Issues with the compiler

[dan94]

Ok so I have my final assignment for an Assembly class and our objective is to find a Pythagorean triple using an algorithm. There's a typical MSB3721 error that prevents it from compiling but all the numbers I see on the output screen are weird ones like +4384199725.

Here's my code:

INCLUDE Irvine32.inc
.data



U DWORD ?  ; variable U
V DWORD ?  ; variable V
GCD DWORD

.code
main PROC

mov U, 2      ; moves 2 to location U

if FirstDo:
mov eax, U      ; moves memory location U to eax
   TEST eax, 1      ; checks for an ODD value
   jnz oddp      ; if not zero, jump
   jmp evenp      ; jumps to evenp
oddp: mov V, 2
mov ebx, V
   jmp endofF1
evenp: mov V, 1
mov ebx, V
   endofF1:
   jb secondDO:

      call GCD   ; executes instruction GCD

   cmp eax, 1      ; compares to 1
   je Equal1
   mov eax, U
   mov ebx, V
   jmp goDo2
   Equal1:
   mov eax, U
   mov ebx, V
   call TRIPLE      ; executes instruction triple
   mov eax, U
   mov ebx, V

   goDo2:   add ebx, 2
         mov V, ebx
         cmp ebx, eax
         add eax, 1
         mov U, eax

cmp U, 10

jb FirstDo

exit

main ENDP

END main

;;;;;;;;;;;;;;;;;;
GCD PROC uses ebx

whileLoop:  cmp ebx, 0
         jbe out1
         mov edx, 0
         div ebx
         mov eax, edx
         xchg eax, edx
         jmp whileLoop

out1:

ret

GCD ENDP

;;;;;;;;;;;;;;;;;

TRIPLE PROC

push eax
push ebx

imul eax, eax
imul ebx, ebx
sub  eax, ebx
mov  ecx, eax
pop  ebx
pop  eax

push eax
push ebx
imul eax, ebx
add eax, eax
mov edx, eax
pop ebx
pop eax

push eax
push ebx
imul eax, eax
imul ebx, ebx
add eax, ebx
mov esi, eax
pop ebx
pop eax

cmp ecx, edx

jb endIf2

xchg ecx, edx

endIf2:

mov eax, ecx
call WriteInt
mov eax, edx
call WriteInt
mov eax, esi
call WriteInt
call crlf
ret

exit

TRIPLE ENDP

END TRIPLE

[gelatine1]

GCD DWORD is not correct syntax I believe.
It should be

Code Select Expand

GCD proto :dword

and I'm not sure if the "if FirstDo:" is correct syntax because of the space

[dedndave]

Code Select Expand

    .if ecx>5
        dec     ecx
    .endif

there is a list of "expression operators" in the masm manual

[raymond]

objective is to find a Pythagorean triple using an algorithm

This may seem harsh but take it in a positive manner.

Before you ever start programming anything scientific, you MUST fully understand the principles behind the objective. In your case, a Pythagorean triple is a set of three integer numbers (a,b,c) being the sides of a right angle triangle such that a² + b² = c². I don't know the origin of the 'algorithm' you are using but either it is totally wrong or you grossly misunderstand it (according to the coding of your TRIPLE PROC).

The same applies to the code for the GCD algo. Its purpose should be to find the Greater Common Denominator between two numbers. If it is 1, the two numbers are then considered co-prime. And using co-prime numbers as the source, you then ensure that the generated Pythagorean triples are only the primitives (which I don't know if it was one of the stated objectives).

For your info, the basic example of a primitive Pythagorean triple is (3,4,5). A non-primitive one would be (6,8,10).

[Gunther]

For your info, the basic example of a primitive Pythagorean triple is (3,4,5). A non-primitive one would be (6,8,10).

5, 12 and 13 is a solution, too. These are so called Indian triples.

Gunther

[dedndave]

sounds like a nice Euler Project problem