pic assembly - macro or subroutine???

[spyghost]

hi,

macros and subroutines have some similarity, right? but there arises this question:

- should i use macro or subroutine?

are there pointers really for using one over the other? or is it just a matter of personal preference?

 

[e]

A macro will shove a chunk of code in everytime you use it, so if its a long macro your code will grow quickly.
I dont like using macros over a few lines (maybe 2 or 3), id rather use subroutines for anything over that length.
Macros are nice to say things like "led_on" instead of "bcf PORTA,2" or something like that, and since the macro is only one line it makes no difference...

 

[Nigel Goodwin]

A macro will shove a chunk of code in everytime you use it, so if its a long macro your code will grow quickly.
I dont like using macros over a few lines (maybe 2 or 3), id rather use subroutines for anything over that length.
Macros are nice to say things like "led_on" instead of "bcf PORTA,2" or something like that, and since the macro is only one line it makes no difference...

I agree, use a subroutine for anything you use more than once, unless it is exceptionally short.

 

[donniedj]

I concur with both above. Macros are short and subroutines are long. My best and most utilized of very few macros are:
MOVF_F REGISTER1, REGISTER 2
LOADF REGISTER, LITERAL
SWAPF REGISTER1, REGISTER 2

Personally, the least macros the better and the purer the assembly code. I believe that a major portion of Microchips popularity is attributed to their 35 instruction set, a set that actually consumes only 5 to 10 different instructions in a program. Logically, macros jeoperdize computed goto(s) because you may forget how much space the nearby macros actually consume.