Re: Proposal: immediate strings

[Paul Eggert]

On 05/29/2012 06:33 AM, Dmitry Antipov wrote:
> On 05/29/2012 11:38 AM, Paul Eggert wrote:
> this allows
> 
> min (MOST_POSITIVE_FIXNUM, (ptrdiff_t) min (SIZE_MAX, PTRDIFF_MAX - 1) - 1)
> 
> in all configurations (so PTRDIFF_MAX - 2 for --with-wide-int), eventually
> uses _all_ bits by eliminating signed values.

That one's clever, but doesn't it grow the size of "struct Lisp_String"
by a word, due to the padding bytes after the gcmarkbit member?

Why does gcmarkbit have to be in the same place for the two kinds
of strings?  If you could put gcmarkbit in different places in the
different union members, you wouldn't need that padding.