NASM - The Netwide Assembler

NASM Forum => Programming with NASM => Topic started by: jdubya on November 22, 2013, 06:13:12 PM

Title: label in section .data
Post by: jdubya on November 22, 2013, 06:13:12 PM

Can someone explain this label to me?  It's in an example and I've never seen one declared like this.  Thanks.

var:  dd 2D,1

Title: Re: label in section .data
Post by: Frank Kotler on November 22, 2013, 06:26:17 PM

I don't think I've seen one quite like that, either. It defines two dwords, 2 (decimal) and 1 (also decimal). Seems like "overkill" to me.

Best,
Frank

Title: Re: label in section .data
Post by: encryptor256 on November 22, 2013, 06:54:26 PM

Hi!

Confirm, it works:

Code: [Select]


      cmp dword [var],dword 2
      je .equal
; was equal

It makes sense, define vars by numerical system:

Code: [Select]

var1: dd 10o; Octal 10 equals 8 Decimal
var2: dd 08h; Hex
var3: dd 08d; Decimal
var4: dd 1000b; Binary

Compare:

Code: [Select]


      cmp dword [var1],dword 8
      je .equal
; was equal

Bye, Encryptor!

Title: Re: label in section .data
Post by: Frank Kotler on November 22, 2013, 07:02:10 PM

Yeah... we can also use uppercase 'O' to indicate octal. Anyone who does so deserves the confusion they will get!

Best,
Frank

Title: Re: label in section .data
Post by: encryptor256 on November 22, 2013, 07:04:59 PM

Quote from: Frank Kotler on November 22, 2013, 07:02:10 PM

Yeah... we can also use uppercase 'O' to indicate octal. Anyone who does so deserves the confusion they will get!

Best,
Frank

No tag:
var1: dd 10O; Octal 10 equals 8 Decimal

Code tag:

Code: [Select]

var1: dd 10O; Octal 10 equals 8 Decimal

Yeah, Frank! :D