"Near jump or call to different CS" error in TASM 8086

user_19892402 0
Viewed 37

I have been learning 8086 assembly using TASM. I am trying to make a jmp but for some reason it gives me the following errors:

Error tarea.ASM(42) Near jump or call to different CS
Error tarea.ASM(46) Near jump or call to different CS
Error tarea.ASM(50) Near jump or call to different CS
Error tarea.ASM(52) Symbol already different kind: SALIR

I'm using several macros (not sure that's their name but that's what my teacher calls them) eg. ImprimeM, but the error isn't in any of the lines with macros.

The code in question would be:

include macs.pbl

Pila Segment
Pila ends
Datos Segment
    var db 1
    var1 db 1
    igualesM DB "Los numeros son iguales$"
    MI1 db "Deme el primer numero$"
    MI2 db "Deme el segundo numero$"
    M1 db "El primero es mayor$"
    M2 db "El segundo es mayor$"
    salir db "Presione s para salir$"
Datos ends

Codigo Segment
Assume cs:Codigo , ds:Datos

Inicio:
xor ax,ax
mov ax,datos
mov ds,ax

vuelta:
ImprimeM MI1

RecibirN
mov ah,var;lo muevo para poder reutilizar la macro manteniendo el primer numero recibido

ImprimeM MI2
RecibirN

mov al,ah   ; lo regreso para poder hacer cmp

cmp al,var
jz iguales
jns mayor1
js mayor2

iguales:
    ImprimeM igualesM
    jmp short salir

mayor2:
    ImprimeM MI2
    jmp short salir

mayor1:
    ImprimeM MI1
    jmp short salir

salir:
    mov ah,4ch
    int 21h

Terminar
ends ;aqui termina el programa
    End inicio

Any help is appreciated

tasm x86-16 dos assembly
2 Answers

The TASM error message "Near jump or call to different CS" is about having written a jmp short salir instruction where the jmp short instruction is a near jump and the target resides in a segment different from the one that contains the instruction itself. Jumping to within a different segment would require a far jump, but also to have executable code at the target address. This would not be the case in your program where the target is within the Datos segment that only contains data.

The TASM error message "Symbol already different kind: SALIR" is about having used the user-defined symbol salir as a label both in the Datos segment as well as in the Codigo segment. A label represents an offset address in the segment where it is defined. Labels that you define have to be unique since it is not possible for the same label to represent 2 different offset addresses.
You could solve it in a number of ways, but adding a suitable prefix to the message label can do the trick:

msgSalir db "Presione s para salir$"

You applied this trick already with iguales vs igualesM.

mayor2:
    ImprimeM MI2

mayor1:
    ImprimeM MI1

The above macro invokations are wrong in that at this point in your program you don't want to display the input messages again. You want to show the results that are labeled M1 and M2.

Here's an optimized version:

  • The xor ax, ax before doing mov ax, datos is redundant! Just remove it.
  • The mov al, ah before doing cmp al, var is redundant! You can replace the pair by a single cmp ah, var.
  • In cmp al,var jz iguales jns mayor1 js mayor2, the last conditional jump can be considered redundant as the SF=1 condition is inevitably the case. With a little bit of restructuring the code, you can omit it from the program. And since you want to compare signed numbers, better use the appropriate signed conditional jumps jg for JumpIfGreater and jl for JumpIfLess. Also, following a cmp it is more idiomatic to use je (JumpIfEqual) than jz (JumpIfZero).
Inicio:
  mov   ax, datos
  mov   ds, ax
vuelta:
  ImprimeM MI1
  RecibirN
  mov   ah, var               ; Copy 1st number to AH
  ImprimeM MI2
  RecibirN
  cmp   ah, var               ; Compare directly from AH
  mov   dx, OFFSET igualesM   ; iguales   num1 is equal to num2
  je    imprime
  mov   dx, OFFSET M1         ; mayor1    num1 is greater than num2
  jg    imprime
  mov   dx, OFFSET M2         ; mayor2    num1 is less than num2
print:
  ImprimeM dx
  mov   ax, 4C00h             ; DOS.TerminateWithReturncode
  int   21h
user_31447700

nvm, I changed the label name "salir" to "sali", that solved it, why? I have no idea

EDIT: turns out im an idiot and I had a variable named salir that i was also trying to use as a label

user_198924020
Related