On 04/23/2014 03:17 AM, Petr Machata wrote: > Wouldn't something like this get us off the hook as well? > > - (var) |= (typeof (var)) __s.i << ((nth) * 7); \ > + (var) |= (typeof (var)) \ > + (((uint64_t) (typeof (var)) __s.i) << ((nth) * 7)); \ > > We are really only using the bitfield trick to avoid having to > sign-extend by hand, but we can shift unsigned without losing anything.
It gets us off the hook, but might introduce a 64-bit shift where only a 32-bit shift was required. Sadly, (unsigned typeof(var)) doesn't work. ;-) But I gave the multiplication change a look, and the compiler is in fact optimizing the multiplication by a power of 2 back into a shift. r~
