr macro num1 str1
  38    push ax
  39    push bx
  40    push cx
  41    push dx
  42    push si
  43    mov ax, num1
  44    mov dl, '$'
  45    push dx
  46    mov si, 10
  47 petlja2:
  48    mov dx, 0
  49    div si
  50    add dx, 48
  51    push dx
  52    cmp ax, 0
  53    jne petlja2
  54
  55    mov bx, offset str1
  56 petlja2a:
  57    pop dx
  58    mov [bx], dl
  59    inc bx
  60    cmp dl, '$'
  61    jne petlja2a
  62    pop si
  63    pop dx
  64    pop cx
  65    pop bx
  66    pop ax
  67 endm
  68
  69 print_num macro num
  70         inttostr num,strNZD
  71         print_str strNZD
  72 endm
  73 ;#macro-commands-end
  74
  75 .code
  76
  77 start:
  78     push 8
  79     push 12
  80     call gcd
  81     pop ax
  82         print_num ax
  83 ; print out a result
  84     end_execution
  85
  86 ;volatile procedure, ruins ax,bx,cx
  87 gcd proc
  88 ;#extra-start
  89     pop cx ;ret adress
  90 ;#extra-end
  91     ;get params
  92     pop ax
  93     pop bx
  94 ;#extra-start
  95     push cx ;ret for later
  96 ;#extra-end
  97     cmp ax,bx
  98     je endequal
  99     ja greatera
 100     ;ensure ax is greater
 101     xchg ax,bx
 102 greatera:
 103     sub ax,bx
 104     push bx
 105     push ax
 106     call gcd
 107     pop ax;result
 108
 109 endequal:
 110 ;#extra-start
 111     pop cx
 112 ;#extra-end
 113     push ax; result
 114 ;#extra-start
 115     push cx;needed before ret
 116 ;#extra-end
 117     ret
 118 gcd endp
 119 .stack
 120 end start