diff --git a/src/Make_cyg_ming.mak b/src/Make_cyg_ming.mak
index 86bbc3e..490ae0b 100644
--- a/src/Make_cyg_ming.mak
+++ b/src/Make_cyg_ming.mak
@@ -379,7 +379,7 @@
 # Any other defines can be included here.
 DEF_GUI=-DFEAT_GUI_W32 -DFEAT_CLIPBOARD
 DEFINES=-DWIN32 -DWINVER=$(WINVER) -D_WIN32_WINNT=$(WINVER) \
-	-DHAVE_PATHDEF -DFEAT_$(FEATURES)
+	-DHAVE_PATHDEF -DFEAT_$(FEATURES) -DHAVE_STDINT_H
 ifeq ($(ARCH),x86-64)
 DEFINES+=-DMS_WIN64
 endif
diff --git a/src/Make_mvc.mak b/src/Make_mvc.mak
index 5687f09..b1a643c 100644
--- a/src/Make_mvc.mak
+++ b/src/Make_mvc.mak
@@ -501,6 +501,11 @@
 CFLAGS=$(CFLAGS) $(WP64CHECK)
 !endif
 
+# VC10 or later has stdint.h.
+!if $(MSVC_MAJOR) >= 10
+CFLAGS = $(CFLAGS) -DHAVE_STDINT_H
+!endif
+
 # Static code analysis generally available starting with VS2012 (VC11) or
 # Windows SDK 7.1 (VC10)
 !if ("$(ANALYZE)" == "yes") && ($(MSVC_MAJOR) >= 10)
diff --git a/src/charset.c b/src/charset.c
index e008399..9fcd88c 100644
--- a/src/charset.c
+++ b/src/charset.c
@@ -1836,14 +1836,14 @@
 				       is bin */
     int			*len,	    /* return: detected length of number */
     int			what,	    /* what numbers to recognize */
-    long		*nptr,	    /* return: signed result */
-    unsigned long	*unptr,	    /* return: unsigned result */
+    varnumber_T		*nptr,	    /* return: signed result */
+    uvarnumber_T	*unptr,	    /* return: unsigned result */
     int			maxlen)     /* max length of string to check */
 {
     char_u	    *ptr = start;
     int		    pre = 0;		/* default is decimal */
     int		    negative = FALSE;
-    unsigned long   un = 0;
+    uvarnumber_T    un = 0;
     int		    n;
 
     if (ptr[0] == '-')
@@ -1912,7 +1912,7 @@
 	/* octal */
 	while ('0' <= *ptr && *ptr <= '7')
 	{
-	    un = 8 * un + (unsigned long)(*ptr - '0');
+	    un = 8 * un + (uvarnumber_T)(*ptr - '0');
 	    ++ptr;
 	    if (n++ == maxlen)
 		break;
@@ -1925,7 +1925,7 @@
 	    n += 2;	    /* skip over "0x" */
 	while (vim_isxdigit(*ptr))
 	{
-	    un = 16 * un + (unsigned long)hex2nr(*ptr);
+	    un = 16 * un + (uvarnumber_T)hex2nr(*ptr);
 	    ++ptr;
 	    if (n++ == maxlen)
 		break;
@@ -1936,7 +1936,7 @@
 	/* decimal */
 	while (VIM_ISDIGIT(*ptr))
 	{
-	    un = 10 * un + (unsigned long)(*ptr - '0');
+	    un = 10 * un + (uvarnumber_T)(*ptr - '0');
 	    ++ptr;
 	    if (n++ == maxlen)
 		break;
@@ -1950,9 +1950,9 @@
     if (nptr != NULL)
     {
 	if (negative)   /* account for leading '-' for decimal numbers */
-	    *nptr = -(long)un;
+	    *nptr = -(varnumber_T)un;
 	else
-	    *nptr = (long)un;
+	    *nptr = (varnumber_T)un;
     }
     if (unptr != NULL)
 	*unptr = un;
diff --git a/src/eval.c b/src/eval.c
index 59a767a..41abe37 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -1376,7 +1376,7 @@
     int		skip)	    /* only parse, don't execute */
 {
     typval_T	tv;
-    int		retval = FALSE;
+    varnumber_T	retval = FALSE;
 
     if (skip)
 	++emsg_skip;
@@ -1394,7 +1394,7 @@
     if (skip)
 	--emsg_skip;
 
-    return retval;
+    return (int)retval;
 }
 
 /*
@@ -1519,11 +1519,11 @@
  * Evaluates "expr" silently.
  * Returns -1 for an error.
  */
-    int
+    varnumber_T
 eval_to_number(char_u *expr)
 {
     typval_T	rettv;
-    int		retval;
+    varnumber_T	retval;
     char_u	*p = skipwhite(expr);
 
     ++emsg_off;
@@ -1628,7 +1628,7 @@
     li = li->li_next;
     if (li == NULL)
 	return -1;
-    return get_tv_number(&li->li_tv);
+    return (int)get_tv_number(&li->li_tv);
 }
 #endif
 
@@ -1669,7 +1669,7 @@
     typval_T	*rettv)
 {
     typval_T	*argvars;
-    long	n;
+    varnumber_T	n;
     int		len;
     int		i;
     int		doesrange;
@@ -1735,7 +1735,7 @@
  * Returns -1 when calling the function fails.
  * Uses argv[argc] for the function arguments.
  */
-    long
+    varnumber_T
 call_func_retnr(
     char_u      *func,
     int		argc,
@@ -1743,7 +1743,7 @@
     int		safe)		/* use the sandbox */
 {
     typval_T	rettv;
-    long	retval;
+    varnumber_T	retval;
 
     /* All arguments are passed as strings, no conversion to number. */
     if (call_vim_function(func, argc, argv, safe, TRUE, &rettv) == FAIL)
@@ -1880,7 +1880,7 @@
 eval_foldexpr(char_u *arg, int *cp)
 {
     typval_T	tv;
-    int		retval;
+    varnumber_T	retval;
     char_u	*s;
     int		use_sandbox = was_set_insecurely((char_u *)"foldexpr",
 								   OPT_LOCAL);
@@ -1915,7 +1915,7 @@
 	--sandbox;
     --textlock;
 
-    return retval;
+    return (int)retval;
 }
 #endif
 
@@ -2480,7 +2480,7 @@
 	    c1 = *p;
 	    *p = NUL;
 
-	    n = get_tv_number(tv);
+	    n = (long)get_tv_number(tv);
 	    s = get_tv_string_chk(tv);	    /* != NULL if number or string */
 	    if (s != NULL && op != NULL && *op != '=')
 	    {
@@ -2888,7 +2888,8 @@
 		lp->ll_n1 = 0;
 	    else
 	    {
-		lp->ll_n1 = get_tv_number(&var1);   /* is number or string */
+		lp->ll_n1 = (long)get_tv_number(&var1);
+						    /* is number or string */
 		clear_tv(&var1);
 	    }
 	    lp->ll_dict = NULL;
@@ -2919,7 +2920,8 @@
 	     */
 	    if (lp->ll_range && !lp->ll_empty2)
 	    {
-		lp->ll_n2 = get_tv_number(&var2);   /* is number or string */
+		lp->ll_n2 = (long)get_tv_number(&var2);
+						    /* is number or string */
 		clear_tv(&var2);
 		if (lp->ll_n2 < 0)
 		{
@@ -3117,7 +3119,7 @@
     static int
 tv_op(typval_T *tv1, typval_T *tv2, char_u *op)
 {
-    long	n;
+    varnumber_T	n;
     char_u	numbuf[NUMBUFLEN];
     char_u	*s;
 
@@ -4468,7 +4470,7 @@
     exptype_T	type = TYPE_UNKNOWN;
     int		type_is = FALSE;    /* TRUE for "is" and "isnot" */
     int		len = 2;
-    long	n1, n2;
+    varnumber_T	n1, n2;
     char_u	*s1, *s2;
     char_u	buf1[NUMBUFLEN], buf2[NUMBUFLEN];
     int		ic;
@@ -4766,7 +4768,7 @@
     typval_T	var2;
     typval_T	var3;
     int		op;
-    long	n1, n2;
+    varnumber_T	n1, n2;
 #ifdef FEAT_FLOAT
     float_T	f1 = 0, f2 = 0;
 #endif
@@ -4951,7 +4953,7 @@
 {
     typval_T	var2;
     int		op;
-    long	n1, n2;
+    varnumber_T	n1, n2;
 #ifdef FEAT_FLOAT
     int		use_float = FALSE;
     float_T	f1 = 0, f2;
@@ -5072,12 +5074,21 @@
 		{
 		    if (n2 == 0)	/* give an error message? */
 		    {
+#ifdef FEAT_NUM64
+			if (n1 == 0)
+			    n1 = -0x7fffffffffffffff - 1; /* similar to NaN */
+			else if (n1 < 0)
+			    n1 = -0x7fffffffffffffff;
+			else
+			    n1 = 0x7fffffffffffffff;
+#else
 			if (n1 == 0)
 			    n1 = -0x7fffffffL - 1L;	/* similar to NaN */
 			else if (n1 < 0)
 			    n1 = -0x7fffffffL;
 			else
 			    n1 = 0x7fffffffL;
+#endif
 		    }
 		    else
 			n1 = n1 / n2;
@@ -5131,7 +5142,7 @@
     int		evaluate,
     int		want_string UNUSED)	/* after "." operator */
 {
-    long	n;
+    varnumber_T	n;
     int		len;
     char_u	*s;
     char_u	*start_leader, *end_leader;
@@ -5356,7 +5367,7 @@
     if (ret == OK && evaluate && end_leader > start_leader)
     {
 	int	    error = FALSE;
-	int	    val = 0;
+	varnumber_T val = 0;
 #ifdef FEAT_FLOAT
 	float_T	    f = 0.0;
 
@@ -6525,7 +6536,7 @@
 	    *errorp = TRUE;
 	return -1L;
     }
-    return get_tv_number_chk(&li->li_tv, errorp);
+    return (long)get_tv_number_chk(&li->li_tv, errorp);
 }
 
 /*
@@ -7770,7 +7781,7 @@
 dict_add_nr_str(
     dict_T	*d,
     char	*key,
-    long	nr,
+    varnumber_T	nr,
     char_u	*str)
 {
     dictitem_T	*item;
@@ -7894,7 +7905,7 @@
  * Get a number item from a dictionary.
  * Returns 0 if the entry doesn't exist.
  */
-    long
+    varnumber_T
 get_dict_number(dict_T *d, char_u *key)
 {
     dictitem_T	*di;
@@ -9612,7 +9623,7 @@
 
     if (argvars[0].v_type != VAR_UNKNOWN)
     {
-	idx = get_tv_number_chk(&argvars[0], NULL);
+	idx = (int)get_tv_number_chk(&argvars[0], NULL);
 	if (idx >= 0 && idx < ARGCOUNT)
 	    rettv->vval.v_string = vim_strsave(alist_name(&ARGLIST[idx]));
 	else
@@ -10012,7 +10023,7 @@
     char_u	buf2[NUMBUFLEN];
     int		error = FALSE;
 
-    save = get_tv_number_chk(&argvars[0], &error);
+    save = (int)get_tv_number_chk(&argvars[0], &error);
     title = get_tv_string_chk(&argvars[1]);
     initdir = get_tv_string_buf_chk(&argvars[2], buf);
     defname = get_tv_string_buf_chk(&argvars[3], buf2);
@@ -10290,7 +10301,7 @@
     char_u	*t;
 #endif
     char_u	*str;
-    long	idx;
+    varnumber_T	idx;
 
     str = get_tv_string_chk(&argvars[0]);
     idx = get_tv_number_chk(&argvars[1], NULL);
@@ -10660,7 +10671,7 @@
 	int	utf8 = 0;
 
 	if (argvars[1].v_type != VAR_UNKNOWN)
-	    utf8 = get_tv_number_chk(&argvars[1], NULL);
+	    utf8 = (int)get_tv_number_chk(&argvars[1], NULL);
 
 	if (utf8)
 	    rettv->vval.v_number = (*utf_ptr2char)(get_tv_string(&argvars[0]));
@@ -10783,7 +10794,7 @@
 	return;
     }
 
-    startcol = get_tv_number_chk(&argvars[0], NULL);
+    startcol = (int)get_tv_number_chk(&argvars[0], NULL);
     if (startcol <= 0)
 	return;
 
@@ -10840,7 +10851,7 @@
 	    error = TRUE;
 	if (argvars[2].v_type != VAR_UNKNOWN)
 	{
-	    def = get_tv_number_chk(&argvars[2], &error);
+	    def = (int)get_tv_number_chk(&argvars[2], &error);
 	    if (argvars[3].v_type != VAR_UNKNOWN)
 	    {
 		typestr = get_tv_string_buf_chk(&argvars[3], buf2);
@@ -10933,10 +10944,10 @@
 	    {
 		int error = FALSE;
 
-		ic = get_tv_number_chk(&argvars[2], &error);
+		ic = (int)get_tv_number_chk(&argvars[2], &error);
 		if (argvars[3].v_type != VAR_UNKNOWN)
 		{
-		    idx = get_tv_number_chk(&argvars[3], &error);
+		    idx = (long)get_tv_number_chk(&argvars[3], &error);
 		    if (!error)
 		    {
 			li = list_find(l, idx);
@@ -10965,7 +10976,7 @@
 
 	    if (argvars[2].v_type != VAR_UNKNOWN)
 	    {
-		ic = get_tv_number_chk(&argvars[2], &error);
+		ic = (int)get_tv_number_chk(&argvars[2], &error);
 		if (argvars[3].v_type != VAR_UNKNOWN)
 		    EMSG(_(e_invarg));
 	    }
@@ -11055,10 +11066,10 @@
     else
     {
 	line = get_tv_lnum(argvars);
-	col = get_tv_number_chk(&argvars[1], NULL);
+	col = (long)get_tv_number_chk(&argvars[1], NULL);
 #ifdef FEAT_VIRTUALEDIT
 	if (argvars[2].v_type != VAR_UNKNOWN)
-	    coladd = get_tv_number_chk(&argvars[2], NULL);
+	    coladd = (long)get_tv_number_chk(&argvars[2], NULL);
 #endif
     }
     if (line < 0 || col < 0
@@ -11096,7 +11107,7 @@
     int		noref = 0;
 
     if (argvars[1].v_type != VAR_UNKNOWN)
-	noref = get_tv_number_chk(&argvars[1], NULL);
+	noref = (int)get_tv_number_chk(&argvars[1], NULL);
     if (noref < 0 || noref > 1)
 	EMSG(_(e_invarg));
     else
@@ -11604,7 +11615,7 @@
 	{
 	    if (argvars[2].v_type != VAR_UNKNOWN)
 	    {
-		before = get_tv_number_chk(&argvars[2], &error);
+		before = (long)get_tv_number_chk(&argvars[2], &error);
 		if (error)
 		    return;		/* type error; errmsg already given */
 
@@ -11807,7 +11818,7 @@
 		path = p;
 
 	    if (argvars[2].v_type != VAR_UNKNOWN)
-		count = get_tv_number_chk(&argvars[2], &error);
+		count = (int)get_tv_number_chk(&argvars[2], &error);
 	}
     }
 
@@ -12043,12 +12054,21 @@
 
     if (get_float_arg(argvars, &f) == OK)
     {
+# ifdef FEAT_NUM64
+	if (f < -0x7fffffffffffffff)
+	    rettv->vval.v_number = -0x7fffffffffffffff;
+	else if (f > 0x7fffffffffffffff)
+	    rettv->vval.v_number = 0x7fffffffffffffff;
+	else
+	    rettv->vval.v_number = (varnumber_T)f;
+# else
 	if (f < -0x7fffffff)
 	    rettv->vval.v_number = -0x7fffffff;
 	else if (f > 0x7fffffff)
 	    rettv->vval.v_number = 0x7fffffff;
 	else
 	    rettv->vval.v_number = (varnumber_T)f;
+# endif
     }
 }
 
@@ -12511,7 +12531,7 @@
 	{
 	    int		error = FALSE;
 
-	    li = list_find(l, get_tv_number_chk(&argvars[1], &error));
+	    li = list_find(l, (long)get_tv_number_chk(&argvars[1], &error));
 	    if (!error && li != NULL)
 		tv = &li->li_tv;
 	}
@@ -13333,9 +13353,9 @@
 	error = strregname == NULL;
 	if (argvars[1].v_type != VAR_UNKNOWN)
 	{
-	    arg2 = get_tv_number_chk(&argvars[1], &error);
+	    arg2 = (int)get_tv_number_chk(&argvars[1], &error);
 	    if (!error && argvars[2].v_type != VAR_UNKNOWN)
-		return_list = get_tv_number_chk(&argvars[2], &error);
+		return_list = (int)get_tv_number_chk(&argvars[2], &error);
 	}
     }
     else
@@ -13558,7 +13578,7 @@
 #endif
     int		nr;
 
-    nr = get_tv_number_chk(vp, NULL);
+    nr = (int)get_tv_number_chk(vp, NULL);
 
 #ifdef FEAT_WINDOWS
     if (nr < 0)
@@ -13601,7 +13621,7 @@
     {
 	if (tvp->v_type != VAR_UNKNOWN)
 	{
-	    n = get_tv_number(tvp);
+	    n = (long)get_tv_number(tvp);
 	    if (n >= 0)
 		tp = find_tabpage(n);
 	}
@@ -14126,6 +14146,9 @@
 	"mzscheme",
 #endif
 #endif
+#ifdef FEAT_NUM64
+	"num64",
+#endif
 #ifdef FEAT_OLE
 	"ole",
 #endif
@@ -14468,7 +14491,7 @@
     {
 	mode = get_tv_string_buf(&argvars[1], buf);
 	if (argvars[2].v_type != VAR_UNKNOWN)
-	    abbr = get_tv_number(&argvars[2]);
+	    abbr = (int)get_tv_number(&argvars[2]);
     }
 
     if (map_to_exists(name, mode, abbr))
@@ -14696,10 +14719,10 @@
 
 	    /* Start at specified item.  Use the cached index that list_find()
 	     * sets, so that a negative number also works. */
-	    item = list_find(l, get_tv_number_chk(&argvars[2], &error));
+	    item = list_find(l, (long)get_tv_number_chk(&argvars[2], &error));
 	    idx = l->lv_idx;
 	    if (argvars[3].v_type != VAR_UNKNOWN)
-		ic = get_tv_number_chk(&argvars[3], &error);
+		ic = (int)get_tv_number_chk(&argvars[3], &error);
 	    if (error)
 		item = NULL;
 	}
@@ -14983,7 +15006,7 @@
 	    && !tv_check_lock(l->lv_lock, (char_u *)N_("insert() argument"), TRUE))
     {
 	if (argvars[2].v_type != VAR_UNKNOWN)
-	    before = get_tv_number_chk(&argvars[2], &error);
+	    before = (long)get_tv_number_chk(&argvars[2], &error);
 	if (error)
 	    return;		/* type error; errmsg already given */
 
@@ -15588,9 +15611,9 @@
 	which = get_tv_string_buf_chk(&argvars[1], buf);
 	if (argvars[2].v_type != VAR_UNKNOWN)
 	{
-	    abbr = get_tv_number(&argvars[2]);
+	    abbr = (int)get_tv_number(&argvars[2]);
 	    if (argvars[3].v_type != VAR_UNKNOWN)
-		get_dict = get_tv_number(&argvars[3]);
+		get_dict = (int)get_tv_number(&argvars[3]);
 	}
     }
     else
@@ -15781,7 +15804,7 @@
     {
 	int	    error = FALSE;
 
-	start = get_tv_number_chk(&argvars[2], &error);
+	start = (long)get_tv_number_chk(&argvars[2], &error);
 	if (error)
 	    goto theend;
 	if (l != NULL)
@@ -15810,7 +15833,7 @@
 	}
 
 	if (argvars[3].v_type != VAR_UNKNOWN)
-	    nth = get_tv_number_chk(&argvars[3], &error);
+	    nth = (long)get_tv_number_chk(&argvars[3], &error);
 	if (error)
 	    goto theend;
     }
@@ -15969,10 +15992,10 @@
 	return;
     if (argvars[2].v_type != VAR_UNKNOWN)
     {
-	prio = get_tv_number_chk(&argvars[2], &error);
+	prio = (int)get_tv_number_chk(&argvars[2], &error);
 	if (argvars[3].v_type != VAR_UNKNOWN)
 	{
-	    id = get_tv_number_chk(&argvars[3], &error);
+	    id = (int)get_tv_number_chk(&argvars[3], &error);
 	    if (argvars[4].v_type != VAR_UNKNOWN)
 	    {
 		if (argvars[4].v_type != VAR_DICT)
@@ -16032,10 +16055,10 @@
 
     if (argvars[2].v_type != VAR_UNKNOWN)
     {
-	prio = get_tv_number_chk(&argvars[2], &error);
+	prio = (int)get_tv_number_chk(&argvars[2], &error);
 	if (argvars[3].v_type != VAR_UNKNOWN)
 	{
-	    id = get_tv_number_chk(&argvars[3], &error);
+	    id = (int)get_tv_number_chk(&argvars[3], &error);
 	    if (argvars[4].v_type != VAR_UNKNOWN)
 	    {
 		if (argvars[4].v_type != VAR_DICT)
@@ -16074,7 +16097,7 @@
     if (rettv_list_alloc(rettv) == OK)
     {
 #ifdef FEAT_SEARCH_EXTRA
-	int	    id = get_tv_number(&argvars[0]);
+	int	    id = (int)get_tv_number(&argvars[0]);
 	matchitem_T *m;
 
 	if (id >= 1 && id <= 3)
@@ -16148,8 +16171,8 @@
     static void
 max_min(typval_T *argvars, typval_T *rettv, int domax)
 {
-    long	n = 0;
-    long	i;
+    varnumber_T	n = 0;
+    varnumber_T	i;
     int		error = FALSE;
 
     if (argvars[0].v_type == VAR_LIST)
@@ -16285,7 +16308,7 @@
 	if (argvars[1].v_type != VAR_UNKNOWN)
 	{
 	    if (argvars[2].v_type != VAR_UNKNOWN)
-		prot = get_tv_number_chk(&argvars[2], NULL);
+		prot = (int)get_tv_number_chk(&argvars[2], NULL);
 	    if (prot != -1 && STRCMP(get_tv_string(&argvars[1]), "p") == 0)
 		mkdir_recurse(dir, prot);
 	}
@@ -16428,7 +16451,7 @@
 	int	utf8 = 0;
 
 	if (argvars[1].v_type != VAR_UNKNOWN)
-	    utf8 = get_tv_number_chk(&argvars[1], NULL);
+	    utf8 = (int)get_tv_number_chk(&argvars[1], NULL);
 	if (utf8)
 	    buf[(*utf_char2bytes)((int)get_tv_number(&argvars[0]), buf)] = NUL;
 	else
@@ -16610,10 +16633,10 @@
     static void
 f_range(typval_T *argvars, typval_T *rettv)
 {
-    long	start;
-    long	end;
-    long	stride = 1;
-    long	i;
+    varnumber_T	start;
+    varnumber_T	end;
+    varnumber_T	stride = 1;
+    varnumber_T	i;
     int		error = FALSE;
 
     start = get_tv_number_chk(&argvars[0], &error);
@@ -16671,7 +16694,7 @@
 	if (STRCMP(get_tv_string(&argvars[1]), "b") == 0)
 	    binary = TRUE;
 	if (argvars[2].v_type != VAR_UNKNOWN)
-	    maxline = get_tv_number(&argvars[2]);
+	    maxline = (long)get_tv_number(&argvars[2]);
     }
 
     if (rettv_list_alloc(rettv) == FAIL)
@@ -17244,7 +17267,7 @@
     {
 	int	    error = FALSE;
 
-	idx = get_tv_number_chk(&argvars[1], &error);
+	idx = (long)get_tv_number_chk(&argvars[1], &error);
 	if (error)
 	    ;		/* type error: do nothing, errmsg already given */
 	else if ((item = list_find(l, idx)) == NULL)
@@ -17261,7 +17284,7 @@
 	    else
 	    {
 		/* Remove range of items, return list with values. */
-		end = get_tv_number_chk(&argvars[2], &error);
+		end = (long)get_tv_number_chk(&argvars[2], &error);
 		if (error)
 		    ;		/* type error: do nothing */
 		else if ((item2 = list_find(l, end)) == NULL)
@@ -17325,7 +17348,7 @@
     char_u	*r;
     int		i;
 
-    n = get_tv_number(&argvars[1]);
+    n = (int)get_tv_number(&argvars[1]);
     if (argvars[0].v_type == VAR_LIST)
     {
 	if (rettv_list_alloc(rettv) == OK && argvars[0].vval.v_list != NULL)
@@ -17696,13 +17719,13 @@
     /* Optional arguments: line number to stop searching and timeout. */
     if (argvars[1].v_type != VAR_UNKNOWN && argvars[2].v_type != VAR_UNKNOWN)
     {
-	lnum_stop = get_tv_number_chk(&argvars[2], NULL);
+	lnum_stop = (long)get_tv_number_chk(&argvars[2], NULL);
 	if (lnum_stop < 0)
 	    goto theend;
 #ifdef FEAT_RELTIME
 	if (argvars[3].v_type != VAR_UNKNOWN)
 	{
-	    time_limit = get_tv_number_chk(&argvars[3], NULL);
+	    time_limit = (long)get_tv_number_chk(&argvars[3], NULL);
 	    if (time_limit < 0)
 		goto theend;
 	}
@@ -17798,8 +17821,8 @@
     int		col;
     int		c;
 
-    row = get_tv_number_chk(&argvars[0], NULL) - 1;
-    col = get_tv_number_chk(&argvars[1], NULL) - 1;
+    row = (int)get_tv_number_chk(&argvars[0], NULL) - 1;
+    col = (int)get_tv_number_chk(&argvars[1], NULL) - 1;
     if (row < 0 || row >= screen_Rows
 	    || col < 0 || col >= screen_Columns)
 	c = -1;
@@ -17819,8 +17842,8 @@
     int		off;
     int		c;
 
-    row = get_tv_number_chk(&argvars[0], NULL) - 1;
-    col = get_tv_number_chk(&argvars[1], NULL) - 1;
+    row = (int)get_tv_number_chk(&argvars[0], NULL) - 1;
+    col = (int)get_tv_number_chk(&argvars[1], NULL) - 1;
     if (row < 0 || row >= screen_Rows
 	    || col < 0 || col >= screen_Columns)
 	c = -1;
@@ -17884,9 +17907,9 @@
     name = get_tv_string_chk(&argvars[0]);
     if (argvars[1].v_type != VAR_UNKNOWN)
     {
-	locally = get_tv_number_chk(&argvars[1], &error) == 0;
+	locally = (int)get_tv_number_chk(&argvars[1], &error) == 0;
 	if (!error && argvars[2].v_type != VAR_UNKNOWN)
-	    thisblock = get_tv_number_chk(&argvars[2], &error) != 0;
+	    thisblock = (int)get_tv_number_chk(&argvars[2], &error) != 0;
     }
     if (!error && name != NULL)
 	rettv->vval.v_number = find_decl(name, (int)STRLEN(name),
@@ -17946,13 +17969,13 @@
 	skip = get_tv_string_buf_chk(&argvars[4], nbuf3);
 	if (argvars[5].v_type != VAR_UNKNOWN)
 	{
-	    lnum_stop = get_tv_number_chk(&argvars[5], NULL);
+	    lnum_stop = (long)get_tv_number_chk(&argvars[5], NULL);
 	    if (lnum_stop < 0)
 		goto theend;
 #ifdef FEAT_RELTIME
 	    if (argvars[6].v_type != VAR_UNKNOWN)
 	    {
-		time_limit = get_tv_number_chk(&argvars[6], NULL);
+		time_limit = (long)get_tv_number_chk(&argvars[6], NULL);
 		if (time_limit < 0)
 		    goto theend;
 	    }
@@ -18267,7 +18290,7 @@
 	    int		error = FALSE;
 
 	    ++varname;
-	    numval = get_tv_number_chk(varp, &error);
+	    numval = (long)get_tv_number_chk(varp, &error);
 	    strval = get_tv_string_buf_chk(varp, nbuf);
 	    if (!error && strval != NULL)
 		set_option_value(varname, numval, strval, OPT_LOCAL);
@@ -18323,7 +18346,7 @@
 
 	di = dict_find(d, (char_u *)"forward", -1);
 	if (di != NULL)
-	    set_csearch_direction(get_tv_number(&di->di_tv)
+	    set_csearch_direction((int)get_tv_number(&di->di_tv)
 							? FORWARD : BACKWARD);
 
 	di = dict_find(d, (char_u *)"until", -1);
@@ -18916,7 +18939,7 @@
 		int		error = FALSE;
 
 		++varname;
-		numval = get_tv_number_chk(varp, &error);
+		numval = (long)get_tv_number_chk(varp, &error);
 		strval = get_tv_string_buf_chk(varp, nbuf);
 		if (!error && strval != NULL)
 		    set_option_value(varname, numval, strval, OPT_LOCAL);
@@ -19083,8 +19106,8 @@
 
     if (sortinfo->item_compare_numbers)
     {
-	long	v1 = get_tv_number(tv1);
-	long	v2 = get_tv_number(tv2);
+	varnumber_T	v1 = get_tv_number(tv1);
+	varnumber_T	v2 = get_tv_number(tv2);
 
 	return v1 == v2 ? 0 : v1 > v2 ? 1 : -1;
     }
@@ -19190,7 +19213,7 @@
     if (res == FAIL)
 	res = ITEM_COMPARE_FAIL;
     else
-	res = get_tv_number_chk(&rettv, &sortinfo->item_compare_func_err);
+	res = (int)get_tv_number_chk(&rettv, &sortinfo->item_compare_func_err);
     if (sortinfo->item_compare_func_err)
 	res = ITEM_COMPARE_FAIL;  /* return value has wrong type */
     clear_tv(&rettv);
@@ -19259,7 +19282,7 @@
 	    {
 		int	    error = FALSE;
 
-		i = get_tv_number_chk(&argvars[1], &error);
+		i = (long)get_tv_number_chk(&argvars[1], &error);
 		if (error)
 		    goto theend;	/* type error; errmsg already given */
 		if (i == 1)
@@ -19516,12 +19539,12 @@
 	str = get_tv_string(&argvars[0]);
 	if (argvars[1].v_type != VAR_UNKNOWN)
 	{
-	    maxcount = get_tv_number_chk(&argvars[1], &typeerr);
+	    maxcount = (int)get_tv_number_chk(&argvars[1], &typeerr);
 	    if (maxcount <= 0)
 		return;
 	    if (argvars[2].v_type != VAR_UNKNOWN)
 	    {
-		need_capital = get_tv_number_chk(&argvars[2], &typeerr);
+		need_capital = (int)get_tv_number_chk(&argvars[2], &typeerr);
 		if (typeerr)
 		    return;
 	    }
@@ -19576,7 +19599,7 @@
 	if (pat == NULL)
 	    typeerr = TRUE;
 	if (argvars[2].v_type != VAR_UNKNOWN)
-	    keepempty = get_tv_number_chk(&argvars[2], &typeerr);
+	    keepempty = (int)get_tv_number_chk(&argvars[2], &typeerr);
     }
     if (pat == NULL || *pat == NUL)
 	pat = (char_u *)"[\\x01- ]\\+";
@@ -19669,12 +19692,12 @@
 {
     int		base = 10;
     char_u	*p;
-    long	n;
+    varnumber_T	n;
     int		what;
 
     if (argvars[1].v_type != VAR_UNKNOWN)
     {
-	base = get_tv_number(&argvars[1]);
+	base = (int)get_tv_number(&argvars[1]);
 	if (base != 2 && base != 8 && base != 10 && base != 16)
 	{
 	    EMSG(_(e_invarg));
@@ -19772,7 +19795,7 @@
     if (str == NULL)
 	return;
     len = (int)STRLEN(str);
-    charidx = get_tv_number_chk(&argvars[1], &error);
+    charidx = (int)get_tv_number_chk(&argvars[1], &error);
     if (error)
 	return;
 #ifdef FEAT_MBYTE
@@ -19819,7 +19842,7 @@
     {
 	int	    error = FALSE;
 
-	start_idx = get_tv_number_chk(&argvars[2], &error);
+	start_idx = (int)get_tv_number_chk(&argvars[2], &error);
 	if (error || start_idx >= (int)STRLEN(haystack))
 	    return;
 	if (start_idx >= 0)
@@ -19872,7 +19895,7 @@
 #endif
 
     if (argvars[1].v_type != VAR_UNKNOWN)
-	skipcc = get_tv_number_chk(&argvars[1], NULL);
+	skipcc = (int)get_tv_number_chk(&argvars[1], NULL);
     if (skipcc < 0 || skipcc > 1)
 	EMSG(_(e_invarg));
     else
@@ -19901,7 +19924,7 @@
     int		col = 0;
 
     if (argvars[1].v_type != VAR_UNKNOWN)
-	col = get_tv_number(&argvars[1]);
+	col = (int)get_tv_number(&argvars[1]);
 
     rettv->vval.v_number = (varnumber_T)(linetabsize_col(col, s) - col);
 }
@@ -19941,7 +19964,7 @@
     p = get_tv_string(&argvars[0]);
     slen = (int)STRLEN(p);
 
-    nchar = get_tv_number_chk(&argvars[1], &error);
+    nchar = (int)get_tv_number_chk(&argvars[1], &error);
     if (!error)
     {
 	if (nchar > 0)
@@ -19954,7 +19977,7 @@
 	    nbyte = nchar;
 	if (argvars[2].v_type != VAR_UNKNOWN)
 	{
-	    charlen = get_tv_number(&argvars[2]);
+	    charlen = (int)get_tv_number(&argvars[2]);
 	    while (charlen > 0 && nbyte + len < slen)
 	    {
 		int off = nbyte + len;
@@ -20008,11 +20031,11 @@
     p = get_tv_string(&argvars[0]);
     slen = (int)STRLEN(p);
 
-    n = get_tv_number_chk(&argvars[1], &error);
+    n = (int)get_tv_number_chk(&argvars[1], &error);
     if (error)
 	len = 0;
     else if (argvars[2].v_type != VAR_UNKNOWN)
-	len = get_tv_number(&argvars[2]);
+	len = (int)get_tv_number(&argvars[2]);
     else
 	len = slen - n;	    /* default len: all bytes that are available. */
 
@@ -20060,7 +20083,7 @@
     if (argvars[2].v_type != VAR_UNKNOWN)
     {
 	/* Third argument: upper limit for index */
-	end_idx = get_tv_number_chk(&argvars[2], NULL);
+	end_idx = (int)get_tv_number_chk(&argvars[2], NULL);
 	if (end_idx < 0)
 	    return;	/* can never find a match */
     }
@@ -20114,7 +20137,7 @@
 	return;
     error = FALSE;
     if (argvars[1].v_type != VAR_UNKNOWN)
-	retList = get_tv_number_chk(&argvars[1], &error);
+	retList = (int)get_tv_number_chk(&argvars[1], &error);
     if (error)
 	return;
 
@@ -20160,14 +20183,14 @@
 {
     int		id = 0;
 #ifdef FEAT_SYN_HL
-    long	lnum;
-    long	col;
+    linenr_T	lnum;
+    colnr_T	col;
     int		trans;
     int		transerr = FALSE;
 
     lnum = get_tv_lnum(argvars);		/* -1 on type error */
-    col = get_tv_number(&argvars[1]) - 1;	/* -1 on type error */
-    trans = get_tv_number_chk(&argvars[2], &transerr);
+    col = (linenr_T)get_tv_number(&argvars[1]) - 1;	/* -1 on type error */
+    trans = (int)get_tv_number_chk(&argvars[2], &transerr);
 
     if (!transerr && lnum >= 1 && lnum <= curbuf->b_ml.ml_line_count
 	    && col >= 0 && col < (long)STRLEN(ml_get(lnum)))
@@ -20191,7 +20214,7 @@
     char_u	modebuf[NUMBUFLEN];
     int		modec;
 
-    id = get_tv_number(&argvars[0]);
+    id = (int)get_tv_number(&argvars[0]);
     what = get_tv_string(&argvars[1]);
     if (argvars[2].v_type != VAR_UNKNOWN)
     {
@@ -20275,7 +20298,7 @@
     int		id;
 
 #ifdef FEAT_SYN_HL
-    id = get_tv_number(&argvars[0]);
+    id = (int)get_tv_number(&argvars[0]);
 
     if (id > 0)
 	id = syn_get_final_id(id);
@@ -20293,8 +20316,8 @@
 f_synconcealed(typval_T *argvars UNUSED, typval_T *rettv)
 {
 #if defined(FEAT_SYN_HL) && defined(FEAT_CONCEAL)
-    long	lnum;
-    long	col;
+    linenr_T	lnum;
+    colnr_T	col;
     int		syntax_flags = 0;
     int		cchar;
     int		matchid = 0;
@@ -20306,7 +20329,7 @@
 
 #if defined(FEAT_SYN_HL) && defined(FEAT_CONCEAL)
     lnum = get_tv_lnum(argvars);		/* -1 on type error */
-    col = get_tv_number(&argvars[1]) - 1;	/* -1 on type error */
+    col = (colnr_T)get_tv_number(&argvars[1]) - 1;	/* -1 on type error */
 
     vim_memset(str, NUL, sizeof(str));
 
@@ -20353,8 +20376,8 @@
 f_synstack(typval_T *argvars UNUSED, typval_T *rettv)
 {
 #ifdef FEAT_SYN_HL
-    long	lnum;
-    long	col;
+    linenr_T	lnum;
+    colnr_T	col;
     int		i;
     int		id;
 #endif
@@ -20364,7 +20387,7 @@
 
 #ifdef FEAT_SYN_HL
     lnum = get_tv_lnum(argvars);		/* -1 on type error */
-    col = get_tv_number(&argvars[1]) - 1;	/* -1 on type error */
+    col = (colnr_T)get_tv_number(&argvars[1]) - 1;	/* -1 on type error */
 
     if (lnum >= 1 && lnum <= curbuf->b_ml.ml_line_count
 	    && col >= 0 && col <= (long)STRLEN(ml_get(lnum))
@@ -20835,7 +20858,7 @@
     static void
 f_test_disable_char_avail(typval_T *argvars, typval_T *rettv UNUSED)
 {
-    disable_char_avail_for_testing = get_tv_number(&argvars[0]);
+    disable_char_avail_for_testing = (int)get_tv_number(&argvars[0]);
 }
 
 /*
@@ -20933,7 +20956,7 @@
     static void
 f_timer_start(typval_T *argvars, typval_T *rettv)
 {
-    long    msec = get_tv_number(&argvars[0]);
+    long    msec = (long)get_tv_number(&argvars[0]);
     timer_T *timer;
     int	    repeat = 0;
     char_u  *callback;
@@ -20980,7 +21003,7 @@
          EMSG(_(e_number_exp));
          return;
     }
-    timer = find_timer(get_tv_number(&argvars[0]));
+    timer = find_timer((int)get_tv_number(&argvars[0]));
     if (timer != NULL)
 	stop_timer(timer);
 }
@@ -21436,29 +21459,29 @@
     else
     {
 	if (dict_find(dict, (char_u *)"lnum", -1) != NULL)
-	    curwin->w_cursor.lnum = get_dict_number(dict, (char_u *)"lnum");
+	    curwin->w_cursor.lnum = (linenr_T)get_dict_number(dict, (char_u *)"lnum");
 	if (dict_find(dict, (char_u *)"col", -1) != NULL)
-	    curwin->w_cursor.col = get_dict_number(dict, (char_u *)"col");
+	    curwin->w_cursor.col = (colnr_T)get_dict_number(dict, (char_u *)"col");
 #ifdef FEAT_VIRTUALEDIT
 	if (dict_find(dict, (char_u *)"coladd", -1) != NULL)
-	    curwin->w_cursor.coladd = get_dict_number(dict, (char_u *)"coladd");
+	    curwin->w_cursor.coladd = (colnr_T)get_dict_number(dict, (char_u *)"coladd");
 #endif
 	if (dict_find(dict, (char_u *)"curswant", -1) != NULL)
 	{
-	    curwin->w_curswant = get_dict_number(dict, (char_u *)"curswant");
+	    curwin->w_curswant = (colnr_T)get_dict_number(dict, (char_u *)"curswant");
 	    curwin->w_set_curswant = FALSE;
 	}
 
 	if (dict_find(dict, (char_u *)"topline", -1) != NULL)
-	    set_topline(curwin, get_dict_number(dict, (char_u *)"topline"));
+	    set_topline(curwin, (linenr_T)get_dict_number(dict, (char_u *)"topline"));
 #ifdef FEAT_DIFF
 	if (dict_find(dict, (char_u *)"topfill", -1) != NULL)
-	    curwin->w_topfill = get_dict_number(dict, (char_u *)"topfill");
+	    curwin->w_topfill = (int)get_dict_number(dict, (char_u *)"topfill");
 #endif
 	if (dict_find(dict, (char_u *)"leftcol", -1) != NULL)
-	    curwin->w_leftcol = get_dict_number(dict, (char_u *)"leftcol");
+	    curwin->w_leftcol = (colnr_T)get_dict_number(dict, (char_u *)"leftcol");
 	if (dict_find(dict, (char_u *)"skipcol", -1) != NULL)
-	    curwin->w_skipcol = get_dict_number(dict, (char_u *)"skipcol");
+	    curwin->w_skipcol = (colnr_T)get_dict_number(dict, (char_u *)"skipcol");
 
 	check_cursor();
 	win_new_height(curwin, curwin->w_height);
@@ -22120,7 +22143,7 @@
  * Set number v: variable to "val".
  */
     void
-set_vim_var_nr(int idx, long val)
+set_vim_var_nr(int idx, varnumber_T val)
 {
     vimvars[idx].vv_nr = val;
 }
@@ -22128,7 +22151,7 @@
 /*
  * Get number v: variable value.
  */
-    long
+    varnumber_T
 get_vim_var_nr(int idx)
 {
     return vimvars[idx].vv_nr;
@@ -22742,7 +22765,7 @@
  * caller of incompatible types: it sets *denote to TRUE if "denote"
  * is not NULL or returns -1 otherwise.
  */
-    long
+    varnumber_T
 get_tv_number(typval_T *varp)
 {
     int		error = FALSE;
@@ -22750,15 +22773,15 @@
     return get_tv_number_chk(varp, &error);	/* return 0L on error */
 }
 
-    long
+    varnumber_T
 get_tv_number_chk(typval_T *varp, int *denote)
 {
-    long	n = 0L;
+    varnumber_T	n = 0L;
 
     switch (varp->v_type)
     {
 	case VAR_NUMBER:
-	    return (long)(varp->vval.v_number);
+	    return varp->vval.v_number;
 	case VAR_FLOAT:
 #ifdef FEAT_FLOAT
 	    EMSG(_("E805: Using a Float as a Number"));
@@ -22858,12 +22881,12 @@
     typval_T	rettv;
     linenr_T	lnum;
 
-    lnum = get_tv_number_chk(&argvars[0], NULL);
+    lnum = (linenr_T)get_tv_number_chk(&argvars[0], NULL);
     if (lnum == 0)  /* no valid number, try using line() */
     {
 	rettv.v_type = VAR_NUMBER;
 	f_line(argvars, &rettv);
-	lnum = rettv.vval.v_number;
+	lnum = (linenr_T)rettv.vval.v_number;
 	clear_tv(&rettv);
     }
     return lnum;
@@ -22882,7 +22905,7 @@
 	    && argvars[0].vval.v_string[0] == '$'
 	    && buf != NULL)
 	return buf->b_ml.ml_line_count;
-    return get_tv_number_chk(&argvars[0], NULL);
+    return (linenr_T)get_tv_number_chk(&argvars[0], NULL);
 }
 
 /*
@@ -22928,7 +22951,8 @@
     switch (varp->v_type)
     {
 	case VAR_NUMBER:
-	    sprintf((char *)buf, "%ld", (long)varp->vval.v_number);
+	    vim_snprintf((char *)buf, NUMBUFLEN, "%lld",
+					    (varnumber_T)varp->vval.v_number);
 	    return buf;
 	case VAR_FUNC:
 	case VAR_PARTIAL:
diff --git a/src/ex_cmds.c b/src/ex_cmds.c
index 088e1ac..e7b3b28 100644
--- a/src/ex_cmds.c
+++ b/src/ex_cmds.c
@@ -289,10 +289,10 @@
     union {
 	struct
 	{
-	    long	start_col_nr;		/* starting column number */
-	    long	end_col_nr;		/* ending column number */
+	    varnumber_T	start_col_nr;		/* starting column number */
+	    varnumber_T	end_col_nr;		/* ending column number */
 	} line;
-	long	value;		/* value if sorting by integer */
+	varnumber_T	value;		/* value if sorting by integer */
 #ifdef FEAT_FLOAT
 	float_T value_flt;	/* value if sorting by float */
 #endif
diff --git a/src/ex_getln.c b/src/ex_getln.c
index fc0d995..36902e5 100644
--- a/src/ex_getln.c
+++ b/src/ex_getln.c
@@ -6005,7 +6005,7 @@
 {
     int		len;
     int		first = FALSE;
-    long	num;
+    varnumber_T	num;
 
     *str = skipwhite(*str);
     if (**str == '-' || vim_isdigit(**str))  /* parse "from" part of range */
diff --git a/src/feature.h b/src/feature.h
index 54f665f..2a090ab 100644
--- a/src/feature.h
+++ b/src/feature.h
@@ -362,12 +362,16 @@
  * +eval		Built-in script language and expression evaluation,
  *			":let", ":if", etc.
  * +float		Floating point variables.
+ * +num64		64-bit Number.
  */
 #ifdef FEAT_NORMAL
 # define FEAT_EVAL
 # if defined(HAVE_FLOAT_FUNCS) || defined(WIN3264) || defined(MACOS)
 #  define FEAT_FLOAT
 # endif
+# if defined(HAVE_STDINT_H) || defined(WIN3264) || (VIM_SIZEOF_LONG >= 8)
+#  define FEAT_NUM64
+# endif
 #endif
 
 /*
diff --git a/src/fileio.c b/src/fileio.c
index 1304190..621281e 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -9481,7 +9481,7 @@
 
 #ifdef FEAT_EVAL
 	/* set v:cmdarg (only when there is a matching pattern) */
-	save_cmdbang = get_vim_var_nr(VV_CMDBANG);
+	save_cmdbang = (long)get_vim_var_nr(VV_CMDBANG);
 	if (eap != NULL)
 	{
 	    save_cmdarg = set_cmdarg(eap, NULL);
diff --git a/src/fold.c b/src/fold.c
index e4c7f41..35ceceb 100644
--- a/src/fold.c
+++ b/src/fold.c
@@ -3032,7 +3032,7 @@
     /* KeyTyped may be reset to 0 when calling a function which invokes
      * do_cmdline().  To make 'foldopen' work correctly restore KeyTyped. */
     save_keytyped = KeyTyped;
-    n = eval_foldexpr(flp->wp->w_p_fde, &c);
+    n = (int)eval_foldexpr(flp->wp->w_p_fde, &c);
     KeyTyped = save_keytyped;
 
     switch (c)
diff --git a/src/json.c b/src/json.c
index aa168ec..89c2fd2 100644
--- a/src/json.c
+++ b/src/json.c
@@ -201,8 +201,8 @@
 	    break;
 
 	case VAR_NUMBER:
-	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%ld",
-						    (long)val->vval.v_number);
+	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%lld",
+						    val->vval.v_number);
 	    ga_concat(gap, numbuf);
 	    break;
 
@@ -538,7 +538,7 @@
     int		len;
     char_u	*p;
     int		c;
-    long	nr;
+    varnumber_T	nr;
 
     if (res != NULL)
 	ga_init2(&ga, 1, 200);
@@ -600,7 +600,7 @@
 			    && (int)(reader->js_end - p) >= 6
 			    && *p == '\\' && *(p+1) == 'u')
 		    {
-			long	nr2 = 0;
+			varnumber_T	nr2 = 0;
 
 			/* decode surrogate pair: \ud812\u3456 */
 			len = 0;
@@ -620,7 +620,7 @@
 			buf[utf_char2bytes((int)nr, buf)] = NUL;
 			ga_concat(&ga, buf);
 #else
-			ga_append(&ga, nr);
+			ga_append(&ga, (int)nr);
 #endif
 		    }
 		    break;
@@ -766,7 +766,7 @@
 		else
 #endif
 		{
-		    long nr;
+		    varnumber_T nr;
 
 		    vim_str2nr(reader->js_buf + reader->js_used,
 			    NULL, &len, 0, /* what */
diff --git a/src/message.c b/src/message.c
index 5bd6027..b86c886 100644
--- a/src/message.c
+++ b/src/message.c
@@ -3846,7 +3846,7 @@
 #if defined(FEAT_EVAL)
 static char *e_printf = N_("E766: Insufficient arguments for printf()");
 
-static long tv_nr(typval_T *tvs, int *idxp);
+static varnumber_T tv_nr(typval_T *tvs, int *idxp);
 static char *tv_str(typval_T *tvs, int *idxp);
 # ifdef FEAT_FLOAT
 static double tv_float(typval_T *tvs, int *idxp);
@@ -3855,11 +3855,11 @@
 /*
  * Get number argument from "idxp" entry in "tvs".  First entry is 1.
  */
-    static long
+    static varnumber_T
 tv_nr(typval_T *tvs, int *idxp)
 {
     int		idx = *idxp - 1;
-    long	n = 0;
+    varnumber_T	n = 0;
     int		err = FALSE;
 
     if (tvs[idx].v_type == VAR_UNKNOWN)
@@ -3912,7 +3912,7 @@
 	if (tvs[idx].v_type == VAR_FLOAT)
 	    f = tvs[idx].vval.v_float;
 	else if (tvs[idx].v_type == VAR_NUMBER)
-	    f = tvs[idx].vval.v_number;
+	    f = (double)tvs[idx].vval.v_number;
 	else
 	    EMSG(_("E807: Expected Float argument for printf()"));
     }
@@ -4170,7 +4170,11 @@
 		if (length_modifier == 'l' && *p == 'l')
 		{
 		    /* double l = long long */
+# ifdef FEAT_NUM64
+		    length_modifier = 'L';
+# else
 		    length_modifier = 'l';	/* treat it as a single 'l' */
+# endif
 		    p++;
 		}
 	    }
@@ -4299,6 +4303,12 @@
 		    long int long_arg = 0;
 		    unsigned long int ulong_arg = 0;
 
+# ifdef FEAT_NUM64
+		    /* only defined for length modifier ll */
+		    varnumber_T llong_arg = 0;
+		    uvarnumber_T ullong_arg = 0;
+# endif
+
 		    /* pointer argument value -only defined for p
 		     * conversion */
 		    void *ptr_arg = NULL;
@@ -4343,6 +4353,19 @@
 			    else if (long_arg < 0)
 				arg_sign = -1;
 			    break;
+# ifdef FEAT_NUM64
+			case 'L':
+			    llong_arg =
+#  if defined(FEAT_EVAL)
+					tvs != NULL ? tv_nr(tvs, &arg_idx) :
+#  endif
+					    va_arg(ap, varnumber_T);
+			    if (llong_arg > 0)
+				arg_sign =  1;
+			    else if (llong_arg < 0)
+				arg_sign = -1;
+			    break;
+# endif
 			}
 		    }
 		    else
@@ -4371,6 +4394,18 @@
 				if (ulong_arg != 0)
 				    arg_sign = 1;
 				break;
+# ifdef FEAT_NUM64
+			    case 'L':
+				ullong_arg =
+#  if defined(FEAT_EVAL)
+					    tvs != NULL ? (uvarnumber_T)
+							tv_nr(tvs, &arg_idx) :
+#  endif
+						va_arg(ap, uvarnumber_T);
+				if (ullong_arg != 0)
+				    arg_sign = 1;
+				break;
+# endif
 			}
 		    }
 
@@ -4415,17 +4450,27 @@
 		    }
 		    else
 		    {
-			char	f[5];
+			char	f[6];
 			int	f_l = 0;
 
 			/* construct a simple format string for sprintf */
 			f[f_l++] = '%';
 			if (!length_modifier)
 			    ;
-			else if (length_modifier == '2')
+			else if (length_modifier == 'L')
 			{
+# ifdef FEAT_NUM64
+#  ifdef WIN3264
+			    f[f_l++] = 'I';
+			    f[f_l++] = '6';
+			    f[f_l++] = '4';
+#  else
 			    f[f_l++] = 'l';
 			    f[f_l++] = 'l';
+#  endif
+# else
+			    f[f_l++] = 'l';
+# endif
 			}
 			else
 			    f[f_l++] = length_modifier;
@@ -4446,6 +4491,11 @@
 			    case 'l': str_arg_l += sprintf(
 						tmp + str_arg_l, f, long_arg);
 				      break;
+# ifdef FEAT_NUM64
+			    case 'L': str_arg_l += sprintf(
+					       tmp + str_arg_l, f, llong_arg);
+				      break;
+# endif
 			    }
 			}
 			else
@@ -4460,6 +4510,11 @@
 			    case 'l': str_arg_l += sprintf(
 					       tmp + str_arg_l, f, ulong_arg);
 				      break;
+# ifdef FEAT_NUM64
+			    case 'L': str_arg_l += sprintf(
+					      tmp + str_arg_l, f, ullong_arg);
+				      break;
+# endif
 			    }
 			}
 
diff --git a/src/misc1.c b/src/misc1.c
index 82522b5..b5394a4 100644
--- a/src/misc1.c
+++ b/src/misc1.c
@@ -9169,7 +9169,7 @@
     if (use_sandbox)
 	++sandbox;
     ++textlock;
-    indent = eval_to_number(curbuf->b_p_inde);
+    indent = (int)eval_to_number(curbuf->b_p_inde);
     if (use_sandbox)
 	--sandbox;
     --textlock;
diff --git a/src/misc2.c b/src/misc2.c
index 2dd89f9..4ed715b 100644
--- a/src/misc2.c
+++ b/src/misc2.c
@@ -2719,7 +2719,7 @@
     int		modifiers;
     int		bit;
     int		key;
-    unsigned long n;
+    uvarnumber_T	n;
     int		l;
 
     src = *srcp;
diff --git a/src/ops.c b/src/ops.c
index 8d62ed0..1767eb5 100644
--- a/src/ops.c
+++ b/src/ops.c
@@ -1179,9 +1179,9 @@
 static int execreg_lastc = NUL;
 
 /*
- * execute a yank register: copy it into the stuff buffer
+ * Execute a yank register: copy it into the stuff buffer.
  *
- * return FAIL for failure, OK otherwise
+ * Return FAIL for failure, OK otherwise.
  */
     int
 do_execreg(
@@ -4755,7 +4755,7 @@
      */
     if (use_sandbox)
 	++sandbox;
-    r = eval_to_number(curbuf->b_p_fex);
+    r = (int)eval_to_number(curbuf->b_p_fex);
     if (use_sandbox)
 	--sandbox;
 
@@ -5449,8 +5449,8 @@
     char_u	buf2[NUMBUFLEN];
     int		pre;		/* 'X'/'x': hex; '0': octal; 'B'/'b': bin */
     static int	hexupper = FALSE;	/* 0xABC */
-    unsigned long n;
-    long_u	oldn;
+    uvarnumber_T	n;
+    uvarnumber_T	oldn;
     char_u	*ptr;
     int		c;
     int		todel;
@@ -5708,9 +5708,9 @@
 
 	oldn = n;
 	if (subtract)
-	    n -= (unsigned long)Prenum1;
+	    n -= (uvarnumber_T)Prenum1;
 	else
-	    n += (unsigned long)Prenum1;
+	    n += (uvarnumber_T)Prenum1;
 	/* handle wraparound for decimal numbers */
 	if (!pre)
 	{
@@ -5718,7 +5718,7 @@
 	    {
 		if (n > oldn)
 		{
-		    n = 1 + (n ^ (unsigned long)-1);
+		    n = 1 + (n ^ (uvarnumber_T)-1);
 		    negative ^= TRUE;
 		}
 	    }
@@ -5727,7 +5727,7 @@
 		/* add */
 		if (n < oldn)
 		{
-		    n = (n ^ (unsigned long)-1);
+		    n = (n ^ (uvarnumber_T)-1);
 		    negative ^= TRUE;
 		}
 	    }
@@ -5803,7 +5803,7 @@
 	{
 	    int i;
 	    int bit = 0;
-	    int bits = sizeof(unsigned long) * 8;
+	    int bits = sizeof(uvarnumber_T) * 8;
 
 	    /* leading zeros */
 	    for (bit = bits; bit > 0; bit--)
@@ -5815,13 +5815,13 @@
 	    buf2[i] = '\0';
 	}
 	else if (pre == 0)
-	    sprintf((char *)buf2, "%lu", n);
+	    vim_snprintf((char *)buf2, NUMBUFLEN, "%llu", n);
 	else if (pre == '0')
-	    sprintf((char *)buf2, "%lo", n);
+	    vim_snprintf((char *)buf2, NUMBUFLEN, "%llo", n);
 	else if (pre && hexupper)
-	    sprintf((char *)buf2, "%lX", n);
+	    vim_snprintf((char *)buf2, NUMBUFLEN, "%llX", n);
 	else
-	    sprintf((char *)buf2, "%lx", n);
+	    vim_snprintf((char *)buf2, NUMBUFLEN, "%llx", n);
 	length -= (int)STRLEN(buf2);
 
 	/*
@@ -7086,7 +7086,7 @@
     vim_memset(oap, 0, sizeof(oparg_T));
 }
 
-static long	line_count_info(char_u *line, long *wc, long *cc, long limit, int eol_size);
+static varnumber_T line_count_info(char_u *line, varnumber_T *wc, varnumber_T *cc, varnumber_T limit, int eol_size);
 
 /*
  *  Count the number of bytes, characters and "words" in a line.
@@ -7102,17 +7102,17 @@
  *  case, eol_size will be added to the character count to account for
  *  the size of the EOL character.
  */
-    static long
+    static varnumber_T
 line_count_info(
     char_u	*line,
-    long	*wc,
-    long	*cc,
-    long	limit,
+    varnumber_T	*wc,
+    varnumber_T	*cc,
+    varnumber_T	limit,
     int		eol_size)
 {
-    long	i;
-    long	words = 0;
-    long	chars = 0;
+    varnumber_T	i;
+    varnumber_T	words = 0;
+    varnumber_T	chars = 0;
     int		is_word = 0;
 
     for (i = 0; i < limit && line[i] != NUL; )
@@ -7162,17 +7162,17 @@
     char_u	buf1[50];
     char_u	buf2[40];
     linenr_T	lnum;
-    long	byte_count = 0;
+    varnumber_T	byte_count = 0;
 #ifdef FEAT_MBYTE
-    long	bom_count  = 0;
+    varnumber_T	bom_count  = 0;
 #endif
-    long	byte_count_cursor = 0;
-    long	char_count = 0;
-    long	char_count_cursor = 0;
-    long	word_count = 0;
-    long	word_count_cursor = 0;
+    varnumber_T	byte_count_cursor = 0;
+    varnumber_T	char_count = 0;
+    varnumber_T	char_count_cursor = 0;
+    varnumber_T	word_count = 0;
+    varnumber_T	word_count_cursor = 0;
     int		eol_size;
-    long	last_check = 100000L;
+    varnumber_T	last_check = 100000L;
     long	line_count_selected = 0;
     pos_T	min_pos, max_pos;
     oparg_T	oparg;
@@ -7308,12 +7308,14 @@
 		    byte_count_cursor = byte_count +
 			line_count_info(ml_get(lnum),
 				&word_count_cursor, &char_count_cursor,
-				  (long)(curwin->w_cursor.col + 1), eol_size);
+				(varnumber_T)(curwin->w_cursor.col + 1),
+				eol_size);
 		}
 	    }
 	    /* Add to the running totals */
 	    byte_count += line_count_info(ml_get(lnum), &word_count,
-					 &char_count, (long)MAXCOL, eol_size);
+					 &char_count, (varnumber_T)MAXCOL,
+					 eol_size);
 	}
 
 	/* Correction for when last line doesn't have an EOL. */
@@ -7337,14 +7339,14 @@
 		if (char_count_cursor == byte_count_cursor
 						    && char_count == byte_count)
 		    vim_snprintf((char *)IObuff, IOSIZE,
-			    _("Selected %s%ld of %ld Lines; %ld of %ld Words; %ld of %ld Bytes"),
+			    _("Selected %s%ld of %ld Lines; %lld of %lld Words; %lld of %lld Bytes"),
 			    buf1, line_count_selected,
 			    (long)curbuf->b_ml.ml_line_count,
 			    word_count_cursor, word_count,
 			    byte_count_cursor, byte_count);
 		else
 		    vim_snprintf((char *)IObuff, IOSIZE,
-			    _("Selected %s%ld of %ld Lines; %ld of %ld Words; %ld of %ld Chars; %ld of %ld Bytes"),
+			    _("Selected %s%ld of %ld Lines; %lld of %lld Words; %lld of %lld Chars; %lld of %lld Bytes"),
 			    buf1, line_count_selected,
 			    (long)curbuf->b_ml.ml_line_count,
 			    word_count_cursor, word_count,
@@ -7363,7 +7365,7 @@
 		if (char_count_cursor == byte_count_cursor
 			&& char_count == byte_count)
 		    vim_snprintf((char *)IObuff, IOSIZE,
-			_("Col %s of %s; Line %ld of %ld; Word %ld of %ld; Byte %ld of %ld"),
+			_("Col %s of %s; Line %ld of %ld; Word %lld of %lld; Byte %lld of %lld"),
 			(char *)buf1, (char *)buf2,
 			(long)curwin->w_cursor.lnum,
 			(long)curbuf->b_ml.ml_line_count,
@@ -7371,7 +7373,7 @@
 			byte_count_cursor, byte_count);
 		else
 		    vim_snprintf((char *)IObuff, IOSIZE,
-			_("Col %s of %s; Line %ld of %ld; Word %ld of %ld; Char %ld of %ld; Byte %ld of %ld"),
+			_("Col %s of %s; Line %ld of %ld; Word %lld of %lld; Char %lld of %lld; Byte %lld of %lld"),
 			(char *)buf1, (char *)buf2,
 			(long)curwin->w_cursor.lnum,
 			(long)curbuf->b_ml.ml_line_count,
@@ -7399,19 +7401,19 @@
 #if defined(FEAT_EVAL)
     if (dict != NULL)
     {
-	dict_add_nr_str(dict, "words", (long)word_count, NULL);
-	dict_add_nr_str(dict, "chars", (long)char_count, NULL);
-	dict_add_nr_str(dict, "bytes", (long)byte_count
+	dict_add_nr_str(dict, "words", word_count, NULL);
+	dict_add_nr_str(dict, "chars", char_count, NULL);
+	dict_add_nr_str(dict, "bytes", byte_count
 # ifdef FEAT_MBYTE
 		+ bom_count
 # endif
 		, NULL);
 	dict_add_nr_str(dict, VIsual_active ? "visual_bytes" : "cursor_bytes",
-		(long)byte_count_cursor, NULL);
+		byte_count_cursor, NULL);
 	dict_add_nr_str(dict, VIsual_active ? "visual_chars" : "cursor_chars",
-		(long)char_count_cursor, NULL);
+		char_count_cursor, NULL);
 	dict_add_nr_str(dict, VIsual_active ? "visual_words" : "cursor_words",
-		(long)word_count_cursor, NULL);
+		word_count_cursor, NULL);
     }
 #endif
 }
diff --git a/src/option.c b/src/option.c
index 80bd867..47bbe73 100644
--- a/src/option.c
+++ b/src/option.c
@@ -4179,7 +4179,7 @@
     int		afterchar;	    /* character just after option name */
     int		len;
     int		i;
-    long	value;
+    varnumber_T	value;
     int		key;
     long_u	flags;		    /* flags for current option */
     char_u	*varp = NULL;	    /* pointer to variable for current option */
@@ -9102,7 +9102,7 @@
 	if ((int *)varp == &curbuf->b_changed)
 	    *numval = curbufIsChanged();
 	else
-	    *numval = *(int *)varp;
+	    *numval = (long) *(varnumber_T *)varp;
     }
     return 1;
 }
diff --git a/src/proto/charset.pro b/src/proto/charset.pro
index 7b4961d..52b741a 100644
--- a/src/proto/charset.pro
+++ b/src/proto/charset.pro
@@ -52,7 +52,7 @@
 char_u *skiptowhite_esc(char_u *p);
 long getdigits(char_u **pp);
 int vim_isblankline(char_u *lbuf);
-void vim_str2nr(char_u *start, int *prep, int *len, int what, long *nptr, unsigned long *unptr, int maxlen);
+void vim_str2nr(char_u *start, int *prep, int *len, int what, varnumber_T *nptr, uvarnumber_T *unptr, int maxlen);
 int hex2nr(int c);
 int hexhex2nr(char_u *p);
 int rem_backslash(char_u *str);
diff --git a/src/proto/eval.pro b/src/proto/eval.pro
index 60fad80..4ff063e 100644
--- a/src/proto/eval.pro
+++ b/src/proto/eval.pro
@@ -19,12 +19,12 @@
 int skip_expr(char_u **pp);
 char_u *eval_to_string(char_u *arg, char_u **nextcmd, int convert);
 char_u *eval_to_string_safe(char_u *arg, char_u **nextcmd, int use_sandbox);
-int eval_to_number(char_u *expr);
+varnumber_T eval_to_number(char_u *expr);
 list_T *eval_spell_expr(char_u *badword, char_u *expr);
 int get_spellword(list_T *list, char_u **pp);
 typval_T *eval_expr(char_u *arg, char_u **nextcmd);
 int call_vim_function(char_u *func, int argc, char_u **argv, int safe, int str_arg_only, typval_T *rettv);
-long call_func_retnr(char_u *func, int argc, char_u **argv, int safe);
+varnumber_T call_func_retnr(char_u *func, int argc, char_u **argv, int safe);
 void *call_func_retstr(char_u *func, int argc, char_u **argv, int safe);
 void *call_func_retlist(char_u *func, int argc, char_u **argv, int safe);
 void *save_funccal(void);
@@ -76,11 +76,11 @@
 dictitem_T *dictitem_alloc(char_u *key);
 void dictitem_free(dictitem_T *item);
 int dict_add(dict_T *d, dictitem_T *item);
-int dict_add_nr_str(dict_T *d, char *key, long nr, char_u *str);
+int dict_add_nr_str(dict_T *d, char *key, varnumber_T nr, char_u *str);
 int dict_add_list(dict_T *d, char *key, list_T *list);
 dictitem_T *dict_find(dict_T *d, char_u *key, int len);
 char_u *get_dict_string(dict_T *d, char_u *key, int save);
-long get_dict_number(dict_T *d, char_u *key);
+varnumber_T get_dict_number(dict_T *d, char_u *key);
 int string2float(char_u *text, float_T *value);
 char_u *get_function_name(expand_T *xp, int idx);
 char_u *get_expr_name(expand_T *xp, int idx);
@@ -92,8 +92,8 @@
 float_T vim_round(float_T f);
 long do_searchpair(char_u *spat, char_u *mpat, char_u *epat, int dir, char_u *skip, int flags, pos_T *match_pos, linenr_T lnum_stop, long time_limit);
 char_u *get_callback(typval_T *arg, partial_T **pp);
-void set_vim_var_nr(int idx, long val);
-long get_vim_var_nr(int idx);
+void set_vim_var_nr(int idx, varnumber_T val);
+varnumber_T get_vim_var_nr(int idx);
 char_u *get_vim_var_str(int idx);
 list_T *get_vim_var_list(int idx);
 void set_vim_var_char(int c);
@@ -108,8 +108,8 @@
 typval_T *alloc_tv(void);
 void free_tv(typval_T *varp);
 void clear_tv(typval_T *varp);
-long get_tv_number(typval_T *varp);
-long get_tv_number_chk(typval_T *varp, int *denote);
+varnumber_T get_tv_number(typval_T *varp);
+varnumber_T get_tv_number_chk(typval_T *varp, int *denote);
 char_u *get_tv_string(typval_T *varp);
 char_u *get_tv_string_buf(typval_T *varp, char_u *buf);
 char_u *get_tv_string_chk(typval_T *varp);
diff --git a/src/quickfix.c b/src/quickfix.c
index 19801e3..b776025 100644
--- a/src/quickfix.c
+++ b/src/quickfix.c
@@ -4377,11 +4377,11 @@
 	    continue;
 
 	filename = get_dict_string(d, (char_u *)"filename", TRUE);
-	bufnum = get_dict_number(d, (char_u *)"bufnr");
-	lnum = get_dict_number(d, (char_u *)"lnum");
-	col = get_dict_number(d, (char_u *)"col");
-	vcol = get_dict_number(d, (char_u *)"vcol");
-	nr = get_dict_number(d, (char_u *)"nr");
+	bufnum = (int)get_dict_number(d, (char_u *)"bufnr");
+	lnum = (int)get_dict_number(d, (char_u *)"lnum");
+	col = (int)get_dict_number(d, (char_u *)"col");
+	vcol = (int)get_dict_number(d, (char_u *)"vcol");
+	nr = (int)get_dict_number(d, (char_u *)"nr");
 	type = get_dict_string(d, (char_u *)"type", TRUE);
 	pattern = get_dict_string(d, (char_u *)"pattern", TRUE);
 	text = get_dict_string(d, (char_u *)"text", TRUE);
diff --git a/src/structs.h b/src/structs.h
index e4d3651..9d19c3c 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -1111,11 +1111,29 @@
 typedef long_u hash_T;		/* Type for hi_hash */
 
 
-#if VIM_SIZEOF_INT <= 3		/* use long if int is smaller than 32 bits */
-typedef long	varnumber_T;
+#ifdef FEAT_NUM64
+/* Use 64-bit Number. */
+# ifdef WIN3264
+typedef __int64		    varnumber_T;
+typedef unsigned __int64    uvarnumber_T;
+# elif defined(HAVE_STDINT_H)
+typedef int64_t		    varnumber_T;
+typedef uint64_t	    uvarnumber_T;
+# else
+typedef long		    varnumber_T;
+typedef unsigned long	    uvarnumber_T;
+# endif
 #else
-typedef int	varnumber_T;
+/* Use 32-bit Number. */
+# if VIM_SIZEOF_INT <= 3	/* use long if int is smaller than 32 bits */
+typedef long		    varnumber_T;
+typedef unsigned long	    uvarnumber_T;
+# else
+typedef int		    varnumber_T;
+typedef unsigned int	    uvarnumber_T;
+# endif
 #endif
+
 typedef double	float_T;
 
 typedef struct listvar_S list_T;
diff --git a/src/testdir/test_viml.vim b/src/testdir/test_viml.vim
index f1dde4b..85baf12 100644
--- a/src/testdir/test_viml.vim
+++ b/src/testdir/test_viml.vim
@@ -1197,6 +1197,34 @@
 endfunc
 
 "-------------------------------------------------------------------------------
+" Test 94:  64-bit Numbers					    {{{1
+"-------------------------------------------------------------------------------
+
+func Test_num64()
+    if !has('num64')
+	return
+    endif
+
+    call assert_notequal( 4294967296, 0)
+    call assert_notequal(-4294967296, 0)
+    call assert_equal( 4294967296,  0xFFFFffff + 1)
+    call assert_equal(-4294967296, -0xFFFFffff - 1)
+
+    call assert_equal( 9223372036854775807,  1 / 0)
+    call assert_equal(-9223372036854775807, -1 / 0)
+    call assert_equal(-9223372036854775808,  0 / 0)
+
+    call assert_equal( 0x7FFFffffFFFFffff, float2nr( 1.0e150))
+    call assert_equal(-0x7FFFffffFFFFffff, float2nr(-1.0e150))
+
+    let rng = range(0xFFFFffff, 0x100000001)
+    call assert_equal([0xFFFFffff, 0x100000000, 0x100000001], rng)
+    call assert_equal(0x100000001, max(rng))
+    call assert_equal(0xFFFFffff, min(rng))
+    call assert_equal(rng, sort(range(0x100000001, 0xFFFFffff, -1), 'N'))
+endfunc
+
+"-------------------------------------------------------------------------------
 " Modelines								    {{{1
 " vim: ts=8 sw=4 tw=80 fdm=marker
 " vim: fdt=substitute(substitute(foldtext(),\ '\\%(^+--\\)\\@<=\\(\\s*\\)\\(.\\{-}\\)\:\ \\%(\"\ \\)\\=\\(Test\ \\d*\\)\:\\s*',\ '\\3\ (\\2)\:\ \\1',\ \"\"),\ '\\(Test\\s*\\)\\(\\d\\)\\D\\@=',\ '\\1\ \\2',\ "")
diff --git a/src/version.c b/src/version.c
index 8a57ba8..78ea040 100644
--- a/src/version.c
+++ b/src/version.c
@@ -455,6 +455,11 @@
 #else
 	"-netbeans_intg",
 #endif
+#ifdef FEAT_NUM64
+	"+num64",
+#else
+	"-num64",
+#endif
 #ifdef FEAT_GUI_W32
 # ifdef FEAT_OLE
 	"+ole",
@@ -754,6 +759,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1976,
+/**/
     1975,
 /**/
     1974,