Turn misc objects into pseudovectors

Eliminate the category of miscellaneous objects, and turn all
such objects into pseudovectors.  The immediate motivation
for this change is to free up an enum Lisp_Type tag value, a
scarce resource that can be better used elsewhere.  However,
this change is worthwhile in its own right, as it improves
performance slightly on my platform, 0.3% faster for 'make
compile-always' on Fedora 28, and it simplifies the garbage
collector and interpreter (Bug#32405).
* doc/lispref/internals.texi (Garbage Collection):
* etc/NEWS:
Document change to garbage-collect return value.
* src/alloc.c (total_markers, total_free_markers):
(union aligned_Lisp_Misc, MARKER_BLOCK_SIZE)
(struct marker_block, marker_block, marker_block_index)
(misc_free_list, allocate_misc, live_misc_holding)
(live_misc_p, sweep_misc):
* src/lisp.h (lisp_h_MARKERP, lisp_h_MISCP, MARKERP, MISCP)
(Lisp_Misc, enum Lisp_Misc_Type, Lisp_Misc_Free)
(Lisp_Misc_Marker, Lisp_Misc_Overlay, Lisp_Misc_Finalizer)
(Lisp_Misc_Ptr, Lisp_Misc_User_Ptr, Lisp_Misc_Limit)
(Lisp_Misc_Bignum)
(XSETMISC, struct Lisp_Misc_Any, XMISCANY, XMISCTYPE)
(struct Lisp_Free, union Lisp_Misc, XMISC):
Remove.  All uses removed.
(cleanup_vector): Clean up objects that were formerly misc
and are now pseudovectors.
(make_misc_ptr, build_overlay, Fmake_marker, build_marker)
(make_bignum_str, make_number, make_pure_bignum)
(make_user_ptr, Fmake_finalizer):
Build as pseudovectors, not as misc objects.
(mark_finalizer_list, queue_doomed_finalizers)
(compact_undo_list, mark_overlay, mark_object)
(unchain_dead_markers):
Mark as vector-like objects, not as misc objects.
(mark_maybe_object, mark_maybe_pointer, valid_lisp_object_p)
(total_bytes_of_live_objects, survives_gc_p):
* src/fns.c (sxhash):
No need to worry about misc objects.
(garbage_collect_1): Do not generate a 'misc' component.
(syms_of_alloc): No need for 'misc' symbol.
* src/buffer.c (overlays_at, overlays_in, overlay_touches_p)
(overlay_strings, recenter_overlay_lists)
(fix_start_end_in_overlays, fix_overlays_before)
(Foverlay_lists, report_overlay_modification)
(evaporate_overlays):
* src/editfns.c (overlays_around):
* src/data.c (Ftype_of):
* src/fns.c (internal_equal):
* src/lisp.h (mint_ptrp, xmint_pointer, FINALIZERP)
(XFINALIZER, MARKERP, XMARKER, OVERLAYP, XOVERLAY, USER_PTRP)
(XUSER_PTR, BIGNUMP, XBIGNUM):
* src/print.c (print_vectorlike, print_object):
* src/undo.c (record_marker_adjustments):
* src/xdisp.c (load_overlay_strings):
Formerly misc objects are now pseudovectors.
* src/lisp.h (PVEC_MARKER, PVEC_OVERLAY, PVEC_FINALIZER)
(PVEC_BIGNUM, PVEC_MISC_PTR, PVEC_USER_PTR):
New constants, replacing their misc versions.  All uses changed.
(struct Lisp_Marker, struct Lisp_Overlay, struct Lisp_Misc_Ptr)
(struct Lisp_Bignum, struct Lisp_User_Ptr, struct Lisp_Finalizer):
Make usable as a pseudovector by using a pseudovector header,
replacing any DIY components, and putting Lisp_Object members
first.  All uses changed.

1 files changed, 5 insertions, 9 deletions

diff --git a/src/undo.c b/src/undo.c
index e80ec58ab09..1975e387e3f 100644
--- a/src/undo.c
+++ b/src/undo.c
@@ -126,15 +126,11 @@ record_insert (ptrdiff_t beg, ptrdiff_t length)
 static void
 record_marker_adjustments (ptrdiff_t from, ptrdiff_t to)
 {
-  Lisp_Object marker;
-  register struct Lisp_Marker *m;
-  register ptrdiff_t charpos, adjustment;
-
-  prepare_record();
+  prepare_record ();
 
-  for (m = BUF_MARKERS (current_buffer); m; m = m->next)
+  for (struct Lisp_Marker *m = BUF_MARKERS (current_buffer); m; m = m->next)
     {
-      charpos = m->charpos;
+      ptrdiff_t charpos = m->charpos;
       eassert (charpos <= Z);
 
       if (from <= charpos && charpos <= to)
@@ -146,11 +142,11 @@ record_marker_adjustments (ptrdiff_t from, ptrdiff_t to)
              insertion_type t markers will automatically move forward
              upon re-inserting the deleted text, so we have to arrange
              for them to move backward to the correct position.  */
-          adjustment = (m->insertion_type ? to : from) - charpos;
+	  ptrdiff_t adjustment = (m->insertion_type ? to : from) - charpos;
 
           if (adjustment)
             {
-              XSETMISC (marker, m);
+	      Lisp_Object marker = make_lisp_ptr (m, Lisp_Vectorlike);
               bset_undo_list
                 (current_buffer,
                  Fcons (Fcons (marker, make_fixnum (adjustment)),