1 files changed, 543 insertions, 276 deletions

diff --git a/src/bytecode.c b/src/bytecode.c
index 50c7abe2891..c765e1be2bc 100644
--- a/src/bytecode.c
+++ b/src/bytecode.c
@@ -1,5 +1,5 @@
 /* Execution of byte code produced by bytecomp.el.
-   Copyright (C) 1985-1988, 1993, 2000-2017 Free Software Foundation,
+   Copyright (C) 1985-1988, 1993, 2000-2022 Free Software Foundation,
    Inc.
 
 This file is part of GNU Emacs.
@@ -21,11 +21,13 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 
 #include "lisp.h"
 #include "blockinput.h"
+#include "sysstdio.h"
 #include "character.h"
 #include "buffer.h"
 #include "keyboard.h"
 #include "syntax.h"
 #include "window.h"
+#include "puresize.h"
 
 /* Work around GCC bug 54561.  */
 #if GNUC_PREREQ (4, 3, 0)
@@ -46,7 +48,7 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
    indirect threaded, using GCC's computed goto extension.  This code,
    as currently implemented, is incompatible with BYTE_CODE_SAFE and
    BYTE_CODE_METER.  */
-#if (defined __GNUC__ && !defined __STRICT_ANSI__ && !defined __CHKP__ \
+#if (defined __GNUC__ && !defined __STRICT_ANSI__ \
      && !BYTE_CODE_SAFE && !defined BYTE_CODE_METER)
 #define BYTE_CODE_THREADED
 #endif
@@ -62,14 +64,14 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 {                                                                       \
   if (byte_metering_on)                                                 \
     {                                                                   \
-      if (XFASTINT (METER_1 (this_code)) < MOST_POSITIVE_FIXNUM)        \
+      if (XFIXNAT (METER_1 (this_code)) < MOST_POSITIVE_FIXNUM) \
         XSETFASTINT (METER_1 (this_code),                               \
-                     XFASTINT (METER_1 (this_code)) + 1);               \
+                     XFIXNAT (METER_1 (this_code)) + 1);                \
       if (last_code                                                     \
-          && (XFASTINT (METER_2 (last_code, this_code))                 \
+          && (XFIXNAT (METER_2 (last_code, this_code))                  \
               < MOST_POSITIVE_FIXNUM))                                  \
         XSETFASTINT (METER_2 (last_code, this_code),                    \
-                     XFASTINT (METER_2 (last_code, this_code)) + 1);    \
+                     XFIXNAT (METER_2 (last_code, this_code)) + 1);     \
     }                                                                   \
 }
 
@@ -174,8 +176,8 @@ DEFINE (Bmin, 0136)							\
 DEFINE (Bmult, 0137)                                                    \
                                                                         \
 DEFINE (Bpoint, 0140)                                                   \
-/* Was Bmark in v17.  */                                                \
-DEFINE (Bsave_current_buffer, 0141) /* Obsolete.  */                    \
+/* 0141 was Bmark in v17, Bsave_current_buffer in 18-19.  */            \
+DEFINE (Bsave_current_buffer_OBSOLETE, 0141)  /* Obsolete since 20. */  \
 DEFINE (Bgoto_char, 0142)                                               \
 DEFINE (Binsert, 0143)                                                  \
 DEFINE (Bpoint_max, 0144)                                               \
@@ -185,13 +187,15 @@ DEFINE (Bfollowing_char, 0147)						\
 DEFINE (Bpreceding_char, 0150)                                          \
 DEFINE (Bcurrent_column, 0151)                                          \
 DEFINE (Bindent_to, 0152)                                               \
+/* 0153 was Bscan_buffer in v17.  */                                    \
 DEFINE (Beolp, 0154)                                                    \
 DEFINE (Beobp, 0155)                                                    \
 DEFINE (Bbolp, 0156)                                                    \
 DEFINE (Bbobp, 0157)                                                    \
 DEFINE (Bcurrent_buffer, 0160)                                          \
 DEFINE (Bset_buffer, 0161)                                              \
-DEFINE (Bsave_current_buffer_1, 0162) /* Replacing Bsave_current_buffer.  */ \
+DEFINE (Bsave_current_buffer, 0162)                                     \
+/* 0163 was Bset_mark in v17.  */                                       \
 DEFINE (Binteractive_p, 0164) /* Obsolete since Emacs-24.1.  */         \
                                                                         \
 DEFINE (Bforward_char, 0165)                                            \
@@ -219,14 +223,14 @@ DEFINE (Bdup, 0211)							\
 DEFINE (Bsave_excursion, 0212)                                          \
 DEFINE (Bsave_window_excursion, 0213) /* Obsolete since Emacs-24.1.  */ \
 DEFINE (Bsave_restriction, 0214)                                        \
-DEFINE (Bcatch, 0215)                                                   \
+DEFINE (Bcatch, 0215)           /* Obsolete since Emacs-25.  */         \
                                                                         \
 DEFINE (Bunwind_protect, 0216)                                          \
-DEFINE (Bcondition_case, 0217)                                          \
+DEFINE (Bcondition_case, 0217)  /* Obsolete since Emacs-25.  */         \
 DEFINE (Btemp_output_buffer_setup, 0220) /* Obsolete since Emacs-24.1.  */ \
 DEFINE (Btemp_output_buffer_show, 0221)  /* Obsolete since Emacs-24.1.  */ \
                                                                         \
-DEFINE (Bunbind_all, 0222)      /* Obsolete.  Never used.  */           \
+/* 0222 was Bunbind_all, never used. */                                 \
                                                                         \
 DEFINE (Bset_marker, 0223)                                              \
 DEFINE (Bmatch_beginning, 0224)                                         \
@@ -252,11 +256,7 @@ DEFINE (Brem, 0246)							\
 DEFINE (Bnumberp, 0247)                                                 \
 DEFINE (Bintegerp, 0250)                                                \
                                                                         \
-DEFINE (BRgoto, 0252)                                                   \
-DEFINE (BRgotoifnil, 0253)                                              \
-DEFINE (BRgotoifnonnil, 0254)                                           \
-DEFINE (BRgotoifnilelsepop, 0255)                                       \
-DEFINE (BRgotoifnonnilelsepop, 0256)                                    \
+/* 0252-0256 were relative jumps, apparently never used.  */            \
                                                                         \
 DEFINE (BlistN, 0257)                                                   \
 DEFINE (BconcatN, 0260)                                                 \
@@ -276,11 +276,6 @@ enum byte_code_op
 #define DEFINE(name, value) name = value,
     BYTE_CODES
 #undef DEFINE
-
-#if BYTE_CODE_SAFE
-    Bscan_buffer = 0153, /* No longer generated as of v18.  */
-    Bset_mark = 0163, /* this loser is no longer generated as of v18 */
-#endif
 };
 
 /* Fetch the next byte from the bytecode stream.  */
@@ -290,7 +285,7 @@ enum byte_code_op
 /* Fetch two bytes from the bytecode stream and make a 16-bit number
    out of them.  */
 
-#define FETCH2 (op = FETCH, op + (FETCH << 8))
+#define FETCH2 (op = FETCH, op | (FETCH << 8))
 
 /* Push X onto the execution stack.  The expression X should not
    contain TOP, to avoid competing side effects.  */
@@ -318,7 +313,20 @@ the third, MAXDEPTH, the maximum stack depth used in this function.
 If the third argument is incorrect, Emacs may crash.  */)
   (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth)
 {
-  return exec_byte_code (bytestr, vector, maxdepth, Qnil, 0, NULL);
+  if (! (STRINGP (bytestr) && VECTORP (vector) && FIXNATP (maxdepth)))
+    error ("Invalid byte-code");
+
+  if (STRING_MULTIBYTE (bytestr))
+    {
+      /* BYTESTR must have been produced by Emacs 20.2 or earlier
+         because it produced a raw 8-bit string for byte-code and now
+         such a byte-code string is loaded as multibyte with raw 8-bit
+         characters converted to multibyte form.  Convert them back to
+         the original unibyte form.  */
+      bytestr = Fstring_as_unibyte (bytestr);
+    }
+  Lisp_Object fun = CALLN (Fmake_byte_code, Qnil, bytestr, vector, maxdepth);
+  return exec_byte_code (fun, 0, 0, NULL);
 }
 
 static void
@@ -327,80 +335,213 @@ bcall0 (Lisp_Object f)
   Ffuncall (1, &f);
 }
 
-/* Execute the byte-code in BYTESTR.  VECTOR is the constant vector, and
-   MAXDEPTH is the maximum stack depth used (if MAXDEPTH is incorrect,
-   emacs may crash!).  If ARGS_TEMPLATE is non-nil, it should be a lisp
-   argument list (including &rest, &optional, etc.), and ARGS, of size
-   NARGS, should be a vector of the actual arguments.  The arguments in
-   ARGS are pushed on the stack according to ARGS_TEMPLATE before
-   executing BYTESTR.  */
+/* The bytecode stack size in bytes.
+   This is a fairly generous amount, but:
+   - if users need more, we could allocate more, or just reserve the address
+     space and allocate on demand
+   - if threads are used more, then it might be a good idea to reduce the
+     per-thread overhead in time and space
+   - for maximum flexibility but a small runtime penalty, we could allocate
+     the stack in smaller chunks as needed
+*/
+#define BC_STACK_SIZE (512 * 1024 * sizeof (Lisp_Object))
+
+/* Bytecode interpreter stack:
+
+           |--------------|         --
+           |fun           |           |                   ^ stack growth
+           |saved_pc      |           |                   | direction
+           |saved_top    -------      |
+     fp--->|saved_fp     ----   |     | current frame
+           |--------------|  |  |     | (called from bytecode in this example)
+           |   (free)     |  |  |     |
+     top-->| ...stack...  |  |  |     |
+           : ...          :  |  |     |
+           |incoming args |  |  |     |
+           |--------------|  |  |   --
+           |fun           |  |  |     |
+           |saved_pc      |  |  |     |
+           |saved_top     |  |  |     |
+           |saved_fp      |<-   |     | previous frame
+           |--------------|     |     |
+           |   (free)     |     |     |
+           | ...stack...  |<----      |
+           : ...          :           |
+           |incoming args |           |
+           |--------------|         --
+           :              :
+*/
+
+/* bytecode stack frame header (footer, actually) */
+struct bc_frame {
+  struct bc_frame *saved_fp;        /* previous frame pointer,
+                                       NULL if bottommost frame */
+
+  /* In a frame called directly from C, the following two members are NULL.  */
+  Lisp_Object *saved_top;           /* previous stack pointer */
+  const unsigned char *saved_pc;    /* previous program counter */
+
+  Lisp_Object fun;                  /* current function object */
+
+  Lisp_Object next_stack[];         /* data stack of next frame */
+};
+
+void
+init_bc_thread (struct bc_thread_state *bc)
+{
+  bc->stack = xmalloc (BC_STACK_SIZE);
+  bc->stack_end = bc->stack + BC_STACK_SIZE;
+  /* Put a dummy header at the bottom to indicate the first free location.  */
+  bc->fp = (struct bc_frame *)bc->stack;
+  memset (bc->fp, 0, sizeof *bc->fp);
+}
+
+void
+free_bc_thread (struct bc_thread_state *bc)
+{
+  xfree (bc->stack);
+}
+
+void
+mark_bytecode (struct bc_thread_state *bc)
+{
+  struct bc_frame *fp = bc->fp;
+  Lisp_Object *top = NULL;     /* stack pointer of topmost frame not known */
+  for (;;)
+    {
+      struct bc_frame *next_fp = fp->saved_fp;
+      /* Only the dummy frame at the bottom has saved_fp = NULL.  */
+      if (!next_fp)
+        break;
+      mark_object (fp->fun);
+      Lisp_Object *frame_base = next_fp->next_stack;
+      if (top)
+        {
+          /* The stack pointer of a frame is known: mark the part of the stack
+             above it conservatively.  This includes any outgoing arguments.  */
+          mark_memory (top + 1, fp);
+          /* Mark the rest of the stack precisely.  */
+          mark_objects (frame_base, top + 1 - frame_base);
+        }
+      else
+        {
+          /* The stack pointer is unknown -- mark everything conservatively.  */
+          mark_memory (frame_base, fp);
+        }
+      top = fp->saved_top;
+      fp = next_fp;
+    }
+}
+
+DEFUN ("internal-stack-stats", Finternal_stack_stats, Sinternal_stack_stats,
+       0, 0, 0,
+       doc: /* internal */)
+  (void)
+{
+  struct bc_thread_state *bc = &current_thread->bc;
+  int nframes = 0;
+  int nruns = 0;
+  for (struct bc_frame *fp = bc->fp; fp; fp = fp->saved_fp)
+    {
+      nframes++;
+      if (fp->saved_top == NULL)
+        nruns++;
+    }
+  fprintf (stderr, "%d stack frames, %d runs\n", nframes, nruns);
+  return Qnil;
+}
+
+/* Whether a stack pointer is valid in the current frame.  */
+static bool
+valid_sp (struct bc_thread_state *bc, Lisp_Object *sp)
+{
+  struct bc_frame *fp = bc->fp;
+  return sp < (Lisp_Object *)fp && sp + 1 >= fp->saved_fp->next_stack;
+}
+
+/* Execute the byte-code in FUN.  ARGS_TEMPLATE is the function arity
+   encoded as an integer (the one in FUN is ignored), and ARGS, of
+   size NARGS, should be a vector of the actual arguments.  The
+   arguments in ARGS are pushed on the stack according to
+   ARGS_TEMPLATE before executing FUN.  */
 
 Lisp_Object
-exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
-                Lisp_Object args_template, ptrdiff_t nargs, Lisp_Object *args)
+exec_byte_code (Lisp_Object fun, ptrdiff_t args_template,
+                ptrdiff_t nargs, Lisp_Object *args)
 {
 #ifdef BYTE_CODE_METER
   int volatile this_op = 0;
 #endif
+  unsigned char quitcounter = 1;
+  struct bc_thread_state *bc = &current_thread->bc;
 
-  CHECK_STRING (bytestr);
-  CHECK_VECTOR (vector);
-  CHECK_NATNUM (maxdepth);
+  /* Values used for the first stack record when called from C.  */
+  Lisp_Object *top = NULL;
+  unsigned char const *pc = NULL;
 
-  ptrdiff_t const_length = ASIZE (vector);
+  Lisp_Object bytestr = AREF (fun, COMPILED_BYTECODE);
 
-  if (STRING_MULTIBYTE (bytestr))
-    /* BYTESTR must have been produced by Emacs 20.2 or the earlier
-       because they produced a raw 8-bit string for byte-code and now
-       such a byte-code string is loaded as multibyte while raw 8-bit
-       characters converted to multibyte form.  Thus, now we must
-       convert them back to the originally intended unibyte form.  */
-    bytestr = Fstring_as_unibyte (bytestr);
-
-  ptrdiff_t bytestr_length = SBYTES (bytestr);
+ setup_frame: ;
+  eassert (!STRING_MULTIBYTE (bytestr));
+  eassert (string_immovable_p (bytestr));
+  /* FIXME: in debug mode (!NDEBUG, BYTE_CODE_SAFE or enabled checking),
+     save the specpdl index on function entry and check that it is the same
+     when returning, to detect unwind imbalances.  This would require adding
+     a field to the frame header.  */
+
+  Lisp_Object vector = AREF (fun, COMPILED_CONSTANTS);
+  Lisp_Object maxdepth = AREF (fun, COMPILED_STACK_DEPTH);
+  ptrdiff_t const_length = ASIZE (vector);
+  ptrdiff_t bytestr_length = SCHARS (bytestr);
   Lisp_Object *vectorp = XVECTOR (vector)->contents;
 
-  unsigned char quitcounter = 1;
-  EMACS_INT stack_items = XFASTINT (maxdepth) + 1;
-  USE_SAFE_ALLOCA;
-  Lisp_Object *stack_base;
-  SAFE_ALLOCA_LISP_EXTRA (stack_base, stack_items, bytestr_length);
-  Lisp_Object *stack_lim = stack_base + stack_items;
-  Lisp_Object *top = stack_base;
-  memcpy (stack_lim, SDATA (bytestr), bytestr_length);
-  void *void_stack_lim = stack_lim;
-  unsigned char const *bytestr_data = void_stack_lim;
-  unsigned char const *pc = bytestr_data;
-  ptrdiff_t count = SPECPDL_INDEX ();
-
-  if (!NILP (args_template))
-    {
-      eassert (INTEGERP (args_template));
-      ptrdiff_t at = XINT (args_template);
-      bool rest = (at & 128) != 0;
-      int mandatory = at & 127;
-      ptrdiff_t nonrest = at >> 8;
-      ptrdiff_t maxargs = rest ? PTRDIFF_MAX : nonrest;
-      if (! (mandatory <= nargs && nargs <= maxargs))
-        Fsignal (Qwrong_number_of_arguments,
-                 list2 (Fcons (make_number (mandatory), make_number (nonrest)),
-                        make_number (nargs)));
-      ptrdiff_t pushedargs = min (nonrest, nargs);
-      for (ptrdiff_t i = 0; i < pushedargs; i++, args++)
-        PUSH (*args);
-      if (nonrest < nargs)
-        PUSH (Flist (nargs - nonrest, args));
-      else
-        for (ptrdiff_t i = nargs - rest; i < nonrest; i++)
-          PUSH (Qnil);
-    }
+  EMACS_INT max_stack = XFIXNAT (maxdepth);
+  Lisp_Object *frame_base = bc->fp->next_stack;
+  struct bc_frame *fp = (struct bc_frame *)(frame_base + max_stack);
+
+  if ((char *)fp->next_stack > bc->stack_end)
+    error ("Bytecode stack overflow");
+
+  /* Save the function object so that the bytecode and vector are
+     held from removal by the GC. */
+  fp->fun = fun;
+  /* Save previous stack pointer and pc in the new frame.  If we came
+     directly from outside, these will be NULL.  */
+  fp->saved_top = top;
+  fp->saved_pc = pc;
+  fp->saved_fp = bc->fp;
+  bc->fp = fp;
+
+  top = frame_base - 1;
+  unsigned char const *bytestr_data = SDATA (bytestr);
+  pc = bytestr_data;
+
+  /* ARGS_TEMPLATE is composed of bit fields:
+     bits 0..6    minimum number of arguments
+     bits 7       1 iff &rest argument present
+     bits 8..14   maximum number of arguments */
+  bool rest = (args_template & 128) != 0;
+  int mandatory = args_template & 127;
+  ptrdiff_t nonrest = args_template >> 8;
+  if (! (mandatory <= nargs && (rest || nargs <= nonrest)))
+    Fsignal (Qwrong_number_of_arguments,
+             list2 (Fcons (make_fixnum (mandatory), make_fixnum (nonrest)),
+                    make_fixnum (nargs)));
+  ptrdiff_t pushedargs = min (nonrest, nargs);
+  for (ptrdiff_t i = 0; i < pushedargs; i++, args++)
+    PUSH (*args);
+  if (nonrest < nargs)
+    PUSH (Flist (nargs - nonrest, args));
+  else
+    for (ptrdiff_t i = nargs - rest; i < nonrest; i++)
+      PUSH (Qnil);
 
   while (true)
     {
       int op;
       enum handlertype type;
 
-      if (BYTE_CODE_SAFE && ! (stack_base <= top && top < stack_lim))
+      if (BYTE_CODE_SAFE && !valid_sp (bc, top))
         emacs_abort ();
 
 #ifdef BYTE_CODE_METER
@@ -448,17 +589,13 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
 
 #ifdef BYTE_CODE_THREADED
 
-      /* A convenience define that saves us a lot of typing and makes
-         the table clearer.  */
-#define LABEL(OP) [OP] = &&insn_ ## OP
-
       /* This is the dispatch table for the threaded interpreter.  */
       static const void *const targets[256] =
         {
           [0 ... (Bconstant - 1)] = &&insn_default,
           [Bconstant ... 255] = &&insn_Bconstant,
 
-#define DEFINE(name, value) LABEL (name) ,
+#define DEFINE(name, value) [name] = &&insn_ ## name,
           BYTE_CODES
 #undef DEFINE
         };
@@ -489,8 +626,8 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
           {
             Lisp_Object v1 = vectorp[op], v2;
             if (!SYMBOLP (v1)
-                || XSYMBOL (v1)->redirect != SYMBOL_PLAINVAL
-                || (v2 = SYMBOL_VAL (XSYMBOL (v1)), EQ (v2, Qunbound)))
+                || XSYMBOL (v1)->u.s.redirect != SYMBOL_PLAINVAL
+                || (v2 = SYMBOL_VAL (XSYMBOL (v1)), BASE_EQ (v2, Qunbound)))
               v2 = Fsymbol_value (v1);
             PUSH (v2);
             NEXT;
@@ -557,8 +694,8 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
 
             /* Inline the most common case.  */
             if (SYMBOLP (sym)
-                && !EQ (val, Qunbound)
-                && !XSYMBOL (sym)->redirect
+                && !BASE_EQ (val, Qunbound)
+                && XSYMBOL (sym)->u.s.redirect == SYMBOL_PLAINVAL
                 && !SYMBOL_TRAPPED_WRITE_P (sym))
               SET_SYMBOL_VAL (XSYMBOL (sym), val);
             else
@@ -618,15 +755,67 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
               {
                 Lisp_Object v1 = TOP;
                 Lisp_Object v2 = Fget (v1, Qbyte_code_meter);
-                if (INTEGERP (v2)
-                    && XINT (v2) < MOST_POSITIVE_FIXNUM)
+                if (FIXNUMP (v2)
+                    && XFIXNUM (v2) < MOST_POSITIVE_FIXNUM)
                   {
-                    XSETINT (v2, XINT (v2) + 1);
+                    XSETINT (v2, XFIXNUM (v2) + 1);
                     Fput (v1, Qbyte_code_meter, v2);
                   }
               }
 #endif
-            TOP = Ffuncall (op + 1, &TOP);
+            maybe_quit ();
+
+            if (++lisp_eval_depth > max_lisp_eval_depth)
+              {
+                if (max_lisp_eval_depth < 100)
+                  max_lisp_eval_depth = 100;
+                if (lisp_eval_depth > max_lisp_eval_depth)
+                  error ("Lisp nesting exceeds `max-lisp-eval-depth'");
+              }
+
+            ptrdiff_t call_nargs = op;
+            Lisp_Object call_fun = TOP;
+            Lisp_Object *call_args = &TOP + 1;
+
+            specpdl_ref count1 = record_in_backtrace (call_fun,
+                                                      call_args, call_nargs);
+            maybe_gc ();
+            if (debug_on_next_call)
+              do_debug_on_call (Qlambda, count1);
+
+            Lisp_Object original_fun = call_fun;
+            if (SYMBOLP (call_fun))
+              call_fun = XSYMBOL (call_fun)->u.s.function;
+            Lisp_Object template;
+            Lisp_Object bytecode;
+            if (COMPILEDP (call_fun)
+                // Lexical binding only.
+                && (template = AREF (call_fun, COMPILED_ARGLIST),
+                    FIXNUMP (template))
+                // No autoloads.
+                && (bytecode = AREF (call_fun, COMPILED_BYTECODE),
+                    !CONSP (bytecode)))
+              {
+                fun = call_fun;
+                bytestr = bytecode;
+                args_template = XFIXNUM (template);
+                nargs = call_nargs;
+                args = call_args;
+                goto setup_frame;
+              }
+
+            Lisp_Object val;
+            if (SUBRP (call_fun) && !SUBR_NATIVE_COMPILED_DYNP (call_fun))
+              val = funcall_subr (XSUBR (call_fun), call_nargs, call_args);
+            else
+              val = funcall_general (original_fun, call_nargs, call_args);
+
+            lisp_eval_depth--;
+            if (backtrace_debug_on_exit (specpdl_ptr - 1))
+              val = call_debugger (list2 (Qexit, val));
+            specpdl_ptr--;
+
+            TOP = val;
             NEXT;
           }
 
@@ -646,20 +835,13 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
         CASE (Bunbind5):
           op -= Bunbind;
         dounbind:
-          unbind_to (SPECPDL_INDEX () - op, Qnil);
-          NEXT;
-
-        CASE (Bunbind_all):     /* Obsolete.  Never used.  */
-          /* To unbind back to the beginning of this frame.  Not used yet,
-             but will be needed for tail-recursion elimination.  */
-          unbind_to (count, Qnil);
+          unbind_to (specpdl_ref_add (SPECPDL_INDEX (), -op), Qnil);
           NEXT;
 
         CASE (Bgoto):
           op = FETCH2;
         op_branch:
           op -= pc - bytestr_data;
-        op_relative_branch:
           if (BYTE_CODE_SAFE
               && ! (bytestr_data - pc <= op
                     && op < bytestr_data + bytestr_length - pc))
@@ -694,38 +876,41 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
           DISCARD (1);
           NEXT;
 
-        CASE (BRgoto):
-          op = FETCH - 128;
-          goto op_relative_branch;
-
-        CASE (BRgotoifnil):
-          op = FETCH - 128;
-          if (NILP (POP))
-            goto op_relative_branch;
-          NEXT;
-
-        CASE (BRgotoifnonnil):
-          op = FETCH - 128;
-          if (!NILP (POP))
-            goto op_relative_branch;
-          NEXT;
-
-        CASE (BRgotoifnilelsepop):
-          op = FETCH - 128;
-          if (NILP (TOP))
-            goto op_relative_branch;
-          DISCARD (1);
-          NEXT;
-
-        CASE (BRgotoifnonnilelsepop):
-          op = FETCH - 128;
-          if (!NILP (TOP))
-            goto op_relative_branch;
-          DISCARD (1);
-          NEXT;
-
         CASE (Breturn):
-          goto exit;
+          {
+            Lisp_Object *saved_top = bc->fp->saved_top;
+            if (saved_top)
+              {
+                Lisp_Object val = TOP;
+
+                lisp_eval_depth--;
+                if (backtrace_debug_on_exit (specpdl_ptr - 1))
+                  val = call_debugger (list2 (Qexit, val));
+                specpdl_ptr--;
+
+                top = saved_top;
+                pc = bc->fp->saved_pc;
+                struct bc_frame *fp = bc->fp->saved_fp;
+                bc->fp = fp;
+
+                Lisp_Object fun = fp->fun;
+                Lisp_Object bytestr = AREF (fun, COMPILED_BYTECODE);
+                Lisp_Object vector = AREF (fun, COMPILED_CONSTANTS);
+                bytestr_data = SDATA (bytestr);
+                vectorp = XVECTOR (vector)->contents;
+                if (BYTE_CODE_SAFE)
+                  {
+                    /* Only required for checking, not for execution.  */
+                    const_length = ASIZE (vector);
+                    bytestr_length = SCHARS (bytestr);
+                  }
+
+                TOP = val;
+                NEXT;
+              }
+            else
+              goto exit;
+          }
 
         CASE (Bdiscard):
           DISCARD (1);
@@ -736,18 +921,17 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
           NEXT;
 
         CASE (Bsave_excursion):
-          record_unwind_protect (save_excursion_restore,
-                                 save_excursion_save ());
+          record_unwind_protect_excursion ();
           NEXT;
 
-        CASE (Bsave_current_buffer): /* Obsolete since ??.  */
-        CASE (Bsave_current_buffer_1):
+        CASE (Bsave_current_buffer_OBSOLETE): /* Obsolete since 20.  */
+        CASE (Bsave_current_buffer):
           record_unwind_current_buffer ();
           NEXT;
 
         CASE (Bsave_window_excursion): /* Obsolete since 24.1.  */
           {
-            ptrdiff_t count1 = SPECPDL_INDEX ();
+            specpdl_ref count1 = SPECPDL_INDEX ();
             record_unwind_protect (restore_window_configuration,
                                    Fcurrent_window_configuration (Qnil));
             TOP = Fprogn (TOP);
@@ -760,7 +944,7 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
                                  save_restriction_save ());
           NEXT;
 
-        CASE (Bcatch):          /* Obsolete since 24.4.  */
+        CASE (Bcatch):          /* Obsolete since 25.  */
           {
             Lisp_Object v1 = POP;
             TOP = internal_catch (TOP, eval_sub, v1);
@@ -781,9 +965,23 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
             if (sys_setjmp (c->jmp))
               {
                 struct handler *c = handlerlist;
+                handlerlist = c->next;
                 top = c->bytecode_top;
                 op = c->bytecode_dest;
-                handlerlist = c->next;
+                struct bc_frame *fp = bc->fp;
+
+                Lisp_Object fun = fp->fun;
+                Lisp_Object bytestr = AREF (fun, COMPILED_BYTECODE);
+                Lisp_Object vector = AREF (fun, COMPILED_CONSTANTS);
+                bytestr_data = SDATA (bytestr);
+                vectorp = XVECTOR (vector)->contents;
+                if (BYTE_CODE_SAFE)
+                  {
+                    /* Only required for checking, not for execution.  */
+                    const_length = ASIZE (vector);
+                    bytestr_length = SCHARS (bytestr);
+                  }
+                pc = bytestr_data;
                 PUSH (c->val);
                 goto op_branch;
               }
@@ -804,7 +1002,7 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
             NEXT;
           }
 
-        CASE (Bcondition_case):         /* Obsolete since 24.4.  */
+        CASE (Bcondition_case):         /* Obsolete since 25.  */
           {
             Lisp_Object handlers = POP, body = POP;
             TOP = internal_lisp_condition_case (TOP, body, handlers);
@@ -823,20 +1021,21 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
             temp_output_buffer_show (TOP);
             TOP = v1;
             /* pop binding of standard-output */
-            unbind_to (SPECPDL_INDEX () - 1, Qnil);
+            unbind_to (specpdl_ref_add (SPECPDL_INDEX (), -1), Qnil);
             NEXT;
           }
 
         CASE (Bnth):
           {
             Lisp_Object v2 = POP, v1 = TOP;
-            CHECK_NUMBER (v1);
-            for (EMACS_INT n = XINT (v1); 0 < n && CONSP (v2); n--)
+            if (RANGED_FIXNUMP (0, v1, SMALL_LIST_LEN_MAX))
               {
-                v2 = XCDR (v2);
-                rarely_quit (n);
+                for (EMACS_INT n = XFIXNUM (v1); 0 < n && CONSP (v2); n--)
+                  v2 = XCDR (v2);
+                TOP = CAR (v2);
               }
-            TOP = CAR (v2);
+            else
+              TOP = Fnth (v1, v2);
             NEXT;
           }
 
@@ -880,12 +1079,12 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
 
         CASE (Blist3):
           DISCARD (2);
-          TOP = Flist (3, &TOP);
+          TOP = list3 (TOP, top[1], top[2]);
           NEXT;
 
         CASE (Blist4):
           DISCARD (3);
-          TOP = Flist (4, &TOP);
+          TOP = list4 (TOP, top[1], top[2], top[3]);
           NEXT;
 
         CASE (BlistN):
@@ -900,15 +1099,39 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
 
         CASE (Baref):
           {
-            Lisp_Object v1 = POP;
-            TOP = Faref (TOP, v1);
+            Lisp_Object idxval = POP;
+            Lisp_Object arrayval = TOP;
+            ptrdiff_t size;
+            ptrdiff_t idx;
+            if (((VECTORP (arrayval) && (size = ASIZE (arrayval), true))
+                 || (RECORDP (arrayval) && (size = PVSIZE (arrayval), true)))
+                && FIXNUMP (idxval)
+                && (idx = XFIXNUM (idxval),
+                    idx >= 0 && idx < size))
+              TOP = AREF (arrayval, idx);
+            else
+              TOP = Faref (arrayval, idxval);
             NEXT;
           }
 
         CASE (Baset):
           {
-            Lisp_Object v2 = POP, v1 = POP;
-            TOP = Faset (TOP, v1, v2);
+            Lisp_Object newelt = POP;
+            Lisp_Object idxval = POP;
+            Lisp_Object arrayval = TOP;
+            ptrdiff_t size;
+            ptrdiff_t idx;
+            if (((VECTORP (arrayval) && (size = ASIZE (arrayval), true))
+                 || (RECORDP (arrayval) && (size = PVSIZE (arrayval), true)))
+                && FIXNUMP (idxval)
+                && (idx = XFIXNUM (idxval),
+                    idx >= 0 && idx < size))
+              {
+                ASET (arrayval, idx, newelt);
+                TOP = newelt;
+              }
+            else
+              TOP = Faset (arrayval, idxval, newelt);
             NEXT;
           }
 
@@ -970,98 +1193,175 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
           NEXT;
 
         CASE (Bsub1):
-          TOP = INTEGERP (TOP) ? make_number (XINT (TOP) - 1) : Fsub1 (TOP);
+          TOP = (FIXNUMP (TOP) && XFIXNUM (TOP) != MOST_NEGATIVE_FIXNUM
+                 ? make_fixnum (XFIXNUM (TOP) - 1)
+                 : Fsub1 (TOP));
           NEXT;
 
         CASE (Badd1):
-          TOP = INTEGERP (TOP) ? make_number (XINT (TOP) + 1) : Fadd1 (TOP);
+          TOP = (FIXNUMP (TOP) && XFIXNUM (TOP) != MOST_POSITIVE_FIXNUM
+                 ? make_fixnum (XFIXNUM (TOP) + 1)
+                 : Fadd1 (TOP));
           NEXT;
 
         CASE (Beqlsign):
           {
-            Lisp_Object v2 = POP, v1 = TOP;
-            if (FLOATP (v1) || FLOATP (v2))
-              TOP = arithcompare (v1, v2, ARITH_EQUAL);
+            Lisp_Object v2 = POP;
+            Lisp_Object v1 = TOP;
+            if (FIXNUMP (v1) && FIXNUMP (v2))
+              TOP = BASE_EQ (v1, v2) ? Qt : Qnil;
             else
-              {
-                CHECK_NUMBER_OR_FLOAT_COERCE_MARKER (v1);
-                CHECK_NUMBER_OR_FLOAT_COERCE_MARKER (v2);
-                TOP = EQ (v1, v2) ? Qt : Qnil;
-              }
+              TOP = arithcompare (v1, v2, ARITH_EQUAL);
             NEXT;
           }
 
         CASE (Bgtr):
           {
-            Lisp_Object v1 = POP;
-            TOP = arithcompare (TOP, v1, ARITH_GRTR);
+            Lisp_Object v2 = POP;
+            Lisp_Object v1 = TOP;
+            if (FIXNUMP (v1) && FIXNUMP (v2))
+              TOP = XFIXNUM (v1) > XFIXNUM (v2) ? Qt : Qnil;
+            else
+              TOP = arithcompare (v1, v2, ARITH_GRTR);
             NEXT;
           }
 
         CASE (Blss):
           {
-            Lisp_Object v1 = POP;
-            TOP = arithcompare (TOP, v1, ARITH_LESS);
+            Lisp_Object v2 = POP;
+            Lisp_Object v1 = TOP;
+            if (FIXNUMP (v1) && FIXNUMP (v2))
+              TOP = XFIXNUM (v1) < XFIXNUM (v2) ? Qt : Qnil;
+            else
+              TOP = arithcompare (v1, v2, ARITH_LESS);
             NEXT;
           }
 
         CASE (Bleq):
           {
-            Lisp_Object v1 = POP;
-            TOP = arithcompare (TOP, v1, ARITH_LESS_OR_EQUAL);
+            Lisp_Object v2 = POP;
+            Lisp_Object v1 = TOP;
+            if (FIXNUMP (v1) && FIXNUMP (v2))
+              TOP = XFIXNUM (v1) <= XFIXNUM (v2) ? Qt : Qnil;
+            else
+              TOP = arithcompare (v1, v2, ARITH_LESS_OR_EQUAL);
             NEXT;
           }
 
         CASE (Bgeq):
           {
-            Lisp_Object v1 = POP;
-            TOP = arithcompare (TOP, v1, ARITH_GRTR_OR_EQUAL);
+            Lisp_Object v2 = POP;
+            Lisp_Object v1 = TOP;
+            if (FIXNUMP (v1) && FIXNUMP (v2))
+              TOP = XFIXNUM (v1) >= XFIXNUM (v2) ? Qt : Qnil;
+            else
+              TOP = arithcompare (v1, v2, ARITH_GRTR_OR_EQUAL);
             NEXT;
           }
 
         CASE (Bdiff):
-          DISCARD (1);
-          TOP = Fminus (2, &TOP);
-          NEXT;
+          {
+            Lisp_Object v2 = POP;
+            Lisp_Object v1 = TOP;
+            EMACS_INT res;
+            if (FIXNUMP (v1) && FIXNUMP (v2)
+                && (res = XFIXNUM (v1) - XFIXNUM (v2),
+                    !FIXNUM_OVERFLOW_P (res)))
+              TOP = make_fixnum (res);
+            else
+              TOP = Fminus (2, &TOP);
+            NEXT;
+          }
 
         CASE (Bnegate):
-          TOP = INTEGERP (TOP) ? make_number (- XINT (TOP)) : Fminus (1, &TOP);
+          TOP = (FIXNUMP (TOP) && XFIXNUM (TOP) != MOST_NEGATIVE_FIXNUM
+                 ? make_fixnum (- XFIXNUM (TOP))
+                 : Fminus (1, &TOP));
           NEXT;
 
         CASE (Bplus):
-          DISCARD (1);
-          TOP = Fplus (2, &TOP);
-          NEXT;
+          {
+            Lisp_Object v2 = POP;
+            Lisp_Object v1 = TOP;
+            EMACS_INT res;
+            if (FIXNUMP (v1) && FIXNUMP (v2)
+                && (res = XFIXNUM (v1) + XFIXNUM (v2),
+                    !FIXNUM_OVERFLOW_P (res)))
+              TOP = make_fixnum (res);
+            else
+              TOP = Fplus (2, &TOP);
+            NEXT;
+          }
 
         CASE (Bmax):
-          DISCARD (1);
-          TOP = Fmax (2, &TOP);
-          NEXT;
+          {
+            Lisp_Object v2 = POP;
+            Lisp_Object v1 = TOP;
+            if (FIXNUMP (v1) && FIXNUMP (v2))
+              {
+                if (XFIXNUM (v2) > XFIXNUM (v1))
+                  TOP = v2;
+              }
+            else
+              TOP = Fmax (2, &TOP);
+            NEXT;
+          }
 
         CASE (Bmin):
-          DISCARD (1);
-          TOP = Fmin (2, &TOP);
-          NEXT;
+          {
+            Lisp_Object v2 = POP;
+            Lisp_Object v1 = TOP;
+            if (FIXNUMP (v1) && FIXNUMP (v2))
+              {
+                if (XFIXNUM (v2) < XFIXNUM (v1))
+                  TOP = v2;
+              }
+            else
+              TOP = Fmin (2, &TOP);
+            NEXT;
+          }
 
         CASE (Bmult):
-          DISCARD (1);
-          TOP = Ftimes (2, &TOP);
-          NEXT;
+          {
+            Lisp_Object v2 = POP;
+            Lisp_Object v1 = TOP;
+            intmax_t res;
+            if (FIXNUMP (v1) && FIXNUMP (v2)
+                && !INT_MULTIPLY_WRAPV (XFIXNUM (v1), XFIXNUM (v2), &res)
+                && !FIXNUM_OVERFLOW_P (res))
+              TOP = make_fixnum (res);
+            else
+              TOP = Ftimes (2, &TOP);
+            NEXT;
+          }
 
         CASE (Bquo):
-          DISCARD (1);
-          TOP = Fquo (2, &TOP);
-          NEXT;
+          {
+            Lisp_Object v2 = POP;
+            Lisp_Object v1 = TOP;
+            EMACS_INT res;
+            if (FIXNUMP (v1) && FIXNUMP (v2) && XFIXNUM (v2) != 0
+                && (res = XFIXNUM (v1) / XFIXNUM (v2),
+                    !FIXNUM_OVERFLOW_P (res)))
+              TOP = make_fixnum (res);
+            else
+              TOP = Fquo (2, &TOP);
+            NEXT;
+          }
 
         CASE (Brem):
           {
-            Lisp_Object v1 = POP;
-            TOP = Frem (TOP, v1);
+            Lisp_Object v2 = POP;
+            Lisp_Object v1 = TOP;
+            if (FIXNUMP (v1) && FIXNUMP (v2) && XFIXNUM (v2) != 0)
+              TOP = make_fixnum (XFIXNUM (v1) % XFIXNUM (v2));
+            else
+              TOP = Frem (v1, v2);
             NEXT;
           }
 
         CASE (Bpoint):
-          PUSH (make_natnum (PT));
+          PUSH (make_fixed_natnum (PT));
           NEXT;
 
         CASE (Bgoto_char):
@@ -1079,15 +1379,11 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
           NEXT;
 
         CASE (Bpoint_max):
-          {
-            Lisp_Object v1;
-            XSETFASTINT (v1, ZV);
-            PUSH (v1);
-            NEXT;
-          }
+          PUSH (make_fixed_natnum (ZV));
+          NEXT;
 
         CASE (Bpoint_min):
-          PUSH (make_natnum (BEGV));
+          PUSH (make_fixed_natnum (BEGV));
           NEXT;
 
         CASE (Bchar_after):
@@ -1103,7 +1399,7 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
           NEXT;
 
         CASE (Bcurrent_column):
-          PUSH (make_natnum (current_column ()));
+          PUSH (make_fixed_natnum (current_column ()));
           NEXT;
 
         CASE (Bindent_to):
@@ -1135,7 +1431,7 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
           NEXT;
 
         CASE (Binteractive_p):  /* Obsolete since 24.1.  */
-          PUSH (call0 (intern ("interactive-p")));
+          PUSH (call0 (Qinteractive_p));
           NEXT;
 
         CASE (Bforward_char):
@@ -1165,13 +1461,7 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
           NEXT;
 
         CASE (Bchar_syntax):
-          {
-            CHECK_CHARACTER (TOP);
-            int c = XFASTINT (TOP);
-            if (NILP (BVAR (current_buffer, enable_multibyte_characters)))
-              MAKE_CHAR_MULTIBYTE (c);
-            XSETFASTINT (TOP, syntax_code_spec[SYNTAX (c)]);
-          }
+          TOP = Fchar_syntax (TOP);
           NEXT;
 
         CASE (Bbuffer_substring):
@@ -1256,23 +1546,16 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
 
         CASE (Belt):
           {
-            if (CONSP (TOP))
+            Lisp_Object v2 = POP, v1 = TOP;
+            if (CONSP (v1) && RANGED_FIXNUMP (0, v2, SMALL_LIST_LEN_MAX))
               {
-                /* Exchange args and then do nth.  */
-                Lisp_Object v2 = POP, v1 = TOP;
-                CHECK_NUMBER (v2);
-                for (EMACS_INT n = XINT (v2); 0 < n && CONSP (v1); n--)
-                  {
-                    v1 = XCDR (v1);
-                    rarely_quit (n);
-                  }
+                /* Like the fast case for Bnth, but with args reversed.  */
+                for (EMACS_INT n = XFIXNUM (v2); 0 < n && CONSP (v1); n--)
+                  v1 = XCDR (v1);
                 TOP = CAR (v1);
               }
             else
-              {
-                Lisp_Object v1 = POP;
-                TOP = Felt (TOP, v1);
-              }
+              TOP = Felt (v1, v2);
             NEXT;
           }
 
@@ -1296,15 +1579,23 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
 
         CASE (Bsetcar):
           {
-            Lisp_Object v1 = POP;
-            TOP = Fsetcar (TOP, v1);
+            Lisp_Object newval = POP;
+            Lisp_Object cell = TOP;
+            CHECK_CONS (cell);
+            CHECK_IMPURE (cell, XCONS (cell));
+            XSETCAR (cell, newval);
+            TOP = newval;
             NEXT;
           }
 
         CASE (Bsetcdr):
           {
-            Lisp_Object v1 = POP;
-            TOP = Fsetcdr (TOP, v1);
+            Lisp_Object newval = POP;
+            Lisp_Object cell = TOP;
+            CHECK_CONS (cell);
+            CHECK_IMPURE (cell, XCONS (cell));
+            XSETCDR (cell, newval);
+            TOP = newval;
             NEXT;
           }
 
@@ -1329,27 +1620,12 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
           TOP = INTEGERP (TOP) ? Qt : Qnil;
           NEXT;
 
-#if BYTE_CODE_SAFE
-          /* These are intentionally written using 'case' syntax,
-             because they are incompatible with the threaded
-             interpreter.  */
-
-        case Bset_mark:
-          error ("set-mark is an obsolete bytecode");
-          break;
-        case Bscan_buffer:
-          error ("scan-buffer is an obsolete bytecode");
-          break;
-#endif
-
         CASE_ABORT:
           /* Actually this is Bstack_ref with offset 0, but we use Bdup
              for that instead.  */
           /* CASE (Bstack_ref): */
-          call3 (Qerror,
-                 build_string ("Invalid byte opcode: op=%s, ptr=%d"),
-                 make_number (op),
-                 make_number (pc - 1 - bytestr_data));
+          error ("Invalid byte opcode: op=%d, ptr=%"pD"d",
+                 op, pc - 1 - bytestr_data);
 
           /* Handy byte-codes for lexical binding.  */
         CASE (Bstack_ref1):
@@ -1402,28 +1678,27 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
             /* TODO: Perhaps introduce another byte-code for switch when the
                number of cases is less, which uses a simple vector for linear
                search as the jump table.  */
+
+            /* TODO: Instead of pushing the table in a separate
+               Bconstant op, use an immediate argument (maybe separate
+               switch opcodes for 1-byte and 2-byte constant indices).
+               This would also get rid of some hacks that assume each
+               Bswitch to be preceded by a Bconstant.  */
             Lisp_Object jmp_table = POP;
             if (BYTE_CODE_SAFE && !HASH_TABLE_P (jmp_table))
-              emacs_abort ();
+              emacs_abort ();
             Lisp_Object v1 = POP;
             ptrdiff_t i;
             struct Lisp_Hash_Table *h = XHASH_TABLE (jmp_table);
 
             /* h->count is a faster approximation for HASH_TABLE_SIZE (h)
                here. */
-            if (h->count <= 5)
+            if (h->count <= 5 && !h->test.cmpfn)
               { /* Do a linear search if there are not many cases
                    FIXME: 5 is arbitrarily chosen.  */
-                Lisp_Object hash_code = h->test.cmpfn
-                  ? make_number (h->test.hashfn (&h->test, v1)) : Qnil;
-
-                for (i = h->count; 0 <= --i; )
-                  if (EQ (v1, HASH_KEY (h, i))
-                      || (h->test.cmpfn
-                          && EQ (hash_code, HASH_HASH (h, i))
-                          && h->test.cmpfn (&h->test, v1, HASH_KEY (h, i))))
-                    break;
-
+                for (i = h->count; 0 <= --i; )
+                  if (EQ (v1, HASH_KEY (h, i)))
+                    break;
               }
             else
               i = hash_lookup (h, v1, NULL);
@@ -1431,9 +1706,9 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
             if (i >= 0)
               {
                 Lisp_Object val = HASH_VALUE (h, i);
-                if (BYTE_CODE_SAFE && !INTEGERP (val))
+                if (BYTE_CODE_SAFE && !FIXNUMP (val))
                   emacs_abort ();
-                op = XINT (val);
+                op = XFIXNUM (val);
                 goto op_branch;
               }
           }
@@ -1451,16 +1726,9 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
 
  exit:
 
-  /* Binds and unbinds are supposed to be compiled balanced.  */
-  if (SPECPDL_INDEX () != count)
-    {
-      if (SPECPDL_INDEX () > count)
-        unbind_to (count, Qnil);
-      error ("binding stack not balanced (serious byte compiler bug)");
-    }
+  bc->fp = bc->fp->saved_fp;
 
   Lisp_Object result = TOP;
-  SAFE_FREE ();
   return result;
 }
 
@@ -1468,20 +1736,23 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
 Lisp_Object
 get_byte_code_arity (Lisp_Object args_template)
 {
-  eassert (NATNUMP (args_template));
-  EMACS_INT at = XINT (args_template);
+  eassert (FIXNATP (args_template));
+  EMACS_INT at = XFIXNUM (args_template);
   bool rest = (at & 128) != 0;
   int mandatory = at & 127;
   EMACS_INT nonrest = at >> 8;
 
-  return Fcons (make_number (mandatory),
-                rest ? Qmany : make_number (nonrest));
+  return Fcons (make_fixnum (mandatory),
+                rest ? Qmany : make_fixnum (nonrest));
 }
 
 void
 syms_of_bytecode (void)
 {
+  DEFSYM (Qinteractive_p, "interactive-p");
+
   defsubr (&Sbyte_code);
+  defsubr (&Sinternal_stack_stats);
 
 #ifdef BYTE_CODE_METER
 
@@ -1500,13 +1771,9 @@ If a symbol has a property named `byte-code-meter' whose value is an
 integer, it is incremented each time that symbol's function is called.  */);
 
   byte_metering_on = false;
-  Vbyte_code_meter = Fmake_vector (make_number (256), make_number (0));
+  Vbyte_code_meter = make_nil_vector (256);
   DEFSYM (Qbyte_code_meter, "byte-code-meter");
-  {
-    int i = 256;
-    while (i--)
-      ASET (Vbyte_code_meter, i,
-           Fmake_vector (make_number (256), make_number (0)));
-  }
+  for (int i = 0; i < 256; i++)
+    ASET (Vbyte_code_meter, i, make_vector (256, make_fixnum (0)));
 #endif
 }