Re: Proposal: block-based vector allocator

[Dmitry Antipov]

On 05/21/2012 05:02 PM, Andreas Schwab wrote:

> It doesn't make much sense to try to find such a trivial but non-std
> macro in a system header.

Hm, glibc provides some not-so-trivial bits (assuming gcc):

# define roundup(x, y)  (__builtin_constant_p (y) && powerof2 (y)             \
                         ? (((x) + (y) - 1) & ~((y) - 1))                     \
                         : ((((x) + ((y) - 1)) / (y)) * (y)))

It seems to be a very negligible optimization, but why not use it if available?

Dmitry