unbind_to performance tuning

* src/alloc.c (which_symbols):
* src/dispnew.c (Fredisplay):
* src/editfns.c (Fsubst_char_in_region):
* src/fileio.c (Fdo_auto_save):
* src/indent.c (Fvertical_motion):
* src/keymap.c (Fcurrent_active_maps):
* src/lread.c (Feval_buffer):
* src/minibuf.c (get_minibuffer):
* src/sysdep.c (system_process_attributes):
* src/textprop.c (Fnext_single_char_property_change)
(Fprevious_single_char_property_change):
* src/window.c (Fscroll_other_window, Fscroll_other_window_down):
* src/xdisp.c (Fformat_mode_line):
Help the compiler eliminate tail recursion in call to unbind_to.
* src/coding.c (decode_coding_gap):
Omit unnecessary unbind_to, as we’re about to call unbind_to anyway.
* src/coding.c (Fread_coding_system):
* src/eval.c (eval_sub):
* src/xdisp.c (handle_single_display_spec, decode_mode_spec):
* src/xselect.c (x_get_local_selection):
Avoid need to save a machine register when calling unbind_to.
* src/minibuf.c (Ftry_completion, Fall_completions):
Omit unnecessary assignment.

1 files changed, 1 insertions, 3 deletions

diff --git a/src/coding.c b/src/coding.c
index 32a9df1c533..8ce902b06d5 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -8005,7 +8005,6 @@ decode_coding_gap (struct coding_system *coding,
       ptrdiff_t prev_Z = Z, prev_Z_BYTE = Z_BYTE;
       Lisp_Object val;
       Lisp_Object undo_list = BVAR (current_buffer, undo_list);
-      ptrdiff_t count1 = SPECPDL_INDEX ();
 
       record_unwind_protect (coding_restore_undo_list,
                              Fcons (undo_list, Fcurrent_buffer ()));
@@ -8016,7 +8015,6 @@ decode_coding_gap (struct coding_system *coding,
       CHECK_NATNUM (val);
       coding->produced_char += Z - prev_Z;
       coding->produced += Z_BYTE - prev_Z_BYTE;
-      unbind_to (count1, Qnil);
     }
 
   unbind_to (count, Qnil);
@@ -8545,7 +8543,7 @@ are lower-case).  */)
   val = Fcompleting_read (prompt, Vcoding_system_alist, Qnil,
                           Qt, Qnil, Qcoding_system_history,
                           default_coding_system, Qnil);
-  unbind_to (count, Qnil);
+  val = unbind_to (count, val);
   return (SCHARS (val) == 0 ? Qnil : Fintern (val, Qnil));
 }