if and else again

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uri

Joined: 09 Apr 2004
Posts: 43
Location: L'viv, Ukraine

uri 06 May 2004, 11:46

Good day, look this

program:

Code:

format MS COFF
macro    select  a,b,c
{
if b > c
   a equ b
else
   a equ c
end if
}

public    main as '_main'
main:
  select      myvar,3,7
mov        eax,myvar
  select   myvar,6,4
mov        eax,myvar
  ret

result:

Code:

B8 07000000  mov     eax, 7
B8 04000000  mov     eax, 4
C3                 retn

why mov eax,4 ? must be mov eax,6

i want to use equ, no = , because i want like this

select myvar, var1, var2

it's possible?

thanks

06 May 2004, 11:46

pelaillo
Missing in inaction

Joined: 19 Jun 2003
Posts: 878
Location: Colombia

pelaillo 06 May 2004, 13:05

Weird, there is a problem with macro substitution. "if-else" does it right.
I'm puzzled Â¿?

Compiling this:

Code:

macro select a,b,c
{
if b > c
   display 'b > c = TRUE',0Dh,0Ah
   display 'before a,b,c = ',a+30h,', ',b+30h,', ',c+30h,', ',0Dh,0Ah
   a equ b
   display 'after equ a,b,c = ',a+30h,', ',b+30h,', ',c+30h,', ',0Dh,0Ah
else
   display 'b > c = FALSE',0Dh,0Ah
   display 'before a,b,c = ',a+30h,', ',b+30h,', ',c+30h,', ',0Dh,0Ah
   a equ c
   display 'after equ a,b,c = ',a+30h,', ',b+30h,', ',c+30h,', ',0Dh,0Ah
end if
}
myvar equ 0
display 'myvar = ',myvar+30h,0Dh,0Ah
select myvar,3,7
display 0Dh,0Ah,'myvar = ',myvar+30h,0Dh,0Ah
select myvar,6,4
display 0Dh,0Ah,'myvar = ',myvar+30h,0Dh,0Ah
myvar equ 6
display 0Dh,0Ah,'myvar = ',myvar+30h

Will result in:

Code:

myvar = 0
b > c = FALSE
before a,b,c = 3, 3, 7, 
after equ a,b,c = 7, 3, 7, 

myvar = 7
b > c = TRUE
before a,b,c = 7, 6, 4, 
after equ a,b,c = 6, 6, 4, 

myvar = 4

myvar = 6

06 May 2004, 13:05

decard

Joined: 11 Sep 2003
Posts: 1092
Location: Poland

decard 06 May 2004, 13:32

maybe it's because IF's are processed at assembly stage, so they will be calculated *after* equ's.

06 May 2004, 13:32

Tomasz Grysztar

Joined: 16 Jun 2003
Posts: 8394
Location: Kraków, Poland

Tomasz Grysztar 06 May 2004, 14:37

See the third question in the FAQ.

Last edited by Tomasz Grysztar on 11 Jun 2005, 18:40; edited 1 time in total

06 May 2004, 14:37

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