Re: Proposal: immediate strings

[Paul Eggert]

On 05/28/2012 11:55 PM, Dmitry Antipov wrote:
> To avoid using 'packed' attribute and speedup an inefficient access to 
> u.dat.size
> field, it's possible to use 'ptrdiff_t X : BITS_PER_PTRDIFF_T - 2'
> bitfields - it's still wide enough to hold the values up to 
> STRING_BYTES_BOUND.

That's not true on 32-bit hosts configured --with-wide-int.
On such hosts, a string can contain up to PTRDIFF_MAX - 1 bytes.
This proposal would lower the limit to PTRDIFF_MAX / 4 bytes.
In contrast, the proposal in
<http://lists.gnu.org/archive/html/emacs-devel/2012-05/msg00460.html>
would merely lower it to PTRDIFF_MAX - 65536 bytes.