On 3 Jan 2015, at 21:15, Sean Nakasone <seannakas...@yahoo.com> wrote: > > Hi, lib/obstack.c has a function, _obstack_newchunk(). > > there's a formula used to calculate a variable new_size > > new_size = (obj_size + length) + (obj_size >> 3) + h->alignment_mask + 100; > > i understand obj_size + length, but what's the other stuff for?
Perhaps some reallocation policy, avoiding too many reallocations. On a C++ class std::vector, one might double the allocations, and half if it gets down below a quarter: some hysteresis, to avoid border cases producing a lot of reallocations. _______________________________________________ help-bison@gnu.org https://lists.gnu.org/mailman/listinfo/help-bison
