Use shortcuts for Flength

When calculating the length of a Lisp object whose type is
known, use a specialized length operation on it to save a bit
of runtime overhead.
* src/callint.c (Fcall_interactively):
* src/minibuf.c (read_minibuf_unwind):
Use ASIZE rather than Flength on values that must be vectors.
* src/charset.c (Fsort_charsets):
* src/coding.c (detect_coding_sjis):
(Fdefine_coding_system_internal):
* src/data.c (wrong_choice):
* src/eval.c (Flet, eval_sub, Fapply, apply_lambda):
* src/fns.c (sort_list):
* src/font.c (font_vconcat_entity_vectors)
(font_find_for_lface):
* src/frame.c (Fmodify_frame_parameters):
* src/fringe.c (get_logical_fringe_bitmap):
* src/ftfont.c (ftfont_get_open_type_spec):
* src/gtkutil.c (xg_print_frames_dialog):
* src/lread.c (read1, read_vector):
* src/keymap.c (Fkey_description):
* src/kqueue.c (Fkqueue_add_watch):
* src/macfont.m (macfont_get_open_type_spec):
* src/menu.c (parse_single_submenu, x_popup_menu_1):
* src/minibuf.c (Finternal_complete_buffer):
* src/nsfont.m (ns_findfonts, nsfont_list_family):
* src/process.c (Fmake_process):
* src/search.c (Fset_match_data):
* src/xfaces.c (Fx_family_fonts):
Use list_length rather than Flength on values that must be lists.
* src/fns.c (list_length): New function.
(Flength): Use it.
* src/nsfont.m (ns_findfonts):
Use !NILP (x) rather than XFIXNUM (Flength (x)) != 0.
* src/xdisp.c (store_mode_line_string):
Use SCHARS rather than Flength on values that must be strings.

23 files changed, 98 insertions, 124 deletions

diff --git a/src/callint.c b/src/callint.c
index dac905e16f4..0911c49ae59 100644
--- a/src/callint.c
+++ b/src/callint.c
@@ -572,7 +572,7 @@ invoke it.  If KEYS is omitted or nil, the return value of
 	    /* If the key sequence ends with a down-event,
 	       discard the following up-event.  */
 	    Lisp_Object teml
-	      = Faref (args[i], make_fixnum (XFIXNUM (Flength (args[i])) - 1));
+	      = Faref (args[i], make_fixnum (ASIZE (args[i]) - 1));
 	    if (CONSP (teml))
 	      teml = XCAR (teml);
 	    if (SYMBOLP (teml))
diff --git a/src/charset.c b/src/charset.c
index 427349b298a..724b35536ed 100644
--- a/src/charset.c
+++ b/src/charset.c
@@ -2242,8 +2242,7 @@ Return the sorted list.  CHARSETS is modified by side effects.
 See also `charset-priority-list' and `set-charset-priority'.  */)
      (Lisp_Object charsets)
 {
-  Lisp_Object len = Flength (charsets);
-  ptrdiff_t n = XFIXNAT (len), i, j;
+  ptrdiff_t n = list_length (charsets), i, j;
   int done;
   Lisp_Object tail, elt, attrs;
   struct charset_sort_data *sort_data;
diff --git a/src/coding.c b/src/coding.c
index 0297c8a100d..1c1462198ca 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -4591,8 +4591,7 @@ detect_coding_sjis (struct coding_system *coding,
   int max_first_byte_of_2_byte_code;
 
   CODING_GET_INFO (coding, attrs, charset_list);
-  max_first_byte_of_2_byte_code
-    = (XFIXNUM (Flength (charset_list)) > 3 ? 0xFC : 0xEF);
+  max_first_byte_of_2_byte_code = list_length (charset_list) <= 3 ? 0xEF : 0xFC;
 
   detect_info->checked |= CATEGORY_MASK_SJIS;
   /* A coding system of this category is always ASCII compatible.  */
@@ -10387,14 +10386,11 @@ usage: (define-coding-system-internal ...)  */)
     }
   else if (EQ (coding_type, Qshift_jis))
     {
-
-      struct charset *charset;
-
-      if (XFIXNUM (Flength (charset_list)) != 3
-	  && XFIXNUM (Flength (charset_list)) != 4)
+      ptrdiff_t charset_list_len = list_length (charset_list);
+      if (charset_list_len != 3 && charset_list_len != 4)
 	error ("There should be three or four charsets");
 
-      charset = CHARSET_FROM_ID (XFIXNUM (XCAR (charset_list)));
+      struct charset *charset = CHARSET_FROM_ID (XFIXNUM (XCAR (charset_list)));
       if (CHARSET_DIMENSION (charset) != 1)
 	error ("Dimension of charset %s is not one",
 	       SDATA (SYMBOL_NAME (CHARSET_NAME (charset))));
@@ -10429,7 +10425,7 @@ usage: (define-coding-system-internal ...)  */)
     {
       struct charset *charset;
 
-      if (XFIXNUM (Flength (charset_list)) != 2)
+      if (list_length (charset_list) != 2)
 	error ("There should be just two charsets");
 
       charset = CHARSET_FROM_ID (XFIXNUM (XCAR (charset_list)));
diff --git a/src/data.c b/src/data.c
index 1c124740815..a9908a34f4f 100644
--- a/src/data.c
+++ b/src/data.c
@@ -980,14 +980,12 @@ chain of aliases, signal a `cyclic-variable-indirection' error.  */)
    swap_in_symval_forwarding for that.  */
 
 Lisp_Object
-do_symval_forwarding (register union Lisp_Fwd *valcontents)
+do_symval_forwarding (union Lisp_Fwd *valcontents)
 {
-  register Lisp_Object val;
   switch (XFWDTYPE (valcontents))
     {
     case Lisp_Fwd_Int:
-      XSETINT (val, *XFIXNUMFWD (valcontents)->intvar);
-      return val;
+      return make_fixnum (*XFIXNUMFWD (valcontents)->intvar);
 
     case Lisp_Fwd_Bool:
       return (*XBOOLFWD (valcontents)->boolvar ? Qt : Qnil);
@@ -1023,7 +1021,7 @@ do_symval_forwarding (register union Lisp_Fwd *valcontents)
 void
 wrong_choice (Lisp_Object choice, Lisp_Object wrong)
 {
-  ptrdiff_t i = 0, len = XFIXNUM (Flength (choice));
+  ptrdiff_t i = 0, len = list_length (choice);
   Lisp_Object obj, *args;
   AUTO_STRING (one_of, "One of ");
   AUTO_STRING (comma, ", ");
diff --git a/src/eval.c b/src/eval.c
index c64a40b955d..28478956e35 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -951,16 +951,15 @@ usage: (let VARLIST BODY...)  */)
   (Lisp_Object args)
 {
   Lisp_Object *temps, tem, lexenv;
-  Lisp_Object elt, varlist;
+  Lisp_Object elt;
   ptrdiff_t count = SPECPDL_INDEX ();
   ptrdiff_t argnum;
   USE_SAFE_ALLOCA;
 
-  varlist = XCAR (args);
-  CHECK_LIST (varlist);
+  Lisp_Object varlist = XCAR (args);
 
   /* Make space to hold the values to give the bound variables.  */
-  EMACS_INT varlist_len = XFIXNAT (Flength (varlist));
+  EMACS_INT varlist_len = list_length (varlist);
   SAFE_ALLOCA_LISP (temps, varlist_len);
   ptrdiff_t nvars = varlist_len;
 
@@ -2263,14 +2262,15 @@ eval_sub (Lisp_Object form)
   if (SUBRP (fun))
     {
       Lisp_Object args_left = original_args;
-      Lisp_Object numargs = Flength (args_left);
+      ptrdiff_t numargs = list_length (args_left);
 
       check_cons_list ();
 
-      if (XFIXNUM (numargs) < XSUBR (fun)->min_args
+      if (numargs < XSUBR (fun)->min_args
 	  || (XSUBR (fun)->max_args >= 0
-	      && XSUBR (fun)->max_args < XFIXNUM (numargs)))
-	xsignal2 (Qwrong_number_of_arguments, original_fun, numargs);
+	      && XSUBR (fun)->max_args < numargs))
+	xsignal2 (Qwrong_number_of_arguments, original_fun,
+		  make_fixnum (numargs));
 
       else if (XSUBR (fun)->max_args == UNEVALLED)
 	val = (XSUBR (fun)->function.aUNEVALLED) (args_left);
@@ -2281,9 +2281,9 @@ eval_sub (Lisp_Object form)
 	  ptrdiff_t argnum = 0;
 	  USE_SAFE_ALLOCA;
 
-	  SAFE_ALLOCA_LISP (vals, XFIXNUM (numargs));
+	  SAFE_ALLOCA_LISP (vals, numargs);
 
-	  while (CONSP (args_left) && argnum < XFIXNUM (numargs))
+	  while (CONSP (args_left) && argnum < numargs)
 	    {
 	      Lisp_Object arg = XCAR (args_left);
 	      args_left = XCDR (args_left);
@@ -2313,7 +2313,7 @@ eval_sub (Lisp_Object form)
 	      args_left = Fcdr (args_left);
 	    }
 
-	  set_backtrace_args (specpdl + count, argvals, XFIXNUM (numargs));
+	  set_backtrace_args (specpdl + count, argvals, numargs);
 
 	  switch (i)
 	    {
@@ -2417,16 +2417,13 @@ Thus, (apply \\='+ 1 2 \\='(3 4)) returns 10.
 usage: (apply FUNCTION &rest ARGUMENTS)  */)
   (ptrdiff_t nargs, Lisp_Object *args)
 {
-  ptrdiff_t i, numargs, funcall_nargs;
-  register Lisp_Object *funcall_args = NULL;
-  register Lisp_Object spread_arg = args[nargs - 1];
+  ptrdiff_t i, funcall_nargs;
+  Lisp_Object *funcall_args = NULL;
+  Lisp_Object spread_arg = args[nargs - 1];
   Lisp_Object fun = args[0];
-  Lisp_Object retval;
   USE_SAFE_ALLOCA;
 
-  CHECK_LIST (spread_arg);
-
-  numargs = XFIXNUM (Flength (spread_arg));
+  ptrdiff_t numargs = list_length (spread_arg);
 
   if (numargs == 0)
     return Ffuncall (nargs - 1, args);
@@ -2476,7 +2473,7 @@ usage: (apply FUNCTION &rest ARGUMENTS)  */)
       spread_arg = XCDR (spread_arg);
     }
 
-  retval = Ffuncall (funcall_nargs, funcall_args);
+  Lisp_Object retval = Ffuncall (funcall_nargs, funcall_args);
 
   SAFE_FREE ();
   return retval;
@@ -2974,25 +2971,22 @@ funcall_subr (struct Lisp_Subr *subr, ptrdiff_t numargs, Lisp_Object *args)
 static Lisp_Object
 apply_lambda (Lisp_Object fun, Lisp_Object args, ptrdiff_t count)
 {
-  Lisp_Object args_left;
-  ptrdiff_t i;
-  EMACS_INT numargs;
   Lisp_Object *arg_vector;
   Lisp_Object tem;
   USE_SAFE_ALLOCA;
 
-  numargs = XFIXNAT (Flength (args));
+  ptrdiff_t numargs = list_length (args);
   SAFE_ALLOCA_LISP (arg_vector, numargs);
-  args_left = args;
+  Lisp_Object args_left = args;
 
-  for (i = 0; i < numargs; )
+  for (ptrdiff_t i = 0; i < numargs; i++)
     {
       tem = Fcar (args_left), args_left = Fcdr (args_left);
       tem = eval_sub (tem);
-      arg_vector[i++] = tem;
+      arg_vector[i] = tem;
     }
 
-  set_backtrace_args (specpdl + count, arg_vector, i);
+  set_backtrace_args (specpdl + count, arg_vector, numargs);
   tem = funcall_lambda (fun, numargs, arg_vector);
 
   check_cons_list ();
diff --git a/src/fns.c b/src/fns.c
index 7791310a313..0fad6f47447 100644
--- a/src/fns.c
+++ b/src/fns.c
@@ -91,42 +91,50 @@ See Info node `(elisp)Random Numbers' for more details.  */)
 
 /* Random data-structure functions.  */
 
+/* Return the length of LIST.  Signal an error if LIST is not a proper
+   list or if the length does not fit into a fixnum or into ptrdiff_t.  */
+
+ptrdiff_t
+list_length (Lisp_Object list)
+{
+  intptr_t i = 0;
+  FOR_EACH_TAIL (list)
+    i++;
+  CHECK_LIST_END (list, list);
+  if (i <= min (PTRDIFF_MAX, MOST_POSITIVE_FIXNUM))
+    return i;
+  overflow_error ();
+}
+
+
 DEFUN ("length", Flength, Slength, 1, 1, 0,
        doc: /* Return the length of vector, list or string SEQUENCE.
 A byte-code function object is also allowed.
 If the string contains multibyte characters, this is not necessarily
 the number of bytes in the string; it is the number of characters.
 To get the number of bytes, use `string-bytes'.  */)
-  (register Lisp_Object sequence)
+  (Lisp_Object sequence)
 {
-  register Lisp_Object val;
+  EMACS_INT val;
 
   if (STRINGP (sequence))
-    XSETFASTINT (val, SCHARS (sequence));
+    val = SCHARS (sequence);
   else if (VECTORP (sequence))
-    XSETFASTINT (val, ASIZE (sequence));
+    val = ASIZE (sequence);
   else if (CHAR_TABLE_P (sequence))
-    XSETFASTINT (val, MAX_CHAR);
+    val = MAX_CHAR;
   else if (BOOL_VECTOR_P (sequence))
-    XSETFASTINT (val, bool_vector_size (sequence));
+    val = bool_vector_size (sequence);
   else if (COMPILEDP (sequence) || RECORDP (sequence))
-    XSETFASTINT (val, PVSIZE (sequence));
+    val = PVSIZE (sequence);
   else if (CONSP (sequence))
-    {
-      intptr_t i = 0;
-      FOR_EACH_TAIL (sequence)
-	i++;
-      CHECK_LIST_END (sequence, sequence);
-      if (MOST_POSITIVE_FIXNUM < i)
-	overflow_error ();
-      val = make_fixnum (i);
-    }
+    val = list_length (sequence);
   else if (NILP (sequence))
-    XSETFASTINT (val, 0);
+    val = 0;
   else
     wrong_type_argument (Qsequencep, sequence);
 
-  return val;
+  return make_fixnum (val);
 }
 
 DEFUN ("safe-length", Fsafe_length, Ssafe_length, 1, 1, 0,
@@ -1957,24 +1965,15 @@ See also the function `nreverse', which is used more often.  */)
 static Lisp_Object
 sort_list (Lisp_Object list, Lisp_Object predicate)
 {
-  Lisp_Object front, back;
-  Lisp_Object len, tem;
-  EMACS_INT length;
-
-  front = list;
-  len = Flength (list);
-  length = XFIXNUM (len);
+  ptrdiff_t length = list_length (list);
   if (length < 2)
     return list;
 
-  XSETINT (len, (length / 2) - 1);
-  tem = Fnthcdr (len, list);
-  back = Fcdr (tem);
+  Lisp_Object tem = Fnthcdr (make_fixnum (length / 2 - 1), list);
+  Lisp_Object back = Fcdr (tem);
   Fsetcdr (tem, Qnil);
 
-  front = Fsort (front, predicate);
-  back = Fsort (back, predicate);
-  return merge (front, back, predicate);
+  return merge (Fsort (list, predicate), Fsort (back, predicate), predicate);
 }
 
 /* Using PRED to compare, return whether A and B are in order.
diff --git a/src/font.c b/src/font.c
index cf68160e59c..3fc77a1d76a 100644
--- a/src/font.c
+++ b/src/font.c
@@ -2174,13 +2174,12 @@ font_score (Lisp_Object entity, Lisp_Object *spec_prop)
 static Lisp_Object
 font_vconcat_entity_vectors (Lisp_Object list)
 {
-  EMACS_INT nargs = XFIXNAT (Flength (list));
+  ptrdiff_t nargs = list_length (list);
   Lisp_Object *args;
   USE_SAFE_ALLOCA;
   SAFE_ALLOCA_LISP (args, nargs);
-  ptrdiff_t i;
 
-  for (i = 0; i < nargs; i++, list = XCDR (list))
+  for (ptrdiff_t i = 0; i < nargs; i++, list = XCDR (list))
     args[i] = XCAR (list);
   Lisp_Object result = Fvconcat (nargs, args);
   SAFE_FREE ();
@@ -3241,7 +3240,7 @@ font_find_for_lface (struct frame *f, Lisp_Object *attrs, Lisp_Object spec, int
 
       if (! NILP (alters))
 	{
-	  EMACS_INT alterslen = XFIXNAT (Flength (alters));
+	  EMACS_INT alterslen = list_length (alters);
 	  SAFE_ALLOCA_LISP (family, alterslen + 2);
 	  for (i = 0; CONSP (alters); i++, alters = XCDR (alters))
 	    family[i] = XCAR (alters);
diff --git a/src/frame.c b/src/frame.c
index 6efc2a61095..ca6704a44c0 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -3190,7 +3190,7 @@ list, but are otherwise ignored.  */)
 #endif
 
     {
-      EMACS_INT length = XFIXNAT (Flength (alist));
+      EMACS_INT length = list_length (alist);
       ptrdiff_t i;
       Lisp_Object *parms;
       Lisp_Object *values;
diff --git a/src/fringe.c b/src/fringe.c
index a7e8dad482e..74f41f00873 100644
--- a/src/fringe.c
+++ b/src/fringe.c
@@ -719,7 +719,7 @@ static int
 get_logical_fringe_bitmap (struct window *w, Lisp_Object bitmap, int right_p, int partial_p)
 {
   Lisp_Object cmap, bm1 = Qnil, bm2 = Qnil, bm;
-  EMACS_INT ln1 = 0, ln2 = 0;
+  ptrdiff_t ln1 = 0, ln2 = 0;
   int ix1 = right_p;
   int ix2 = ix1 + (partial_p ? 2 : 0);
 
@@ -743,7 +743,7 @@ get_logical_fringe_bitmap (struct window *w, Lisp_Object bitmap, int right_p, in
 	    return NO_FRINGE_BITMAP;
 	  if (CONSP (bm1))
 	    {
-	      ln1 = XFIXNUM (Flength (bm1));
+	      ln1 = list_length (bm1);
 	      if (partial_p)
 		{
 		  if (ln1 > ix2)
@@ -778,7 +778,7 @@ get_logical_fringe_bitmap (struct window *w, Lisp_Object bitmap, int right_p, in
 	    {
 	      if (CONSP (bm2))
 		{
-		  ln2 = XFIXNUM (Flength (bm2));
+		  ln2 = list_length (bm2);
 		  if (partial_p)
 		    {
 		      if (ln2 > ix2)
diff --git a/src/ftfont.c b/src/ftfont.c
index 6899a5763a8..f5a225be056 100644
--- a/src/ftfont.c
+++ b/src/ftfont.c
@@ -594,16 +594,14 @@ ftfont_get_open_type_spec (Lisp_Object otf_spec)
   spec->nfeatures[0] = spec->nfeatures[1] = 0;
   for (i = 0; i < 2 && ! NILP (otf_spec); i++, otf_spec = XCDR (otf_spec))
     {
-      Lisp_Object len;
-
       val = XCAR (otf_spec);
       if (NILP (val))
 	continue;
-      len = Flength (val);
+      ptrdiff_t len = list_length (val);
       spec->features[i] =
-	(min (PTRDIFF_MAX, SIZE_MAX) / sizeof (int) < XFIXNUM (len)
+	(min (PTRDIFF_MAX, SIZE_MAX) / sizeof (int) < len
 	 ? 0
-	 : malloc (XFIXNUM (len) * sizeof *spec->features[i]));
+	 : malloc (len * sizeof *spec->features[i]));
       if (! spec->features[i])
 	{
 	  if (i > 0 && spec->features[0])
diff --git a/src/gtkutil.c b/src/gtkutil.c
index 2eac28798bc..92199bb0af2 100644
--- a/src/gtkutil.c
+++ b/src/gtkutil.c
@@ -4299,7 +4299,7 @@ xg_print_frames_dialog (Lisp_Object frames)
     gtk_print_operation_set_print_settings (print, print_settings);
   if (page_setup != NULL)
     gtk_print_operation_set_default_page_setup (print, page_setup);
-  gtk_print_operation_set_n_pages (print, XFIXNUM (Flength (frames)));
+  gtk_print_operation_set_n_pages (print, list_length (frames));
   g_signal_connect (print, "draw-page", G_CALLBACK (draw_page), &frames);
   res = gtk_print_operation_run (print, GTK_PRINT_OPERATION_ACTION_PRINT_DIALOG,
                                  NULL, NULL);
diff --git a/src/keymap.c b/src/keymap.c
index 21d37328ade..dda552ba471 100644
--- a/src/keymap.c
+++ b/src/keymap.c
@@ -2042,7 +2042,7 @@ For an approximate inverse of this, see `kbd'.  */)
   else if (VECTORP (list))
     size = ASIZE (list);
   else if (CONSP (list))
-    size = XFIXNUM (Flength (list));
+    size = list_length (list);
   else
     wrong_type_argument (Qarrayp, list);
 
diff --git a/src/kqueue.c b/src/kqueue.c
index 655bfd58d3b..43e75cac310 100644
--- a/src/kqueue.c
+++ b/src/kqueue.c
@@ -395,11 +395,12 @@ only when the upper directory of the renamed file is watched.  */)
     maxfd = 256;
 
   /* We assume 50 file descriptors are sufficient for the rest of Emacs.  */
-  if ((maxfd - 50) < XFIXNUM (Flength (watch_list)))
+  ptrdiff_t watch_list_len = list_length (watch_list);
+  if (maxfd - 50 < watch_list_len)
     xsignal2
       (Qfile_notify_error,
        build_string ("File watching not possible, no file descriptor left"),
-       Flength (watch_list));
+       make_fixnum (watch_list_len));
 
   if (kqueuefd < 0)
     {
diff --git a/src/lisp.h b/src/lisp.h
index dce61c165cf..faf5a4ad407 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -3413,6 +3413,7 @@ extern void syms_of_syntax (void);
 
 /* Defined in fns.c.  */
 enum { NEXT_ALMOST_PRIME_LIMIT = 11 };
+extern ptrdiff_t list_length (Lisp_Object);
 extern EMACS_INT next_almost_prime (EMACS_INT) ATTRIBUTE_CONST;
 extern Lisp_Object larger_vector (Lisp_Object, ptrdiff_t, ptrdiff_t);
 extern void sweep_weak_hash_tables (void);
diff --git a/src/lread.c b/src/lread.c
index 02f7caadeda..5a595f2119b 100644
--- a/src/lread.c
+++ b/src/lread.c
@@ -2879,7 +2879,7 @@ read1 (Lisp_Object readcharfun, int *pch, bool first_in_list)
 		  /* Sub char-table can't be read as a regular
 		     vector because of a two C integer fields.  */
 		  Lisp_Object tbl, tmp = read_list (1, readcharfun);
-		  ptrdiff_t size = XFIXNUM (Flength (tmp));
+		  ptrdiff_t size = list_length (tmp);
 		  int i, depth, min_char;
 		  struct Lisp_Cons *cell;
 
@@ -3846,8 +3846,7 @@ static Lisp_Object
 read_vector (Lisp_Object readcharfun, bool bytecodeflag)
 {
   Lisp_Object tem = read_list (1, readcharfun);
-  Lisp_Object len = Flength (tem);
-  ptrdiff_t size = XFIXNAT (len);
+  ptrdiff_t size = list_length (tem);
   if (bytecodeflag && size <= COMPILED_STACK_DEPTH)
     error ("Invalid byte code");
   Lisp_Object vector = make_nil_vector (size);
diff --git a/src/macfont.m b/src/macfont.m
index 0e90eb44eeb..09c4ff31c88 100644
--- a/src/macfont.m
+++ b/src/macfont.m
@@ -1791,16 +1791,14 @@ macfont_get_open_type_spec (Lisp_Object otf_spec)
   spec->nfeatures[0] = spec->nfeatures[1] = 0;
   for (i = 0; i < 2 && ! NILP (otf_spec); i++, otf_spec = XCDR (otf_spec))
     {
-      Lisp_Object len;
-
       val = XCAR (otf_spec);
       if (NILP (val))
         continue;
-      len = Flength (val);
+      ptrdiff_t len = list_length (val);
       spec->features[i] =
-        (min (PTRDIFF_MAX, SIZE_MAX) / sizeof (int) < XFIXNUM (len)
+        (min (PTRDIFF_MAX, SIZE_MAX) / sizeof (int) < len
          ? 0
-         : malloc (XFIXNUM (len) * sizeof *spec->features[i]));
+         : malloc (len * sizeof *spec->features[i]));
       if (! spec->features[i])
         {
           if (i > 0 && spec->features[0])
diff --git a/src/menu.c b/src/menu.c
index c35d711b314..c0e5bd9caf6 100644
--- a/src/menu.c
+++ b/src/menu.c
@@ -524,19 +524,15 @@ bool
 parse_single_submenu (Lisp_Object item_key, Lisp_Object item_name,
 		      Lisp_Object maps)
 {
-  Lisp_Object length;
-  EMACS_INT len;
   Lisp_Object *mapvec;
-  ptrdiff_t i;
   bool top_level_items = 0;
   USE_SAFE_ALLOCA;
 
-  length = Flength (maps);
-  len = XFIXNUM (length);
+  ptrdiff_t len = list_length (maps);
 
   /* Convert the list MAPS into a vector MAPVEC.  */
   SAFE_ALLOCA_LISP (mapvec, len);
-  for (i = 0; i < len; i++)
+  for (ptrdiff_t i = 0; i < len; i++)
     {
       mapvec[i] = Fcar (maps);
       maps = Fcdr (maps);
@@ -544,7 +540,7 @@ parse_single_submenu (Lisp_Object item_key, Lisp_Object item_name,
 
   /* Loop over the given keymaps, making a pane for each map.
      But don't make a pane that is empty--ignore that map instead.  */
-  for (i = 0; i < len; i++)
+  for (ptrdiff_t i = 0; i < len; i++)
     {
       if (!KEYMAPP (mapvec[i]))
 	{
@@ -1309,7 +1305,7 @@ x_popup_menu_1 (Lisp_Object position, Lisp_Object menu)
   else if (CONSP (menu) && KEYMAPP (XCAR (menu)))
     {
       /* We were given a list of keymaps.  */
-      EMACS_INT nmaps = XFIXNAT (Flength (menu));
+      ptrdiff_t nmaps = list_length (menu);
       Lisp_Object *maps;
       ptrdiff_t i;
       USE_SAFE_ALLOCA;
diff --git a/src/minibuf.c b/src/minibuf.c
index 8017da194b0..c1fbfb40857 100644
--- a/src/minibuf.c
+++ b/src/minibuf.c
@@ -780,8 +780,7 @@ read_minibuf_unwind (void)
 
   /* Restore prompt, etc, from outer minibuffer level.  */
   Lisp_Object key_vec = Fcar (minibuf_save_list);
-  eassert (VECTORP (key_vec));
-  this_command_key_count = XFIXNAT (Flength (key_vec));
+  this_command_key_count = ASIZE (key_vec);
   this_command_keys = key_vec;
   minibuf_save_list = Fcdr (minibuf_save_list);
   minibuf_prompt = Fcar (minibuf_save_list);
@@ -1783,7 +1782,7 @@ If FLAG is nil, invoke `try-completion'; if it is t, invoke
 	  while (CONSP (bufs) && SREF (XCAR (bufs), 0) == ' ')
 	    bufs = XCDR (bufs);
 	  if (NILP (bufs))
-	    return (EQ (Flength (res), Flength (Vbuffer_alist))
+	    return (list_length (res) == list_length (Vbuffer_alist)
 		    /* If all bufs are internal don't strip them out.  */
 		    ? res : bufs);
 	  res = bufs;
diff --git a/src/nsfont.m b/src/nsfont.m
index d4639dcca8c..b59f87f4682 100644
--- a/src/nsfont.m
+++ b/src/nsfont.m
@@ -576,7 +576,7 @@ ns_findfonts (Lisp_Object font_spec, BOOL isMatch)
 
     /* Add synthItal member if needed.  */
     family = [fdesc objectForKey: NSFontFamilyAttribute];
-    if (family != nil && !foundItal && XFIXNUM (Flength (list)) > 0)
+    if (family != nil && !foundItal && !NILP (list))
       {
         NSFontDescriptor *s1 = [NSFontDescriptor new];
         NSFontDescriptor *sDesc
@@ -595,8 +595,8 @@ ns_findfonts (Lisp_Object font_spec, BOOL isMatch)
       return ns_fallback_entity ();
 
     if (NSFONT_TRACE)
-	fprintf (stderr, "    Returning %"pI"d entities.\n",
-                 XFIXNUM (Flength (list)));
+	fprintf (stderr, "    Returning %"pD"d entities.\n",
+		 list_length (list));
 
     return list;
 }
@@ -667,8 +667,8 @@ nsfont_list_family (struct frame *f)
   /* FIXME: escape the name?  */
 
   if (NSFONT_TRACE)
-    fprintf (stderr, "nsfont: list families returning %"pI"d entries\n",
-	     XFIXNUM (Flength (list)));
+    fprintf (stderr, "nsfont: list families returning %"pD"d entries\n",
+	     list_length (list));
 
   unblock_input ();
   return list;
diff --git a/src/process.c b/src/process.c
index b2a7f38317a..edf633e512e 100644
--- a/src/process.c
+++ b/src/process.c
@@ -1804,7 +1804,7 @@ usage: (make-process &rest ARGS)  */)
       val = Vcoding_system_for_read;
     if (NILP (val))
       {
-	ptrdiff_t nargs2 = 3 + XFIXNUM (Flength (command));
+	ptrdiff_t nargs2 = 3 + list_length (command);
 	Lisp_Object tem2;
 	SAFE_ALLOCA_LISP (args2, nargs2);
 	ptrdiff_t i = 0;
@@ -1834,7 +1834,7 @@ usage: (make-process &rest ARGS)  */)
       {
 	if (EQ (coding_systems, Qt))
 	  {
-	    ptrdiff_t nargs2 = 3 + XFIXNUM (Flength (command));
+	    ptrdiff_t nargs2 = 3 + list_length (command);
 	    Lisp_Object tem2;
 	    SAFE_ALLOCA_LISP (args2, nargs2);
 	    ptrdiff_t i = 0;
diff --git a/src/search.c b/src/search.c
index 702e6e3d8e7..f97dbe73341 100644
--- a/src/search.c
+++ b/src/search.c
@@ -2992,13 +2992,11 @@ If optional arg RESEAT is non-nil, make markers on LIST point nowhere.  */)
 
   /* Allocate registers if they don't already exist.  */
   {
-    EMACS_INT length = XFIXNAT (Flength (list)) / 2;
+    ptrdiff_t length = list_length (list) / 2;
 
     if (length > search_regs.num_regs)
       {
 	ptrdiff_t num_regs = search_regs.num_regs;
-	if (PTRDIFF_MAX < length)
-	  memory_full (SIZE_MAX);
 	search_regs.start =
 	  xpalloc (search_regs.start, &num_regs, length - num_regs,
 		   min (PTRDIFF_MAX, UINT_MAX), sizeof *search_regs.start);
diff --git a/src/xdisp.c b/src/xdisp.c
index 8b091c81bef..7725570ced3 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -24137,7 +24137,7 @@ store_mode_line_string (const char *string, Lisp_Object lisp_string,
     }
   else
     {
-      len = XFIXNAT (Flength (lisp_string));
+      len = SCHARS (lisp_string);
       if (precision > 0 && len > precision)
 	{
 	  len = precision;
diff --git a/src/xfaces.c b/src/xfaces.c
index 8fe99e7655d..cffa89e1f39 100644
--- a/src/xfaces.c
+++ b/src/xfaces.c
@@ -1424,7 +1424,6 @@ the face font sort order.  */)
   Lisp_Object font_spec, list, *drivers, vec;
   struct frame *f = decode_live_frame (frame);
   ptrdiff_t i, nfonts;
-  EMACS_INT ndrivers;
   Lisp_Object result;
   USE_SAFE_ALLOCA;
 
@@ -1457,7 +1456,7 @@ the face font sort order.  */)
   font_props_for_sorting[i++] = FONT_ADSTYLE_INDEX;
   font_props_for_sorting[i++] = FONT_REGISTRY_INDEX;
 
-  ndrivers = XFIXNUM (Flength (list));
+  ptrdiff_t ndrivers = list_length (list);
   SAFE_ALLOCA_LISP (drivers, ndrivers);
   for (i = 0; i < ndrivers; i++, list = XCDR (list))
     drivers[i] = XCAR (list);