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, 74 insertions, 91 deletions

diff --git a/src/print.c b/src/print.c
index 3819c505b12..824f8d75779 100644
--- a/src/print.c
+++ b/src/print.c
@@ -1367,6 +1367,76 @@ print_vectorlike (Lisp_Object obj, Lisp_Object printcharfun, bool escapeflag,
 {
   switch (PSEUDOVECTOR_TYPE (XVECTOR (obj)))
     {
+    case PVEC_BIGNUM:
+      {
+	struct Lisp_Bignum *b = XBIGNUM (obj);
+	char *str = mpz_get_str (NULL, 10, b->value);
+	record_unwind_protect_ptr (xfree, str);
+	print_c_string (str, printcharfun);
+      }
+      break;
+
+    case PVEC_MARKER:
+      print_c_string ("#<marker ", printcharfun);
+      /* Do you think this is necessary?  */
+      if (XMARKER (obj)->insertion_type != 0)
+	print_c_string ("(moves after insertion) ", printcharfun);
+      if (! XMARKER (obj)->buffer)
+	print_c_string ("in no buffer", printcharfun);
+      else
+	{
+	  int len = sprintf (buf, "at %"pD"d in ", marker_position (obj));
+	  strout (buf, len, len, printcharfun);
+	  print_string (BVAR (XMARKER (obj)->buffer, name), printcharfun);
+	}
+      printchar ('>', printcharfun);
+      break;
+
+    case PVEC_OVERLAY:
+      print_c_string ("#<overlay ", printcharfun);
+      if (! XMARKER (OVERLAY_START (obj))->buffer)
+	print_c_string ("in no buffer", printcharfun);
+      else
+	{
+	  int len = sprintf (buf, "from %"pD"d to %"pD"d in ",
+			     marker_position (OVERLAY_START (obj)),
+			     marker_position (OVERLAY_END   (obj)));
+	  strout (buf, len, len, printcharfun);
+	  print_string (BVAR (XMARKER (OVERLAY_START (obj))->buffer, name),
+			printcharfun);
+	}
+      printchar ('>', printcharfun);
+      break;
+
+#ifdef HAVE_MODULES
+    case PVEC_USER_PTR:
+      {
+	print_c_string ("#<user-ptr ", printcharfun);
+	int i = sprintf (buf, "ptr=%p finalizer=%p",
+			 XUSER_PTR (obj)->p,
+			 XUSER_PTR (obj)->finalizer);
+	strout (buf, i, i, printcharfun);
+	printchar ('>', printcharfun);
+      }
+      break;
+#endif
+
+    case PVEC_FINALIZER:
+      print_c_string ("#<finalizer", printcharfun);
+      if (NILP (XFINALIZER (obj)->function))
+	print_c_string (" used", printcharfun);
+      printchar ('>', printcharfun);
+      break;
+
+    case PVEC_MISC_PTR:
+      {
+	/* This shouldn't happen in normal usage, but let's
+	   print it anyway for the benefit of the debugger.  */
+	int i = sprintf (buf, "#<ptr %p>", xmint_pointer (obj));
+	strout (buf, i, i, printcharfun);
+      }
+      break;
+
     case PVEC_PROCESS:
       if (escapeflag)
 	{
@@ -2096,103 +2166,16 @@ print_object (Lisp_Object obj, Lisp_Object printcharfun, bool escapeflag)
       break;
 
     case Lisp_Vectorlike:
-      if (! print_vectorlike (obj, printcharfun, escapeflag, buf))
-	goto badtype;
-      break;
-
-    case Lisp_Misc:
-      switch (XMISCTYPE (obj))
-	{
-	case Lisp_Misc_Marker:
-	  print_c_string ("#<marker ", printcharfun);
-	  /* Do you think this is necessary?  */
-	  if (XMARKER (obj)->insertion_type != 0)
-	    print_c_string ("(moves after insertion) ", printcharfun);
-	  if (! XMARKER (obj)->buffer)
-	    print_c_string ("in no buffer", printcharfun);
-	  else
-	    {
-	      int len = sprintf (buf, "at %"pD"d in ", marker_position (obj));
-	      strout (buf, len, len, printcharfun);
-	      print_string (BVAR (XMARKER (obj)->buffer, name), printcharfun);
-	    }
-	  printchar ('>', printcharfun);
-	  break;
-
-	case Lisp_Misc_Overlay:
-	  print_c_string ("#<overlay ", printcharfun);
-	  if (! XMARKER (OVERLAY_START (obj))->buffer)
-	    print_c_string ("in no buffer", printcharfun);
-	  else
-	    {
-	      int len = sprintf (buf, "from %"pD"d to %"pD"d in ",
-				 marker_position (OVERLAY_START (obj)),
-				 marker_position (OVERLAY_END   (obj)));
-	      strout (buf, len, len, printcharfun);
-	      print_string (BVAR (XMARKER (OVERLAY_START (obj))->buffer, name),
-			    printcharfun);
-	    }
-	  printchar ('>', printcharfun);
-          break;
-
-#ifdef HAVE_MODULES
-	case Lisp_Misc_User_Ptr:
-	  {
-	    print_c_string ("#<user-ptr ", printcharfun);
-	    int i = sprintf (buf, "ptr=%p finalizer=%p",
-			     XUSER_PTR (obj)->p,
-			     XUSER_PTR (obj)->finalizer);
-	    strout (buf, i, i, printcharfun);
-	    printchar ('>', printcharfun);
-	    break;
-	  }
-#endif
-
-        case Lisp_Misc_Finalizer:
-          print_c_string ("#<finalizer", printcharfun);
-          if (NILP (XFINALIZER (obj)->function))
-            print_c_string (" used", printcharfun);
-	  printchar ('>', printcharfun);
-          break;
-
-	  /* Remaining cases shouldn't happen in normal usage, but let's
-	     print them anyway for the benefit of the debugger.  */
-
-	case Lisp_Misc_Free:
-	  print_c_string ("#<misc free cell>", printcharfun);
-	  break;
-
-	case Lisp_Misc_Ptr:
-	  {
-	    int i = sprintf (buf, "#<ptr %p>", xmint_pointer (obj));
-	    strout (buf, i, i, printcharfun);
-	  }
-	  break;
-
-	case Lisp_Misc_Bignum:
-	  {
-	    struct Lisp_Bignum *b = XBIGNUM (obj);
-	    char *str = mpz_get_str (NULL, 10, b->value);
-	    record_unwind_protect_ptr (xfree, str);
-	    print_c_string (str, printcharfun);
-	  }
-	  break;
-
-	default:
-	  goto badtype;
-	}
-      break;
-
+      if (print_vectorlike (obj, printcharfun, escapeflag, buf))
+	break;
+      FALLTHROUGH;
     default:
-    badtype:
       {
 	int len;
 	/* We're in trouble if this happens!
 	   Probably should just emacs_abort ().  */
 	print_c_string ("#<EMACS BUG: INVALID DATATYPE ", printcharfun);
-	if (MISCP (obj))
-	  len = sprintf (buf, "(MISC 0x%04x)", (unsigned) XMISCTYPE (obj));
-	else if (VECTORLIKEP (obj))
+	if (VECTORLIKEP (obj))
 	  len = sprintf (buf, "(PVEC 0x%08zx)", (size_t) ASIZE (obj));
 	else
 	  len = sprintf (buf, "(0x%02x)", (unsigned) XTYPE (obj));