Re: USE_LSB_TAG and MS-DOS

[Stefan Monnier]

> I found the villain: dos-unsupported-char-glyph was being initialized
> with a literal numerical value instead of going thru make_number.

>From the ChangeLog text it seems that cmpiling with USE_LISP_UNION_TYPE
would have caught that eons ago.

> Btw, is pure[] usage supposed to go up when USE_LSB_TAG is in effect?
> AFAICS, it went from 977KB to 1019KB with almost no changes in Lisp
> files since the previous build.

There is likely to be an increase of about "2bytes * nb objects" due to the
additional alignment constraint.  Actually, most objects have a size that's
a multiple of 8, so the extra alignment should only happen after allocating
an array or a string, so it's probably more like "2b * nb arrays-or-strings".


        Stefan


PS: Reminds me I have a local hack to save space for small strings and pure
    strings where the string data is placed at the end of the string object
    rather than going through an indirection.  This saves 4bytes per pure
    string (about 70KB in my case IIRC).  And it saves 8 bytes per string of
    3bytes or less (on 32bit machines) and of 7bytes or less (on 64
    machines).  Strings of 3bytes or less account for almost half of all the
    strings ever allocated, IIRC.