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

[Erik Walthinsen]

E. Weddington wrote:
> 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).

This is specifically why I included both bit_set() and bit_set_mask(). 
They serve different purposes, and, being convenience macros, both are 
relevant.

As per docs, bit_set() takes a bit position, and bit_set_mask() takes 
any arbitrary value containing multiple bits:

bit_set(PORTB, 3);
bit_set_mask(PORTB, BIT(3) | BIT(5) | BIT(7));

IMO if the only macro set provided is a bit_set() that requires the bit 
position already converted with BIT(), then there really is no point in 
having the macros at all.  The point in having a basic bit_set() routine 
in my opinion is to make it trivial to quickly and *obviously* flip a 
single bit in a register.  If I'm flipping more than one, I probably 
wouldn't use bit_set_mask() anyway, personally.