Re: [avr-libc-dev] RFC: avr/bits.h

[E. Weddington]

Bob Paddock wrote:

> On Tue, 01 Mar 2005 10:00:13 -0700, E. Weddington <address@hidden> 
> wrote:
>
> > Bob Paddock wrote:
> >
> > > I wanted to do a test case
>
> Doing the test case right in the first place always help.
> You can not us a BIT() inside of a bit_set(). :-(
It depends on how bit_set() is defined. ;-)

I was going under a false assumption about how they were defined.
I personally do not support the macros as written by Erik Walthinsen 
(sorry, Erik).

> <test>
>
> All of the code lookes reasonable now that I don't
> have recursive macros, even got the proper sbi for PORTD.
>
>
>   34                   foo:
>   35                   .LFB2:
>   36                   .LM1:
>   37                   /* prologue: frame size=0 */
>   38                   /* prologue end (size=0) */
>   39                   .LM2:
>   40 0000 939A              sbi 50-0x20,3
>   41                   /* epilogue: frame size=0 */
That's good!

> Is there some case where the construct ((uint32_t)1<<(bitpos))
> is really going to promote to 32 bit code?
Well it won't "promote" to 32 bits as it's there already. The other 
macros that I defined will then trim that value down to the specified 
length (8/16 bits).

Eric