Re: [avr-libc-dev] [bug #32650] Missing include in util/delay.h

[Stu Bell]

On 3/3/2011 10:04 PM, Weddington, Eric wrote:
> > -----Original Message-----
> > From: address@hidden
> > [mailto:address@hidden On
> > Behalf Of Stu Bell
> > Sent: Thursday, March 03, 2011 9:49 PM
> > To: Alastair D'Silva; Stu Bell; address@hidden
> > Subject: [avr-libc-dev] [bug #32650] Missing include in util/delay.h
> >
> > Follow-up Comment #1, bug #32650 (project avr-libc):
> >
> > The math library is not needed if you do not pass a variable to _delay_ms
> > (or
> > _delay_us) as the instructions to avr-libc warn you not to do.  Only
> > constants
> > can be supplied to the delay functions.
> >
> > In fact, following your path will bring in the floating-point library
> > unnecessarily and will cause the delay functions to generate far more
> > delay
> > that requested.
> Remember, just including a header file (like math.h) does not mean that the 
> library is automatically linked in.
>
> The library is only linked in if the linker detects that it is needed. And even 
> then it doesn't pull in the entire library, just the module that is needed.
I suppose.  Has this changed in the latest version of the _delay_* routines?  I 
don't recall needing this before.

Stu Bell