topic Re: C Macro with asm in ColdFire/68K Microcontrollers and Processors

C Macro with asm

Nouchi — Wed, 25 Oct 2006 14:28:47 GMT

Hello,

here's my C macro

Code:

volatile uint32 myVar;#define myMACRO() asm {\  TST.L myVar\  BEQ LABEL\  ADD.L %-1,myVar\LABEL:\   }

I would like to know how to to genarate unique label each time the macro is used, I tried "\@" after label name but it doesn't work.
What's the right syntax ?

tahnks

Re: C Macro with asm

Nouchi — Wed, 25 Oct 2006 20:57:48 GMT

Somebody has an idea ?
Can I use branch relative instructions inside C macro ?

Emmanuel

Message Edited by BugMan on 2006-10-2504:02 PM

[SOLVED] Re: C Macro with asm

Nouchi — Thu, 26 Oct 2006 13:36:09 GMT

Hi, The right syntax is in the header files: Code:

extern volatile uint32 myVar;inline asm void myFunction(void){  TST.L myVar  BEQ LABEL  ADD.L %-1,myVarLABEL:}#define myMACRO() myFunction()

Emmanuel,

Re: C Macro with asm

ynaught — Sat, 18 Nov 2006 00:09:19 GMT

I don't know what your compiler is, but GCC has a Very Useful Feature that allows silliness like:

#define myMACRO() asm {\
TST.L myVar\
BEQ 1f\
ADD.L %-1,myVar\
1:\
}

It appears in this case to search forward ( indicated by the 'f' ) for the next label 1: ... I really like this in that it frees you from coming up with unique labels for landing points within subroutines, which you'd never call from outside.

I have NO IDEA if other compilers allow this.

Re: C Macro with asm

Nouchi — Mon, 20 Nov 2006 16:31:50 GMT

Hello,

Sorry, I forgot to mention that it was CodeWarrior 6.3 for ColdFire.
I think that CW documentation isn't clear enough about asm macro.
This kind of feature seems only works with in lined asm function in CodeWarrior.

Emmanuel