[Patch, AVR]: QI builtins for parity, popcount, 1<< n

[Georg-Johann Lay]

Joseph S. Myers schrieb:
> On Thu, 16 Jun 2011, Georg-Johann Lay wrote:
> 
>> The recent implementation of some asm function in libgcc added
>> __popcountqi2 and __parityqi2. This patch makes these functions
>> available as __builtin_avr_popcount8 resp. __builtin_avr_parity8.
>>
>> Moreover, just out of a mood, I wrote a builtin for 1<<n.
>> 1<<n is sometimes used to set a variable SFR bit. The builtin supplies
>> a fast, loop-free implementation.
> 
> I hope this whole patch is just intended as an example of how to add 
> built-in functions and not as a serious proposal for an addition to GCC, 
> since it doesn't make sense to add machine-specific built-in functions for 
> things that can so readily be represented in generic GNU C; instead, you 
> should make generic GNU C generate the right code (for example, by 
> handling __builtin_parity and __builtin_popcount smartly on zero-extended 
> values if QImode patterns are available - if it doesn't already do so).
> 
> Joseph S. Myers

I don't see what's bat with the patch, it's straight forward.

As I don't intend to introduce new register classes and constraints
(hard regnos won't do any more if combine is intended to come up with
new insn, what it actually does) just for that... Dropping the patch.

Johann