Re: Proposal: block-based vector allocator

[Paul Eggert]

On 05/31/2012 10:15 PM, Dmitry Antipov wrote:
> On non-USE_LSB_TAG system, roundup_size is orthogonal to pointer
> values (roundup_size can't be less than sizeof (Lisp_Object), of course).

Ah, OK, then we can make roundup_size be the equivalent of
COMMON_MULTIPLE (sizeof (Lisp_Object), defined USE_LSB_TAG ? 8 : 1).

> For example, 32-bit system (non-wide-int, i.e. sizeof (Lisp_Object) == 4)
> without USE_LSB_TAG is expected to work with roundup_size = 4, but I can't
> test this and have no ideas why it's worth trying at all.

It would waste less memory due to internal fragmentation, which
would be a win.  I don't see the downside -- perhaps you could
explain?