[avr-gcc-list] Re: AVR byte swap optimization

[Denis Vlasenko]

On Saturday 18 November 2006 00:30, Shaun Jackman wrote:
> The following macro expands to some rather frightful code on the AVR:
> 
> #define BSWAP_16(x) \
>      ((((x) >> 8) & 0xff) | (((x) & 0xff) << 8))

Sometimes gcc is generating better code if you cast
values instead of masking. Try:

      ( (uint8_t)((x) >> 8) | ((uint8_t)(x)) << 8 )

--
vda