Re: [avr-libc-dev] [patch #6418] Yet another delay routines

[David Brown]

Carlos Lamas wrote:
> David:
>
> I've only received a private copy of your message. Would you mind to 
> repost again at Savannah or avr-libc-dev list to continue the discussion 
> in a public forum for the sake of the general interest?
>
> Best regards,
>
> Carlos.

No problem - I guess I pressed the wrong "Reply To" button earlier and 
sent the message only to you.

mvh.,

David


> David Brown wrote:
>
> > Carlos Lamas wrote:
> > <snip>
> >
> > > Problem 2. The proposed solution is to check the constant parameter 
> > > passed
> > > against an inline assembler constraint in an empty dummy asm() 
> > > instruction.
> > > This also requires to transform the inline function in a macro. 
> > > Passing a
> > > variable as the argument to the macro generates an error a bit 
> > > obfuscated.
> >
> > <snip>
> >
> > Hi Carlos,
> >
> > I don't know if you've considered it, but the 
> > __builtin_constant_p(exp) function might be a better way to check for 
> > constant parameters:
> >
> > http://gcc.gnu.org/onlinedocs/gcc-4.2.2/gcc/Other-Builtins.html
> >
> > Best regards,
> >
> > David