diff --git a/runtime/doc/repeat.txt b/runtime/doc/repeat.txt
index fc699a1..195a202 100644
--- a/runtime/doc/repeat.txt
+++ b/runtime/doc/repeat.txt
@@ -1,4 +1,4 @@
-*repeat.txt*    For Vim version 8.2.  Last change: 2021 Jan 02
+*repeat.txt*    For Vim version 8.2.  Last change: 2021 Jan 23
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -354,7 +354,7 @@
 			Vim version, or update Vim to a newer version.  See
 			|vimscript-version| for what changed between versions.
 
-:vim9script [noclear]				*:vim9* *:vim9script*
+:vim9[script] [noclear]				*:vim9* *:vim9script*
 			Marks a script file as containing |Vim9-script|
 			commands.  Also see |vim9-namespace|.
 			Must be the first command in the file.
@@ -899,8 +899,9 @@
 matches ".../plugin/explorer.vim" and "explorer.vim" in any other directory.
 
 The match for functions is done against the name as it's shown in the output
-of ":function".  For local functions this means that something like "<SNR>99_"
-is prepended.
+of ":function".  However, for local functions the script-specific prefix such
+as "<SNR>99_" is ignored to make it easier to match script-local functions
+without knowing the ID of the script.
 
 Note that functions are first loaded and later executed.  When they are loaded
 the "file" breakpoints are checked, when they are executed the "func"
@@ -955,10 +956,10 @@
 
 Profiling means that Vim measures the time that is spent on executing
 functions and/or scripts.  The |+profile| feature is required for this.
-It is only included when Vim was compiled with "huge" features.
+It is included when Vim was compiled with "huge" features.
 
 You can also use the |reltime()| function to measure time.  This only requires
-the |+reltime| feature, which is present more often.
+the |+reltime| feature, which is present in more builds.
 
 For profiling syntax highlighting see |:syntime|.
 
@@ -1005,7 +1006,12 @@
 
 
 You must always start with a ":profile start fname" command.  The resulting
-file is written when Vim exits.  Here is an example of the output, with line
+file is written when Vim exits.  For example, to profile one specific
+function: >
+	profile start /tmp/vimprofile
+	profile func MyFunc
+
+Here is an example of the output, with line
 numbers prepended for the explanation:
 
   1 FUNCTION  Test2() ~
diff --git a/src/debugger.c b/src/debugger.c
index f745761..4e8a173 100644
--- a/src/debugger.c
+++ b/src/debugger.c
@@ -864,7 +864,7 @@
  */
     static linenr_T
 debuggy_find(
-    int		file,	    // TRUE for a file, FALSE for a function
+    int		is_file,    // TRUE for a file, FALSE for a function
     char_u	*fname,	    // file or function name
     linenr_T	after,	    // after this line number
     garray_T	*gap,	    // either &dbg_breakp or &prof_ga
@@ -873,20 +873,25 @@
     struct debuggy *bp;
     int		i;
     linenr_T	lnum = 0;
-    char_u	*name = fname;
+    char_u	*name = NULL;
+    char_u	*short_name = fname;
     int		prev_got_int;
 
     // Return quickly when there are no breakpoints.
     if (gap->ga_len == 0)
 	return (linenr_T)0;
 
-    // Replace K_SNR in function name with "<SNR>".
-    if (!file && fname[0] == K_SPECIAL)
+    // For a script-local function remove the prefix, so that
+    // "profile func Func" matches "Func" in any script.  Otherwise it's very
+    // difficult to profile/debug a script-local function.  It may match a
+    // function in the wrong script, but that is much better than not being
+    // able to profile/debug a function in a script with unknown ID.
+    // Also match a script-specific name.
+    if (!is_file && fname[0] == K_SPECIAL)
     {
+	short_name = vim_strchr(fname, '_') + 1;
 	name = alloc(STRLEN(fname) + 3);
-	if (name == NULL)
-	    name = fname;
-	else
+	if (name != NULL)
 	{
 	    STRCPY(name, "<SNR>");
 	    STRCPY(name + 5, fname + 3);
@@ -898,8 +903,8 @@
 	// Skip entries that are not useful or are for a line that is beyond
 	// an already found breakpoint.
 	bp = &DEBUGGY(gap, i);
-	if (((bp->dbg_type == DBG_FILE) == file &&
-		bp->dbg_type != DBG_EXPR && (
+	if (((bp->dbg_type == DBG_FILE) == is_file
+		    && bp->dbg_type != DBG_EXPR && (
 #ifdef FEAT_PROFILE
 		gap == &prof_ga ||
 #endif
@@ -910,7 +915,10 @@
 	    // while matching should abort it.
 	    prev_got_int = got_int;
 	    got_int = FALSE;
-	    if (vim_regexec_prog(&bp->dbg_prog, FALSE, name, (colnr_T)0))
+	    if ((name != NULL
+		   && vim_regexec_prog(&bp->dbg_prog, FALSE, name, (colnr_T)0))
+		    || vim_regexec_prog(&bp->dbg_prog, FALSE,
+						       short_name, (colnr_T)0))
 	    {
 		lnum = bp->dbg_lnum;
 		if (fp != NULL)
diff --git a/src/ex_cmds.h b/src/ex_cmds.h
index 30f5221..01c6156 100644
--- a/src/ex_cmds.h
+++ b/src/ex_cmds.h
@@ -489,7 +489,7 @@
 	EX_BANG|EX_EXTRA|EX_TRLBAR|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_disassemble,	"disassemble",	ex_disassemble,
-	EX_EXTRA|EX_NEEDARG|EX_TRLBAR|EX_CMDWIN|EX_LOCK_OK,
+	EX_BANG|EX_EXTRA|EX_NEEDARG|EX_TRLBAR|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_djump,	"djump",	ex_findpat,
 	EX_BANG|EX_RANGE|EX_DFLALL|EX_WHOLEFOLD|EX_EXTRA,
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index b9ae13d..3dec65e 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -866,7 +866,7 @@
 	    if (do_profiling == PROF_YES)
 	    {
 		if (getline_is_func)
-		    func_line_start(real_cookie);
+		    func_line_start(real_cookie, SOURCING_LNUM);
 		else if (getline_equal(fgetline, cookie, getsourceline))
 		    script_line_start();
 	    }
diff --git a/src/profiler.c b/src/profiler.c
index 7896897..46ab3e3 100644
--- a/src/profiler.c
+++ b/src/profiler.c
@@ -555,6 +555,51 @@
 }
 
 /*
+ * When calling a function: may initialize for profiling.
+ */
+    void
+profile_may_start_func(profinfo_T *info, ufunc_T *fp, funccall_T *fc)
+{
+    if (do_profiling == PROF_YES)
+    {
+	if (!fp->uf_profiling && has_profiling(FALSE, fp->uf_name, NULL))
+	{
+	    info->pi_started_profiling = TRUE;
+	    func_do_profile(fp);
+	}
+	if (fp->uf_profiling
+		    || (fc->caller != NULL && fc->caller->func->uf_profiling))
+	{
+	    ++fp->uf_tm_count;
+	    profile_start(&info->pi_call_start);
+	    profile_zero(&fp->uf_tm_children);
+	}
+	script_prof_save(&info->pi_wait_start);
+    }
+}
+
+/*
+ * After calling a function: may handle profiling.  profile_may_start_func()
+ * must have been called previously.
+ */
+    void
+profile_may_end_func(profinfo_T *info, ufunc_T *fp, funccall_T *fc)
+{
+    profile_end(&info->pi_call_start);
+    profile_sub_wait(&info->pi_wait_start, &info->pi_call_start);
+    profile_add(&fp->uf_tm_total, &info->pi_call_start);
+    profile_self(&fp->uf_tm_self, &info->pi_call_start, &fp->uf_tm_children);
+    if (fc->caller != NULL && fc->caller->func->uf_profiling)
+    {
+	profile_add(&fc->caller->func->uf_tm_children, &info->pi_call_start);
+	profile_add(&fc->caller->func->uf_tml_children, &info->pi_call_start);
+    }
+    if (info->pi_started_profiling)
+	// make a ":profdel func" stop profiling the function
+	fp->uf_profiling = FALSE;
+}
+
+/*
  * Prepare profiling for entering a child or something else that is not
  * counted for the script/function itself.
  * Should always be called in pair with prof_child_exit().
@@ -597,15 +642,14 @@
  * until later and we need to store the time now.
  */
     void
-func_line_start(void *cookie)
+func_line_start(void *cookie, long lnum)
 {
     funccall_T	*fcp = (funccall_T *)cookie;
     ufunc_T	*fp = fcp->func;
 
-    if (fp->uf_profiling && SOURCING_LNUM >= 1
-				      && SOURCING_LNUM <= fp->uf_lines.ga_len)
+    if (fp->uf_profiling && lnum >= 1 && lnum <= fp->uf_lines.ga_len)
     {
-	fp->uf_tml_idx = SOURCING_LNUM - 1;
+	fp->uf_tml_idx = lnum - 1;
 	// Skip continuation lines.
 	while (fp->uf_tml_idx > 0 && FUNCLINE(fp, fp->uf_tml_idx) == NULL)
 	    --fp->uf_tml_idx;
diff --git a/src/proto/profiler.pro b/src/proto/profiler.pro
index 5e0b6a2..b2070df 100644
--- a/src/proto/profiler.pro
+++ b/src/proto/profiler.pro
@@ -19,9 +19,11 @@
 void prof_inchar_exit(void);
 int prof_def_func(void);
 void func_do_profile(ufunc_T *fp);
+void profile_may_start_func(profinfo_T *info, ufunc_T *fp, funccall_T *fc);
+void profile_may_end_func(profinfo_T *info, ufunc_T *fp, funccall_T *fc);
 void prof_child_enter(proftime_T *tm);
 void prof_child_exit(proftime_T *tm);
-void func_line_start(void *cookie);
+void func_line_start(void *cookie, long lnum);
 void func_line_exec(void *cookie);
 void func_line_end(void *cookie);
 void script_do_profile(scriptitem_T *si);
diff --git a/src/proto/vim9compile.pro b/src/proto/vim9compile.pro
index d1d1b0c..04c3c5e 100644
--- a/src/proto/vim9compile.pro
+++ b/src/proto/vim9compile.pro
@@ -3,6 +3,7 @@
 int check_compare_types(exprtype_T type, typval_T *tv1, typval_T *tv2);
 int use_typecheck(type_T *actual, type_T *expected);
 int need_type(type_T *actual, type_T *expected, int offset, int arg_idx, cctx_T *cctx, int silent, int actual_is_const);
+int func_needs_compiling(ufunc_T *ufunc, int profile);
 int get_script_item_idx(int sid, char_u *name, int check_writable, cctx_T *cctx);
 imported_T *find_imported(char_u *name, size_t len, cctx_T *cctx);
 imported_T *find_imported_in_script(char_u *name, size_t len, int sid);
@@ -15,7 +16,7 @@
 int assignment_len(char_u *p, int *heredoc);
 void vim9_declare_error(char_u *name);
 int check_vim9_unlet(char_u *name);
-int compile_def_function(ufunc_T *ufunc, int check_return_type, cctx_T *outer_cctx);
+int compile_def_function(ufunc_T *ufunc, int check_return_type, int profiling, cctx_T *outer_cctx);
 void set_function_type(ufunc_T *ufunc);
 void delete_instr(isn_T *isn);
 void unlink_def_function(ufunc_T *ufunc);
diff --git a/src/structs.h b/src/structs.h
index d6bf667..b092b45 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -1577,7 +1577,7 @@
 #if defined(FEAT_EVAL) || defined(PROTO)
 typedef struct funccall_S funccall_T;
 
-// values used for "uf_dfunc_idx"
+// values used for "uf_def_status"
 typedef enum {
     UF_NOT_COMPILED,
     UF_TO_BE_COMPILED,
@@ -1899,6 +1899,13 @@
 } sn_prl_T;
 
 #  define PRL_ITEM(si, idx)	(((sn_prl_T *)(si)->sn_prl_ga.ga_data)[(idx)])
+
+typedef struct {
+    int		pi_started_profiling;
+    proftime_T	pi_wait_start;
+    proftime_T	pi_call_start;
+} profinfo_T;
+
 # endif
 #else
 // dummy typedefs for use in function prototypes
diff --git a/src/testdir/test_profile.vim b/src/testdir/test_profile.vim
index 7bac118..9c7cb5c 100644
--- a/src/testdir/test_profile.vim
+++ b/src/testdir/test_profile.vim
@@ -7,22 +7,27 @@
 source screendump.vim
 
 func Test_profile_func()
+  call RunProfileFunc('func', 'let', 'let')
+  call RunProfileFunc('def', 'var', '')
+endfunc
+
+func RunProfileFunc(command, declare, assign)
   let lines =<< trim [CODE]
     profile start Xprofile_func.log
     profile func Foo*
-    func! Foo1()
-    endfunc
-    func! Foo2()
-      let l:count = 100
-      while l:count > 0
-        let l:count = l:count - 1
+    XXX Foo1()
+    endXXX
+    XXX Foo2()
+      DDD counter = 100
+      while counter > 0
+        AAA counter = counter - 1
       endwhile
       sleep 1m
-    endfunc
-    func! Foo3()
-    endfunc
-    func! Bar()
-    endfunc
+    endXXX
+    XXX Foo3()
+    endXXX
+    XXX Bar()
+    endXXX
     call Foo1()
     call Foo1()
     profile pause
@@ -37,6 +42,10 @@
     delfunc Foo3
   [CODE]
 
+  call map(lines, {k, v -> substitute(v, 'XXX', a:command, '') })
+  call map(lines, {k, v -> substitute(v, 'DDD', a:declare, '') })
+  call map(lines, {k, v -> substitute(v, 'AAA', a:assign, '') })
+
   call writefile(lines, 'Xprofile_func.vim')
   call system(GetVimCommand()
     \ . ' -es --clean'
@@ -69,10 +78,10 @@
   call assert_match('^ Self time:\s\+\d\+\.\d\+$',                 lines[12])
   call assert_equal('',                                            lines[13])
   call assert_equal('count  total (s)   self (s)',                 lines[14])
-  call assert_match('^\s*1\s\+.*\slet l:count = 100$',             lines[15])
-  call assert_match('^\s*101\s\+.*\swhile l:count > 0$',           lines[16])
-  call assert_match('^\s*100\s\+.*\s  let l:count = l:count - 1$', lines[17])
-  call assert_match('^\s*101\s\+.*\sendwhile$',                    lines[18])
+  call assert_match('^\s*1\s\+.*\s\(let\|var\) counter = 100$',    lines[15])
+  call assert_match('^\s*101\s\+.*\swhile counter > 0$',           lines[16])
+  call assert_match('^\s*100\s\+.*\s  \(let\)\= counter = counter - 1$', lines[17])
+  call assert_match('^\s*10[01]\s\+.*\sendwhile$',                 lines[18])
   call assert_match('^\s*1\s\+.\+sleep 1m$',                       lines[19])
   call assert_equal('',                                            lines[20])
   call assert_equal('FUNCTIONS SORTED ON TOTAL TIME',              lines[21])
diff --git a/src/testdir/test_vim9_disassemble.vim b/src/testdir/test_vim9_disassemble.vim
index f40bcf0..9a3401f 100644
--- a/src/testdir/test_vim9_disassemble.vim
+++ b/src/testdir/test_vim9_disassemble.vim
@@ -1842,6 +1842,27 @@
         res)
 enddef
 
+def s:Profiled(): string
+  echo "profiled"
+  return "done"
+enddef
+
+def Test_profiled()
+  var res = execute('disass! s:Profiled')
+  assert_match('<SNR>\d*_Profiled\_s*' ..
+        'echo "profiled"\_s*' ..
+        '\d PROFILE START line 1\_s*' ..
+        '\d PUSHS "profiled"\_s*' ..
+        '\d ECHO 1\_s*' ..
+        '\d PROFILE END\_s*' ..
+        'return "done"\_s*' ..
+        '\d PROFILE START line 2\_s*' ..
+        '\d PUSHS "done"\_s*' ..
+        '\d RETURN\_s*' ..
+        '\d PROFILE END',
+        res)
+enddef
+
 def s:SilentReturn(): string
   silent return "done"
 enddef
diff --git a/src/userfunc.c b/src/userfunc.c
index 5372260..9216685 100644
--- a/src/userfunc.c
+++ b/src/userfunc.c
@@ -1601,12 +1601,14 @@
     char_u	numbuf[NUMBUFLEN];
     char_u	*name;
 #ifdef FEAT_PROFILE
-    proftime_T	wait_start;
-    proftime_T	call_start;
-    int		started_profiling = FALSE;
+    profinfo_T	profile_info;
 #endif
     ESTACK_CHECK_DECLARATION
 
+#ifdef FEAT_PROFILE
+    CLEAR_FIELD(profile_info);
+#endif
+
     // If depth of calling is getting too high, don't execute the function.
     if (funcdepth_increment() == FAIL)
     {
@@ -1635,8 +1637,16 @@
     if (fp->uf_def_status != UF_NOT_COMPILED)
     {
 	// Execute the function, possibly compiling it first.
+#ifdef FEAT_PROFILE
+	profile_may_start_func(&profile_info, fp, fc);
+#endif
 	call_def_function(fp, argcount, argvars, funcexe->partial, rettv);
 	funcdepth_decrement();
+#ifdef FEAT_PROFILE
+	if (do_profiling == PROF_YES && (fp->uf_profiling
+		    || (fc->caller != NULL && fc->caller->func->uf_profiling)))
+	    profile_may_end_func(&profile_info, fp, fc);
+#endif
 	current_funccal = fc->caller;
 	free_funccal(fc);
 	return;
@@ -1849,22 +1859,7 @@
 	--no_wait_return;
     }
 #ifdef FEAT_PROFILE
-    if (do_profiling == PROF_YES)
-    {
-	if (!fp->uf_profiling && has_profiling(FALSE, fp->uf_name, NULL))
-	{
-	    started_profiling = TRUE;
-	    func_do_profile(fp);
-	}
-	if (fp->uf_profiling
-		    || (fc->caller != NULL && fc->caller->func->uf_profiling))
-	{
-	    ++fp->uf_tm_count;
-	    profile_start(&call_start);
-	    profile_zero(&fp->uf_tm_children);
-	}
-	script_prof_save(&wait_start);
-    }
+    profile_may_start_func(&profile_info, fp, fc);
 #endif
 
     save_current_sctx = current_sctx;
@@ -1902,20 +1897,7 @@
 #ifdef FEAT_PROFILE
     if (do_profiling == PROF_YES && (fp->uf_profiling
 		    || (fc->caller != NULL && fc->caller->func->uf_profiling)))
-    {
-	profile_end(&call_start);
-	profile_sub_wait(&wait_start, &call_start);
-	profile_add(&fp->uf_tm_total, &call_start);
-	profile_self(&fp->uf_tm_self, &call_start, &fp->uf_tm_children);
-	if (fc->caller != NULL && fc->caller->func->uf_profiling)
-	{
-	    profile_add(&fc->caller->func->uf_tm_children, &call_start);
-	    profile_add(&fc->caller->func->uf_tml_children, &call_start);
-	}
-	if (started_profiling)
-	    // make a ":profdel func" stop profiling the function
-	    fp->uf_profiling = FALSE;
-    }
+	profile_may_end_func(&profile_info, fp, fc);
 #endif
 
     // when being verbose, mention the return value
@@ -1964,7 +1946,7 @@
     current_sctx = save_current_sctx;
 #ifdef FEAT_PROFILE
     if (do_profiling == PROF_YES)
-	script_prof_restore(&wait_start);
+	script_prof_restore(&profile_info.pi_wait_start);
 #endif
     if (using_sandbox)
 	--sandbox;
@@ -3982,7 +3964,7 @@
 
 /*
  * :defcompile - compile all :def functions in the current script that need to
- * be compiled.  Except dead functions.
+ * be compiled.  Except dead functions.  Doesn't do profiling.
  */
     void
 ex_defcompile(exarg_T *eap UNUSED)
@@ -4002,7 +3984,7 @@
 		    && ufunc->uf_def_status == UF_TO_BE_COMPILED
 		    && (ufunc->uf_flags & FC_DEAD) == 0)
 	    {
-		compile_def_function(ufunc, FALSE, NULL);
+		compile_def_function(ufunc, FALSE, FALSE, NULL);
 
 		if (func_hashtab.ht_changed != changed)
 		{
@@ -4698,7 +4680,7 @@
 	    SOURCING_LNUM = fcp->linenr;
 #ifdef FEAT_PROFILE
 	    if (do_profiling == PROF_YES)
-		func_line_start(cookie);
+		func_line_start(cookie, SOURCING_LNUM);
 #endif
 	}
     }
diff --git a/src/version.c b/src/version.c
index 55ce713..41858ba 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2400,
+/**/
     2399,
 /**/
     2398,
diff --git a/src/vim9.h b/src/vim9.h
index 8d4faa3..9446c15 100644
--- a/src/vim9.h
+++ b/src/vim9.h
@@ -152,6 +152,9 @@
     ISN_CMDMOD,	    // set cmdmod
     ISN_CMDMOD_REV, // undo ISN_CMDMOD
 
+    ISN_PROF_START, // start a line for profiling
+    ISN_PROF_END,   // end a line for profiling
+
     ISN_UNPACK,	    // unpack list into items, uses isn_arg.unpack
     ISN_SHUFFLE,    // move item on stack up or down
     ISN_DROP	    // pop stack and discard value
@@ -366,8 +369,12 @@
 				    // was compiled.
 
     garray_T	df_def_args_isn;    // default argument instructions
+
+    // After compiling "df_instr" and/or "df_instr_prof" is not NULL.
     isn_T	*df_instr;	    // function body to be executed
-    int		df_instr_count;
+    int		df_instr_count;	    // size of "df_instr"
+    isn_T	*df_instr_prof;		// like "df_instr" with profiling
+    int		df_instr_prof_count;	// size of "df_instr_prof"
 
     int		df_varcount;	    // number of local variables
     int		df_has_closure;	    // one if a closure was created
diff --git a/src/vim9compile.c b/src/vim9compile.c
index ae5cb12..5a7da12 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -123,6 +123,8 @@
     char_u	*ctx_line_start;    // start of current line or NULL
     garray_T	ctx_instr;	    // generated instructions
 
+    int		ctx_profiling;	    // when TRUE generate ISN_PROF_START
+
     garray_T	ctx_locals;	    // currently visible local variables
     int		ctx_locals_count;   // total number of local variables
 
@@ -1693,6 +1695,29 @@
 }
 
 /*
+ * Return TRUE if "ufunc" should be compiled, taking into account whether
+ * "profile" indicates profiling is to be done.
+ */
+    int
+func_needs_compiling(ufunc_T *ufunc, int profile)
+{
+    switch (ufunc->uf_def_status)
+    {
+	case UF_NOT_COMPILED: return FALSE;
+	case UF_TO_BE_COMPILED: return TRUE;
+	case UF_COMPILED:
+	{
+	    dfunc_T *dfunc = ((dfunc_T *)def_functions.ga_data)
+							 + ufunc->uf_dfunc_idx;
+
+	    return profile ? dfunc->df_instr_prof == NULL
+			   : dfunc->df_instr == NULL;
+	}
+	case UF_COMPILING: return FALSE;
+    }
+}
+
+/*
  * Generate an ISN_DCALL or ISN_UCALL instruction.
  * Return FAIL if the number of arguments is wrong.
  */
@@ -1744,10 +1769,10 @@
 		return FAIL;
 	    }
 	}
-	if (ufunc->uf_def_status == UF_TO_BE_COMPILED)
-	    if (compile_def_function(ufunc, ufunc->uf_ret_type == NULL, NULL)
-								       == FAIL)
-		return FAIL;
+	if (func_needs_compiling(ufunc, cctx->ctx_profiling)
+		&& compile_def_function(ufunc, ufunc->uf_ret_type == NULL,
+					    cctx->ctx_profiling, NULL) == FAIL)
+	    return FAIL;
     }
 
     if ((isn = generate_instr(cctx,
@@ -2063,6 +2088,19 @@
     return OK;
 }
 
+    static void
+may_generate_prof_end(cctx_T *cctx, int prof_lnum)
+{
+    if (cctx->ctx_profiling && prof_lnum >= 0)
+    {
+	int save_lnum = cctx->ctx_lnum;
+
+	cctx->ctx_lnum = prof_lnum;
+	generate_instr(cctx, ISN_PROF_END);
+	cctx->ctx_lnum = save_lnum;
+    }
+}
+
 /*
  * Reserve space for a local variable.
  * Return the variable or NULL if it failed.
@@ -2575,9 +2613,10 @@
 	return FAIL;
 
     // Need to compile any default values to get the argument types.
-    if (ufunc->uf_def_status == UF_TO_BE_COMPILED)
-	if (compile_def_function(ufunc, TRUE, NULL) == FAIL)
-	    return FAIL;
+    if (func_needs_compiling(ufunc, cctx->ctx_profiling)
+	    && compile_def_function(ufunc, TRUE, cctx->ctx_profiling, NULL)
+								       == FAIL)
+	return FAIL;
     return generate_PUSHFUNC(cctx, ufunc->uf_name, ufunc->uf_func_type);
 }
 
@@ -3070,7 +3109,7 @@
     clear_tv(&rettv);
 
     // Compile the function into instructions.
-    compile_def_function(ufunc, TRUE, cctx);
+    compile_def_function(ufunc, TRUE, cctx->ctx_profiling, cctx);
 
     clear_evalarg(&evalarg, NULL);
 
@@ -5047,8 +5086,9 @@
 	r = eap->skip ? OK : FAIL;
 	goto theend;
     }
-    if (ufunc->uf_def_status == UF_TO_BE_COMPILED
-	    && compile_def_function(ufunc, TRUE, cctx) == FAIL)
+    if (func_needs_compiling(ufunc, cctx->ctx_profiling)
+	    && compile_def_function(ufunc, TRUE, cctx->ctx_profiling, cctx)
+								       == FAIL)
     {
 	func_ptr_unref(ufunc);
 	goto theend;
@@ -7101,7 +7141,11 @@
     if (scope == NULL)
 	return NULL;
 
+    // "endwhile" jumps back here, one before when profiling
     scope->se_u.se_while.ws_top_label = instr->ga_len;
+    if (cctx->ctx_profiling && ((isn_T *)instr->ga_data)[instr->ga_len - 1]
+						   .isn_type == ISN_PROF_START)
+	--scope->se_u.se_while.ws_top_label;
 
     // compile "expr"
     if (compile_expr0(&p, cctx) == FAIL)
@@ -7134,6 +7178,9 @@
     cctx->ctx_scope = scope->se_outer;
     unwind_locals(cctx, scope->se_local_count);
 
+    // count the endwhile before jumping
+    may_generate_prof_end(cctx, cctx->ctx_lnum);
+
     // At end of ":for" scope jump back to the FOR instruction.
     generate_JUMP(cctx, JUMP_ALWAYS, scope->se_u.se_while.ws_top_label);
 
@@ -7794,13 +7841,18 @@
  * When "check_return_type" is set then set ufunc->uf_ret_type to the type of
  * the return statement (used for lambda).  When uf_ret_type is already set
  * then check that it matches.
+ * When "profiling" is true add ISN_PROF_START instructions.
  * "outer_cctx" is set for a nested function.
  * This can be used recursively through compile_lambda(), which may reallocate
  * "def_functions".
  * Returns OK or FAIL.
  */
     int
-compile_def_function(ufunc_T *ufunc, int check_return_type, cctx_T *outer_cctx)
+compile_def_function(
+	ufunc_T	    *ufunc,
+	int	    check_return_type,
+	int	    profiling,
+	cctx_T	    *outer_cctx)
 {
     char_u	*line = NULL;
     char_u	*p;
@@ -7813,6 +7865,7 @@
     int		save_estack_compiling = estack_compiling;
     int		do_estack_push;
     int		new_def_function = FALSE;
+    int		prof_lnum = -1;
 
     // When using a function that was compiled before: Free old instructions.
     // The index is reused.  Otherwise add a new entry in "def_functions".
@@ -7832,6 +7885,8 @@
     ufunc->uf_def_status = UF_COMPILING;
 
     CLEAR_FIELD(cctx);
+
+    cctx.ctx_profiling = profiling;
     cctx.ctx_ufunc = ufunc;
     cctx.ctx_lnum = -1;
     cctx.ctx_outer = outer_cctx;
@@ -7932,22 +7987,35 @@
 	{
 	    line = next_line_from_context(&cctx, FALSE);
 	    if (cctx.ctx_lnum >= ufunc->uf_lines.ga_len)
+	    {
 		// beyond the last line
+		may_generate_prof_end(&cctx, prof_lnum);
 		break;
+	    }
 	}
 
 	CLEAR_FIELD(ea);
 	ea.cmdlinep = &line;
 	ea.cmd = skipwhite(line);
 
+	if (*ea.cmd == '#')
+	{
+	    // "#" starts a comment
+	    line = (char_u *)"";
+	    continue;
+	}
+
+	if (cctx.ctx_profiling && cctx.ctx_lnum != prof_lnum)
+	{
+	    may_generate_prof_end(&cctx, prof_lnum);
+
+	    prof_lnum = cctx.ctx_lnum;
+	    generate_instr(&cctx, ISN_PROF_START);
+	}
+
 	// Some things can be recognized by the first character.
 	switch (*ea.cmd)
 	{
-	    case '#':
-		// "#" starts a comment
-		line = (char_u *)"";
-		continue;
-
 	    case '}':
 		{
 		    // "}" ends a block scope
@@ -8308,8 +8376,16 @@
 							 + ufunc->uf_dfunc_idx;
 	dfunc->df_deleted = FALSE;
 	dfunc->df_script_seq = current_sctx.sc_seq;
-	dfunc->df_instr = instr->ga_data;
-	dfunc->df_instr_count = instr->ga_len;
+	if (cctx.ctx_profiling)
+	{
+	    dfunc->df_instr_prof = instr->ga_data;
+	    dfunc->df_instr_prof_count = instr->ga_len;
+	}
+	else
+	{
+	    dfunc->df_instr = instr->ga_data;
+	    dfunc->df_instr_count = instr->ga_len;
+	}
 	dfunc->df_varcount = cctx.ctx_locals_count;
 	dfunc->df_has_closure = cctx.ctx_has_closure;
 	if (cctx.ctx_outer_used)
@@ -8586,6 +8662,8 @@
 	case ISN_OPNR:
 	case ISN_PCALL:
 	case ISN_PCALL_END:
+	case ISN_PROF_END:
+	case ISN_PROF_START:
 	case ISN_PUSHBOOL:
 	case ISN_PUSHF:
 	case ISN_PUSHNR:
diff --git a/src/vim9execute.c b/src/vim9execute.c
index 232c84e..e494885 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -294,7 +294,7 @@
     // Set execution state to the start of the called function.
     ectx->ec_dfunc_idx = cdf_idx;
     ectx->ec_instr = dfunc->df_instr;
-    entry = estack_push_ufunc(dfunc->df_ufunc, 1);
+    entry = estack_push_ufunc(ufunc, 1);
     if (entry != NULL)
     {
 	// Set the script context to the script where the function was defined.
@@ -645,9 +645,10 @@
     int		error;
     int		idx;
     int		did_emsg_before = did_emsg;
+    int		profiling = do_profiling == PROF_YES && ufunc->uf_profiling;
 
-    if (ufunc->uf_def_status == UF_TO_BE_COMPILED
-	    && compile_def_function(ufunc, FALSE, NULL) == FAIL)
+    if (func_needs_compiling(ufunc, profiling)
+		&& compile_def_function(ufunc, FALSE, profiling, NULL) == FAIL)
 	return FAIL;
     if (ufunc->uf_def_status == UF_COMPILED)
     {
@@ -1130,6 +1131,7 @@
     int		save_did_emsg_def = did_emsg_def;
     int		trylevel_at_start = trylevel;
     int		orig_funcdepth;
+    int		profiling = do_profiling == PROF_YES && ufunc->uf_profiling;
 
 // Get pointer to item in the stack.
 #define STACK_TV(idx) (((typval_T *)ectx.ec_stack.ga_data) + idx)
@@ -1142,8 +1144,9 @@
 #define STACK_TV_VAR(idx) (((typval_T *)ectx.ec_stack.ga_data) + ectx.ec_frame_idx + STACK_FRAME_SIZE + idx)
 
     if (ufunc->uf_def_status == UF_NOT_COMPILED
-	    || (ufunc->uf_def_status == UF_TO_BE_COMPILED
-			  && compile_def_function(ufunc, FALSE, NULL) == FAIL))
+	    || (func_needs_compiling(ufunc, profiling)
+			 && compile_def_function(ufunc, FALSE, profiling, NULL)
+								      == FAIL))
     {
 	if (did_emsg_cumul + did_emsg == did_emsg_before)
 	    semsg(_(e_function_is_not_compiled_str),
@@ -1155,7 +1158,7 @@
 	// Check the function was really compiled.
 	dfunc_T	*dfunc = ((dfunc_T *)def_functions.ga_data)
 							 + ufunc->uf_dfunc_idx;
-	if (dfunc->df_instr == NULL)
+	if ((profiling ? dfunc->df_instr_prof : dfunc->df_instr) == NULL)
 	{
 	    iemsg("using call_def_function() on not compiled function");
 	    return FAIL;
@@ -1294,7 +1297,7 @@
 	    ++ectx.ec_stack.ga_len;
 	}
 
-	ectx.ec_instr = dfunc->df_instr;
+	ectx.ec_instr = profiling ? dfunc->df_instr_prof : dfunc->df_instr;
     }
 
     // Following errors are in the function, not the caller.
@@ -3495,6 +3498,26 @@
 		}
 		break;
 
+	    case ISN_PROF_START:
+	    case ISN_PROF_END:
+		{
+		    funccall_T cookie;
+		    ufunc_T	    *cur_ufunc =
+				    (((dfunc_T *)def_functions.ga_data)
+						 + ectx.ec_dfunc_idx)->df_ufunc;
+
+		    cookie.func = cur_ufunc;
+		    if (iptr->isn_type == ISN_PROF_START)
+		    {
+			func_line_start(&cookie, iptr->isn_lnum);
+			// if we get here the instruction is executed
+			func_line_exec(&cookie);
+		    }
+		    else
+			func_line_end(&cookie);
+		}
+		break;
+
 	    case ISN_SHUFFLE:
 		{
 		    typval_T	tmp_tv;
@@ -3642,6 +3665,7 @@
     ufunc_T	*ufunc;
     dfunc_T	*dfunc;
     isn_T	*instr;
+    int		instr_count;
     int		current;
     int		line_idx = 0;
     int		prev_current = 0;
@@ -3677,8 +3701,8 @@
 	semsg(_(e_cannot_find_function_str), eap->arg);
 	return;
     }
-    if (ufunc->uf_def_status == UF_TO_BE_COMPILED
-	    && compile_def_function(ufunc, FALSE, NULL) == FAIL)
+    if (func_needs_compiling(ufunc, eap->forceit)
+	    && compile_def_function(ufunc, FALSE, eap->forceit, NULL) == FAIL)
 	return;
     if (ufunc->uf_def_status != UF_COMPILED)
     {
@@ -3691,8 +3715,10 @@
 	msg((char *)ufunc->uf_name);
 
     dfunc = ((dfunc_T *)def_functions.ga_data) + ufunc->uf_dfunc_idx;
-    instr = dfunc->df_instr;
-    for (current = 0; current < dfunc->df_instr_count; ++current)
+    instr = eap->forceit ? dfunc->df_instr_prof : dfunc->df_instr;
+    instr_count = eap->forceit ? dfunc->df_instr_prof_count
+						       : dfunc->df_instr_count;
+    for (current = 0; current < instr_count; ++current)
     {
 	isn_T	    *iptr = &instr[current];
 	char	    *line;
@@ -4319,6 +4345,14 @@
 		}
 	    case ISN_CMDMOD_REV: smsg("%4d CMDMOD_REV", current); break;
 
+	    case ISN_PROF_START:
+		 smsg("%4d PROFILE START line %d", current, iptr->isn_lnum);
+		 break;
+
+	    case ISN_PROF_END:
+		smsg("%4d PROFILE END", current);
+		break;
+
 	    case ISN_UNPACK: smsg("%4d UNPACK %d%s", current,
 			iptr->isn_arg.unpack.unp_count,
 			iptr->isn_arg.unpack.unp_semicolon ? " semicolon" : "");
diff --git a/src/vim9type.c b/src/vim9type.c
index 81b0db2..1374cee 100644
--- a/src/vim9type.c
+++ b/src/vim9type.c
@@ -336,7 +336,8 @@
 	    // May need to get the argument types from default values by
 	    // compiling the function.
 	    if (ufunc->uf_def_status == UF_TO_BE_COMPILED
-			    && compile_def_function(ufunc, TRUE, NULL) == FAIL)
+			    && compile_def_function(ufunc, TRUE, FALSE, NULL)
+								       == FAIL)
 		return NULL;
 	    if (ufunc->uf_func_type == NULL)
 		set_function_type(ufunc);