A MOV question

[bolzano_1989]

In the following tutorial:
http://www.friedspace.com/assembly/moving.php
, could you tell me the differences and the effects of the differences between the following statements?

Code Select Expand

MOV [myvar1],CH

Code Select Expand

MOV myvar1,CH

[NoCforMe]

Um, one has square brackets and the other one doesn't?

Really, that's the answer. There's no functional difference between the two statements.

The brackets come in handy when you need to index variables or do other fancy stuff:

Code Select Expand



MOV AX, [BX + Table + 10]



[bolzano_1989]

I think they're not the same.

[Rockphorr]

In the following tutorial:
http://www.friedspace.com/assembly/moving.php
, could you tell me the differences and the effects of the differences between the following statements?

Code Select Expand

MOV [myvar1],CH

Code Select Expand

MOV myvar1,CH

in masm it is the same

but
mov DX,2
and
mov DX,[2]
is diferent - couse first source data is  imm, and second source data is mem.

[Rockphorr]

in mov instruction the target always is address or register name
but source also may be immediate (imm) opperand.
by default masm compiler assumes that is imm if it is digit, when it is register that is awesome.

feel diference betveen masm and fasm


masm                                                                                      fasm
memory_label                                                                           [memory_label]
[memory_label]  <-bracets is not req here                                    [memory_label]
offset(memory_label)                                                                 memory_label

[NoCforMe]

I think they're not the same.

They are.

From the MASM Programmer's Guide (Microsoft):

The index operator can contain any direct memory operand. The following statements are equivalent:

Code Select Expand



mov ax, var
mov ax, [var]



Some programmers prefer to enclose the operand in brackets to show that the contents, not the address, are used.

[bolzano_1989]

Thank you, Rockphorr and NoCforMe for pointing out some differences between MASM and FASM, I'm reading more.

[dedndave]

this may vary from one assembler to another   :U
some may even require the braces

[FORTRANS]

this may vary from one assembler to another   :U
some may even require the braces

Hi,

   Yes, NASM, (The Netwide Assemble)r (and FASM?) do require
them.

Regards,

Steve N.

Code Select Expand


    MASM                  NASM

MOV AL,Label          MOV AL,[Label]
MOV AL,[Label]        MOV AL,[Label]
MOV EAX OFFSET Label  MOV EAX,label


[dedndave]

NASM refers to the address of the label if they are not there
so, there can be a difference   :bg