From 029f72b1a93430b24b88eb3a72c6114d9f149737 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Wed, 10 Apr 2024 22:09:20 +0200
Subject: Adding upstream version 2:9.1.0016.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 src/regexp_bt.c | 5623 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 5623 insertions(+)
 create mode 100644 src/regexp_bt.c

(limited to 'src/regexp_bt.c')

diff --git a/src/regexp_bt.c b/src/regexp_bt.c
new file mode 100644
index 0000000..198946e
--- /dev/null
+++ b/src/regexp_bt.c
@@ -0,0 +1,5623 @@
+/* vi:set ts=8 sts=4 sw=4 noet:
+ *
+ * Backtracking regular expression implementation.
+ *
+ * This file is included in "regexp.c".
+ *
+ * NOTICE:
+ *
+ * This is NOT the original regular expression code as written by Henry
+ * Spencer.  This code has been modified specifically for use with the VIM
+ * editor, and should not be used separately from Vim.  If you want a good
+ * regular expression library, get the original code.  The copyright notice
+ * that follows is from the original.
+ *
+ * END NOTICE
+ *
+ *	Copyright (c) 1986 by University of Toronto.
+ *	Written by Henry Spencer.  Not derived from licensed software.
+ *
+ *	Permission is granted to anyone to use this software for any
+ *	purpose on any computer system, and to redistribute it freely,
+ *	subject to the following restrictions:
+ *
+ *	1. The author is not responsible for the consequences of use of
+ *		this software, no matter how awful, even if they arise
+ *		from defects in it.
+ *
+ *	2. The origin of this software must not be misrepresented, either
+ *		by explicit claim or by omission.
+ *
+ *	3. Altered versions must be plainly marked as such, and must not
+ *		be misrepresented as being the original software.
+ *
+ * Beware that some of this code is subtly aware of the way operator
+ * precedence is structured in regular expressions.  Serious changes in
+ * regular-expression syntax might require a total rethink.
+ *
+ * Changes have been made by Tony Andrews, Olaf 'Rhialto' Seibert, Robert
+ * Webb, Ciaran McCreesh and Bram Moolenaar.
+ * Named character class support added by Walter Briscoe (1998 Jul 01)
+ */
+
+/*
+ * The "internal use only" fields in regexp.h are present to pass info from
+ * compile to execute that permits the execute phase to run lots faster on
+ * simple cases.  They are:
+ *
+ * regstart	char that must begin a match; NUL if none obvious; Can be a
+ *		multi-byte character.
+ * reganch	is the match anchored (at beginning-of-line only)?
+ * regmust	string (pointer into program) that match must include, or NULL
+ * regmlen	length of regmust string
+ * regflags	RF_ values or'ed together
+ *
+ * Regstart and reganch permit very fast decisions on suitable starting points
+ * for a match, cutting down the work a lot.  Regmust permits fast rejection
+ * of lines that cannot possibly match.  The regmust tests are costly enough
+ * that vim_regcomp() supplies a regmust only if the r.e. contains something
+ * potentially expensive (at present, the only such thing detected is * or +
+ * at the start of the r.e., which can involve a lot of backup).  Regmlen is
+ * supplied because the test in vim_regexec() needs it and vim_regcomp() is
+ * computing it anyway.
+ */
+
+/*
+ * Structure for regexp "program".  This is essentially a linear encoding
+ * of a nondeterministic finite-state machine (aka syntax charts or
+ * "railroad normal form" in parsing technology).  Each node is an opcode
+ * plus a "next" pointer, possibly plus an operand.  "Next" pointers of
+ * all nodes except BRANCH and BRACES_COMPLEX implement concatenation; a "next"
+ * pointer with a BRANCH on both ends of it is connecting two alternatives.
+ * (Here we have one of the subtle syntax dependencies:	an individual BRANCH
+ * (as opposed to a collection of them) is never concatenated with anything
+ * because of operator precedence).  The "next" pointer of a BRACES_COMPLEX
+ * node points to the node after the stuff to be repeated.
+ * The operand of some types of node is a literal string; for others, it is a
+ * node leading into a sub-FSM.  In particular, the operand of a BRANCH node
+ * is the first node of the branch.
+ * (NB this is *not* a tree structure: the tail of the branch connects to the
+ * thing following the set of BRANCHes.)
+ *
+ * pattern	is coded like:
+ *
+ *			  +-----------------+
+ *			  |		    V
+ * <aa>\|<bb>	BRANCH <aa> BRANCH <bb> --> END
+ *		     |	    ^	 |	    ^
+ *		     +------+	 +----------+
+ *
+ *
+ *		       +------------------+
+ *		       V		  |
+ * <aa>*	BRANCH BRANCH <aa> --> BACK BRANCH --> NOTHING --> END
+ *		     |	    |		    ^			   ^
+ *		     |	    +---------------+			   |
+ *		     +---------------------------------------------+
+ *
+ *
+ *		       +----------------------+
+ *		       V		      |
+ * <aa>\+	BRANCH <aa> --> BRANCH --> BACK  BRANCH --> NOTHING --> END
+ *		     |		     |		 ^			^
+ *		     |		     +-----------+			|
+ *		     +--------------------------------------------------+
+ *
+ *
+ *					+-------------------------+
+ *					V			  |
+ * <aa>\{}	BRANCH BRACE_LIMITS --> BRACE_COMPLEX <aa> --> BACK  END
+ *		     |				    |		     ^
+ *		     |				    +----------------+
+ *		     +-----------------------------------------------+
+ *
+ *
+ * <aa>\@!<bb>	BRANCH NOMATCH <aa> --> END  <bb> --> END
+ *		     |	     |		      ^       ^
+ *		     |	     +----------------+       |
+ *		     +--------------------------------+
+ *
+ *						      +---------+
+ *						      |		V
+ * \z[abc]	BRANCH BRANCH  a  BRANCH  b  BRANCH  c	BRANCH	NOTHING --> END
+ *		     |	    |	       |	  |	^		    ^
+ *		     |	    |	       |	  +-----+		    |
+ *		     |	    |	       +----------------+		    |
+ *		     |	    +---------------------------+		    |
+ *		     +------------------------------------------------------+
+ *
+ * They all start with a BRANCH for "\|" alternatives, even when there is only
+ * one alternative.
+ */
+
+/*
+ * The opcodes are:
+ */
+
+// definition	number		   opnd?    meaning
+#define END		0	//	End of program or NOMATCH operand.
+#define BOL		1	//	Match "" at beginning of line.
+#define EOL		2	//	Match "" at end of line.
+#define BRANCH		3	// node Match this alternative, or the
+				//	next...
+#define BACK		4	//	Match "", "next" ptr points backward.
+#define EXACTLY		5	// str	Match this string.
+#define NOTHING		6	//	Match empty string.
+#define STAR		7	// node Match this (simple) thing 0 or more
+				//	times.
+#define PLUS		8	// node Match this (simple) thing 1 or more
+				//	times.
+#define MATCH		9	// node match the operand zero-width
+#define NOMATCH		10	// node check for no match with operand
+#define BEHIND		11	// node look behind for a match with operand
+#define NOBEHIND	12	// node look behind for no match with operand
+#define SUBPAT		13	// node match the operand here
+#define BRACE_SIMPLE	14	// node Match this (simple) thing between m and
+				//	n times (\{m,n\}).
+#define BOW		15	//	Match "" after [^a-zA-Z0-9_]
+#define EOW		16	//	Match "" at    [^a-zA-Z0-9_]
+#define BRACE_LIMITS	17	// nr nr  define the min & max for BRACE_SIMPLE
+				//	and BRACE_COMPLEX.
+#define NEWL		18	//	Match line-break
+#define BHPOS		19	//	End position for BEHIND or NOBEHIND
+
+
+// character classes: 20-48 normal, 50-78 include a line-break
+#define ADD_NL		30
+#define FIRST_NL	ANY + ADD_NL
+#define ANY		20	//	Match any one character.
+#define ANYOF		21	// str	Match any character in this string.
+#define ANYBUT		22	// str	Match any character not in this
+				//	string.
+#define IDENT		23	//	Match identifier char
+#define SIDENT		24	//	Match identifier char but no digit
+#define KWORD		25	//	Match keyword char
+#define SKWORD		26	//	Match word char but no digit
+#define FNAME		27	//	Match file name char
+#define SFNAME		28	//	Match file name char but no digit
+#define PRINT		29	//	Match printable char
+#define SPRINT		30	//	Match printable char but no digit
+#define WHITE		31	//	Match whitespace char
+#define NWHITE		32	//	Match non-whitespace char
+#define DIGIT		33	//	Match digit char
+#define NDIGIT		34	//	Match non-digit char
+#define HEX		35	//	Match hex char
+#define NHEX		36	//	Match non-hex char
+#define OCTAL		37	//	Match octal char
+#define NOCTAL		38	//	Match non-octal char
+#define WORD		39	//	Match word char
+#define NWORD		40	//	Match non-word char
+#define HEAD		41	//	Match head char
+#define NHEAD		42	//	Match non-head char
+#define ALPHA		43	//	Match alpha char
+#define NALPHA		44	//	Match non-alpha char
+#define LOWER		45	//	Match lowercase char
+#define NLOWER		46	//	Match non-lowercase char
+#define UPPER		47	//	Match uppercase char
+#define NUPPER		48	//	Match non-uppercase char
+#define LAST_NL		NUPPER + ADD_NL
+#define WITH_NL(op)	((op) >= FIRST_NL && (op) <= LAST_NL)
+
+#define MOPEN		80  // -89	 Mark this point in input as start of
+				//	 \( subexpr.  MOPEN + 0 marks start of
+				//	 match.
+#define MCLOSE		90  // -99	 Analogous to MOPEN.  MCLOSE + 0 marks
+				//	 end of match.
+#define BACKREF		100 // -109 node Match same string again \1-\9
+
+#ifdef FEAT_SYN_HL
+# define ZOPEN		110 // -119	 Mark this point in input as start of
+				//	 \z( subexpr.
+# define ZCLOSE		120 // -129	 Analogous to ZOPEN.
+# define ZREF		130 // -139 node Match external submatch \z1-\z9
+#endif
+
+#define BRACE_COMPLEX	140 // -149 node Match nodes between m & n times
+
+#define NOPEN		150	//	Mark this point in input as start of
+				//	\%( subexpr.
+#define NCLOSE		151	//	Analogous to NOPEN.
+
+#define MULTIBYTECODE	200	// mbc	Match one multi-byte character
+#define RE_BOF		201	//	Match "" at beginning of file.
+#define RE_EOF		202	//	Match "" at end of file.
+#define CURSOR		203	//	Match location of cursor.
+
+#define RE_LNUM		204	// nr cmp  Match line number
+#define RE_COL		205	// nr cmp  Match column number
+#define RE_VCOL		206	// nr cmp  Match virtual column number
+
+#define RE_MARK		207	// mark cmp  Match mark position
+#define RE_VISUAL	208	//	Match Visual area
+#define RE_COMPOSING	209	// any composing characters
+
+/*
+ * Flags to be passed up and down.
+ */
+#define HASWIDTH	0x1	// Known never to match null string.
+#define SIMPLE		0x2	// Simple enough to be STAR/PLUS operand.
+#define SPSTART		0x4	// Starts with * or +.
+#define HASNL		0x8	// Contains some \n.
+#define HASLOOKBH	0x10	// Contains "\@<=" or "\@<!".
+#define WORST		0	// Worst case.
+
+static int	num_complex_braces; // Complex \{...} count
+static char_u	*regcode;	// Code-emit pointer, or JUST_CALC_SIZE
+static long	regsize;	// Code size.
+static int	reg_toolong;	// TRUE when offset out of range
+static char_u	had_endbrace[NSUBEXP];	// flags, TRUE if end of () found
+static long	brace_min[10];	// Minimums for complex brace repeats
+static long	brace_max[10];	// Maximums for complex brace repeats
+static int	brace_count[10]; // Current counts for complex brace repeats
+static int	one_exactly = FALSE;	// only do one char for EXACTLY
+
+// When making changes to classchars also change nfa_classcodes.
+static char_u	*classchars = (char_u *)".iIkKfFpPsSdDxXoOwWhHaAlLuU";
+static int	classcodes[] = {
+    ANY, IDENT, SIDENT, KWORD, SKWORD,
+    FNAME, SFNAME, PRINT, SPRINT,
+    WHITE, NWHITE, DIGIT, NDIGIT,
+    HEX, NHEX, OCTAL, NOCTAL,
+    WORD, NWORD, HEAD, NHEAD,
+    ALPHA, NALPHA, LOWER, NLOWER,
+    UPPER, NUPPER
+};
+
+/*
+ * When regcode is set to this value, code is not emitted and size is computed
+ * instead.
+ */
+#define JUST_CALC_SIZE	((char_u *) -1)
+
+// Values for rs_state in regitem_T.
+typedef enum regstate_E
+{
+    RS_NOPEN = 0	// NOPEN and NCLOSE
+    , RS_MOPEN		// MOPEN + [0-9]
+    , RS_MCLOSE		// MCLOSE + [0-9]
+#ifdef FEAT_SYN_HL
+    , RS_ZOPEN		// ZOPEN + [0-9]
+    , RS_ZCLOSE		// ZCLOSE + [0-9]
+#endif
+    , RS_BRANCH		// BRANCH
+    , RS_BRCPLX_MORE	// BRACE_COMPLEX and trying one more match
+    , RS_BRCPLX_LONG	// BRACE_COMPLEX and trying longest match
+    , RS_BRCPLX_SHORT	// BRACE_COMPLEX and trying shortest match
+    , RS_NOMATCH	// NOMATCH
+    , RS_BEHIND1	// BEHIND / NOBEHIND matching rest
+    , RS_BEHIND2	// BEHIND / NOBEHIND matching behind part
+    , RS_STAR_LONG	// STAR/PLUS/BRACE_SIMPLE longest match
+    , RS_STAR_SHORT	// STAR/PLUS/BRACE_SIMPLE shortest match
+} regstate_T;
+
+/*
+ * Structure used to save the current input state, when it needs to be
+ * restored after trying a match.  Used by reg_save() and reg_restore().
+ * Also stores the length of "backpos".
+ */
+typedef struct
+{
+    union
+    {
+	char_u	*ptr;	// rex.input pointer, for single-line regexp
+	lpos_T	pos;	// rex.input pos, for multi-line regexp
+    } rs_u;
+    int		rs_len;
+} regsave_T;
+
+// struct to save start/end pointer/position in for \(\)
+typedef struct
+{
+    union
+    {
+	char_u	*ptr;
+	lpos_T	pos;
+    } se_u;
+} save_se_T;
+
+// used for BEHIND and NOBEHIND matching
+typedef struct regbehind_S
+{
+    regsave_T	save_after;
+    regsave_T	save_behind;
+    int		save_need_clear_subexpr;
+    save_se_T   save_start[NSUBEXP];
+    save_se_T   save_end[NSUBEXP];
+} regbehind_T;
+
+/*
+ * When there are alternatives a regstate_T is put on the regstack to remember
+ * what we are doing.
+ * Before it may be another type of item, depending on rs_state, to remember
+ * more things.
+ */
+typedef struct regitem_S
+{
+    regstate_T	rs_state;	// what we are doing, one of RS_ above
+    short	rs_no;		// submatch nr or BEHIND/NOBEHIND
+    char_u	*rs_scan;	// current node in program
+    union
+    {
+	save_se_T  sesave;
+	regsave_T  regsave;
+    } rs_un;			// room for saving rex.input
+} regitem_T;
+
+
+// used for STAR, PLUS and BRACE_SIMPLE matching
+typedef struct regstar_S
+{
+    int		nextb;		// next byte
+    int		nextb_ic;	// next byte reverse case
+    long	count;
+    long	minval;
+    long	maxval;
+} regstar_T;
+
+// used to store input position when a BACK was encountered, so that we now if
+// we made any progress since the last time.
+typedef struct backpos_S
+{
+    char_u	*bp_scan;	// "scan" where BACK was encountered
+    regsave_T	bp_pos;		// last input position
+} backpos_T;
+
+/*
+ * "regstack" and "backpos" are used by regmatch().  They are kept over calls
+ * to avoid invoking malloc() and free() often.
+ * "regstack" is a stack with regitem_T items, sometimes preceded by regstar_T
+ * or regbehind_T.
+ * "backpos_T" is a table with backpos_T for BACK
+ */
+static garray_T	regstack = {0, 0, 0, 0, NULL};
+static garray_T	backpos = {0, 0, 0, 0, NULL};
+
+static regsave_T behind_pos;
+
+/*
+ * Both for regstack and backpos tables we use the following strategy of
+ * allocation (to reduce malloc/free calls):
+ * - Initial size is fairly small.
+ * - When needed, the tables are grown bigger (8 times at first, double after
+ *   that).
+ * - After executing the match we free the memory only if the array has grown.
+ *   Thus the memory is kept allocated when it's at the initial size.
+ * This makes it fast while not keeping a lot of memory allocated.
+ * A three times speed increase was observed when using many simple patterns.
+ */
+#define REGSTACK_INITIAL	2048
+#define BACKPOS_INITIAL		64
+
+/*
+ * Opcode notes:
+ *
+ * BRANCH	The set of branches constituting a single choice are hooked
+ *		together with their "next" pointers, since precedence prevents
+ *		anything being concatenated to any individual branch.  The
+ *		"next" pointer of the last BRANCH in a choice points to the
+ *		thing following the whole choice.  This is also where the
+ *		final "next" pointer of each individual branch points; each
+ *		branch starts with the operand node of a BRANCH node.
+ *
+ * BACK		Normal "next" pointers all implicitly point forward; BACK
+ *		exists to make loop structures possible.
+ *
+ * STAR,PLUS	'=', and complex '*' and '+', are implemented as circular
+ *		BRANCH structures using BACK.  Simple cases (one character
+ *		per match) are implemented with STAR and PLUS for speed
+ *		and to minimize recursive plunges.
+ *
+ * BRACE_LIMITS	This is always followed by a BRACE_SIMPLE or BRACE_COMPLEX
+ *		node, and defines the min and max limits to be used for that
+ *		node.
+ *
+ * MOPEN,MCLOSE	...are numbered at compile time.
+ * ZOPEN,ZCLOSE	...ditto
+ */
+
+/*
+ * A node is one char of opcode followed by two chars of "next" pointer.
+ * "Next" pointers are stored as two 8-bit bytes, high order first.  The
+ * value is a positive offset from the opcode of the node containing it.
+ * An operand, if any, simply follows the node.  (Note that much of the
+ * code generation knows about this implicit relationship.)
+ *
+ * Using two bytes for the "next" pointer is vast overkill for most things,
+ * but allows patterns to get big without disasters.
+ */
+#define OP(p)		((int)*(p))
+#define NEXT(p)		(((*((p) + 1) & 0377) << 8) + (*((p) + 2) & 0377))
+#define OPERAND(p)	((p) + 3)
+// Obtain an operand that was stored as four bytes, MSB first.
+#define OPERAND_MIN(p)	(((long)(p)[3] << 24) + ((long)(p)[4] << 16) \
+			+ ((long)(p)[5] << 8) + (long)(p)[6])
+// Obtain a second operand stored as four bytes.
+#define OPERAND_MAX(p)	OPERAND_MIN((p) + 4)
+// Obtain a second single-byte operand stored after a four bytes operand.
+#define OPERAND_CMP(p)	(p)[7]
+
+static char_u *reg(int paren, int *flagp);
+
+#ifdef BT_REGEXP_DUMP
+static void	regdump(char_u *, bt_regprog_T *);
+#endif
+
+static int	re_num_cmp(long_u val, char_u *scan);
+
+#ifdef DEBUG
+static char_u	*regprop(char_u *);
+
+static int	regnarrate = 0;
+#endif
+
+
+/*
+ * Setup to parse the regexp.  Used once to get the length and once to do it.
+ */
+    static void
+regcomp_start(
+    char_u	*expr,
+    int		re_flags)	    // see vim_regcomp()
+{
+    initchr(expr);
+    if (re_flags & RE_MAGIC)
+	reg_magic = MAGIC_ON;
+    else
+	reg_magic = MAGIC_OFF;
+    reg_string = (re_flags & RE_STRING);
+    reg_strict = (re_flags & RE_STRICT);
+    get_cpo_flags();
+
+    num_complex_braces = 0;
+    regnpar = 1;
+    CLEAR_FIELD(had_endbrace);
+#ifdef FEAT_SYN_HL
+    regnzpar = 1;
+    re_has_z = 0;
+#endif
+    regsize = 0L;
+    reg_toolong = FALSE;
+    regflags = 0;
+#if defined(FEAT_SYN_HL) || defined(PROTO)
+    had_eol = FALSE;
+#endif
+}
+
+/*
+ * Return TRUE if MULTIBYTECODE should be used instead of EXACTLY for
+ * character "c".
+ */
+    static int
+use_multibytecode(int c)
+{
+    return has_mbyte && (*mb_char2len)(c) > 1
+		     && (re_multi_type(peekchr()) != NOT_MULTI
+			     || (enc_utf8 && utf_iscomposing(c)));
+}
+
+/*
+ * Emit (if appropriate) a byte of code
+ */
+    static void
+regc(int b)
+{
+    if (regcode == JUST_CALC_SIZE)
+	regsize++;
+    else
+	*regcode++ = b;
+}
+
+/*
+ * Emit (if appropriate) a multi-byte character of code
+ */
+    static void
+regmbc(int c)
+{
+    if (!has_mbyte && c > 0xff)
+	return;
+    if (regcode == JUST_CALC_SIZE)
+	regsize += (*mb_char2len)(c);
+    else
+	regcode += (*mb_char2bytes)(c, regcode);
+}
+
+
+/*
+ * Produce the bytes for equivalence class "c".
+ * Currently only handles latin1, latin9 and utf-8.
+ * NOTE: When changing this function, also change nfa_emit_equi_class()
+ */
+    static void
+reg_equi_class(int c)
+{
+    if (enc_utf8 || STRCMP(p_enc, "latin1") == 0
+					 || STRCMP(p_enc, "iso-8859-15") == 0)
+    {
+	switch (c)
+	{
+	    // Do not use '\300' style, it results in a negative number.
+	    case 'A': case 0xc0: case 0xc1: case 0xc2: case 0xc3: case 0xc4:
+	    case 0xc5: case 0x100: case 0x102: case 0x104: case 0x1cd:
+	    case 0x1de: case 0x1e0: case 0x1fa: case 0x202: case 0x226:
+	    case 0x23a: case 0x1e00: case 0x1ea0: case 0x1ea2: case 0x1ea4:
+	    case 0x1ea6: case 0x1ea8: case 0x1eaa: case 0x1eac: case 0x1eae:
+	    case 0x1eb0: case 0x1eb2: case 0x1eb4: case 0x1eb6:
+		      regmbc('A'); regmbc(0xc0); regmbc(0xc1); regmbc(0xc2);
+		      regmbc(0xc3); regmbc(0xc4); regmbc(0xc5);
+		      regmbc(0x100); regmbc(0x102); regmbc(0x104);
+		      regmbc(0x1cd); regmbc(0x1de); regmbc(0x1e0);
+		      regmbc(0x1fa); regmbc(0x202); regmbc(0x226);
+		      regmbc(0x23a); regmbc(0x1e00); regmbc(0x1ea0);
+		      regmbc(0x1ea2); regmbc(0x1ea4); regmbc(0x1ea6);
+		      regmbc(0x1ea8); regmbc(0x1eaa); regmbc(0x1eac);
+		      regmbc(0x1eae); regmbc(0x1eb0); regmbc(0x1eb2);
+		      regmbc(0x1eb4); regmbc(0x1eb6);
+		      return;
+	    case 'B': case 0x181: case 0x243: case 0x1e02:
+	    case 0x1e04: case 0x1e06:
+		      regmbc('B');
+		      regmbc(0x181); regmbc(0x243); regmbc(0x1e02);
+		      regmbc(0x1e04); regmbc(0x1e06);
+		      return;
+	    case 'C': case 0xc7:
+	    case 0x106: case 0x108: case 0x10a: case 0x10c: case 0x187:
+	    case 0x23b: case 0x1e08: case 0xa792:
+		      regmbc('C'); regmbc(0xc7);
+		      regmbc(0x106); regmbc(0x108); regmbc(0x10a);
+		      regmbc(0x10c); regmbc(0x187); regmbc(0x23b);
+		      regmbc(0x1e08); regmbc(0xa792);
+		      return;
+	    case 'D': case 0x10e: case 0x110: case 0x18a:
+	    case 0x1e0a: case 0x1e0c: case 0x1e0e: case 0x1e10:
+	    case 0x1e12:
+		      regmbc('D'); regmbc(0x10e); regmbc(0x110);
+		      regmbc(0x18a); regmbc(0x1e0a); regmbc(0x1e0c);
+		      regmbc(0x1e0e); regmbc(0x1e10); regmbc(0x1e12);
+		      return;
+	    case 'E': case 0xc8: case 0xc9: case 0xca: case 0xcb:
+	    case 0x112: case 0x114: case 0x116: case 0x118: case 0x11a:
+	    case 0x204: case 0x206: case 0x228: case 0x246: case 0x1e14:
+	    case 0x1e16: case 0x1e18: case 0x1e1a: case 0x1e1c:
+	    case 0x1eb8: case 0x1eba: case 0x1ebc: case 0x1ebe:
+	    case 0x1ec0: case 0x1ec2: case 0x1ec4: case 0x1ec6:
+		      regmbc('E'); regmbc(0xc8); regmbc(0xc9);
+		      regmbc(0xca); regmbc(0xcb); regmbc(0x112);
+		      regmbc(0x114); regmbc(0x116); regmbc(0x118);
+		      regmbc(0x11a); regmbc(0x204); regmbc(0x206);
+		      regmbc(0x228); regmbc(0x246); regmbc(0x1e14);
+		      regmbc(0x1e16); regmbc(0x1e18); regmbc(0x1e1a);
+		      regmbc(0x1e1c); regmbc(0x1eb8); regmbc(0x1eba);
+		      regmbc(0x1ebc); regmbc(0x1ebe); regmbc(0x1ec0);
+		      regmbc(0x1ec2); regmbc(0x1ec4); regmbc(0x1ec6);
+		      return;
+	    case 'F': case 0x191: case 0x1e1e: case 0xa798:
+		      regmbc('F'); regmbc(0x191); regmbc(0x1e1e);
+		      regmbc(0xa798);
+		      return;
+	    case 'G': case 0x11c: case 0x11e: case 0x120:
+	    case 0x122: case 0x193: case 0x1e4: case 0x1e6:
+	    case 0x1f4: case 0x1e20: case 0xa7a0:
+		      regmbc('G'); regmbc(0x11c); regmbc(0x11e);
+		      regmbc(0x120); regmbc(0x122); regmbc(0x193);
+		      regmbc(0x1e4); regmbc(0x1e6); regmbc(0x1f4);
+		      regmbc(0x1e20); regmbc(0xa7a0);
+		      return;
+	    case 'H': case 0x124: case 0x126: case 0x21e:
+	    case 0x1e22: case 0x1e24: case 0x1e26:
+	    case 0x1e28: case 0x1e2a: case 0x2c67:
+		      regmbc('H'); regmbc(0x124); regmbc(0x126);
+		      regmbc(0x21e); regmbc(0x1e22); regmbc(0x1e24);
+		      regmbc(0x1e26); regmbc(0x1e28); regmbc(0x1e2a);
+		      regmbc(0x2c67);
+		      return;
+	    case 'I': case 0xcc: case 0xcd: case 0xce: case 0xcf:
+	    case 0x128: case 0x12a: case 0x12c: case 0x12e:
+	    case 0x130: case 0x197: case 0x1cf: case 0x208:
+	    case 0x20a: case 0x1e2c: case 0x1e2e: case 0x1ec8:
+	    case 0x1eca:
+		      regmbc('I'); regmbc(0xcc); regmbc(0xcd);
+		      regmbc(0xce); regmbc(0xcf); regmbc(0x128);
+		      regmbc(0x12a); regmbc(0x12c); regmbc(0x12e);
+		      regmbc(0x130); regmbc(0x197); regmbc(0x1cf);
+		      regmbc(0x208); regmbc(0x20a); regmbc(0x1e2c);
+		      regmbc(0x1e2e); regmbc(0x1ec8); regmbc(0x1eca);
+		      return;
+	    case 'J': case 0x134: case 0x248:
+		      regmbc('J'); regmbc(0x134); regmbc(0x248);
+		      return;
+	    case 'K': case 0x136: case 0x198: case 0x1e8: case 0x1e30:
+	    case 0x1e32: case 0x1e34: case 0x2c69: case 0xa740:
+		      regmbc('K'); regmbc(0x136); regmbc(0x198);
+		      regmbc(0x1e8); regmbc(0x1e30); regmbc(0x1e32);
+		      regmbc(0x1e34); regmbc(0x2c69); regmbc(0xa740);
+		      return;
+	    case 'L': case 0x139: case 0x13b: case 0x13d: case 0x13f:
+	    case 0x141: case 0x23d: case 0x1e36: case 0x1e38:
+	    case 0x1e3a: case 0x1e3c: case 0x2c60:
+		      regmbc('L'); regmbc(0x139); regmbc(0x13b);
+		      regmbc(0x13d); regmbc(0x13f); regmbc(0x141);
+		      regmbc(0x23d); regmbc(0x1e36); regmbc(0x1e38);
+		      regmbc(0x1e3a); regmbc(0x1e3c); regmbc(0x2c60);
+		      return;
+	    case 'M': case 0x1e3e: case 0x1e40: case 0x1e42:
+		      regmbc('M'); regmbc(0x1e3e); regmbc(0x1e40);
+		      regmbc(0x1e42);
+		      return;
+	    case 'N': case 0xd1:
+	    case 0x143: case 0x145: case 0x147: case 0x1f8:
+	    case 0x1e44: case 0x1e46: case 0x1e48: case 0x1e4a:
+	    case 0xa7a4:
+		      regmbc('N'); regmbc(0xd1);
+		      regmbc(0x143); regmbc(0x145); regmbc(0x147);
+		      regmbc(0x1f8); regmbc(0x1e44); regmbc(0x1e46);
+		      regmbc(0x1e48); regmbc(0x1e4a); regmbc(0xa7a4);
+		      return;
+	    case 'O': case 0xd2: case 0xd3: case 0xd4: case 0xd5: case 0xd6:
+	    case 0xd8: case 0x14c: case 0x14e: case 0x150: case 0x19f:
+	    case 0x1a0: case 0x1d1: case 0x1ea: case 0x1ec: case 0x1fe:
+	    case 0x20c: case 0x20e: case 0x22a: case 0x22c: case 0x22e:
+	    case 0x230: case 0x1e4c: case 0x1e4e: case 0x1e50: case 0x1e52:
+	    case 0x1ecc: case 0x1ece: case 0x1ed0: case 0x1ed2: case 0x1ed4:
+	    case 0x1ed6: case 0x1ed8: case 0x1eda: case 0x1edc: case 0x1ede:
+	    case 0x1ee0: case 0x1ee2:
+		      regmbc('O'); regmbc(0xd2); regmbc(0xd3); regmbc(0xd4);
+		      regmbc(0xd5); regmbc(0xd6); regmbc(0xd8);
+		      regmbc(0x14c); regmbc(0x14e); regmbc(0x150);
+		      regmbc(0x19f); regmbc(0x1a0); regmbc(0x1d1);
+		      regmbc(0x1ea); regmbc(0x1ec); regmbc(0x1fe);
+		      regmbc(0x20c); regmbc(0x20e); regmbc(0x22a);
+		      regmbc(0x22c); regmbc(0x22e); regmbc(0x230);
+		      regmbc(0x1e4c); regmbc(0x1e4e); regmbc(0x1e50);
+		      regmbc(0x1e52); regmbc(0x1ecc); regmbc(0x1ece);
+		      regmbc(0x1ed0); regmbc(0x1ed2); regmbc(0x1ed4);
+		      regmbc(0x1ed6); regmbc(0x1ed8); regmbc(0x1eda);
+		      regmbc(0x1edc); regmbc(0x1ede); regmbc(0x1ee0);
+		      regmbc(0x1ee2);
+		      return;
+	    case 'P': case 0x1a4: case 0x1e54: case 0x1e56: case 0x2c63:
+		      regmbc('P'); regmbc(0x1a4); regmbc(0x1e54);
+		      regmbc(0x1e56); regmbc(0x2c63);
+		      return;
+	    case 'Q': case 0x24a:
+		      regmbc('Q'); regmbc(0x24a);
+		      return;
+	    case 'R': case 0x154: case 0x156: case 0x158: case 0x210:
+	    case 0x212: case 0x24c: case 0x1e58: case 0x1e5a:
+	    case 0x1e5c: case 0x1e5e: case 0x2c64: case 0xa7a6:
+		      regmbc('R'); regmbc(0x154); regmbc(0x156);
+		      regmbc(0x210); regmbc(0x212); regmbc(0x158);
+		      regmbc(0x24c); regmbc(0x1e58); regmbc(0x1e5a);
+		      regmbc(0x1e5c); regmbc(0x1e5e); regmbc(0x2c64);
+		      regmbc(0xa7a6);
+		      return;
+	    case 'S': case 0x15a: case 0x15c: case 0x15e: case 0x160:
+	    case 0x218: case 0x1e60: case 0x1e62: case 0x1e64:
+	    case 0x1e66: case 0x1e68: case 0x2c7e: case 0xa7a8:
+		      regmbc('S'); regmbc(0x15a); regmbc(0x15c);
+		      regmbc(0x15e); regmbc(0x160); regmbc(0x218);
+		      regmbc(0x1e60); regmbc(0x1e62); regmbc(0x1e64);
+		      regmbc(0x1e66); regmbc(0x1e68); regmbc(0x2c7e);
+			  regmbc(0xa7a8);
+		      return;
+	    case 'T': case 0x162: case 0x164: case 0x166: case 0x1ac:
+	    case 0x1ae: case 0x21a: case 0x23e: case 0x1e6a: case 0x1e6c:
+	    case 0x1e6e: case 0x1e70:
+		      regmbc('T'); regmbc(0x162); regmbc(0x164);
+		      regmbc(0x166); regmbc(0x1ac); regmbc(0x23e);
+		      regmbc(0x1ae); regmbc(0x21a); regmbc(0x1e6a);
+		      regmbc(0x1e6c); regmbc(0x1e6e); regmbc(0x1e70);
+		      return;
+	    case 'U': case 0xd9: case 0xda: case 0xdb: case 0xdc:
+	    case 0x168: case 0x16a: case 0x16c: case 0x16e:
+	    case 0x170: case 0x172: case 0x1af: case 0x1d3:
+	    case 0x1d5: case 0x1d7: case 0x1d9: case 0x1db:
+	    case 0x214: case 0x216: case 0x244: case 0x1e72:
+	    case 0x1e74: case 0x1e76: case 0x1e78: case 0x1e7a:
+	    case 0x1ee4: case 0x1ee6: case 0x1ee8: case 0x1eea:
+	    case 0x1eec: case 0x1eee: case 0x1ef0:
+		      regmbc('U'); regmbc(0xd9); regmbc(0xda);
+		      regmbc(0xdb); regmbc(0xdc); regmbc(0x168);
+		      regmbc(0x16a); regmbc(0x16c); regmbc(0x16e);
+		      regmbc(0x170); regmbc(0x172); regmbc(0x1af);
+		      regmbc(0x1d3); regmbc(0x1d5); regmbc(0x1d7);
+		      regmbc(0x1d9); regmbc(0x1db); regmbc(0x214);
+		      regmbc(0x216); regmbc(0x244); regmbc(0x1e72);
+		      regmbc(0x1e74); regmbc(0x1e76); regmbc(0x1e78);
+		      regmbc(0x1e7a); regmbc(0x1ee4); regmbc(0x1ee6);
+		      regmbc(0x1ee8); regmbc(0x1eea); regmbc(0x1eec);
+		      regmbc(0x1eee); regmbc(0x1ef0);
+		      return;
+	    case 'V': case 0x1b2: case 0x1e7c: case 0x1e7e:
+		      regmbc('V'); regmbc(0x1b2); regmbc(0x1e7c);
+		      regmbc(0x1e7e);
+		      return;
+	    case 'W': case 0x174: case 0x1e80: case 0x1e82:
+	    case 0x1e84: case 0x1e86: case 0x1e88:
+		      regmbc('W'); regmbc(0x174); regmbc(0x1e80);
+		      regmbc(0x1e82); regmbc(0x1e84); regmbc(0x1e86);
+		      regmbc(0x1e88);
+		      return;
+	    case 'X': case 0x1e8a: case 0x1e8c:
+		      regmbc('X'); regmbc(0x1e8a); regmbc(0x1e8c);
+		      return;
+	    case 'Y': case 0xdd:
+	    case 0x176: case 0x178: case 0x1b3: case 0x232: case 0x24e:
+	    case 0x1e8e: case 0x1ef2: case 0x1ef6: case 0x1ef4: case 0x1ef8:
+		      regmbc('Y'); regmbc(0xdd); regmbc(0x176);
+		      regmbc(0x178); regmbc(0x1b3); regmbc(0x232);
+		      regmbc(0x24e); regmbc(0x1e8e); regmbc(0x1ef2);
+		      regmbc(0x1ef4); regmbc(0x1ef6); regmbc(0x1ef8);
+		      return;
+	    case 'Z': case 0x179: case 0x17b: case 0x17d: case 0x1b5:
+	    case 0x1e90: case 0x1e92: case 0x1e94: case 0x2c6b:
+		      regmbc('Z'); regmbc(0x179); regmbc(0x17b);
+		      regmbc(0x17d); regmbc(0x1b5); regmbc(0x1e90);
+		      regmbc(0x1e92); regmbc(0x1e94); regmbc(0x2c6b);
+		      return;
+	    case 'a': case 0xe0: case 0xe1: case 0xe2:
+	    case 0xe3: case 0xe4: case 0xe5: case 0x101: case 0x103:
+	    case 0x105: case 0x1ce: case 0x1df: case 0x1e1: case 0x1fb:
+	    case 0x201: case 0x203: case 0x227: case 0x1d8f: case 0x1e01:
+	    case 0x1e9a: case 0x1ea1: case 0x1ea3: case 0x1ea5:
+	    case 0x1ea7: case 0x1ea9: case 0x1eab: case 0x1ead:
+	    case 0x1eaf: case 0x1eb1: case 0x1eb3: case 0x1eb5:
+	    case 0x1eb7: case 0x2c65:
+		      regmbc('a'); regmbc(0xe0); regmbc(0xe1);
+		      regmbc(0xe2); regmbc(0xe3); regmbc(0xe4);
+		      regmbc(0xe5); regmbc(0x101); regmbc(0x103);
+		      regmbc(0x105); regmbc(0x1ce); regmbc(0x1df);
+		      regmbc(0x1e1); regmbc(0x1fb); regmbc(0x201);
+		      regmbc(0x203); regmbc(0x227); regmbc(0x1d8f);
+		      regmbc(0x1e01); regmbc(0x1e9a); regmbc(0x1ea1);
+		      regmbc(0x1ea3); regmbc(0x1ea5); regmbc(0x1ea7);
+		      regmbc(0x1ea9); regmbc(0x1eab); regmbc(0x1ead);
+		      regmbc(0x1eaf); regmbc(0x1eb1); regmbc(0x1eb3);
+		      regmbc(0x1eb5); regmbc(0x1eb7); regmbc(0x2c65);
+		      return;
+	    case 'b': case 0x180: case 0x253: case 0x1d6c: case 0x1d80:
+	    case 0x1e03: case 0x1e05: case 0x1e07:
+		      regmbc('b');
+		      regmbc(0x180); regmbc(0x253); regmbc(0x1d6c);
+		      regmbc(0x1d80); regmbc(0x1e03); regmbc(0x1e05);
+		      regmbc(0x1e07);
+		      return;
+	    case 'c': case 0xe7:
+	    case 0x107: case 0x109: case 0x10b: case 0x10d: case 0x188:
+	    case 0x23c: case 0x1e09: case 0xa793: case 0xa794:
+		      regmbc('c'); regmbc(0xe7); regmbc(0x107);
+		      regmbc(0x109); regmbc(0x10b); regmbc(0x10d);
+		      regmbc(0x188); regmbc(0x23c); regmbc(0x1e09);
+		      regmbc(0xa793); regmbc(0xa794);
+		      return;
+	    case 'd': case 0x10f: case 0x111: case 0x257: case 0x1d6d:
+	    case 0x1d81: case 0x1d91: case 0x1e0b: case 0x1e0d:
+	    case 0x1e0f: case 0x1e11: case 0x1e13:
+		      regmbc('d'); regmbc(0x10f); regmbc(0x111);
+		      regmbc(0x257); regmbc(0x1d6d); regmbc(0x1d81);
+		      regmbc(0x1d91); regmbc(0x1e0b); regmbc(0x1e0d);
+		      regmbc(0x1e0f); regmbc(0x1e11); regmbc(0x1e13);
+		      return;
+	    case 'e': case 0xe8: case 0xe9: case 0xea: case 0xeb:
+	    case 0x113: case 0x115: case 0x117: case 0x119:
+	    case 0x11b: case 0x205: case 0x207: case 0x229:
+	    case 0x247: case 0x1d92: case 0x1e15: case 0x1e17:
+	    case 0x1e19: case 0x1e1b: case 0x1eb9: case 0x1ebb:
+	    case 0x1e1d: case 0x1ebd: case 0x1ebf: case 0x1ec1:
+	    case 0x1ec3: case 0x1ec5: case 0x1ec7:
+		      regmbc('e'); regmbc(0xe8); regmbc(0xe9);
+		      regmbc(0xea); regmbc(0xeb); regmbc(0x113);
+		      regmbc(0x115); regmbc(0x117); regmbc(0x119);
+		      regmbc(0x11b); regmbc(0x205); regmbc(0x207);
+		      regmbc(0x229); regmbc(0x247); regmbc(0x1d92);
+		      regmbc(0x1e15); regmbc(0x1e17); regmbc(0x1e19);
+		      regmbc(0x1e1b); regmbc(0x1e1d); regmbc(0x1eb9);
+		      regmbc(0x1ebb); regmbc(0x1ebd); regmbc(0x1ebf);
+		      regmbc(0x1ec1); regmbc(0x1ec3); regmbc(0x1ec5);
+		      regmbc(0x1ec7);
+		      return;
+	    case 'f': case 0x192: case 0x1d6e: case 0x1d82:
+	    case 0x1e1f: case 0xa799:
+		     regmbc('f'); regmbc(0x192); regmbc(0x1d6e);
+		     regmbc(0x1d82); regmbc(0x1e1f); regmbc(0xa799);
+		     return;
+	    case 'g': case 0x11d: case 0x11f: case 0x121: case 0x123:
+	    case 0x1e5: case 0x1e7: case 0x260: case 0x1f5: case 0x1d83:
+	    case 0x1e21: case 0xa7a1:
+		      regmbc('g'); regmbc(0x11d); regmbc(0x11f);
+		      regmbc(0x121); regmbc(0x123); regmbc(0x1e5);
+		      regmbc(0x1e7); regmbc(0x1f5); regmbc(0x260);
+		      regmbc(0x1d83); regmbc(0x1e21); regmbc(0xa7a1);
+		      return;
+	    case 'h': case 0x125: case 0x127: case 0x21f: case 0x1e23:
+	    case 0x1e25: case 0x1e27: case 0x1e29: case 0x1e2b:
+	    case 0x1e96: case 0x2c68: case 0xa795:
+		      regmbc('h'); regmbc(0x125); regmbc(0x127);
+		      regmbc(0x21f); regmbc(0x1e23); regmbc(0x1e25);
+		      regmbc(0x1e27); regmbc(0x1e29); regmbc(0x1e2b);
+		      regmbc(0x1e96); regmbc(0x2c68); regmbc(0xa795);
+		      return;
+	    case 'i': case 0xec: case 0xed: case 0xee: case 0xef:
+	    case 0x129: case 0x12b: case 0x12d: case 0x12f:
+	    case 0x1d0: case 0x209: case 0x20b: case 0x268:
+	    case 0x1d96: case 0x1e2d: case 0x1e2f: case 0x1ec9:
+	    case 0x1ecb:
+		      regmbc('i'); regmbc(0xec); regmbc(0xed);
+		      regmbc(0xee); regmbc(0xef); regmbc(0x129);
+		      regmbc(0x12b); regmbc(0x12d); regmbc(0x12f);
+		      regmbc(0x1d0); regmbc(0x209); regmbc(0x20b);
+		      regmbc(0x268); regmbc(0x1d96); regmbc(0x1e2d);
+		      regmbc(0x1e2f); regmbc(0x1ec9); regmbc(0x1ecb);
+		      return;
+	    case 'j': case 0x135: case 0x1f0: case 0x249:
+		      regmbc('j'); regmbc(0x135); regmbc(0x1f0);
+		      regmbc(0x249);
+		      return;
+	    case 'k': case 0x137: case 0x199: case 0x1e9:
+	    case 0x1d84: case 0x1e31: case 0x1e33: case 0x1e35:
+	    case 0x2c6a: case 0xa741:
+		      regmbc('k'); regmbc(0x137); regmbc(0x199);
+		      regmbc(0x1e9); regmbc(0x1d84); regmbc(0x1e31);
+		      regmbc(0x1e33); regmbc(0x1e35); regmbc(0x2c6a);
+		      regmbc(0xa741);
+		      return;
+	    case 'l': case 0x13a: case 0x13c: case 0x13e:
+	    case 0x140: case 0x142: case 0x19a: case 0x1e37:
+	    case 0x1e39: case 0x1e3b: case 0x1e3d: case 0x2c61:
+		      regmbc('l'); regmbc(0x13a); regmbc(0x13c);
+		      regmbc(0x13e); regmbc(0x140); regmbc(0x142);
+		      regmbc(0x19a); regmbc(0x1e37); regmbc(0x1e39);
+		      regmbc(0x1e3b); regmbc(0x1e3d); regmbc(0x2c61);
+		      return;
+	    case 'm': case 0x1d6f: case 0x1e3f: case 0x1e41: case 0x1e43:
+		      regmbc('m'); regmbc(0x1d6f); regmbc(0x1e3f);
+		      regmbc(0x1e41); regmbc(0x1e43);
+		      return;
+	    case 'n': case 0xf1: case 0x144: case 0x146: case 0x148:
+	    case 0x149: case 0x1f9: case 0x1d70: case 0x1d87:
+	    case 0x1e45: case 0x1e47: case 0x1e49: case 0x1e4b:
+	    case 0xa7a5:
+		      regmbc('n'); regmbc(0xf1); regmbc(0x144);
+		      regmbc(0x146); regmbc(0x148); regmbc(0x149);
+		      regmbc(0x1f9); regmbc(0x1d70); regmbc(0x1d87);
+		      regmbc(0x1e45); regmbc(0x1e47); regmbc(0x1e49);
+		      regmbc(0x1e4b); regmbc(0xa7a5);
+		      return;
+	    case 'o': case 0xf2: case 0xf3: case 0xf4: case 0xf5:
+	    case 0xf6: case 0xf8: case 0x14d: case 0x14f: case 0x151:
+	    case 0x1a1: case 0x1d2: case 0x1eb: case 0x1ed: case 0x1ff:
+	    case 0x20d: case 0x20f: case 0x22b: case 0x22d: case 0x22f:
+	    case 0x231: case 0x275: case 0x1e4d: case 0x1e4f:
+	    case 0x1e51: case 0x1e53: case 0x1ecd: case 0x1ecf:
+	    case 0x1ed1: case 0x1ed3: case 0x1ed5: case 0x1ed7:
+	    case 0x1ed9: case 0x1edb: case 0x1edd: case 0x1edf:
+	    case 0x1ee1: case 0x1ee3:
+		      regmbc('o'); regmbc(0xf2); regmbc(0xf3);
+		      regmbc(0xf4); regmbc(0xf5); regmbc(0xf6);
+		      regmbc(0xf8); regmbc(0x14d); regmbc(0x14f);
+		      regmbc(0x151); regmbc(0x1a1); regmbc(0x1d2);
+		      regmbc(0x1eb); regmbc(0x1ed); regmbc(0x1ff);
+		      regmbc(0x20d); regmbc(0x20f); regmbc(0x22b);
+		      regmbc(0x22d); regmbc(0x22f); regmbc(0x231);
+		      regmbc(0x275); regmbc(0x1e4d); regmbc(0x1e4f);
+		      regmbc(0x1e51); regmbc(0x1e53); regmbc(0x1ecd);
+		      regmbc(0x1ecf); regmbc(0x1ed1); regmbc(0x1ed3);
+		      regmbc(0x1ed5); regmbc(0x1ed7); regmbc(0x1ed9);
+		      regmbc(0x1edb); regmbc(0x1edd); regmbc(0x1edf);
+		      regmbc(0x1ee1); regmbc(0x1ee3);
+		      return;
+	    case 'p': case 0x1a5: case 0x1d71: case 0x1d88: case 0x1d7d:
+	    case 0x1e55: case 0x1e57:
+		      regmbc('p'); regmbc(0x1a5); regmbc(0x1d71);
+		      regmbc(0x1d7d); regmbc(0x1d88); regmbc(0x1e55);
+		      regmbc(0x1e57);
+		      return;
+	    case 'q': case 0x24b: case 0x2a0:
+		      regmbc('q'); regmbc(0x24b); regmbc(0x2a0);
+		      return;
+	    case 'r': case 0x155: case 0x157: case 0x159: case 0x211:
+	    case 0x213: case 0x24d: case 0x27d: case 0x1d72: case 0x1d73:
+	    case 0x1d89: case 0x1e59: case 0x1e5b: case 0x1e5d: case 0x1e5f:
+	    case 0xa7a7:
+		      regmbc('r'); regmbc(0x155); regmbc(0x157);
+		      regmbc(0x159); regmbc(0x211); regmbc(0x213);
+		      regmbc(0x24d); regmbc(0x1d72); regmbc(0x1d73);
+		      regmbc(0x1d89); regmbc(0x1e59); regmbc(0x27d);
+		      regmbc(0x1e5b); regmbc(0x1e5d); regmbc(0x1e5f);
+		      regmbc(0xa7a7);
+		      return;
+	    case 's': case 0x15b: case 0x15d: case 0x15f: case 0x161:
+	    case 0x1e61: case 0x219: case 0x23f: case 0x1d74: case 0x1d8a:
+	    case 0x1e63: case 0x1e65: case 0x1e67: case 0x1e69: case 0xa7a9:
+		      regmbc('s'); regmbc(0x15b); regmbc(0x15d);
+		      regmbc(0x15f); regmbc(0x161); regmbc(0x23f);
+		      regmbc(0x219); regmbc(0x1d74); regmbc(0x1d8a);
+		      regmbc(0x1e61); regmbc(0x1e63); regmbc(0x1e65);
+		      regmbc(0x1e67); regmbc(0x1e69); regmbc(0xa7a9);
+		      return;
+	    case 't': case 0x163: case 0x165: case 0x167: case 0x1ab:
+	    case 0x1ad: case 0x21b: case 0x288: case 0x1d75: case 0x1e6b:
+	    case 0x1e6d: case 0x1e6f: case 0x1e71: case 0x1e97: case 0x2c66:
+		      regmbc('t'); regmbc(0x163); regmbc(0x165);
+		      regmbc(0x167); regmbc(0x1ab); regmbc(0x21b);
+		      regmbc(0x1ad); regmbc(0x288); regmbc(0x1d75);
+		      regmbc(0x1e6b); regmbc(0x1e6d); regmbc(0x1e6f);
+		      regmbc(0x1e71); regmbc(0x1e97); regmbc(0x2c66);
+		      return;
+	    case 'u': case 0xf9: case 0xfa: case 0xfb: case 0xfc:
+	    case 0x169: case 0x16b: case 0x16d: case 0x16f:
+	    case 0x171: case 0x173: case 0x1b0: case 0x1d4:
+	    case 0x1d6: case 0x1d8: case 0x1da: case 0x1dc:
+	    case 0x215: case 0x217: case 0x289: case 0x1e73:
+	    case 0x1d7e: case 0x1d99: case 0x1e75: case 0x1e77:
+	    case 0x1e79: case 0x1e7b: case 0x1ee5: case 0x1ee7:
+	    case 0x1ee9: case 0x1eeb: case 0x1eed: case 0x1eef:
+	    case 0x1ef1:
+		      regmbc('u'); regmbc(0xf9); regmbc(0xfa);
+		      regmbc(0xfb); regmbc(0xfc); regmbc(0x169);
+		      regmbc(0x16b); regmbc(0x16d); regmbc(0x16f);
+		      regmbc(0x171); regmbc(0x173); regmbc(0x1d6);
+		      regmbc(0x1d8); regmbc(0x1da); regmbc(0x1dc);
+		      regmbc(0x215); regmbc(0x217); regmbc(0x1b0);
+		      regmbc(0x1d4); regmbc(0x289); regmbc(0x1d7e);
+		      regmbc(0x1d99); regmbc(0x1e73); regmbc(0x1e75);
+		      regmbc(0x1e77); regmbc(0x1e79); regmbc(0x1e7b);
+		      regmbc(0x1ee5); regmbc(0x1ee7); regmbc(0x1ee9);
+		      regmbc(0x1eeb); regmbc(0x1eed); regmbc(0x1eef);
+		      regmbc(0x1ef1);
+		      return;
+	    case 'v': case 0x28b: case 0x1d8c: case 0x1e7d: case 0x1e7f:
+		      regmbc('v'); regmbc(0x28b); regmbc(0x1d8c);
+		      regmbc(0x1e7d); regmbc(0x1e7f);
+		      return;
+	    case 'w': case 0x175: case 0x1e81: case 0x1e83:
+	    case 0x1e85: case 0x1e87: case 0x1e89: case 0x1e98:
+		      regmbc('w'); regmbc(0x175); regmbc(0x1e81);
+		      regmbc(0x1e83); regmbc(0x1e85); regmbc(0x1e87);
+		      regmbc(0x1e89); regmbc(0x1e98);
+		      return;
+	    case 'x': case 0x1e8b: case 0x1e8d:
+		      regmbc('x'); regmbc(0x1e8b); regmbc(0x1e8d);
+		      return;
+	    case 'y': case 0xfd: case 0xff: case 0x177: case 0x1b4:
+	    case 0x233: case 0x24f: case 0x1e8f: case 0x1e99: case 0x1ef3:
+	    case 0x1ef5: case 0x1ef7: case 0x1ef9:
+		      regmbc('y'); regmbc(0xfd); regmbc(0xff);
+		      regmbc(0x177); regmbc(0x1b4); regmbc(0x233);
+		      regmbc(0x24f); regmbc(0x1e8f); regmbc(0x1e99);
+		      regmbc(0x1ef3); regmbc(0x1ef5); regmbc(0x1ef7);
+		      regmbc(0x1ef9);
+		      return;
+	    case 'z': case 0x17a: case 0x17c: case 0x17e: case 0x1b6:
+	    case 0x1d76: case 0x1d8e: case 0x1e91: case 0x1e93:
+	    case 0x1e95: case 0x2c6c:
+		      regmbc('z'); regmbc(0x17a); regmbc(0x17c);
+		      regmbc(0x17e); regmbc(0x1b6); regmbc(0x1d76);
+		      regmbc(0x1d8e); regmbc(0x1e91); regmbc(0x1e93);
+		      regmbc(0x1e95); regmbc(0x2c6c);
+		      return;
+	}
+    }
+    regmbc(c);
+}
+
+/*
+ * Emit a node.
+ * Return pointer to generated code.
+ */
+    static char_u *
+regnode(int op)
+{
+    char_u  *ret;
+
+    ret = regcode;
+    if (ret == JUST_CALC_SIZE)
+	regsize += 3;
+    else
+    {
+	*regcode++ = op;
+	*regcode++ = NUL;		// Null "next" pointer.
+	*regcode++ = NUL;
+    }
+    return ret;
+}
+
+/*
+ * Write a long as four bytes at "p" and return pointer to the next char.
+ */
+    static char_u *
+re_put_long(char_u *p, long_u val)
+{
+    *p++ = (char_u) ((val >> 24) & 0377);
+    *p++ = (char_u) ((val >> 16) & 0377);
+    *p++ = (char_u) ((val >> 8) & 0377);
+    *p++ = (char_u) (val & 0377);
+    return p;
+}
+
+/*
+ * regnext - dig the "next" pointer out of a node
+ * Returns NULL when calculating size, when there is no next item and when
+ * there is an error.
+ */
+    static char_u *
+regnext(char_u *p)
+{
+    int	    offset;
+
+    if (p == JUST_CALC_SIZE || reg_toolong)
+	return NULL;
+
+    offset = NEXT(p);
+    if (offset == 0)
+	return NULL;
+
+    if (OP(p) == BACK)
+	return p - offset;
+    else
+	return p + offset;
+}
+
+/*
+ * Set the next-pointer at the end of a node chain.
+ */
+    static void
+regtail(char_u *p, char_u *val)
+{
+    char_u	*scan;
+    char_u	*temp;
+    int		offset;
+
+    if (p == JUST_CALC_SIZE)
+	return;
+
+    // Find last node.
+    scan = p;
+    for (;;)
+    {
+	temp = regnext(scan);
+	if (temp == NULL)
+	    break;
+	scan = temp;
+    }
+
+    if (OP(scan) == BACK)
+	offset = (int)(scan - val);
+    else
+	offset = (int)(val - scan);
+    // When the offset uses more than 16 bits it can no longer fit in the two
+    // bytes available.  Use a global flag to avoid having to check return
+    // values in too many places.
+    if (offset > 0xffff)
+	reg_toolong = TRUE;
+    else
+    {
+	*(scan + 1) = (char_u) (((unsigned)offset >> 8) & 0377);
+	*(scan + 2) = (char_u) (offset & 0377);
+    }
+}
+
+/*
+ * Like regtail, on item after a BRANCH; nop if none.
+ */
+    static void
+regoptail(char_u *p, char_u *val)
+{
+    // When op is neither BRANCH nor BRACE_COMPLEX0-9, it is "operandless"
+    if (p == NULL || p == JUST_CALC_SIZE
+	    || (OP(p) != BRANCH
+		&& (OP(p) < BRACE_COMPLEX || OP(p) > BRACE_COMPLEX + 9)))
+	return;
+    regtail(OPERAND(p), val);
+}
+
+/*
+ * Insert an operator in front of already-emitted operand
+ *
+ * Means relocating the operand.
+ */
+    static void
+reginsert(int op, char_u *opnd)
+{
+    char_u	*src;
+    char_u	*dst;
+    char_u	*place;
+
+    if (regcode == JUST_CALC_SIZE)
+    {
+	regsize += 3;
+	return;
+    }
+    src = regcode;
+    regcode += 3;
+    dst = regcode;
+    while (src > opnd)
+	*--dst = *--src;
+
+    place = opnd;		// Op node, where operand used to be.
+    *place++ = op;
+    *place++ = NUL;
+    *place = NUL;
+}
+
+/*
+ * Insert an operator in front of already-emitted operand.
+ * Add a number to the operator.
+ */
+    static void
+reginsert_nr(int op, long val, char_u *opnd)
+{
+    char_u	*src;
+    char_u	*dst;
+    char_u	*place;
+
+    if (regcode == JUST_CALC_SIZE)
+    {
+	regsize += 7;
+	return;
+    }
+    src = regcode;
+    regcode += 7;
+    dst = regcode;
+    while (src > opnd)
+	*--dst = *--src;
+
+    place = opnd;		// Op node, where operand used to be.
+    *place++ = op;
+    *place++ = NUL;
+    *place++ = NUL;
+    re_put_long(place, (long_u)val);
+}
+
+/*
+ * Insert an operator in front of already-emitted operand.
+ * The operator has the given limit values as operands.  Also set next pointer.
+ *
+ * Means relocating the operand.
+ */
+    static void
+reginsert_limits(
+    int		op,
+    long	minval,
+    long	maxval,
+    char_u	*opnd)
+{
+    char_u	*src;
+    char_u	*dst;
+    char_u	*place;
+
+    if (regcode == JUST_CALC_SIZE)
+    {
+	regsize += 11;
+	return;
+    }
+    src = regcode;
+    regcode += 11;
+    dst = regcode;
+    while (src > opnd)
+	*--dst = *--src;
+
+    place = opnd;		// Op node, where operand used to be.
+    *place++ = op;
+    *place++ = NUL;
+    *place++ = NUL;
+    place = re_put_long(place, (long_u)minval);
+    place = re_put_long(place, (long_u)maxval);
+    regtail(opnd, place);
+}
+
+/*
+ * Return TRUE if the back reference is legal. We must have seen the close
+ * brace.
+ * TODO: Should also check that we don't refer to something that is repeated
+ * (+*=): what instance of the repetition should we match?
+ */
+    static int
+seen_endbrace(int refnum)
+{
+    if (!had_endbrace[refnum])
+    {
+	char_u *p;
+
+	// Trick: check if "@<=" or "@<!" follows, in which case
+	// the \1 can appear before the referenced match.
+	for (p = regparse; *p != NUL; ++p)
+	    if (p[0] == '@' && p[1] == '<' && (p[2] == '!' || p[2] == '='))
+		break;
+	if (*p == NUL)
+	{
+	    emsg(_(e_illegal_back_reference));
+	    rc_did_emsg = TRUE;
+	    return FALSE;
+	}
+    }
+    return TRUE;
+}
+
+/*
+ * Parse the lowest level.
+ *
+ * Optimization:  gobbles an entire sequence of ordinary characters so that
+ * it can turn them into a single node, which is smaller to store and
+ * faster to run.  Don't do this when one_exactly is set.
+ */
+    static char_u *
+regatom(int *flagp)
+{
+    char_u	    *ret;
+    int		    flags;
+    int		    c;
+    char_u	    *p;
+    int		    extra = 0;
+    int		    save_prev_at_start = prev_at_start;
+
+    *flagp = WORST;		// Tentatively.
+
+    c = getchr();
+    switch (c)
+    {
+      case Magic('^'):
+	ret = regnode(BOL);
+	break;
+
+      case Magic('$'):
+	ret = regnode(EOL);
+#if defined(FEAT_SYN_HL) || defined(PROTO)
+	had_eol = TRUE;
+#endif
+	break;
+
+      case Magic('<'):
+	ret = regnode(BOW);
+	break;
+
+      case Magic('>'):
+	ret = regnode(EOW);
+	break;
+
+      case Magic('_'):
+	c = no_Magic(getchr());
+	if (c == '^')		// "\_^" is start-of-line
+	{
+	    ret = regnode(BOL);
+	    break;
+	}
+	if (c == '$')		// "\_$" is end-of-line
+	{
+	    ret = regnode(EOL);
+#if defined(FEAT_SYN_HL) || defined(PROTO)
+	    had_eol = TRUE;
+#endif
+	    break;
+	}
+
+	extra = ADD_NL;
+	*flagp |= HASNL;
+
+	// "\_[" is character range plus newline
+	if (c == '[')
+	    goto collection;
+
+	// "\_x" is character class plus newline
+	// FALLTHROUGH
+
+	// Character classes.
+      case Magic('.'):
+      case Magic('i'):
+      case Magic('I'):
+      case Magic('k'):
+      case Magic('K'):
+      case Magic('f'):
+      case Magic('F'):
+      case Magic('p'):
+      case Magic('P'):
+      case Magic('s'):
+      case Magic('S'):
+      case Magic('d'):
+      case Magic('D'):
+      case Magic('x'):
+      case Magic('X'):
+      case Magic('o'):
+      case Magic('O'):
+      case Magic('w'):
+      case Magic('W'):
+      case Magic('h'):
+      case Magic('H'):
+      case Magic('a'):
+      case Magic('A'):
+      case Magic('l'):
+      case Magic('L'):
+      case Magic('u'):
+      case Magic('U'):
+	p = vim_strchr(classchars, no_Magic(c));
+	if (p == NULL)
+	    EMSG_RET_NULL(_(e_invalid_use_of_underscore));
+
+	// When '.' is followed by a composing char ignore the dot, so that
+	// the composing char is matched here.
+	if (enc_utf8 && c == Magic('.') && utf_iscomposing(peekchr()))
+	{
+	    c = getchr();
+	    goto do_multibyte;
+	}
+	ret = regnode(classcodes[p - classchars] + extra);
+	*flagp |= HASWIDTH | SIMPLE;
+	break;
+
+      case Magic('n'):
+	if (reg_string)
+	{
+	    // In a string "\n" matches a newline character.
+	    ret = regnode(EXACTLY);
+	    regc(NL);
+	    regc(NUL);
+	    *flagp |= HASWIDTH | SIMPLE;
+	}
+	else
+	{
+	    // In buffer text "\n" matches the end of a line.
+	    ret = regnode(NEWL);
+	    *flagp |= HASWIDTH | HASNL;
+	}
+	break;
+
+      case Magic('('):
+	if (one_exactly)
+	    EMSG_ONE_RET_NULL;
+	ret = reg(REG_PAREN, &flags);
+	if (ret == NULL)
+	    return NULL;
+	*flagp |= flags & (HASWIDTH | SPSTART | HASNL | HASLOOKBH);
+	break;
+
+      case NUL:
+      case Magic('|'):
+      case Magic('&'):
+      case Magic(')'):
+	if (one_exactly)
+	    EMSG_ONE_RET_NULL;
+	// Supposed to be caught earlier.
+	IEMSG_RET_NULL(e_internal_error_in_regexp);
+	// NOTREACHED
+
+      case Magic('='):
+      case Magic('?'):
+      case Magic('+'):
+      case Magic('@'):
+      case Magic('{'):
+      case Magic('*'):
+	c = no_Magic(c);
+	EMSG3_RET_NULL(_(e_str_chr_follows_nothing),
+		(c == '*' ? reg_magic >= MAGIC_ON : reg_magic == MAGIC_ALL), c);
+	// NOTREACHED
+
+      case Magic('~'):		// previous substitute pattern
+	    if (reg_prev_sub != NULL)
+	    {
+		char_u	    *lp;
+
+		ret = regnode(EXACTLY);
+		lp = reg_prev_sub;
+		while (*lp != NUL)
+		    regc(*lp++);
+		regc(NUL);
+		if (*reg_prev_sub != NUL)
+		{
+		    *flagp |= HASWIDTH;
+		    if ((lp - reg_prev_sub) == 1)
+			*flagp |= SIMPLE;
+		}
+	    }
+	    else
+		EMSG_RET_NULL(_(e_no_previous_substitute_regular_expression));
+	    break;
+
+      case Magic('1'):
+      case Magic('2'):
+      case Magic('3'):
+      case Magic('4'):
+      case Magic('5'):
+      case Magic('6'):
+      case Magic('7'):
+      case Magic('8'):
+      case Magic('9'):
+	    {
+		int		    refnum;
+
+		refnum = c - Magic('0');
+		if (!seen_endbrace(refnum))
+		    return NULL;
+		ret = regnode(BACKREF + refnum);
+	    }
+	    break;
+
+      case Magic('z'):
+	{
+	    c = no_Magic(getchr());
+	    switch (c)
+	    {
+#ifdef FEAT_SYN_HL
+		case '(': if ((reg_do_extmatch & REX_SET) == 0)
+			      EMSG_RET_NULL(_(e_z_not_allowed_here));
+			  if (one_exactly)
+			      EMSG_ONE_RET_NULL;
+			  ret = reg(REG_ZPAREN, &flags);
+			  if (ret == NULL)
+			      return NULL;
+			  *flagp |= flags & (HASWIDTH|SPSTART|HASNL|HASLOOKBH);
+			  re_has_z = REX_SET;
+			  break;
+
+		case '1':
+		case '2':
+		case '3':
+		case '4':
+		case '5':
+		case '6':
+		case '7':
+		case '8':
+		case '9': if ((reg_do_extmatch & REX_USE) == 0)
+			      EMSG_RET_NULL(_(e_z1_z9_not_allowed_here));
+			  ret = regnode(ZREF + c - '0');
+			  re_has_z = REX_USE;
+			  break;
+#endif
+
+		case 's': ret = regnode(MOPEN + 0);
+			  if (re_mult_next("\\zs") == FAIL)
+			      return NULL;
+			  break;
+
+		case 'e': ret = regnode(MCLOSE + 0);
+			  if (re_mult_next("\\ze") == FAIL)
+			      return NULL;
+			  break;
+
+		default:  EMSG_RET_NULL(_(e_invalid_character_after_bsl_z));
+	    }
+	}
+	break;
+
+      case Magic('%'):
+	{
+	    c = no_Magic(getchr());
+	    switch (c)
+	    {
+		// () without a back reference
+		case '(':
+		    if (one_exactly)
+			EMSG_ONE_RET_NULL;
+		    ret = reg(REG_NPAREN, &flags);
+		    if (ret == NULL)
+			return NULL;
+		    *flagp |= flags & (HASWIDTH | SPSTART | HASNL | HASLOOKBH);
+		    break;
+
+		// Catch \%^ and \%$ regardless of where they appear in the
+		// pattern -- regardless of whether or not it makes sense.
+		case '^':
+		    ret = regnode(RE_BOF);
+		    break;
+
+		case '$':
+		    ret = regnode(RE_EOF);
+		    break;
+
+		case '#':
+		    if (regparse[0] == '=' && regparse[1] >= 48
+							  && regparse[1] <= 50)
+		    {
+			// misplaced \%#=1
+			semsg(_(e_atom_engine_must_be_at_start_of_pattern),
+								  regparse[1]);
+			return FAIL;
+		    }
+		    ret = regnode(CURSOR);
+		    break;
+
+		case 'V':
+		    ret = regnode(RE_VISUAL);
+		    break;
+
+		case 'C':
+		    ret = regnode(RE_COMPOSING);
+		    break;
+
+		// \%[abc]: Emit as a list of branches, all ending at the last
+		// branch which matches nothing.
+		case '[':
+			  if (one_exactly)	// doesn't nest
+			      EMSG_ONE_RET_NULL;
+			  {
+			      char_u	*lastbranch;
+			      char_u	*lastnode = NULL;
+			      char_u	*br;
+
+			      ret = NULL;
+			      while ((c = getchr()) != ']')
+			      {
+				  if (c == NUL)
+				      EMSG2_RET_NULL(_(e_missing_sb_after_str),
+						      reg_magic == MAGIC_ALL);
+				  br = regnode(BRANCH);
+				  if (ret == NULL)
+				      ret = br;
+				  else
+				  {
+				      regtail(lastnode, br);
+				      if (reg_toolong)
+					  return NULL;
+				  }
+
+				  ungetchr();
+				  one_exactly = TRUE;
+				  lastnode = regatom(flagp);
+				  one_exactly = FALSE;
+				  if (lastnode == NULL)
+				      return NULL;
+			      }
+			      if (ret == NULL)
+				  EMSG2_RET_NULL(_(e_empty_str_brackets),
+						      reg_magic == MAGIC_ALL);
+			      lastbranch = regnode(BRANCH);
+			      br = regnode(NOTHING);
+			      if (ret != JUST_CALC_SIZE)
+			      {
+				  regtail(lastnode, br);
+				  regtail(lastbranch, br);
+				  // connect all branches to the NOTHING
+				  // branch at the end
+				  for (br = ret; br != lastnode; )
+				  {
+				      if (OP(br) == BRANCH)
+				      {
+					  regtail(br, lastbranch);
+					  if (reg_toolong)
+					      return NULL;
+					  br = OPERAND(br);
+				      }
+				      else
+					  br = regnext(br);
+				  }
+			      }
+			      *flagp &= ~(HASWIDTH | SIMPLE);
+			      break;
+			  }
+
+		case 'd':   // %d123 decimal
+		case 'o':   // %o123 octal
+		case 'x':   // %xab hex 2
+		case 'u':   // %uabcd hex 4
+		case 'U':   // %U1234abcd hex 8
+			  {
+			      long i;
+
+			      switch (c)
+			      {
+				  case 'd': i = getdecchrs(); break;
+				  case 'o': i = getoctchrs(); break;
+				  case 'x': i = gethexchrs(2); break;
+				  case 'u': i = gethexchrs(4); break;
+				  case 'U': i = gethexchrs(8); break;
+				  default:  i = -1; break;
+			      }
+
+			      if (i < 0 || i > INT_MAX)
+				  EMSG2_RET_NULL(
+					    _(e_invalid_character_after_str_2),
+						       reg_magic == MAGIC_ALL);
+			      if (use_multibytecode(i))
+				  ret = regnode(MULTIBYTECODE);
+			      else
+				  ret = regnode(EXACTLY);
+			      if (i == 0)
+				  regc(0x0a);
+			      else
+				  regmbc(i);
+			      regc(NUL);
+			      *flagp |= HASWIDTH;
+			      break;
+			  }
+
+		default:
+			  if (VIM_ISDIGIT(c) || c == '<' || c == '>'
+						|| c == '\'' || c == '.')
+			  {
+			      long_u	n = 0;
+			      int	cmp;
+			      int	cur = FALSE;
+			      int	got_digit = FALSE;
+
+			      cmp = c;
+			      if (cmp == '<' || cmp == '>')
+				  c = getchr();
+			      if (no_Magic(c) == '.')
+			      {
+				  cur = TRUE;
+				  c = getchr();
+			      }
+			      while (VIM_ISDIGIT(c))
+			      {
+				  got_digit = TRUE;
+				  n = n * 10 + (c - '0');
+				  c = getchr();
+			      }
+			      if (c == '\'' && n == 0)
+			      {
+				  // "\%'m", "\%<'m" and "\%>'m": Mark
+				  c = getchr();
+				  ret = regnode(RE_MARK);
+				  if (ret == JUST_CALC_SIZE)
+				      regsize += 2;
+				  else
+				  {
+				      *regcode++ = c;
+				      *regcode++ = cmp;
+				  }
+				  break;
+			      }
+			      else if ((c == 'l' || c == 'c' || c == 'v')
+					  && (cur || got_digit))
+			      {
+				  if (cur && n)
+				  {
+				    semsg(_(e_regexp_number_after_dot_pos_search_chr),
+								  no_Magic(c));
+				    rc_did_emsg = TRUE;
+				    return NULL;
+				  }
+				  if (c == 'l')
+				  {
+				      if (cur)
+					  n = curwin->w_cursor.lnum;
+				      ret = regnode(RE_LNUM);
+				      if (save_prev_at_start)
+					  at_start = TRUE;
+				  }
+				  else if (c == 'c')
+				  {
+				      if (cur)
+				      {
+					  n = curwin->w_cursor.col;
+					  n++;
+				      }
+				      ret = regnode(RE_COL);
+				  }
+				  else
+				  {
+				      if (cur)
+				      {
+					  colnr_T vcol = 0;
+
+					  getvvcol(curwin, &curwin->w_cursor,
+							    NULL, NULL, &vcol);
+					  ++vcol;
+					  n = vcol;
+				      }
+				      ret = regnode(RE_VCOL);
+				  }
+				  if (ret == JUST_CALC_SIZE)
+				      regsize += 5;
+				  else
+				  {
+				      // put the number and the optional
+				      // comparator after the opcode
+				      regcode = re_put_long(regcode, n);
+				      *regcode++ = cmp;
+				  }
+				  break;
+			      }
+			  }
+
+			  EMSG2_RET_NULL(_(e_invalid_character_after_str),
+						      reg_magic == MAGIC_ALL);
+	    }
+	}
+	break;
+
+      case Magic('['):
+collection:
+	{
+	    char_u	*lp;
+
+	    // If there is no matching ']', we assume the '[' is a normal
+	    // character.  This makes 'incsearch' and ":help [" work.
+	    lp = skip_anyof(regparse);
+	    if (*lp == ']')	// there is a matching ']'
+	    {
+		int	startc = -1;	// > 0 when next '-' is a range
+		int	endc;
+
+		// In a character class, different parsing rules apply.
+		// Not even \ is special anymore, nothing is.
+		if (*regparse == '^')	    // Complement of range.
+		{
+		    ret = regnode(ANYBUT + extra);
+		    regparse++;
+		}
+		else
+		    ret = regnode(ANYOF + extra);
+
+		// At the start ']' and '-' mean the literal character.
+		if (*regparse == ']' || *regparse == '-')
+		{
+		    startc = *regparse;
+		    regc(*regparse++);
+		}
+
+		while (*regparse != NUL && *regparse != ']')
+		{
+		    if (*regparse == '-')
+		    {
+			++regparse;
+			// The '-' is not used for a range at the end and
+			// after or before a '\n'.
+			if (*regparse == ']' || *regparse == NUL
+				|| startc == -1
+				|| (regparse[0] == '\\' && regparse[1] == 'n'))
+			{
+			    regc('-');
+			    startc = '-';	// [--x] is a range
+			}
+			else
+			{
+			    // Also accept "a-[.z.]"
+			    endc = 0;
+			    if (*regparse == '[')
+				endc = get_coll_element(&regparse);
+			    if (endc == 0)
+			    {
+				if (has_mbyte)
+				    endc = mb_ptr2char_adv(&regparse);
+				else
+				    endc = *regparse++;
+			    }
+
+			    // Handle \o40, \x20 and \u20AC style sequences
+			    if (endc == '\\' && !reg_cpo_lit && !reg_cpo_bsl)
+				endc = coll_get_char();
+
+			    if (startc > endc)
+				EMSG_RET_NULL(_(e_reverse_range_in_character_class));
+			    if (has_mbyte && ((*mb_char2len)(startc) > 1
+						 || (*mb_char2len)(endc) > 1))
+			    {
+				// Limit to a range of 256 chars.
+				if (endc > startc + 256)
+				    EMSG_RET_NULL(_(e_range_too_large_in_character_class));
+				while (++startc <= endc)
+				    regmbc(startc);
+			    }
+			    else
+			    {
+				while (++startc <= endc)
+				    regc(startc);
+			    }
+			    startc = -1;
+			}
+		    }
+		    // Only "\]", "\^", "\]" and "\\" are special in Vi.  Vim
+		    // accepts "\t", "\e", etc., but only when the 'l' flag in
+		    // 'cpoptions' is not included.
+		    // Posix doesn't recognize backslash at all.
+		    else if (*regparse == '\\'
+			    && !reg_cpo_bsl
+			    && (vim_strchr(REGEXP_INRANGE, regparse[1]) != NULL
+				|| (!reg_cpo_lit
+				    && vim_strchr(REGEXP_ABBR,
+						       regparse[1]) != NULL)))
+		    {
+			regparse++;
+			if (*regparse == 'n')
+			{
+			    // '\n' in range: also match NL
+			    if (ret != JUST_CALC_SIZE)
+			    {
+				// Using \n inside [^] does not change what
+				// matches. "[^\n]" is the same as ".".
+				if (*ret == ANYOF)
+				{
+				    *ret = ANYOF + ADD_NL;
+				    *flagp |= HASNL;
+				}
+				// else: must have had a \n already
+			    }
+			    regparse++;
+			    startc = -1;
+			}
+			else if (*regparse == 'd'
+				|| *regparse == 'o'
+				|| *regparse == 'x'
+				|| *regparse == 'u'
+				|| *regparse == 'U')
+			{
+			    startc = coll_get_char();
+			    if (startc == 0)
+				regc(0x0a);
+			    else
+				regmbc(startc);
+			}
+			else
+			{
+			    startc = backslash_trans(*regparse++);
+			    regc(startc);
+			}
+		    }
+		    else if (*regparse == '[')
+		    {
+			int c_class;
+			int cu;
+
+			c_class = get_char_class(&regparse);
+			startc = -1;
+			// Characters assumed to be 8 bits!
+			switch (c_class)
+			{
+			    case CLASS_NONE:
+				c_class = get_equi_class(&regparse);
+				if (c_class != 0)
+				{
+				    // produce equivalence class
+				    reg_equi_class(c_class);
+				}
+				else if ((c_class =
+					    get_coll_element(&regparse)) != 0)
+				{
+				    // produce a collating element
+				    regmbc(c_class);
+				}
+				else
+				{
+				    // literal '[', allow [[-x] as a range
+				    startc = *regparse++;
+				    regc(startc);
+				}
+				break;
+			    case CLASS_ALNUM:
+				for (cu = 1; cu < 128; cu++)
+				    if (isalnum(cu))
+					regmbc(cu);
+				break;
+			    case CLASS_ALPHA:
+				for (cu = 1; cu < 128; cu++)
+				    if (isalpha(cu))
+					regmbc(cu);
+				break;
+			    case CLASS_BLANK:
+				regc(' ');
+				regc('\t');
+				break;
+			    case CLASS_CNTRL:
+				for (cu = 1; cu <= 127; cu++)
+				    if (iscntrl(cu))
+					regmbc(cu);
+				break;
+			    case CLASS_DIGIT:
+				for (cu = 1; cu <= 127; cu++)
+				    if (VIM_ISDIGIT(cu))
+					regmbc(cu);
+				break;
+			    case CLASS_GRAPH:
+				for (cu = 1; cu <= 127; cu++)
+				    if (isgraph(cu))
+					regmbc(cu);
+				break;
+			    case CLASS_LOWER:
+				for (cu = 1; cu <= 255; cu++)
+				    if (MB_ISLOWER(cu) && cu != 170
+								 && cu != 186)
+					regmbc(cu);
+				break;
+			    case CLASS_PRINT:
+				for (cu = 1; cu <= 255; cu++)
+				    if (vim_isprintc(cu))
+					regmbc(cu);
+				break;
+			    case CLASS_PUNCT:
+				for (cu = 1; cu < 128; cu++)
+				    if (ispunct(cu))
+					regmbc(cu);
+				break;
+			    case CLASS_SPACE:
+				for (cu = 9; cu <= 13; cu++)
+				    regc(cu);
+				regc(' ');
+				break;
+			    case CLASS_UPPER:
+				for (cu = 1; cu <= 255; cu++)
+				    if (MB_ISUPPER(cu))
+					regmbc(cu);
+				break;
+			    case CLASS_XDIGIT:
+				for (cu = 1; cu <= 255; cu++)
+				    if (vim_isxdigit(cu))
+					regmbc(cu);
+				break;
+			    case CLASS_TAB:
+				regc('\t');
+				break;
+			    case CLASS_RETURN:
+				regc('\r');
+				break;
+			    case CLASS_BACKSPACE:
+				regc('\b');
+				break;
+			    case CLASS_ESCAPE:
+				regc('\033');
+				break;
+			    case CLASS_IDENT:
+				for (cu = 1; cu <= 255; cu++)
+				    if (vim_isIDc(cu))
+					regmbc(cu);
+				break;
+			    case CLASS_KEYWORD:
+				for (cu = 1; cu <= 255; cu++)
+				    if (reg_iswordc(cu))
+					regmbc(cu);
+				break;
+			    case CLASS_FNAME:
+				for (cu = 1; cu <= 255; cu++)
+				    if (vim_isfilec(cu))
+					regmbc(cu);
+				break;
+			}
+		    }
+		    else
+		    {
+			if (has_mbyte)
+			{
+			    int	len;
+
+			    // produce a multibyte character, including any
+			    // following composing characters
+			    startc = mb_ptr2char(regparse);
+			    len = (*mb_ptr2len)(regparse);
+			    if (enc_utf8 && utf_char2len(startc) != len)
+				startc = -1;	// composing chars
+			    while (--len >= 0)
+				regc(*regparse++);
+			}
+			else
+			{
+			    startc = *regparse++;
+			    regc(startc);
+			}
+		    }
+		}
+		regc(NUL);
+		prevchr_len = 1;	// last char was the ']'
+		if (*regparse != ']')
+		    EMSG_RET_NULL(_(e_too_many_brackets));  // Cannot happen?
+		skipchr();	    // let's be friends with the lexer again
+		*flagp |= HASWIDTH | SIMPLE;
+		break;
+	    }
+	    else if (reg_strict)
+		EMSG2_RET_NULL(_(e_missing_rsb_after_str_lsb),
+							reg_magic > MAGIC_OFF);
+	}
+	// FALLTHROUGH
+
+      default:
+	{
+	    int		len;
+
+	    // A multi-byte character is handled as a separate atom if it's
+	    // before a multi and when it's a composing char.
+	    if (use_multibytecode(c))
+	    {
+do_multibyte:
+		ret = regnode(MULTIBYTECODE);
+		regmbc(c);
+		*flagp |= HASWIDTH | SIMPLE;
+		break;
+	    }
+
+	    ret = regnode(EXACTLY);
+
+	    // Append characters as long as:
+	    // - there is no following multi, we then need the character in
+	    //   front of it as a single character operand
+	    // - not running into a Magic character
+	    // - "one_exactly" is not set
+	    // But always emit at least one character.  Might be a Multi,
+	    // e.g., a "[" without matching "]".
+	    for (len = 0; c != NUL && (len == 0
+			|| (re_multi_type(peekchr()) == NOT_MULTI
+			    && !one_exactly
+			    && !is_Magic(c))); ++len)
+	    {
+		c = no_Magic(c);
+		if (has_mbyte)
+		{
+		    regmbc(c);
+		    if (enc_utf8)
+		    {
+			int	l;
+
+			// Need to get composing character too.
+			for (;;)
+			{
+			    l = utf_ptr2len(regparse);
+			    if (!UTF_COMPOSINGLIKE(regparse, regparse + l))
+				break;
+			    regmbc(utf_ptr2char(regparse));
+			    skipchr();
+			}
+		    }
+		}
+		else
+		    regc(c);
+		c = getchr();
+	    }
+	    ungetchr();
+
+	    regc(NUL);
+	    *flagp |= HASWIDTH;
+	    if (len == 1)
+		*flagp |= SIMPLE;
+	}
+	break;
+    }
+
+    return ret;
+}
+
+/*
+ * Parse something followed by possible [*+=].
+ *
+ * Note that the branching code sequences used for = and the general cases
+ * of * and + are somewhat optimized:  they use the same NOTHING node as
+ * both the endmarker for their branch list and the body of the last branch.
+ * It might seem that this node could be dispensed with entirely, but the
+ * endmarker role is not redundant.
+ */
+    static char_u *
+regpiece(int *flagp)
+{
+    char_u	    *ret;
+    int		    op;
+    char_u	    *next;
+    int		    flags;
+    long	    minval;
+    long	    maxval;
+
+    ret = regatom(&flags);
+    if (ret == NULL)
+	return NULL;
+
+    op = peekchr();
+    if (re_multi_type(op) == NOT_MULTI)
+    {
+	*flagp = flags;
+	return ret;
+    }
+    // default flags
+    *flagp = (WORST | SPSTART | (flags & (HASNL | HASLOOKBH)));
+
+    skipchr();
+    switch (op)
+    {
+	case Magic('*'):
+	    if (flags & SIMPLE)
+		reginsert(STAR, ret);
+	    else
+	    {
+		// Emit x* as (x&|), where & means "self".
+		reginsert(BRANCH, ret); // Either x
+		regoptail(ret, regnode(BACK));	// and loop
+		regoptail(ret, ret);	// back
+		regtail(ret, regnode(BRANCH));	// or
+		regtail(ret, regnode(NOTHING)); // null.
+	    }
+	    break;
+
+	case Magic('+'):
+	    if (flags & SIMPLE)
+		reginsert(PLUS, ret);
+	    else
+	    {
+		// Emit x+ as x(&|), where & means "self".
+		next = regnode(BRANCH); // Either
+		regtail(ret, next);
+		regtail(regnode(BACK), ret);	// loop back
+		regtail(next, regnode(BRANCH)); // or
+		regtail(ret, regnode(NOTHING)); // null.
+	    }
+	    *flagp = (WORST | HASWIDTH | (flags & (HASNL | HASLOOKBH)));
+	    break;
+
+	case Magic('@'):
+	    {
+		int	lop = END;
+		long	nr;
+
+		nr = getdecchrs();
+		switch (no_Magic(getchr()))
+		{
+		    case '=': lop = MATCH; break;		  // \@=
+		    case '!': lop = NOMATCH; break;		  // \@!
+		    case '>': lop = SUBPAT; break;		  // \@>
+		    case '<': switch (no_Magic(getchr()))
+			      {
+				  case '=': lop = BEHIND; break;   // \@<=
+				  case '!': lop = NOBEHIND; break; // \@<!
+			      }
+		}
+		if (lop == END)
+		    EMSG2_RET_NULL(_(e_invalid_character_after_str_at),
+						      reg_magic == MAGIC_ALL);
+		// Look behind must match with behind_pos.
+		if (lop == BEHIND || lop == NOBEHIND)
+		{
+		    regtail(ret, regnode(BHPOS));
+		    *flagp |= HASLOOKBH;
+		}
+		regtail(ret, regnode(END)); // operand ends
+		if (lop == BEHIND || lop == NOBEHIND)
+		{
+		    if (nr < 0)
+			nr = 0; // no limit is same as zero limit
+		    reginsert_nr(lop, nr, ret);
+		}
+		else
+		    reginsert(lop, ret);
+		break;
+	    }
+
+	case Magic('?'):
+	case Magic('='):
+	    // Emit x= as (x|)
+	    reginsert(BRANCH, ret);		// Either x
+	    regtail(ret, regnode(BRANCH));	// or
+	    next = regnode(NOTHING);		// null.
+	    regtail(ret, next);
+	    regoptail(ret, next);
+	    break;
+
+	case Magic('{'):
+	    if (!read_limits(&minval, &maxval))
+		return NULL;
+	    if (flags & SIMPLE)
+	    {
+		reginsert(BRACE_SIMPLE, ret);
+		reginsert_limits(BRACE_LIMITS, minval, maxval, ret);
+	    }
+	    else
+	    {
+		if (num_complex_braces >= 10)
+		    EMSG2_RET_NULL(_(e_too_many_complex_str_curly),
+						      reg_magic == MAGIC_ALL);
+		reginsert(BRACE_COMPLEX + num_complex_braces, ret);
+		regoptail(ret, regnode(BACK));
+		regoptail(ret, ret);
+		reginsert_limits(BRACE_LIMITS, minval, maxval, ret);
+		++num_complex_braces;
+	    }
+	    if (minval > 0 && maxval > 0)
+		*flagp = (HASWIDTH | (flags & (HASNL | HASLOOKBH)));
+	    break;
+    }
+    if (re_multi_type(peekchr()) != NOT_MULTI)
+    {
+	// Can't have a multi follow a multi.
+	if (peekchr() == Magic('*'))
+	    EMSG2_RET_NULL(_(e_nested_str), reg_magic >= MAGIC_ON);
+	EMSG3_RET_NULL(_(e_nested_str_chr), reg_magic == MAGIC_ALL,
+							  no_Magic(peekchr()));
+    }
+
+    return ret;
+}
+
+/*
+ * Parse one alternative of an | or & operator.
+ * Implements the concatenation operator.
+ */
+    static char_u *
+regconcat(int *flagp)
+{
+    char_u	*first = NULL;
+    char_u	*chain = NULL;
+    char_u	*latest;
+    int		flags;
+    int		cont = TRUE;
+
+    *flagp = WORST;		// Tentatively.
+
+    while (cont)
+    {
+	switch (peekchr())
+	{
+	    case NUL:
+	    case Magic('|'):
+	    case Magic('&'):
+	    case Magic(')'):
+			    cont = FALSE;
+			    break;
+	    case Magic('Z'):
+			    regflags |= RF_ICOMBINE;
+			    skipchr_keepstart();
+			    break;
+	    case Magic('c'):
+			    regflags |= RF_ICASE;
+			    skipchr_keepstart();
+			    break;
+	    case Magic('C'):
+			    regflags |= RF_NOICASE;
+			    skipchr_keepstart();
+			    break;
+	    case Magic('v'):
+			    reg_magic = MAGIC_ALL;
+			    skipchr_keepstart();
+			    curchr = -1;
+			    break;
+	    case Magic('m'):
+			    reg_magic = MAGIC_ON;
+			    skipchr_keepstart();
+			    curchr = -1;
+			    break;
+	    case Magic('M'):
+			    reg_magic = MAGIC_OFF;
+			    skipchr_keepstart();
+			    curchr = -1;
+			    break;
+	    case Magic('V'):
+			    reg_magic = MAGIC_NONE;
+			    skipchr_keepstart();
+			    curchr = -1;
+			    break;
+	    default:
+			    latest = regpiece(&flags);
+			    if (latest == NULL || reg_toolong)
+				return NULL;
+			    *flagp |= flags & (HASWIDTH | HASNL | HASLOOKBH);
+			    if (chain == NULL)	// First piece.
+				*flagp |= flags & SPSTART;
+			    else
+				regtail(chain, latest);
+			    chain = latest;
+			    if (first == NULL)
+				first = latest;
+			    break;
+	}
+    }
+    if (first == NULL)		// Loop ran zero times.
+	first = regnode(NOTHING);
+    return first;
+}
+
+/*
+ * Parse one alternative of an | operator.
+ * Implements the & operator.
+ */
+    static char_u *
+regbranch(int *flagp)
+{
+    char_u	*ret;
+    char_u	*chain = NULL;
+    char_u	*latest;
+    int		flags;
+
+    *flagp = WORST | HASNL;		// Tentatively.
+
+    ret = regnode(BRANCH);
+    for (;;)
+    {
+	latest = regconcat(&flags);
+	if (latest == NULL)
+	    return NULL;
+	// If one of the branches has width, the whole thing has.  If one of
+	// the branches anchors at start-of-line, the whole thing does.
+	// If one of the branches uses look-behind, the whole thing does.
+	*flagp |= flags & (HASWIDTH | SPSTART | HASLOOKBH);
+	// If one of the branches doesn't match a line-break, the whole thing
+	// doesn't.
+	*flagp &= ~HASNL | (flags & HASNL);
+	if (chain != NULL)
+	    regtail(chain, latest);
+	if (peekchr() != Magic('&'))
+	    break;
+	skipchr();
+	regtail(latest, regnode(END)); // operand ends
+	if (reg_toolong)
+	    break;
+	reginsert(MATCH, latest);
+	chain = latest;
+    }
+
+    return ret;
+}
+
+/*
+ * Parse regular expression, i.e. main body or parenthesized thing.
+ *
+ * Caller must absorb opening parenthesis.
+ *
+ * Combining parenthesis handling with the base level of regular expression
+ * is a trifle forced, but the need to tie the tails of the branches to what
+ * follows makes it hard to avoid.
+ */
+    static char_u *
+reg(
+    int		paren,	// REG_NOPAREN, REG_PAREN, REG_NPAREN or REG_ZPAREN
+    int		*flagp)
+{
+    char_u	*ret;
+    char_u	*br;
+    char_u	*ender;
+    int		parno = 0;
+    int		flags;
+
+    *flagp = HASWIDTH;		// Tentatively.
+
+#ifdef FEAT_SYN_HL
+    if (paren == REG_ZPAREN)
+    {
+	// Make a ZOPEN node.
+	if (regnzpar >= NSUBEXP)
+	    EMSG_RET_NULL(_(e_too_many_z));
+	parno = regnzpar;
+	regnzpar++;
+	ret = regnode(ZOPEN + parno);
+    }
+    else
+#endif
+	if (paren == REG_PAREN)
+    {
+	// Make a MOPEN node.
+	if (regnpar >= NSUBEXP)
+	    EMSG2_RET_NULL(_(e_too_many_str_open), reg_magic == MAGIC_ALL);
+	parno = regnpar;
+	++regnpar;
+	ret = regnode(MOPEN + parno);
+    }
+    else if (paren == REG_NPAREN)
+    {
+	// Make a NOPEN node.
+	ret = regnode(NOPEN);
+    }
+    else
+	ret = NULL;
+
+    // Pick up the branches, linking them together.
+    br = regbranch(&flags);
+    if (br == NULL)
+	return NULL;
+    if (ret != NULL)
+	regtail(ret, br);	// [MZ]OPEN -> first.
+    else
+	ret = br;
+    // If one of the branches can be zero-width, the whole thing can.
+    // If one of the branches has * at start or matches a line-break, the
+    // whole thing can.
+    if (!(flags & HASWIDTH))
+	*flagp &= ~HASWIDTH;
+    *flagp |= flags & (SPSTART | HASNL | HASLOOKBH);
+    while (peekchr() == Magic('|'))
+    {
+	skipchr();
+	br = regbranch(&flags);
+	if (br == NULL || reg_toolong)
+	    return NULL;
+	regtail(ret, br);	// BRANCH -> BRANCH.
+	if (!(flags & HASWIDTH))
+	    *flagp &= ~HASWIDTH;
+	*flagp |= flags & (SPSTART | HASNL | HASLOOKBH);
+    }
+
+    // Make a closing node, and hook it on the end.
+    ender = regnode(
+#ifdef FEAT_SYN_HL
+	    paren == REG_ZPAREN ? ZCLOSE + parno :
+#endif
+	    paren == REG_PAREN ? MCLOSE + parno :
+	    paren == REG_NPAREN ? NCLOSE : END);
+    regtail(ret, ender);
+
+    // Hook the tails of the branches to the closing node.
+    for (br = ret; br != NULL; br = regnext(br))
+	regoptail(br, ender);
+
+    // Check for proper termination.
+    if (paren != REG_NOPAREN && getchr() != Magic(')'))
+    {
+#ifdef FEAT_SYN_HL
+	if (paren == REG_ZPAREN)
+	    EMSG_RET_NULL(_(e_unmatched_z));
+	else
+#endif
+	    if (paren == REG_NPAREN)
+	    EMSG2_RET_NULL(_(e_unmatched_str_percent_open), reg_magic == MAGIC_ALL);
+	else
+	    EMSG2_RET_NULL(_(e_unmatched_str_open), reg_magic == MAGIC_ALL);
+    }
+    else if (paren == REG_NOPAREN && peekchr() != NUL)
+    {
+	if (curchr == Magic(')'))
+	    EMSG2_RET_NULL(_(e_unmatched_str_close), reg_magic == MAGIC_ALL);
+	else
+	    EMSG_RET_NULL(_(e_trailing_characters));	// "Can't happen".
+	// NOTREACHED
+    }
+    // Here we set the flag allowing back references to this set of
+    // parentheses.
+    if (paren == REG_PAREN)
+	had_endbrace[parno] = TRUE;	// have seen the close paren
+    return ret;
+}
+
+/*
+ * bt_regcomp() - compile a regular expression into internal code for the
+ * traditional back track matcher.
+ * Returns the program in allocated space.  Returns NULL for an error.
+ *
+ * We can't allocate space until we know how big the compiled form will be,
+ * but we can't compile it (and thus know how big it is) until we've got a
+ * place to put the code.  So we cheat:  we compile it twice, once with code
+ * generation turned off and size counting turned on, and once "for real".
+ * This also means that we don't allocate space until we are sure that the
+ * thing really will compile successfully, and we never have to move the
+ * code and thus invalidate pointers into it.  (Note that it has to be in
+ * one piece because vim_free() must be able to free it all.)
+ *
+ * Whether upper/lower case is to be ignored is decided when executing the
+ * program, it does not matter here.
+ *
+ * Beware that the optimization-preparation code in here knows about some
+ * of the structure of the compiled regexp.
+ * "re_flags": RE_MAGIC and/or RE_STRING.
+ */
+    static regprog_T *
+bt_regcomp(char_u *expr, int re_flags)
+{
+    bt_regprog_T    *r;
+    char_u	*scan;
+    char_u	*longest;
+    int		len;
+    int		flags;
+
+    if (expr == NULL)
+	IEMSG_RET_NULL(e_null_argument);
+
+    init_class_tab();
+
+    // First pass: determine size, legality.
+    regcomp_start(expr, re_flags);
+    regcode = JUST_CALC_SIZE;
+    regc(REGMAGIC);
+    if (reg(REG_NOPAREN, &flags) == NULL)
+	return NULL;
+
+    // Allocate space.
+    r = alloc(offsetof(bt_regprog_T, program) + regsize);
+    if (r == NULL)
+	return NULL;
+    r->re_in_use = FALSE;
+
+    // Second pass: emit code.
+    regcomp_start(expr, re_flags);
+    regcode = r->program;
+    regc(REGMAGIC);
+    if (reg(REG_NOPAREN, &flags) == NULL || reg_toolong)
+    {
+	vim_free(r);
+	if (reg_toolong)
+	    EMSG_RET_NULL(_(e_pattern_too_long));
+	return NULL;
+    }
+
+    // Dig out information for optimizations.
+    r->regstart = NUL;		// Worst-case defaults.
+    r->reganch = 0;
+    r->regmust = NULL;
+    r->regmlen = 0;
+    r->regflags = regflags;
+    if (flags & HASNL)
+	r->regflags |= RF_HASNL;
+    if (flags & HASLOOKBH)
+	r->regflags |= RF_LOOKBH;
+#ifdef FEAT_SYN_HL
+    // Remember whether this pattern has any \z specials in it.
+    r->reghasz = re_has_z;
+#endif
+    scan = r->program + 1;	// First BRANCH.
+    if (OP(regnext(scan)) == END)   // Only one top-level choice.
+    {
+	scan = OPERAND(scan);
+
+	// Starting-point info.
+	if (OP(scan) == BOL || OP(scan) == RE_BOF)
+	{
+	    r->reganch++;
+	    scan = regnext(scan);
+	}
+
+	if (OP(scan) == EXACTLY)
+	{
+	    if (has_mbyte)
+		r->regstart = (*mb_ptr2char)(OPERAND(scan));
+	    else
+		r->regstart = *OPERAND(scan);
+	}
+	else if ((OP(scan) == BOW
+		    || OP(scan) == EOW
+		    || OP(scan) == NOTHING
+		    || OP(scan) == MOPEN + 0 || OP(scan) == NOPEN
+		    || OP(scan) == MCLOSE + 0 || OP(scan) == NCLOSE)
+		 && OP(regnext(scan)) == EXACTLY)
+	{
+	    if (has_mbyte)
+		r->regstart = (*mb_ptr2char)(OPERAND(regnext(scan)));
+	    else
+		r->regstart = *OPERAND(regnext(scan));
+	}
+
+	// If there's something expensive in the r.e., find the longest
+	// literal string that must appear and make it the regmust.  Resolve
+	// ties in favor of later strings, since the regstart check works
+	// with the beginning of the r.e. and avoiding duplication
+	// strengthens checking.  Not a strong reason, but sufficient in the
+	// absence of others.
+
+	// When the r.e. starts with BOW, it is faster to look for a regmust
+	// first. Used a lot for "#" and "*" commands. (Added by mool).
+	if ((flags & SPSTART || OP(scan) == BOW || OP(scan) == EOW)
+							  && !(flags & HASNL))
+	{
+	    longest = NULL;
+	    len = 0;
+	    for (; scan != NULL; scan = regnext(scan))
+		if (OP(scan) == EXACTLY && STRLEN(OPERAND(scan)) >= (size_t)len)
+		{
+		    longest = OPERAND(scan);
+		    len = (int)STRLEN(OPERAND(scan));
+		}
+	    r->regmust = longest;
+	    r->regmlen = len;
+	}
+    }
+#ifdef BT_REGEXP_DUMP
+    regdump(expr, r);
+#endif
+    r->engine = &bt_regengine;
+    return (regprog_T *)r;
+}
+
+#if defined(FEAT_SYN_HL) || defined(PROTO)
+/*
+ * Check if during the previous call to vim_regcomp the EOL item "$" has been
+ * found.  This is messy, but it works fine.
+ */
+    int
+vim_regcomp_had_eol(void)
+{
+    return had_eol;
+}
+#endif
+
+/*
+ * Get a number after a backslash that is inside [].
+ * When nothing is recognized return a backslash.
+ */
+    static int
+coll_get_char(void)
+{
+    long	nr = -1;
+
+    switch (*regparse++)
+    {
+	case 'd': nr = getdecchrs(); break;
+	case 'o': nr = getoctchrs(); break;
+	case 'x': nr = gethexchrs(2); break;
+	case 'u': nr = gethexchrs(4); break;
+	case 'U': nr = gethexchrs(8); break;
+    }
+    if (nr < 0 || nr > INT_MAX)
+    {
+	// If getting the number fails be backwards compatible: the character
+	// is a backslash.
+	--regparse;
+	nr = '\\';
+    }
+    return nr;
+}
+
+/*
+ * Free a compiled regexp program, returned by bt_regcomp().
+ */
+    static void
+bt_regfree(regprog_T *prog)
+{
+    vim_free(prog);
+}
+
+#define ADVANCE_REGINPUT() MB_PTR_ADV(rex.input)
+
+/*
+ * The arguments from BRACE_LIMITS are stored here.  They are actually local
+ * to regmatch(), but they are here to reduce the amount of stack space used
+ * (it can be called recursively many times).
+ */
+static long	bl_minval;
+static long	bl_maxval;
+
+/*
+ * Save the input line and position in a regsave_T.
+ */
+    static void
+reg_save(regsave_T *save, garray_T *gap)
+{
+    if (REG_MULTI)
+    {
+	save->rs_u.pos.col = (colnr_T)(rex.input - rex.line);
+	save->rs_u.pos.lnum = rex.lnum;
+    }
+    else
+	save->rs_u.ptr = rex.input;
+    save->rs_len = gap->ga_len;
+}
+
+/*
+ * Restore the input line and position from a regsave_T.
+ */
+    static void
+reg_restore(regsave_T *save, garray_T *gap)
+{
+    if (REG_MULTI)
+    {
+	if (rex.lnum != save->rs_u.pos.lnum)
+	{
+	    // only call reg_getline() when the line number changed to save
+	    // a bit of time
+	    rex.lnum = save->rs_u.pos.lnum;
+	    rex.line = reg_getline(rex.lnum);
+	}
+	rex.input = rex.line + save->rs_u.pos.col;
+    }
+    else
+	rex.input = save->rs_u.ptr;
+    gap->ga_len = save->rs_len;
+}
+
+/*
+ * Return TRUE if current position is equal to saved position.
+ */
+    static int
+reg_save_equal(regsave_T *save)
+{
+    if (REG_MULTI)
+	return rex.lnum == save->rs_u.pos.lnum
+				  && rex.input == rex.line + save->rs_u.pos.col;
+    return rex.input == save->rs_u.ptr;
+}
+
+// Save the sub-expressions before attempting a match.
+#define save_se(savep, posp, pp) \
+    REG_MULTI ? save_se_multi((savep), (posp)) : save_se_one((savep), (pp))
+
+// After a failed match restore the sub-expressions.
+#define restore_se(savep, posp, pp) \
+{ \
+    if (REG_MULTI) \
+	*(posp) = (savep)->se_u.pos; \
+    else \
+	*(pp) = (savep)->se_u.ptr; \
+}
+
+/*
+ * Tentatively set the sub-expression start to the current position (after
+ * calling regmatch() they will have changed).  Need to save the existing
+ * values for when there is no match.
+ * Use se_save() to use pointer (save_se_multi()) or position (save_se_one()),
+ * depending on REG_MULTI.
+ */
+    static void
+save_se_multi(save_se_T *savep, lpos_T *posp)
+{
+    savep->se_u.pos = *posp;
+    posp->lnum = rex.lnum;
+    posp->col = (colnr_T)(rex.input - rex.line);
+}
+
+    static void
+save_se_one(save_se_T *savep, char_u **pp)
+{
+    savep->se_u.ptr = *pp;
+    *pp = rex.input;
+}
+
+/*
+ * regrepeat - repeatedly match something simple, return how many.
+ * Advances rex.input (and rex.lnum) to just after the matched chars.
+ */
+    static int
+regrepeat(
+    char_u	*p,
+    long	maxcount)   // maximum number of matches allowed
+{
+    long	count = 0;
+    char_u	*scan;
+    char_u	*opnd;
+    int		mask;
+    int		testval = 0;
+
+    scan = rex.input;	    // Make local copy of rex.input for speed.
+    opnd = OPERAND(p);
+    switch (OP(p))
+    {
+      case ANY:
+      case ANY + ADD_NL:
+	while (count < maxcount)
+	{
+	    // Matching anything means we continue until end-of-line (or
+	    // end-of-file for ANY + ADD_NL), only limited by maxcount.
+	    while (*scan != NUL && count < maxcount)
+	    {
+		++count;
+		MB_PTR_ADV(scan);
+	    }
+	    if (!REG_MULTI || !WITH_NL(OP(p)) || rex.lnum > rex.reg_maxline
+				      || rex.reg_line_lbr || count == maxcount)
+		break;
+	    ++count;		// count the line-break
+	    reg_nextline();
+	    scan = rex.input;
+	    if (got_int)
+		break;
+	}
+	break;
+
+      case IDENT:
+      case IDENT + ADD_NL:
+	testval = TRUE;
+	// FALLTHROUGH
+      case SIDENT:
+      case SIDENT + ADD_NL:
+	while (count < maxcount)
+	{
+	    if (vim_isIDc(PTR2CHAR(scan)) && (testval || !VIM_ISDIGIT(*scan)))
+	    {
+		MB_PTR_ADV(scan);
+	    }
+	    else if (*scan == NUL)
+	    {
+		if (!REG_MULTI || !WITH_NL(OP(p)) || rex.lnum > rex.reg_maxline
+							   || rex.reg_line_lbr)
+		    break;
+		reg_nextline();
+		scan = rex.input;
+		if (got_int)
+		    break;
+	    }
+	    else if (rex.reg_line_lbr && *scan == '\n' && WITH_NL(OP(p)))
+		++scan;
+	    else
+		break;
+	    ++count;
+	}
+	break;
+
+      case KWORD:
+      case KWORD + ADD_NL:
+	testval = TRUE;
+	// FALLTHROUGH
+      case SKWORD:
+      case SKWORD + ADD_NL:
+	while (count < maxcount)
+	{
+	    if (vim_iswordp_buf(scan, rex.reg_buf)
+					  && (testval || !VIM_ISDIGIT(*scan)))
+	    {
+		MB_PTR_ADV(scan);
+	    }
+	    else if (*scan == NUL)
+	    {
+		if (!REG_MULTI || !WITH_NL(OP(p)) || rex.lnum > rex.reg_maxline
+							   || rex.reg_line_lbr)
+		    break;
+		reg_nextline();
+		scan = rex.input;
+		if (got_int)
+		    break;
+	    }
+	    else if (rex.reg_line_lbr && *scan == '\n' && WITH_NL(OP(p)))
+		++scan;
+	    else
+		break;
+	    ++count;
+	}
+	break;
+
+      case FNAME:
+      case FNAME + ADD_NL:
+	testval = TRUE;
+	// FALLTHROUGH
+      case SFNAME:
+      case SFNAME + ADD_NL:
+	while (count < maxcount)
+	{
+	    if (vim_isfilec(PTR2CHAR(scan)) && (testval || !VIM_ISDIGIT(*scan)))
+	    {
+		MB_PTR_ADV(scan);
+	    }
+	    else if (*scan == NUL)
+	    {
+		if (!REG_MULTI || !WITH_NL(OP(p)) || rex.lnum > rex.reg_maxline
+							   || rex.reg_line_lbr)
+		    break;
+		reg_nextline();
+		scan = rex.input;
+		if (got_int)
+		    break;
+	    }
+	    else if (rex.reg_line_lbr && *scan == '\n' && WITH_NL(OP(p)))
+		++scan;
+	    else
+		break;
+	    ++count;
+	}
+	break;
+
+      case PRINT:
+      case PRINT + ADD_NL:
+	testval = TRUE;
+	// FALLTHROUGH
+      case SPRINT:
+      case SPRINT + ADD_NL:
+	while (count < maxcount)
+	{
+	    if (*scan == NUL)
+	    {
+		if (!REG_MULTI || !WITH_NL(OP(p)) || rex.lnum > rex.reg_maxline
+							   || rex.reg_line_lbr)
+		    break;
+		reg_nextline();
+		scan = rex.input;
+		if (got_int)
+		    break;
+	    }
+	    else if (vim_isprintc(PTR2CHAR(scan)) == 1
+					  && (testval || !VIM_ISDIGIT(*scan)))
+	    {
+		MB_PTR_ADV(scan);
+	    }
+	    else if (rex.reg_line_lbr && *scan == '\n' && WITH_NL(OP(p)))
+		++scan;
+	    else
+		break;
+	    ++count;
+	}
+	break;
+
+      case WHITE:
+      case WHITE + ADD_NL:
+	testval = mask = RI_WHITE;
+do_class:
+	while (count < maxcount)
+	{
+	    int		l;
+
+	    if (*scan == NUL)
+	    {
+		if (!REG_MULTI || !WITH_NL(OP(p)) || rex.lnum > rex.reg_maxline
+							   || rex.reg_line_lbr)
+		    break;
+		reg_nextline();
+		scan = rex.input;
+		if (got_int)
+		    break;
+	    }
+	    else if (has_mbyte && (l = (*mb_ptr2len)(scan)) > 1)
+	    {
+		if (testval != 0)
+		    break;
+		scan += l;
+	    }
+	    else if ((class_tab[*scan] & mask) == testval)
+		++scan;
+	    else if (rex.reg_line_lbr && *scan == '\n' && WITH_NL(OP(p)))
+		++scan;
+	    else
+		break;
+	    ++count;
+	}
+	break;
+
+      case NWHITE:
+      case NWHITE + ADD_NL:
+	mask = RI_WHITE;
+	goto do_class;
+      case DIGIT:
+      case DIGIT + ADD_NL:
+	testval = mask = RI_DIGIT;
+	goto do_class;
+      case NDIGIT:
+      case NDIGIT + ADD_NL:
+	mask = RI_DIGIT;
+	goto do_class;
+      case HEX:
+      case HEX + ADD_NL:
+	testval = mask = RI_HEX;
+	goto do_class;
+      case NHEX:
+      case NHEX + ADD_NL:
+	mask = RI_HEX;
+	goto do_class;
+      case OCTAL:
+      case OCTAL + ADD_NL:
+	testval = mask = RI_OCTAL;
+	goto do_class;
+      case NOCTAL:
+      case NOCTAL + ADD_NL:
+	mask = RI_OCTAL;
+	goto do_class;
+      case WORD:
+      case WORD + ADD_NL:
+	testval = mask = RI_WORD;
+	goto do_class;
+      case NWORD:
+      case NWORD + ADD_NL:
+	mask = RI_WORD;
+	goto do_class;
+      case HEAD:
+      case HEAD + ADD_NL:
+	testval = mask = RI_HEAD;
+	goto do_class;
+      case NHEAD:
+      case NHEAD + ADD_NL:
+	mask = RI_HEAD;
+	goto do_class;
+      case ALPHA:
+      case ALPHA + ADD_NL:
+	testval = mask = RI_ALPHA;
+	goto do_class;
+      case NALPHA:
+      case NALPHA + ADD_NL:
+	mask = RI_ALPHA;
+	goto do_class;
+      case LOWER:
+      case LOWER + ADD_NL:
+	testval = mask = RI_LOWER;
+	goto do_class;
+      case NLOWER:
+      case NLOWER + ADD_NL:
+	mask = RI_LOWER;
+	goto do_class;
+      case UPPER:
+      case UPPER + ADD_NL:
+	testval = mask = RI_UPPER;
+	goto do_class;
+      case NUPPER:
+      case NUPPER + ADD_NL:
+	mask = RI_UPPER;
+	goto do_class;
+
+      case EXACTLY:
+	{
+	    int	    cu, cl;
+
+	    // This doesn't do a multi-byte character, because a MULTIBYTECODE
+	    // would have been used for it.  It does handle single-byte
+	    // characters, such as latin1.
+	    if (rex.reg_ic)
+	    {
+		cu = MB_TOUPPER(*opnd);
+		cl = MB_TOLOWER(*opnd);
+		while (count < maxcount && (*scan == cu || *scan == cl))
+		{
+		    count++;
+		    scan++;
+		}
+	    }
+	    else
+	    {
+		cu = *opnd;
+		while (count < maxcount && *scan == cu)
+		{
+		    count++;
+		    scan++;
+		}
+	    }
+	    break;
+	}
+
+      case MULTIBYTECODE:
+	{
+	    int		i, len, cf = 0;
+
+	    // Safety check (just in case 'encoding' was changed since
+	    // compiling the program).
+	    if ((len = (*mb_ptr2len)(opnd)) > 1)
+	    {
+		if (rex.reg_ic && enc_utf8)
+		    cf = utf_fold(utf_ptr2char(opnd));
+		while (count < maxcount && (*mb_ptr2len)(scan) >= len)
+		{
+		    for (i = 0; i < len; ++i)
+			if (opnd[i] != scan[i])
+			    break;
+		    if (i < len && (!rex.reg_ic || !enc_utf8
+					|| utf_fold(utf_ptr2char(scan)) != cf))
+			break;
+		    scan += len;
+		    ++count;
+		}
+	    }
+	}
+	break;
+
+      case ANYOF:
+      case ANYOF + ADD_NL:
+	testval = TRUE;
+	// FALLTHROUGH
+
+      case ANYBUT:
+      case ANYBUT + ADD_NL:
+	while (count < maxcount)
+	{
+	    int len;
+
+	    if (*scan == NUL)
+	    {
+		if (!REG_MULTI || !WITH_NL(OP(p)) || rex.lnum > rex.reg_maxline
+							   || rex.reg_line_lbr)
+		    break;
+		reg_nextline();
+		scan = rex.input;
+		if (got_int)
+		    break;
+	    }
+	    else if (rex.reg_line_lbr && *scan == '\n' && WITH_NL(OP(p)))
+		++scan;
+	    else if (has_mbyte && (len = (*mb_ptr2len)(scan)) > 1)
+	    {
+		if ((cstrchr(opnd, (*mb_ptr2char)(scan)) == NULL) == testval)
+		    break;
+		scan += len;
+	    }
+	    else
+	    {
+		if ((cstrchr(opnd, *scan) == NULL) == testval)
+		    break;
+		++scan;
+	    }
+	    ++count;
+	}
+	break;
+
+      case NEWL:
+	while (count < maxcount
+		&& ((*scan == NUL && rex.lnum <= rex.reg_maxline
+				       && !rex.reg_line_lbr && REG_MULTI)
+		    || (*scan == '\n' && rex.reg_line_lbr)))
+	{
+	    count++;
+	    if (rex.reg_line_lbr)
+		ADVANCE_REGINPUT();
+	    else
+		reg_nextline();
+	    scan = rex.input;
+	    if (got_int)
+		break;
+	}
+	break;
+
+      default:			// Oh dear.  Called inappropriately.
+	iemsg(e_corrupted_regexp_program);
+#ifdef DEBUG
+	printf("Called regrepeat with op code %d\n", OP(p));
+#endif
+	break;
+    }
+
+    rex.input = scan;
+
+    return (int)count;
+}
+
+/*
+ * Push an item onto the regstack.
+ * Returns pointer to new item.  Returns NULL when out of memory.
+ */
+    static regitem_T *
+regstack_push(regstate_T state, char_u *scan)
+{
+    regitem_T	*rp;
+
+    if ((long)((unsigned)regstack.ga_len >> 10) >= p_mmp)
+    {
+	emsg(_(e_pattern_uses_more_memory_than_maxmempattern));
+	return NULL;
+    }
+    if (ga_grow(&regstack, sizeof(regitem_T)) == FAIL)
+	return NULL;
+
+    rp = (regitem_T *)((char *)regstack.ga_data + regstack.ga_len);
+    rp->rs_state = state;
+    rp->rs_scan = scan;
+
+    regstack.ga_len += sizeof(regitem_T);
+    return rp;
+}
+
+/*
+ * Pop an item from the regstack.
+ */
+    static void
+regstack_pop(char_u **scan)
+{
+    regitem_T	*rp;
+
+    rp = (regitem_T *)((char *)regstack.ga_data + regstack.ga_len) - 1;
+    *scan = rp->rs_scan;
+
+    regstack.ga_len -= sizeof(regitem_T);
+}
+
+#ifdef FEAT_RELTIME
+/*
+ * Check if the timer expired, return TRUE if so.
+ */
+    static int
+bt_did_time_out(int *timed_out)
+{
+    if (*timeout_flag)
+    {
+	if (timed_out != NULL)
+	{
+# ifdef FEAT_EVAL
+	    if (!*timed_out)
+		ch_log(NULL, "BT regexp timed out");
+# endif
+	    *timed_out = TRUE;
+	}
+	return TRUE;
+    }
+    return FALSE;
+}
+#endif
+
+/*
+ * Save the current subexpr to "bp", so that they can be restored
+ * later by restore_subexpr().
+ */
+    static void
+save_subexpr(regbehind_T *bp)
+{
+    int i;
+
+    // When "rex.need_clear_subexpr" is set we don't need to save the values,
+    // only remember that this flag needs to be set again when restoring.
+    bp->save_need_clear_subexpr = rex.need_clear_subexpr;
+    if (rex.need_clear_subexpr)
+	return;
+
+    for (i = 0; i < NSUBEXP; ++i)
+    {
+	if (REG_MULTI)
+	{
+	    bp->save_start[i].se_u.pos = rex.reg_startpos[i];
+	    bp->save_end[i].se_u.pos = rex.reg_endpos[i];
+	}
+	else
+	{
+	    bp->save_start[i].se_u.ptr = rex.reg_startp[i];
+	    bp->save_end[i].se_u.ptr = rex.reg_endp[i];
+	}
+    }
+}
+
+/*
+ * Restore the subexpr from "bp".
+ */
+    static void
+restore_subexpr(regbehind_T *bp)
+{
+    int i;
+
+    // Only need to restore saved values when they are not to be cleared.
+    rex.need_clear_subexpr = bp->save_need_clear_subexpr;
+    if (rex.need_clear_subexpr)
+	return;
+
+    for (i = 0; i < NSUBEXP; ++i)
+    {
+	if (REG_MULTI)
+	{
+	    rex.reg_startpos[i] = bp->save_start[i].se_u.pos;
+	    rex.reg_endpos[i] = bp->save_end[i].se_u.pos;
+	}
+	else
+	{
+	    rex.reg_startp[i] = bp->save_start[i].se_u.ptr;
+	    rex.reg_endp[i] = bp->save_end[i].se_u.ptr;
+	}
+    }
+}
+
+/*
+ * regmatch - main matching routine
+ *
+ * Conceptually the strategy is simple: Check to see whether the current node
+ * matches, push an item onto the regstack and loop to see whether the rest
+ * matches, and then act accordingly.  In practice we make some effort to
+ * avoid using the regstack, in particular by going through "ordinary" nodes
+ * (that don't need to know whether the rest of the match failed) by a nested
+ * loop.
+ *
+ * Returns TRUE when there is a match.  Leaves rex.input and rex.lnum just after
+ * the last matched character.
+ * Returns FALSE when there is no match.  Leaves rex.input and rex.lnum in an
+ * undefined state!
+ */
+    static int
+regmatch(
+    char_u	*scan,		    // Current node.
+    int		*timed_out UNUSED)  // flag set on timeout or NULL
+{
+  char_u	*next;		// Next node.
+  int		op;
+  int		c;
+  regitem_T	*rp;
+  int		no;
+  int		status;		// one of the RA_ values:
+
+  // Make "regstack" and "backpos" empty.  They are allocated and freed in
+  // bt_regexec_both() to reduce malloc()/free() calls.
+  regstack.ga_len = 0;
+  backpos.ga_len = 0;
+
+  // Repeat until "regstack" is empty.
+  for (;;)
+  {
+    // Some patterns may take a long time to match, e.g., "\([a-z]\+\)\+Q".
+    // Allow interrupting them with CTRL-C.
+    fast_breakcheck();
+
+#ifdef DEBUG
+    if (scan != NULL && regnarrate)
+    {
+	mch_errmsg((char *)regprop(scan));
+	mch_errmsg("(\n");
+    }
+#endif
+
+    // Repeat for items that can be matched sequentially, without using the
+    // regstack.
+    for (;;)
+    {
+	if (got_int || scan == NULL)
+	{
+	    status = RA_FAIL;
+	    break;
+	}
+#ifdef FEAT_RELTIME
+	if (bt_did_time_out(timed_out))
+	{
+	    status = RA_FAIL;
+	    break;
+	}
+#endif
+	status = RA_CONT;
+
+#ifdef DEBUG
+	if (regnarrate)
+	{
+	    mch_errmsg((char *)regprop(scan));
+	    mch_errmsg("...\n");
+# ifdef FEAT_SYN_HL
+	    if (re_extmatch_in != NULL)
+	    {
+		int i;
+
+		mch_errmsg(_("External submatches:\n"));
+		for (i = 0; i < NSUBEXP; i++)
+		{
+		    mch_errmsg("    \"");
+		    if (re_extmatch_in->matches[i] != NULL)
+			mch_errmsg((char *)re_extmatch_in->matches[i]);
+		    mch_errmsg("\"\n");
+		}
+	    }
+# endif
+	}
+#endif
+	next = regnext(scan);
+
+	op = OP(scan);
+	// Check for character class with NL added.
+	if (!rex.reg_line_lbr && WITH_NL(op) && REG_MULTI
+			     && *rex.input == NUL && rex.lnum <= rex.reg_maxline)
+	{
+	    reg_nextline();
+	}
+	else if (rex.reg_line_lbr && WITH_NL(op) && *rex.input == '\n')
+	{
+	    ADVANCE_REGINPUT();
+	}
+	else
+	{
+	  if (WITH_NL(op))
+	      op -= ADD_NL;
+	  if (has_mbyte)
+	      c = (*mb_ptr2char)(rex.input);
+	  else
+	      c = *rex.input;
+	  switch (op)
+	  {
+	  case BOL:
+	    if (rex.input != rex.line)
+		status = RA_NOMATCH;
+	    break;
+
+	  case EOL:
+	    if (c != NUL)
+		status = RA_NOMATCH;
+	    break;
+
+	  case RE_BOF:
+	    // We're not at the beginning of the file when below the first
+	    // line where we started, not at the start of the line or we
+	    // didn't start at the first line of the buffer.
+	    if (rex.lnum != 0 || rex.input != rex.line
+				       || (REG_MULTI && rex.reg_firstlnum > 1))
+		status = RA_NOMATCH;
+	    break;
+
+	  case RE_EOF:
+	    if (rex.lnum != rex.reg_maxline || c != NUL)
+		status = RA_NOMATCH;
+	    break;
+
+	  case CURSOR:
+	    // Check if the buffer is in a window and compare the
+	    // rex.reg_win->w_cursor position to the match position.
+	    if (rex.reg_win == NULL
+		    || (rex.lnum + rex.reg_firstlnum
+						 != rex.reg_win->w_cursor.lnum)
+		    || ((colnr_T)(rex.input - rex.line)
+						 != rex.reg_win->w_cursor.col))
+		status = RA_NOMATCH;
+	    break;
+
+	  case RE_MARK:
+	    // Compare the mark position to the match position.
+	    {
+		int	mark = OPERAND(scan)[0];
+		int	cmp = OPERAND(scan)[1];
+		pos_T	*pos;
+		size_t	col = REG_MULTI ? rex.input - rex.line : 0;
+
+		pos = getmark_buf(rex.reg_buf, mark, FALSE);
+
+		// Line may have been freed, get it again.
+		if (REG_MULTI)
+		{
+		    rex.line = reg_getline(rex.lnum);
+		    rex.input = rex.line + col;
+		}
+
+		if (pos == NULL		     // mark doesn't exist
+			|| pos->lnum <= 0)   // mark isn't set in reg_buf
+		{
+		    status = RA_NOMATCH;
+		}
+		else
+		{
+		    colnr_T pos_col = pos->lnum == rex.lnum + rex.reg_firstlnum
+							  && pos->col == MAXCOL
+				      ? (colnr_T)STRLEN(reg_getline(
+						pos->lnum - rex.reg_firstlnum))
+				      : pos->col;
+
+		    if ((pos->lnum == rex.lnum + rex.reg_firstlnum
+				? (pos_col == (colnr_T)(rex.input - rex.line)
+				    ? (cmp == '<' || cmp == '>')
+				    : (pos_col < (colnr_T)(rex.input - rex.line)
+					? cmp != '>'
+					: cmp != '<'))
+				: (pos->lnum < rex.lnum + rex.reg_firstlnum
+				    ? cmp != '>'
+				    : cmp != '<')))
+		    status = RA_NOMATCH;
+		}
+	    }
+	    break;
+
+	  case RE_VISUAL:
+	    if (!reg_match_visual())
+		status = RA_NOMATCH;
+	    break;
+
+	  case RE_LNUM:
+	    if (!REG_MULTI || !re_num_cmp((long_u)(rex.lnum + rex.reg_firstlnum),
+									scan))
+		status = RA_NOMATCH;
+	    break;
+
+	  case RE_COL:
+	    if (!re_num_cmp((long_u)(rex.input - rex.line) + 1, scan))
+		status = RA_NOMATCH;
+	    break;
+
+	  case RE_VCOL:
+	    {
+		win_T	    *wp = rex.reg_win == NULL ? curwin : rex.reg_win;
+		linenr_T    lnum = REG_MULTI ? rex.reg_firstlnum + rex.lnum : 1;
+		long_u	    vcol;
+
+		if (REG_MULTI && (lnum <= 0
+				   || lnum > wp->w_buffer->b_ml.ml_line_count))
+		    lnum = 1;
+		vcol = (long_u)win_linetabsize(wp, lnum, rex.line,
+					      (colnr_T)(rex.input - rex.line));
+		if (!re_num_cmp(vcol + 1, scan))
+		    status = RA_NOMATCH;
+	    }
+	    break;
+
+	  case BOW:	// \<word; rex.input points to w
+	    if (c == NUL)	// Can't match at end of line
+		status = RA_NOMATCH;
+	    else if (has_mbyte)
+	    {
+		int this_class;
+
+		// Get class of current and previous char (if it exists).
+		this_class = mb_get_class_buf(rex.input, rex.reg_buf);
+		if (this_class <= 1)
+		    status = RA_NOMATCH;  // not on a word at all
+		else if (reg_prev_class() == this_class)
+		    status = RA_NOMATCH;  // previous char is in same word
+	    }
+	    else
+	    {
+		if (!vim_iswordc_buf(c, rex.reg_buf) || (rex.input > rex.line
+				&& vim_iswordc_buf(rex.input[-1], rex.reg_buf)))
+		    status = RA_NOMATCH;
+	    }
+	    break;
+
+	  case EOW:	// word\>; rex.input points after d
+	    if (rex.input == rex.line)    // Can't match at start of line
+		status = RA_NOMATCH;
+	    else if (has_mbyte)
+	    {
+		int this_class, prev_class;
+
+		// Get class of current and previous char (if it exists).
+		this_class = mb_get_class_buf(rex.input, rex.reg_buf);
+		prev_class = reg_prev_class();
+		if (this_class == prev_class
+			|| prev_class == 0 || prev_class == 1)
+		    status = RA_NOMATCH;
+	    }
+	    else
+	    {
+		if (!vim_iswordc_buf(rex.input[-1], rex.reg_buf)
+			|| (rex.input[0] != NUL
+					   && vim_iswordc_buf(c, rex.reg_buf)))
+		    status = RA_NOMATCH;
+	    }
+	    break; // Matched with EOW
+
+	  case ANY:
+	    // ANY does not match new lines.
+	    if (c == NUL)
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case IDENT:
+	    if (!vim_isIDc(c))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case SIDENT:
+	    if (VIM_ISDIGIT(*rex.input) || !vim_isIDc(c))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case KWORD:
+	    if (!vim_iswordp_buf(rex.input, rex.reg_buf))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case SKWORD:
+	    if (VIM_ISDIGIT(*rex.input)
+				    || !vim_iswordp_buf(rex.input, rex.reg_buf))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case FNAME:
+	    if (!vim_isfilec(c))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case SFNAME:
+	    if (VIM_ISDIGIT(*rex.input) || !vim_isfilec(c))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case PRINT:
+	    if (!vim_isprintc(PTR2CHAR(rex.input)))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case SPRINT:
+	    if (VIM_ISDIGIT(*rex.input) || !vim_isprintc(PTR2CHAR(rex.input)))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case WHITE:
+	    if (!VIM_ISWHITE(c))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case NWHITE:
+	    if (c == NUL || VIM_ISWHITE(c))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case DIGIT:
+	    if (!ri_digit(c))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case NDIGIT:
+	    if (c == NUL || ri_digit(c))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case HEX:
+	    if (!ri_hex(c))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case NHEX:
+	    if (c == NUL || ri_hex(c))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case OCTAL:
+	    if (!ri_octal(c))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case NOCTAL:
+	    if (c == NUL || ri_octal(c))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case WORD:
+	    if (!ri_word(c))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case NWORD:
+	    if (c == NUL || ri_word(c))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case HEAD:
+	    if (!ri_head(c))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case NHEAD:
+	    if (c == NUL || ri_head(c))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case ALPHA:
+	    if (!ri_alpha(c))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case NALPHA:
+	    if (c == NUL || ri_alpha(c))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case LOWER:
+	    if (!ri_lower(c))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case NLOWER:
+	    if (c == NUL || ri_lower(c))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case UPPER:
+	    if (!ri_upper(c))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case NUPPER:
+	    if (c == NUL || ri_upper(c))
+		status = RA_NOMATCH;
+	    else
+		ADVANCE_REGINPUT();
+	    break;
+
+	  case EXACTLY:
+	    {
+		int	len;
+		char_u	*opnd;
+
+		opnd = OPERAND(scan);
+		// Inline the first byte, for speed.
+		if (*opnd != *rex.input
+			&& (!rex.reg_ic
+			    || (!enc_utf8
+			      && MB_TOLOWER(*opnd) != MB_TOLOWER(*rex.input))))
+		    status = RA_NOMATCH;
+		else if (*opnd == NUL)
+		{
+		    // match empty string always works; happens when "~" is
+		    // empty.
+		}
+		else
+		{
+		    if (opnd[1] == NUL && !(enc_utf8 && rex.reg_ic))
+		    {
+			len = 1;	// matched a single byte above
+		    }
+		    else
+		    {
+			// Need to match first byte again for multi-byte.
+			len = (int)STRLEN(opnd);
+			if (cstrncmp(opnd, rex.input, &len) != 0)
+			    status = RA_NOMATCH;
+		    }
+		    // Check for following composing character, unless %C
+		    // follows (skips over all composing chars).
+		    if (status != RA_NOMATCH
+			    && enc_utf8
+			    && UTF_COMPOSINGLIKE(rex.input, rex.input + len)
+			    && !rex.reg_icombine
+			    && OP(next) != RE_COMPOSING)
+		    {
+			// raaron: This code makes a composing character get
+			// ignored, which is the correct behavior (sometimes)
+			// for voweled Hebrew texts.
+			status = RA_NOMATCH;
+		    }
+		    if (status != RA_NOMATCH)
+			rex.input += len;
+		}
+	    }
+	    break;
+
+	  case ANYOF:
+	  case ANYBUT:
+	    {
+		char_u  *q = OPERAND(scan);
+
+		if (c == NUL)
+		    status = RA_NOMATCH;
+		else if ((cstrchr(q, c) == NULL) == (op == ANYOF))
+		    status = RA_NOMATCH;
+		else
+		{
+		    // Check following combining characters
+		    int	len = 0;
+		    int i;
+
+		    if (enc_utf8)
+			len = utfc_ptr2len(q) - utf_ptr2len(q);
+
+		    MB_CPTR_ADV(rex.input);
+		    MB_CPTR_ADV(q);
+
+		    if (!enc_utf8 || len == 0)
+			break;
+
+		    for (i = 0; i < len; ++i)
+			if (q[i] != rex.input[i])
+			{
+			    status = RA_NOMATCH;
+			    break;
+			}
+		    rex.input += len;
+		}
+		break;
+	    }
+
+	  case MULTIBYTECODE:
+	    if (has_mbyte)
+	    {
+		int	i, len;
+		char_u	*opnd;
+		int	opndc = 0, inpc;
+
+		opnd = OPERAND(scan);
+		// Safety check (just in case 'encoding' was changed since
+		// compiling the program).
+		if ((len = (*mb_ptr2len)(opnd)) < 2)
+		{
+		    status = RA_NOMATCH;
+		    break;
+		}
+		if (enc_utf8)
+		    opndc = utf_ptr2char(opnd);
+		if (enc_utf8 && utf_iscomposing(opndc))
+		{
+		    // When only a composing char is given match at any
+		    // position where that composing char appears.
+		    status = RA_NOMATCH;
+		    for (i = 0; rex.input[i] != NUL;
+						i += utf_ptr2len(rex.input + i))
+		    {
+			inpc = utf_ptr2char(rex.input + i);
+			if (!utf_iscomposing(inpc))
+			{
+			    if (i > 0)
+				break;
+			}
+			else if (opndc == inpc)
+			{
+			    // Include all following composing chars.
+			    len = i + utfc_ptr2len(rex.input + i);
+			    status = RA_MATCH;
+			    break;
+			}
+		    }
+		}
+		else
+		    for (i = 0; i < len; ++i)
+			if (opnd[i] != rex.input[i])
+			{
+			    status = RA_NOMATCH;
+			    break;
+			}
+		rex.input += len;
+	    }
+	    else
+		status = RA_NOMATCH;
+	    break;
+	  case RE_COMPOSING:
+	    if (enc_utf8)
+	    {
+		// Skip composing characters.
+		while (utf_iscomposing(utf_ptr2char(rex.input)))
+		    MB_CPTR_ADV(rex.input);
+	    }
+	    break;
+
+	  case NOTHING:
+	    break;
+
+	  case BACK:
+	    {
+		int		i;
+		backpos_T	*bp;
+
+		// When we run into BACK we need to check if we don't keep
+		// looping without matching any input.  The second and later
+		// times a BACK is encountered it fails if the input is still
+		// at the same position as the previous time.
+		// The positions are stored in "backpos" and found by the
+		// current value of "scan", the position in the RE program.
+		bp = (backpos_T *)backpos.ga_data;
+		for (i = 0; i < backpos.ga_len; ++i)
+		    if (bp[i].bp_scan == scan)
+			break;
+		if (i == backpos.ga_len)
+		{
+		    // First time at this BACK, make room to store the pos.
+		    if (ga_grow(&backpos, 1) == FAIL)
+			status = RA_FAIL;
+		    else
+		    {
+			// get "ga_data" again, it may have changed
+			bp = (backpos_T *)backpos.ga_data;
+			bp[i].bp_scan = scan;
+			++backpos.ga_len;
+		    }
+		}
+		else if (reg_save_equal(&bp[i].bp_pos))
+		    // Still at same position as last time, fail.
+		    status = RA_NOMATCH;
+
+		if (status != RA_FAIL && status != RA_NOMATCH)
+		    reg_save(&bp[i].bp_pos, &backpos);
+	    }
+	    break;
+
+	  case MOPEN + 0:   // Match start: \zs
+	  case MOPEN + 1:   // \(
+	  case MOPEN + 2:
+	  case MOPEN + 3:
+	  case MOPEN + 4:
+	  case MOPEN + 5:
+	  case MOPEN + 6:
+	  case MOPEN + 7:
+	  case MOPEN + 8:
+	  case MOPEN + 9:
+	    {
+		no = op - MOPEN;
+		cleanup_subexpr();
+		rp = regstack_push(RS_MOPEN, scan);
+		if (rp == NULL)
+		    status = RA_FAIL;
+		else
+		{
+		    rp->rs_no = no;
+		    save_se(&rp->rs_un.sesave, &rex.reg_startpos[no],
+							  &rex.reg_startp[no]);
+		    // We simply continue and handle the result when done.
+		}
+	    }
+	    break;
+
+	  case NOPEN:	    // \%(
+	  case NCLOSE:	    // \) after \%(
+		if (regstack_push(RS_NOPEN, scan) == NULL)
+		    status = RA_FAIL;
+		// We simply continue and handle the result when done.
+		break;
+
+#ifdef FEAT_SYN_HL
+	  case ZOPEN + 1:
+	  case ZOPEN + 2:
+	  case ZOPEN + 3:
+	  case ZOPEN + 4:
+	  case ZOPEN + 5:
+	  case ZOPEN + 6:
+	  case ZOPEN + 7:
+	  case ZOPEN + 8:
+	  case ZOPEN + 9:
+	    {
+		no = op - ZOPEN;
+		cleanup_zsubexpr();
+		rp = regstack_push(RS_ZOPEN, scan);
+		if (rp == NULL)
+		    status = RA_FAIL;
+		else
+		{
+		    rp->rs_no = no;
+		    save_se(&rp->rs_un.sesave, &reg_startzpos[no],
+							     &reg_startzp[no]);
+		    // We simply continue and handle the result when done.
+		}
+	    }
+	    break;
+#endif
+
+	  case MCLOSE + 0:  // Match end: \ze
+	  case MCLOSE + 1:  // \)
+	  case MCLOSE + 2:
+	  case MCLOSE + 3:
+	  case MCLOSE + 4:
+	  case MCLOSE + 5:
+	  case MCLOSE + 6:
+	  case MCLOSE + 7:
+	  case MCLOSE + 8:
+	  case MCLOSE + 9:
+	    {
+		no = op - MCLOSE;
+		cleanup_subexpr();
+		rp = regstack_push(RS_MCLOSE, scan);
+		if (rp == NULL)
+		    status = RA_FAIL;
+		else
+		{
+		    rp->rs_no = no;
+		    save_se(&rp->rs_un.sesave, &rex.reg_endpos[no],
+							    &rex.reg_endp[no]);
+		    // We simply continue and handle the result when done.
+		}
+	    }
+	    break;
+
+#ifdef FEAT_SYN_HL
+	  case ZCLOSE + 1:  // \) after \z(
+	  case ZCLOSE + 2:
+	  case ZCLOSE + 3:
+	  case ZCLOSE + 4:
+	  case ZCLOSE + 5:
+	  case ZCLOSE + 6:
+	  case ZCLOSE + 7:
+	  case ZCLOSE + 8:
+	  case ZCLOSE + 9:
+	    {
+		no = op - ZCLOSE;
+		cleanup_zsubexpr();
+		rp = regstack_push(RS_ZCLOSE, scan);
+		if (rp == NULL)
+		    status = RA_FAIL;
+		else
+		{
+		    rp->rs_no = no;
+		    save_se(&rp->rs_un.sesave, &reg_endzpos[no],
+							      &reg_endzp[no]);
+		    // We simply continue and handle the result when done.
+		}
+	    }
+	    break;
+#endif
+
+	  case BACKREF + 1:
+	  case BACKREF + 2:
+	  case BACKREF + 3:
+	  case BACKREF + 4:
+	  case BACKREF + 5:
+	  case BACKREF + 6:
+	  case BACKREF + 7:
+	  case BACKREF + 8:
+	  case BACKREF + 9:
+	    {
+		int		len;
+
+		no = op - BACKREF;
+		cleanup_subexpr();
+		if (!REG_MULTI)		// Single-line regexp
+		{
+		    if (rex.reg_startp[no] == NULL || rex.reg_endp[no] == NULL)
+		    {
+			// Backref was not set: Match an empty string.
+			len = 0;
+		    }
+		    else
+		    {
+			// Compare current input with back-ref in the same
+			// line.
+			len = (int)(rex.reg_endp[no] - rex.reg_startp[no]);
+			if (cstrncmp(rex.reg_startp[no], rex.input, &len) != 0)
+			    status = RA_NOMATCH;
+		    }
+		}
+		else				// Multi-line regexp
+		{
+		    if (rex.reg_startpos[no].lnum < 0
+						|| rex.reg_endpos[no].lnum < 0)
+		    {
+			// Backref was not set: Match an empty string.
+			len = 0;
+		    }
+		    else
+		    {
+			if (rex.reg_startpos[no].lnum == rex.lnum
+				&& rex.reg_endpos[no].lnum == rex.lnum)
+			{
+			    // Compare back-ref within the current line.
+			    len = rex.reg_endpos[no].col
+						    - rex.reg_startpos[no].col;
+			    if (cstrncmp(rex.line + rex.reg_startpos[no].col,
+							  rex.input, &len) != 0)
+				status = RA_NOMATCH;
+			}
+			else
+			{
+			    // Messy situation: Need to compare between two
+			    // lines.
+			    int r = match_with_backref(
+					    rex.reg_startpos[no].lnum,
+					    rex.reg_startpos[no].col,
+					    rex.reg_endpos[no].lnum,
+					    rex.reg_endpos[no].col,
+					    &len);
+
+			    if (r != RA_MATCH)
+				status = r;
+			}
+		    }
+		}
+
+		// Matched the backref, skip over it.
+		rex.input += len;
+	    }
+	    break;
+
+#ifdef FEAT_SYN_HL
+	  case ZREF + 1:
+	  case ZREF + 2:
+	  case ZREF + 3:
+	  case ZREF + 4:
+	  case ZREF + 5:
+	  case ZREF + 6:
+	  case ZREF + 7:
+	  case ZREF + 8:
+	  case ZREF + 9:
+	    {
+		int	len;
+
+		cleanup_zsubexpr();
+		no = op - ZREF;
+		if (re_extmatch_in != NULL
+			&& re_extmatch_in->matches[no] != NULL)
+		{
+		    len = (int)STRLEN(re_extmatch_in->matches[no]);
+		    if (cstrncmp(re_extmatch_in->matches[no],
+							  rex.input, &len) != 0)
+			status = RA_NOMATCH;
+		    else
+			rex.input += len;
+		}
+		else
+		{
+		    // Backref was not set: Match an empty string.
+		}
+	    }
+	    break;
+#endif
+
+	  case BRANCH:
+	    {
+		if (OP(next) != BRANCH) // No choice.
+		    next = OPERAND(scan);	// Avoid recursion.
+		else
+		{
+		    rp = regstack_push(RS_BRANCH, scan);
+		    if (rp == NULL)
+			status = RA_FAIL;
+		    else
+			status = RA_BREAK;	// rest is below
+		}
+	    }
+	    break;
+
+	  case BRACE_LIMITS:
+	    {
+		if (OP(next) == BRACE_SIMPLE)
+		{
+		    bl_minval = OPERAND_MIN(scan);
+		    bl_maxval = OPERAND_MAX(scan);
+		}
+		else if (OP(next) >= BRACE_COMPLEX
+			&& OP(next) < BRACE_COMPLEX + 10)
+		{
+		    no = OP(next) - BRACE_COMPLEX;
+		    brace_min[no] = OPERAND_MIN(scan);
+		    brace_max[no] = OPERAND_MAX(scan);
+		    brace_count[no] = 0;
+		}
+		else
+		{
+		    internal_error("BRACE_LIMITS");
+		    status = RA_FAIL;
+		}
+	    }
+	    break;
+
+	  case BRACE_COMPLEX + 0:
+	  case BRACE_COMPLEX + 1:
+	  case BRACE_COMPLEX + 2:
+	  case BRACE_COMPLEX + 3:
+	  case BRACE_COMPLEX + 4:
+	  case BRACE_COMPLEX + 5:
+	  case BRACE_COMPLEX + 6:
+	  case BRACE_COMPLEX + 7:
+	  case BRACE_COMPLEX + 8:
+	  case BRACE_COMPLEX + 9:
+	    {
+		no = op - BRACE_COMPLEX;
+		++brace_count[no];
+
+		// If not matched enough times yet, try one more
+		if (brace_count[no] <= (brace_min[no] <= brace_max[no]
+					     ? brace_min[no] : brace_max[no]))
+		{
+		    rp = regstack_push(RS_BRCPLX_MORE, scan);
+		    if (rp == NULL)
+			status = RA_FAIL;
+		    else
+		    {
+			rp->rs_no = no;
+			reg_save(&rp->rs_un.regsave, &backpos);
+			next = OPERAND(scan);
+			// We continue and handle the result when done.
+		    }
+		    break;
+		}
+
+		// If matched enough times, may try matching some more
+		if (brace_min[no] <= brace_max[no])
+		{
+		    // Range is the normal way around, use longest match
+		    if (brace_count[no] <= brace_max[no])
+		    {
+			rp = regstack_push(RS_BRCPLX_LONG, scan);
+			if (rp == NULL)
+			    status = RA_FAIL;
+			else
+			{
+			    rp->rs_no = no;
+			    reg_save(&rp->rs_un.regsave, &backpos);
+			    next = OPERAND(scan);
+			    // We continue and handle the result when done.
+			}
+		    }
+		}
+		else
+		{
+		    // Range is backwards, use shortest match first
+		    if (brace_count[no] <= brace_min[no])
+		    {
+			rp = regstack_push(RS_BRCPLX_SHORT, scan);
+			if (rp == NULL)
+			    status = RA_FAIL;
+			else
+			{
+			    reg_save(&rp->rs_un.regsave, &backpos);
+			    // We continue and handle the result when done.
+			}
+		    }
+		}
+	    }
+	    break;
+
+	  case BRACE_SIMPLE:
+	  case STAR:
+	  case PLUS:
+	    {
+		regstar_T	rst;
+
+		// Lookahead to avoid useless match attempts when we know
+		// what character comes next.
+		if (OP(next) == EXACTLY)
+		{
+		    rst.nextb = *OPERAND(next);
+		    if (rex.reg_ic)
+		    {
+			if (MB_ISUPPER(rst.nextb))
+			    rst.nextb_ic = MB_TOLOWER(rst.nextb);
+			else
+			    rst.nextb_ic = MB_TOUPPER(rst.nextb);
+		    }
+		    else
+			rst.nextb_ic = rst.nextb;
+		}
+		else
+		{
+		    rst.nextb = NUL;
+		    rst.nextb_ic = NUL;
+		}
+		if (op != BRACE_SIMPLE)
+		{
+		    rst.minval = (op == STAR) ? 0 : 1;
+		    rst.maxval = MAX_LIMIT;
+		}
+		else
+		{
+		    rst.minval = bl_minval;
+		    rst.maxval = bl_maxval;
+		}
+
+		// When maxval > minval, try matching as much as possible, up
+		// to maxval.  When maxval < minval, try matching at least the
+		// minimal number (since the range is backwards, that's also
+		// maxval!).
+		rst.count = regrepeat(OPERAND(scan), rst.maxval);
+		if (got_int)
+		{
+		    status = RA_FAIL;
+		    break;
+		}
+		if (rst.minval <= rst.maxval
+			  ? rst.count >= rst.minval : rst.count >= rst.maxval)
+		{
+		    // It could match.  Prepare for trying to match what
+		    // follows.  The code is below.  Parameters are stored in
+		    // a regstar_T on the regstack.
+		    if ((long)((unsigned)regstack.ga_len >> 10) >= p_mmp)
+		    {
+			emsg(_(e_pattern_uses_more_memory_than_maxmempattern));
+			status = RA_FAIL;
+		    }
+		    else if (ga_grow(&regstack, sizeof(regstar_T)) == FAIL)
+			status = RA_FAIL;
+		    else
+		    {
+			regstack.ga_len += sizeof(regstar_T);
+			rp = regstack_push(rst.minval <= rst.maxval
+					? RS_STAR_LONG : RS_STAR_SHORT, scan);
+			if (rp == NULL)
+			    status = RA_FAIL;
+			else
+			{
+			    *(((regstar_T *)rp) - 1) = rst;
+			    status = RA_BREAK;	    // skip the restore bits
+			}
+		    }
+		}
+		else
+		    status = RA_NOMATCH;
+
+	    }
+	    break;
+
+	  case NOMATCH:
+	  case MATCH:
+	  case SUBPAT:
+	    rp = regstack_push(RS_NOMATCH, scan);
+	    if (rp == NULL)
+		status = RA_FAIL;
+	    else
+	    {
+		rp->rs_no = op;
+		reg_save(&rp->rs_un.regsave, &backpos);
+		next = OPERAND(scan);
+		// We continue and handle the result when done.
+	    }
+	    break;
+
+	  case BEHIND:
+	  case NOBEHIND:
+	    // Need a bit of room to store extra positions.
+	    if ((long)((unsigned)regstack.ga_len >> 10) >= p_mmp)
+	    {
+		emsg(_(e_pattern_uses_more_memory_than_maxmempattern));
+		status = RA_FAIL;
+	    }
+	    else if (ga_grow(&regstack, sizeof(regbehind_T)) == FAIL)
+		status = RA_FAIL;
+	    else
+	    {
+		regstack.ga_len += sizeof(regbehind_T);
+		rp = regstack_push(RS_BEHIND1, scan);
+		if (rp == NULL)
+		    status = RA_FAIL;
+		else
+		{
+		    // Need to save the subexpr to be able to restore them
+		    // when there is a match but we don't use it.
+		    save_subexpr(((regbehind_T *)rp) - 1);
+
+		    rp->rs_no = op;
+		    reg_save(&rp->rs_un.regsave, &backpos);
+		    // First try if what follows matches.  If it does then we
+		    // check the behind match by looping.
+		}
+	    }
+	    break;
+
+	  case BHPOS:
+	    if (REG_MULTI)
+	    {
+		if (behind_pos.rs_u.pos.col != (colnr_T)(rex.input - rex.line)
+			|| behind_pos.rs_u.pos.lnum != rex.lnum)
+		    status = RA_NOMATCH;
+	    }
+	    else if (behind_pos.rs_u.ptr != rex.input)
+		status = RA_NOMATCH;
+	    break;
+
+	  case NEWL:
+	    if ((c != NUL || !REG_MULTI || rex.lnum > rex.reg_maxline
+			     || rex.reg_line_lbr)
+					   && (c != '\n' || !rex.reg_line_lbr))
+		status = RA_NOMATCH;
+	    else if (rex.reg_line_lbr)
+		ADVANCE_REGINPUT();
+	    else
+		reg_nextline();
+	    break;
+
+	  case END:
+	    status = RA_MATCH;	// Success!
+	    break;
+
+	  default:
+	    iemsg(e_corrupted_regexp_program);
+#ifdef DEBUG
+	    printf("Illegal op code %d\n", op);
+#endif
+	    status = RA_FAIL;
+	    break;
+	  }
+	}
+
+	// If we can't continue sequentially, break the inner loop.
+	if (status != RA_CONT)
+	    break;
+
+	// Continue in inner loop, advance to next item.
+	scan = next;
+
+    } // end of inner loop
+
+    // If there is something on the regstack execute the code for the state.
+    // If the state is popped then loop and use the older state.
+    while (regstack.ga_len > 0 && status != RA_FAIL)
+    {
+	rp = (regitem_T *)((char *)regstack.ga_data + regstack.ga_len) - 1;
+	switch (rp->rs_state)
+	{
+	  case RS_NOPEN:
+	    // Result is passed on as-is, simply pop the state.
+	    regstack_pop(&scan);
+	    break;
+
+	  case RS_MOPEN:
+	    // Pop the state.  Restore pointers when there is no match.
+	    if (status == RA_NOMATCH)
+		restore_se(&rp->rs_un.sesave, &rex.reg_startpos[rp->rs_no],
+						  &rex.reg_startp[rp->rs_no]);
+	    regstack_pop(&scan);
+	    break;
+
+#ifdef FEAT_SYN_HL
+	  case RS_ZOPEN:
+	    // Pop the state.  Restore pointers when there is no match.
+	    if (status == RA_NOMATCH)
+		restore_se(&rp->rs_un.sesave, &reg_startzpos[rp->rs_no],
+						 &reg_startzp[rp->rs_no]);
+	    regstack_pop(&scan);
+	    break;
+#endif
+
+	  case RS_MCLOSE:
+	    // Pop the state.  Restore pointers when there is no match.
+	    if (status == RA_NOMATCH)
+		restore_se(&rp->rs_un.sesave, &rex.reg_endpos[rp->rs_no],
+						    &rex.reg_endp[rp->rs_no]);
+	    regstack_pop(&scan);
+	    break;
+
+#ifdef FEAT_SYN_HL
+	  case RS_ZCLOSE:
+	    // Pop the state.  Restore pointers when there is no match.
+	    if (status == RA_NOMATCH)
+		restore_se(&rp->rs_un.sesave, &reg_endzpos[rp->rs_no],
+						   &reg_endzp[rp->rs_no]);
+	    regstack_pop(&scan);
+	    break;
+#endif
+
+	  case RS_BRANCH:
+	    if (status == RA_MATCH)
+		// this branch matched, use it
+		regstack_pop(&scan);
+	    else
+	    {
+		if (status != RA_BREAK)
+		{
+		    // After a non-matching branch: try next one.
+		    reg_restore(&rp->rs_un.regsave, &backpos);
+		    scan = rp->rs_scan;
+		}
+		if (scan == NULL || OP(scan) != BRANCH)
+		{
+		    // no more branches, didn't find a match
+		    status = RA_NOMATCH;
+		    regstack_pop(&scan);
+		}
+		else
+		{
+		    // Prepare to try a branch.
+		    rp->rs_scan = regnext(scan);
+		    reg_save(&rp->rs_un.regsave, &backpos);
+		    scan = OPERAND(scan);
+		}
+	    }
+	    break;
+
+	  case RS_BRCPLX_MORE:
+	    // Pop the state.  Restore pointers when there is no match.
+	    if (status == RA_NOMATCH)
+	    {
+		reg_restore(&rp->rs_un.regsave, &backpos);
+		--brace_count[rp->rs_no];	// decrement match count
+	    }
+	    regstack_pop(&scan);
+	    break;
+
+	  case RS_BRCPLX_LONG:
+	    // Pop the state.  Restore pointers when there is no match.
+	    if (status == RA_NOMATCH)
+	    {
+		// There was no match, but we did find enough matches.
+		reg_restore(&rp->rs_un.regsave, &backpos);
+		--brace_count[rp->rs_no];
+		// continue with the items after "\{}"
+		status = RA_CONT;
+	    }
+	    regstack_pop(&scan);
+	    if (status == RA_CONT)
+		scan = regnext(scan);
+	    break;
+
+	  case RS_BRCPLX_SHORT:
+	    // Pop the state.  Restore pointers when there is no match.
+	    if (status == RA_NOMATCH)
+		// There was no match, try to match one more item.
+		reg_restore(&rp->rs_un.regsave, &backpos);
+	    regstack_pop(&scan);
+	    if (status == RA_NOMATCH)
+	    {
+		scan = OPERAND(scan);
+		status = RA_CONT;
+	    }
+	    break;
+
+	  case RS_NOMATCH:
+	    // Pop the state.  If the operand matches for NOMATCH or
+	    // doesn't match for MATCH/SUBPAT, we fail.  Otherwise backup,
+	    // except for SUBPAT, and continue with the next item.
+	    if (status == (rp->rs_no == NOMATCH ? RA_MATCH : RA_NOMATCH))
+		status = RA_NOMATCH;
+	    else
+	    {
+		status = RA_CONT;
+		if (rp->rs_no != SUBPAT)	// zero-width
+		    reg_restore(&rp->rs_un.regsave, &backpos);
+	    }
+	    regstack_pop(&scan);
+	    if (status == RA_CONT)
+		scan = regnext(scan);
+	    break;
+
+	  case RS_BEHIND1:
+	    if (status == RA_NOMATCH)
+	    {
+		regstack_pop(&scan);
+		regstack.ga_len -= sizeof(regbehind_T);
+	    }
+	    else
+	    {
+		// The stuff after BEHIND/NOBEHIND matches.  Now try if
+		// the behind part does (not) match before the current
+		// position in the input.  This must be done at every
+		// position in the input and checking if the match ends at
+		// the current position.
+
+		// save the position after the found match for next
+		reg_save(&(((regbehind_T *)rp) - 1)->save_after, &backpos);
+
+		// Start looking for a match with operand at the current
+		// position.  Go back one character until we find the
+		// result, hitting the start of the line or the previous
+		// line (for multi-line matching).
+		// Set behind_pos to where the match should end, BHPOS
+		// will match it.  Save the current value.
+		(((regbehind_T *)rp) - 1)->save_behind = behind_pos;
+		behind_pos = rp->rs_un.regsave;
+
+		rp->rs_state = RS_BEHIND2;
+
+		reg_restore(&rp->rs_un.regsave, &backpos);
+		scan = OPERAND(rp->rs_scan) + 4;
+	    }
+	    break;
+
+	  case RS_BEHIND2:
+	    // Looping for BEHIND / NOBEHIND match.
+	    if (status == RA_MATCH && reg_save_equal(&behind_pos))
+	    {
+		// found a match that ends where "next" started
+		behind_pos = (((regbehind_T *)rp) - 1)->save_behind;
+		if (rp->rs_no == BEHIND)
+		    reg_restore(&(((regbehind_T *)rp) - 1)->save_after,
+								    &backpos);
+		else
+		{
+		    // But we didn't want a match.  Need to restore the
+		    // subexpr, because what follows matched, so they have
+		    // been set.
+		    status = RA_NOMATCH;
+		    restore_subexpr(((regbehind_T *)rp) - 1);
+		}
+		regstack_pop(&scan);
+		regstack.ga_len -= sizeof(regbehind_T);
+	    }
+	    else
+	    {
+		long limit;
+
+		// No match or a match that doesn't end where we want it: Go
+		// back one character.  May go to previous line once.
+		no = OK;
+		limit = OPERAND_MIN(rp->rs_scan);
+		if (REG_MULTI)
+		{
+		    if (limit > 0
+			    && ((rp->rs_un.regsave.rs_u.pos.lnum
+						    < behind_pos.rs_u.pos.lnum
+				    ? (colnr_T)STRLEN(rex.line)
+				    : behind_pos.rs_u.pos.col)
+				- rp->rs_un.regsave.rs_u.pos.col >= limit))
+			no = FAIL;
+		    else if (rp->rs_un.regsave.rs_u.pos.col == 0)
+		    {
+			if (rp->rs_un.regsave.rs_u.pos.lnum
+					< behind_pos.rs_u.pos.lnum
+				|| reg_getline(
+					--rp->rs_un.regsave.rs_u.pos.lnum)
+								  == NULL)
+			    no = FAIL;
+			else
+			{
+			    reg_restore(&rp->rs_un.regsave, &backpos);
+			    rp->rs_un.regsave.rs_u.pos.col =
+						 (colnr_T)STRLEN(rex.line);
+			}
+		    }
+		    else
+		    {
+			if (has_mbyte)
+			{
+			    char_u *line =
+				  reg_getline(rp->rs_un.regsave.rs_u.pos.lnum);
+
+			    rp->rs_un.regsave.rs_u.pos.col -=
+				(*mb_head_off)(line, line
+				    + rp->rs_un.regsave.rs_u.pos.col - 1) + 1;
+			}
+			else
+			    --rp->rs_un.regsave.rs_u.pos.col;
+		    }
+		}
+		else
+		{
+		    if (rp->rs_un.regsave.rs_u.ptr == rex.line)
+			no = FAIL;
+		    else
+		    {
+			MB_PTR_BACK(rex.line, rp->rs_un.regsave.rs_u.ptr);
+			if (limit > 0 && (long)(behind_pos.rs_u.ptr
+				     - rp->rs_un.regsave.rs_u.ptr) > limit)
+			    no = FAIL;
+		    }
+		}
+		if (no == OK)
+		{
+		    // Advanced, prepare for finding match again.
+		    reg_restore(&rp->rs_un.regsave, &backpos);
+		    scan = OPERAND(rp->rs_scan) + 4;
+		    if (status == RA_MATCH)
+		    {
+			// We did match, so subexpr may have been changed,
+			// need to restore them for the next try.
+			status = RA_NOMATCH;
+			restore_subexpr(((regbehind_T *)rp) - 1);
+		    }
+		}
+		else
+		{
+		    // Can't advance.  For NOBEHIND that's a match.
+		    behind_pos = (((regbehind_T *)rp) - 1)->save_behind;
+		    if (rp->rs_no == NOBEHIND)
+		    {
+			reg_restore(&(((regbehind_T *)rp) - 1)->save_after,
+								    &backpos);
+			status = RA_MATCH;
+		    }
+		    else
+		    {
+			// We do want a proper match.  Need to restore the
+			// subexpr if we had a match, because they may have
+			// been set.
+			if (status == RA_MATCH)
+			{
+			    status = RA_NOMATCH;
+			    restore_subexpr(((regbehind_T *)rp) - 1);
+			}
+		    }
+		    regstack_pop(&scan);
+		    regstack.ga_len -= sizeof(regbehind_T);
+		}
+	    }
+	    break;
+
+	  case RS_STAR_LONG:
+	  case RS_STAR_SHORT:
+	    {
+		regstar_T	    *rst = ((regstar_T *)rp) - 1;
+
+		if (status == RA_MATCH)
+		{
+		    regstack_pop(&scan);
+		    regstack.ga_len -= sizeof(regstar_T);
+		    break;
+		}
+
+		// Tried once already, restore input pointers.
+		if (status != RA_BREAK)
+		    reg_restore(&rp->rs_un.regsave, &backpos);
+
+		// Repeat until we found a position where it could match.
+		for (;;)
+		{
+		    if (status != RA_BREAK)
+		    {
+			// Tried first position already, advance.
+			if (rp->rs_state == RS_STAR_LONG)
+			{
+			    // Trying for longest match, but couldn't or
+			    // didn't match -- back up one char.
+			    if (--rst->count < rst->minval)
+				break;
+			    if (rex.input == rex.line)
+			    {
+				// backup to last char of previous line
+				if (rex.lnum == 0)
+				{
+				    status = RA_NOMATCH;
+				    break;
+				}
+				--rex.lnum;
+				rex.line = reg_getline(rex.lnum);
+				// Just in case regrepeat() didn't count
+				// right.
+				if (rex.line == NULL)
+				    break;
+				rex.input = rex.line + STRLEN(rex.line);
+				fast_breakcheck();
+			    }
+			    else
+				MB_PTR_BACK(rex.line, rex.input);
+			}
+			else
+			{
+			    // Range is backwards, use shortest match first.
+			    // Careful: maxval and minval are exchanged!
+			    // Couldn't or didn't match: try advancing one
+			    // char.
+			    if (rst->count == rst->minval
+				  || regrepeat(OPERAND(rp->rs_scan), 1L) == 0)
+				break;
+			    ++rst->count;
+			}
+			if (got_int)
+			    break;
+		    }
+		    else
+			status = RA_NOMATCH;
+
+		    // If it could match, try it.
+		    if (rst->nextb == NUL || *rex.input == rst->nextb
+					     || *rex.input == rst->nextb_ic)
+		    {
+			reg_save(&rp->rs_un.regsave, &backpos);
+			scan = regnext(rp->rs_scan);
+			status = RA_CONT;
+			break;
+		    }
+		}
+		if (status != RA_CONT)
+		{
+		    // Failed.
+		    regstack_pop(&scan);
+		    regstack.ga_len -= sizeof(regstar_T);
+		    status = RA_NOMATCH;
+		}
+	    }
+	    break;
+	}
+
+	// If we want to continue the inner loop or didn't pop a state
+	// continue matching loop
+	if (status == RA_CONT || rp == (regitem_T *)
+			     ((char *)regstack.ga_data + regstack.ga_len) - 1)
+	    break;
+
+#ifdef FEAT_RELTIME
+	if (bt_did_time_out(timed_out))
+	{
+	    status = RA_FAIL;
+	    break;
+	}
+#endif
+    }
+
+    // May need to continue with the inner loop, starting at "scan".
+    if (status == RA_CONT)
+	continue;
+
+    // If the regstack is empty or something failed we are done.
+    if (regstack.ga_len == 0 || status == RA_FAIL)
+    {
+	if (scan == NULL)
+	{
+	    // We get here only if there's trouble -- normally "case END" is
+	    // the terminating point.
+	    iemsg(e_corrupted_regexp_program);
+#ifdef DEBUG
+	    printf("Premature EOL\n");
+#endif
+	}
+	return (status == RA_MATCH);
+    }
+
+  } // End of loop until the regstack is empty.
+
+  // NOTREACHED
+}
+
+/*
+ * regtry - try match of "prog" with at rex.line["col"].
+ * Returns 0 for failure, number of lines contained in the match otherwise.
+ */
+    static long
+regtry(
+    bt_regprog_T	*prog,
+    colnr_T		col,
+    int			*timed_out)	// flag set on timeout or NULL
+{
+    rex.input = rex.line + col;
+    rex.need_clear_subexpr = TRUE;
+#ifdef FEAT_SYN_HL
+    // Clear the external match subpointers if necessary.
+    rex.need_clear_zsubexpr = (prog->reghasz == REX_SET);
+#endif
+
+    if (regmatch(prog->program + 1, timed_out) == 0)
+	return 0;
+
+    cleanup_subexpr();
+    if (REG_MULTI)
+    {
+	if (rex.reg_startpos[0].lnum < 0)
+	{
+	    rex.reg_startpos[0].lnum = 0;
+	    rex.reg_startpos[0].col = col;
+	}
+	if (rex.reg_endpos[0].lnum < 0)
+	{
+	    rex.reg_endpos[0].lnum = rex.lnum;
+	    rex.reg_endpos[0].col = (int)(rex.input - rex.line);
+	}
+	else
+	    // Use line number of "\ze".
+	    rex.lnum = rex.reg_endpos[0].lnum;
+    }
+    else
+    {
+	if (rex.reg_startp[0] == NULL)
+	    rex.reg_startp[0] = rex.line + col;
+	if (rex.reg_endp[0] == NULL)
+	    rex.reg_endp[0] = rex.input;
+    }
+#ifdef FEAT_SYN_HL
+    // Package any found \z(...\) matches for export. Default is none.
+    unref_extmatch(re_extmatch_out);
+    re_extmatch_out = NULL;
+
+    if (prog->reghasz == REX_SET)
+    {
+	int		i;
+
+	cleanup_zsubexpr();
+	re_extmatch_out = make_extmatch();
+	if (re_extmatch_out == NULL)
+	    return 0;
+	for (i = 0; i < NSUBEXP; i++)
+	{
+	    if (REG_MULTI)
+	    {
+		// Only accept single line matches.
+		if (reg_startzpos[i].lnum >= 0
+			&& reg_endzpos[i].lnum == reg_startzpos[i].lnum
+			&& reg_endzpos[i].col >= reg_startzpos[i].col)
+		    re_extmatch_out->matches[i] =
+			vim_strnsave(reg_getline(reg_startzpos[i].lnum)
+						       + reg_startzpos[i].col,
+				   reg_endzpos[i].col - reg_startzpos[i].col);
+	    }
+	    else
+	    {
+		if (reg_startzp[i] != NULL && reg_endzp[i] != NULL)
+		    re_extmatch_out->matches[i] =
+			    vim_strnsave(reg_startzp[i],
+						reg_endzp[i] - reg_startzp[i]);
+	    }
+	}
+    }
+#endif
+    return 1 + rex.lnum;
+}
+
+/*
+ * Match a regexp against a string ("line" points to the string) or multiple
+ * lines (if "line" is NULL, use reg_getline()).
+ * Returns 0 for failure, number of lines contained in the match otherwise.
+ */
+    static long
+bt_regexec_both(
+    char_u	*line,
+    colnr_T	startcol,	// column to start looking for match
+    int		*timed_out)	// flag set on timeout or NULL
+{
+    bt_regprog_T    *prog;
+    char_u	    *s;
+    colnr_T	    col = startcol;
+    long	    retval = 0L;
+
+    // Create "regstack" and "backpos" if they are not allocated yet.
+    // We allocate *_INITIAL amount of bytes first and then set the grow size
+    // to much bigger value to avoid many malloc calls in case of deep regular
+    // expressions.
+    if (regstack.ga_data == NULL)
+    {
+	// Use an item size of 1 byte, since we push different things
+	// onto the regstack.
+	ga_init2(&regstack, 1, REGSTACK_INITIAL);
+	(void)ga_grow(&regstack, REGSTACK_INITIAL);
+	regstack.ga_growsize = REGSTACK_INITIAL * 8;
+    }
+
+    if (backpos.ga_data == NULL)
+    {
+	ga_init2(&backpos, sizeof(backpos_T), BACKPOS_INITIAL);
+	(void)ga_grow(&backpos, BACKPOS_INITIAL);
+	backpos.ga_growsize = BACKPOS_INITIAL * 8;
+    }
+
+    if (REG_MULTI)
+    {
+	prog = (bt_regprog_T *)rex.reg_mmatch->regprog;
+	line = reg_getline((linenr_T)0);
+	rex.reg_startpos = rex.reg_mmatch->startpos;
+	rex.reg_endpos = rex.reg_mmatch->endpos;
+    }
+    else
+    {
+	prog = (bt_regprog_T *)rex.reg_match->regprog;
+	rex.reg_startp = rex.reg_match->startp;
+	rex.reg_endp = rex.reg_match->endp;
+    }
+
+    // Be paranoid...
+    if (prog == NULL || line == NULL)
+    {
+	iemsg(e_null_argument);
+	goto theend;
+    }
+
+    // Check validity of program.
+    if (prog_magic_wrong())
+	goto theend;
+
+    // If the start column is past the maximum column: no need to try.
+    if (rex.reg_maxcol > 0 && col >= rex.reg_maxcol)
+	goto theend;
+
+    // If pattern contains "\c" or "\C": overrule value of rex.reg_ic
+    if (prog->regflags & RF_ICASE)
+	rex.reg_ic = TRUE;
+    else if (prog->regflags & RF_NOICASE)
+	rex.reg_ic = FALSE;
+
+    // If pattern contains "\Z" overrule value of rex.reg_icombine
+    if (prog->regflags & RF_ICOMBINE)
+	rex.reg_icombine = TRUE;
+
+    // If there is a "must appear" string, look for it.
+    if (prog->regmust != NULL)
+    {
+	int c;
+
+	if (has_mbyte)
+	    c = (*mb_ptr2char)(prog->regmust);
+	else
+	    c = *prog->regmust;
+	s = line + col;
+
+	// This is used very often, esp. for ":global".  Use three versions of
+	// the loop to avoid overhead of conditions.
+	if (!rex.reg_ic && !has_mbyte)
+	    while ((s = vim_strbyte(s, c)) != NULL)
+	    {
+		if (cstrncmp(s, prog->regmust, &prog->regmlen) == 0)
+		    break;		// Found it.
+		++s;
+	    }
+	else if (!rex.reg_ic || (!enc_utf8 && mb_char2len(c) > 1))
+	    while ((s = vim_strchr(s, c)) != NULL)
+	    {
+		if (cstrncmp(s, prog->regmust, &prog->regmlen) == 0)
+		    break;		// Found it.
+		MB_PTR_ADV(s);
+	    }
+	else
+	    while ((s = cstrchr(s, c)) != NULL)
+	    {
+		if (cstrncmp(s, prog->regmust, &prog->regmlen) == 0)
+		    break;		// Found it.
+		MB_PTR_ADV(s);
+	    }
+	if (s == NULL)		// Not present.
+	    goto theend;
+    }
+
+    rex.line = line;
+    rex.lnum = 0;
+    reg_toolong = FALSE;
+
+    // Simplest case: Anchored match need be tried only once.
+    if (prog->reganch)
+    {
+	int	c;
+
+	if (has_mbyte)
+	    c = (*mb_ptr2char)(rex.line + col);
+	else
+	    c = rex.line[col];
+	if (prog->regstart == NUL
+		|| prog->regstart == c
+		|| (rex.reg_ic
+		    && (((enc_utf8 && utf_fold(prog->regstart) == utf_fold(c)))
+			|| (c < 255 && prog->regstart < 255 &&
+			    MB_TOLOWER(prog->regstart) == MB_TOLOWER(c)))))
+	    retval = regtry(prog, col, timed_out);
+	else
+	    retval = 0;
+    }
+    else
+    {
+	// Messy cases:  unanchored match.
+	while (!got_int)
+	{
+	    if (prog->regstart != NUL)
+	    {
+		// Skip until the char we know it must start with.
+		// Used often, do some work to avoid call overhead.
+		if (!rex.reg_ic && !has_mbyte)
+		    s = vim_strbyte(rex.line + col, prog->regstart);
+		else
+		    s = cstrchr(rex.line + col, prog->regstart);
+		if (s == NULL)
+		{
+		    retval = 0;
+		    break;
+		}
+		col = (int)(s - rex.line);
+	    }
+
+	    // Check for maximum column to try.
+	    if (rex.reg_maxcol > 0 && col >= rex.reg_maxcol)
+	    {
+		retval = 0;
+		break;
+	    }
+
+	    retval = regtry(prog, col, timed_out);
+	    if (retval > 0)
+		break;
+
+	    // if not currently on the first line, get it again
+	    if (rex.lnum != 0)
+	    {
+		rex.lnum = 0;
+		rex.line = reg_getline((linenr_T)0);
+	    }
+	    if (rex.line[col] == NUL)
+		break;
+	    if (has_mbyte)
+		col += (*mb_ptr2len)(rex.line + col);
+	    else
+		++col;
+#ifdef FEAT_RELTIME
+	    if (bt_did_time_out(timed_out))
+		break;
+#endif
+	}
+    }
+
+theend:
+    // Free "reg_tofree" when it's a bit big.
+    // Free regstack and backpos if they are bigger than their initial size.
+    if (reg_tofreelen > 400)
+	VIM_CLEAR(reg_tofree);
+    if (regstack.ga_maxlen > REGSTACK_INITIAL)
+	ga_clear(&regstack);
+    if (backpos.ga_maxlen > BACKPOS_INITIAL)
+	ga_clear(&backpos);
+
+    if (retval > 0)
+    {
+	// Make sure the end is never before the start.  Can happen when \zs
+	// and \ze are used.
+	if (REG_MULTI)
+	{
+	    lpos_T *start = &rex.reg_mmatch->startpos[0];
+	    lpos_T *end = &rex.reg_mmatch->endpos[0];
+
+	    if (end->lnum < start->lnum
+			|| (end->lnum == start->lnum && end->col < start->col))
+		rex.reg_mmatch->endpos[0] = rex.reg_mmatch->startpos[0];
+
+	    // startpos[0] may be set by "\zs", also return the column where
+	    // the whole pattern matched.
+	    rex.reg_mmatch->rmm_matchcol = col;
+	}
+	else
+	{
+	    if (rex.reg_match->endp[0] < rex.reg_match->startp[0])
+		rex.reg_match->endp[0] = rex.reg_match->startp[0];
+
+	    // startpos[0] may be set by "\zs", also return the column where
+	    // the whole pattern matched.
+	    rex.reg_match->rm_matchcol = col;
+	}
+    }
+
+    return retval;
+}
+
+/*
+ * Match a regexp against a string.
+ * "rmp->regprog" is a compiled regexp as returned by vim_regcomp().
+ * Uses curbuf for line count and 'iskeyword'.
+ * if "line_lbr" is TRUE  consider a "\n" in "line" to be a line break.
+ *
+ * Returns 0 for failure, number of lines contained in the match otherwise.
+ */
+    static int
+bt_regexec_nl(
+    regmatch_T	*rmp,
+    char_u	*line,	// string to match against
+    colnr_T	col,	// column to start looking for match
+    int		line_lbr)
+{
+    rex.reg_match = rmp;
+    rex.reg_mmatch = NULL;
+    rex.reg_maxline = 0;
+    rex.reg_line_lbr = line_lbr;
+    rex.reg_buf = curbuf;
+    rex.reg_win = NULL;
+    rex.reg_ic = rmp->rm_ic;
+    rex.reg_icombine = FALSE;
+    rex.reg_maxcol = 0;
+
+    return bt_regexec_both(line, col, NULL);
+}
+
+/*
+ * Match a regexp against multiple lines.
+ * "rmp->regprog" is a compiled regexp as returned by vim_regcomp().
+ * Uses curbuf for line count and 'iskeyword'.
+ *
+ * Return zero if there is no match.  Return number of lines contained in the
+ * match otherwise.
+ */
+    static long
+bt_regexec_multi(
+    regmmatch_T	*rmp,
+    win_T	*win,		// window in which to search or NULL
+    buf_T	*buf,		// buffer in which to search
+    linenr_T	lnum,		// nr of line to start looking for match
+    colnr_T	col,		// column to start looking for match
+    int		*timed_out)	// flag set on timeout or NULL
+{
+    init_regexec_multi(rmp, win, buf, lnum);
+    return bt_regexec_both(NULL, col, timed_out);
+}
+
+/*
+ * Compare a number with the operand of RE_LNUM, RE_COL or RE_VCOL.
+ */
+    static int
+re_num_cmp(long_u val, char_u *scan)
+{
+    long_u  n = OPERAND_MIN(scan);
+
+    if (OPERAND_CMP(scan) == '>')
+	return val > n;
+    if (OPERAND_CMP(scan) == '<')
+	return val < n;
+    return val == n;
+}
+
+#ifdef BT_REGEXP_DUMP
+
+/*
+ * regdump - dump a regexp onto stdout in vaguely comprehensible form
+ */
+    static void
+regdump(char_u *pattern, bt_regprog_T *r)
+{
+    char_u  *s;
+    int	    op = EXACTLY;	// Arbitrary non-END op.
+    char_u  *next;
+    char_u  *end = NULL;
+    FILE    *f;
+
+#ifdef BT_REGEXP_LOG
+    f = fopen("bt_regexp_log.log", "a");
+#else
+    f = stdout;
+#endif
+    if (f == NULL)
+	return;
+    fprintf(f, "-------------------------------------\n\r\nregcomp(%s):\r\n", pattern);
+
+    s = r->program + 1;
+    // Loop until we find the END that isn't before a referred next (an END
+    // can also appear in a NOMATCH operand).
+    while (op != END || s <= end)
+    {
+	op = OP(s);
+	fprintf(f, "%2d%s", (int)(s - r->program), regprop(s)); // Where, what.
+	next = regnext(s);
+	if (next == NULL)	// Next ptr.
+	    fprintf(f, "(0)");
+	else
+	    fprintf(f, "(%d)", (int)((s - r->program) + (next - s)));
+	if (end < next)
+	    end = next;
+	if (op == BRACE_LIMITS)
+	{
+	    // Two ints
+	    fprintf(f, " minval %ld, maxval %ld", OPERAND_MIN(s), OPERAND_MAX(s));
+	    s += 8;
+	}
+	else if (op == BEHIND || op == NOBEHIND)
+	{
+	    // one int
+	    fprintf(f, " count %ld", OPERAND_MIN(s));
+	    s += 4;
+	}
+	else if (op == RE_LNUM || op == RE_COL || op == RE_VCOL)
+	{
+	    // one int plus comparator
+	    fprintf(f, " count %ld", OPERAND_MIN(s));
+	    s += 5;
+	}
+	s += 3;
+	if (op == ANYOF || op == ANYOF + ADD_NL
+		|| op == ANYBUT || op == ANYBUT + ADD_NL
+		|| op == EXACTLY)
+	{
+	    // Literal string, where present.
+	    fprintf(f, "\nxxxxxxxxx\n");
+	    while (*s != NUL)
+		fprintf(f, "%c", *s++);
+	    fprintf(f, "\nxxxxxxxxx\n");
+	    s++;
+	}
+	fprintf(f, "\r\n");
+    }
+
+    // Header fields of interest.
+    if (r->regstart != NUL)
+	fprintf(f, "start `%s' 0x%x; ", r->regstart < 256
+		? (char *)transchar(r->regstart)
+		: "multibyte", r->regstart);
+    if (r->reganch)
+	fprintf(f, "anchored; ");
+    if (r->regmust != NULL)
+	fprintf(f, "must have \"%s\"", r->regmust);
+    fprintf(f, "\r\n");
+
+#ifdef BT_REGEXP_LOG
+    fclose(f);
+#endif
+}
+#endif	    // BT_REGEXP_DUMP
+
+#ifdef DEBUG
+/*
+ * regprop - printable representation of opcode
+ */
+    static char_u *
+regprop(char_u *op)
+{
+    char	    *p;
+    static char	    buf[50];
+
+    STRCPY(buf, ":");
+
+    switch ((int) OP(op))
+    {
+      case BOL:
+	p = "BOL";
+	break;
+      case EOL:
+	p = "EOL";
+	break;
+      case RE_BOF:
+	p = "BOF";
+	break;
+      case RE_EOF:
+	p = "EOF";
+	break;
+      case CURSOR:
+	p = "CURSOR";
+	break;
+      case RE_VISUAL:
+	p = "RE_VISUAL";
+	break;
+      case RE_LNUM:
+	p = "RE_LNUM";
+	break;
+      case RE_MARK:
+	p = "RE_MARK";
+	break;
+      case RE_COL:
+	p = "RE_COL";
+	break;
+      case RE_VCOL:
+	p = "RE_VCOL";
+	break;
+      case BOW:
+	p = "BOW";
+	break;
+      case EOW:
+	p = "EOW";
+	break;
+      case ANY:
+	p = "ANY";
+	break;
+      case ANY + ADD_NL:
+	p = "ANY+NL";
+	break;
+      case ANYOF:
+	p = "ANYOF";
+	break;
+      case ANYOF + ADD_NL:
+	p = "ANYOF+NL";
+	break;
+      case ANYBUT:
+	p = "ANYBUT";
+	break;
+      case ANYBUT + ADD_NL:
+	p = "ANYBUT+NL";
+	break;
+      case IDENT:
+	p = "IDENT";
+	break;
+      case IDENT + ADD_NL:
+	p = "IDENT+NL";
+	break;
+      case SIDENT:
+	p = "SIDENT";
+	break;
+      case SIDENT + ADD_NL:
+	p = "SIDENT+NL";
+	break;
+      case KWORD:
+	p = "KWORD";
+	break;
+      case KWORD + ADD_NL:
+	p = "KWORD+NL";
+	break;
+      case SKWORD:
+	p = "SKWORD";
+	break;
+      case SKWORD + ADD_NL:
+	p = "SKWORD+NL";
+	break;
+      case FNAME:
+	p = "FNAME";
+	break;
+      case FNAME + ADD_NL:
+	p = "FNAME+NL";
+	break;
+      case SFNAME:
+	p = "SFNAME";
+	break;
+      case SFNAME + ADD_NL:
+	p = "SFNAME+NL";
+	break;
+      case PRINT:
+	p = "PRINT";
+	break;
+      case PRINT + ADD_NL:
+	p = "PRINT+NL";
+	break;
+      case SPRINT:
+	p = "SPRINT";
+	break;
+      case SPRINT + ADD_NL:
+	p = "SPRINT+NL";
+	break;
+      case WHITE:
+	p = "WHITE";
+	break;
+      case WHITE + ADD_NL:
+	p = "WHITE+NL";
+	break;
+      case NWHITE:
+	p = "NWHITE";
+	break;
+      case NWHITE + ADD_NL:
+	p = "NWHITE+NL";
+	break;
+      case DIGIT:
+	p = "DIGIT";
+	break;
+      case DIGIT + ADD_NL:
+	p = "DIGIT+NL";
+	break;
+      case NDIGIT:
+	p = "NDIGIT";
+	break;
+      case NDIGIT + ADD_NL:
+	p = "NDIGIT+NL";
+	break;
+      case HEX:
+	p = "HEX";
+	break;
+      case HEX + ADD_NL:
+	p = "HEX+NL";
+	break;
+      case NHEX:
+	p = "NHEX";
+	break;
+      case NHEX + ADD_NL:
+	p = "NHEX+NL";
+	break;
+      case OCTAL:
+	p = "OCTAL";
+	break;
+      case OCTAL + ADD_NL:
+	p = "OCTAL+NL";
+	break;
+      case NOCTAL:
+	p = "NOCTAL";
+	break;
+      case NOCTAL + ADD_NL:
+	p = "NOCTAL+NL";
+	break;
+      case WORD:
+	p = "WORD";
+	break;
+      case WORD + ADD_NL:
+	p = "WORD+NL";
+	break;
+      case NWORD:
+	p = "NWORD";
+	break;
+      case NWORD + ADD_NL:
+	p = "NWORD+NL";
+	break;
+      case HEAD:
+	p = "HEAD";
+	break;
+      case HEAD + ADD_NL:
+	p = "HEAD+NL";
+	break;
+      case NHEAD:
+	p = "NHEAD";
+	break;
+      case NHEAD + ADD_NL:
+	p = "NHEAD+NL";
+	break;
+      case ALPHA:
+	p = "ALPHA";
+	break;
+      case ALPHA + ADD_NL:
+	p = "ALPHA+NL";
+	break;
+      case NALPHA:
+	p = "NALPHA";
+	break;
+      case NALPHA + ADD_NL:
+	p = "NALPHA+NL";
+	break;
+      case LOWER:
+	p = "LOWER";
+	break;
+      case LOWER + ADD_NL:
+	p = "LOWER+NL";
+	break;
+      case NLOWER:
+	p = "NLOWER";
+	break;
+      case NLOWER + ADD_NL:
+	p = "NLOWER+NL";
+	break;
+      case UPPER:
+	p = "UPPER";
+	break;
+      case UPPER + ADD_NL:
+	p = "UPPER+NL";
+	break;
+      case NUPPER:
+	p = "NUPPER";
+	break;
+      case NUPPER + ADD_NL:
+	p = "NUPPER+NL";
+	break;
+      case BRANCH:
+	p = "BRANCH";
+	break;
+      case EXACTLY:
+	p = "EXACTLY";
+	break;
+      case NOTHING:
+	p = "NOTHING";
+	break;
+      case BACK:
+	p = "BACK";
+	break;
+      case END:
+	p = "END";
+	break;
+      case MOPEN + 0:
+	p = "MATCH START";
+	break;
+      case MOPEN + 1:
+      case MOPEN + 2:
+      case MOPEN + 3:
+      case MOPEN + 4:
+      case MOPEN + 5:
+      case MOPEN + 6:
+      case MOPEN + 7:
+      case MOPEN + 8:
+      case MOPEN + 9:
+	sprintf(buf + STRLEN(buf), "MOPEN%d", OP(op) - MOPEN);
+	p = NULL;
+	break;
+      case MCLOSE + 0:
+	p = "MATCH END";
+	break;
+      case MCLOSE + 1:
+      case MCLOSE + 2:
+      case MCLOSE + 3:
+      case MCLOSE + 4:
+      case MCLOSE + 5:
+      case MCLOSE + 6:
+      case MCLOSE + 7:
+      case MCLOSE + 8:
+      case MCLOSE + 9:
+	sprintf(buf + STRLEN(buf), "MCLOSE%d", OP(op) - MCLOSE);
+	p = NULL;
+	break;
+      case BACKREF + 1:
+      case BACKREF + 2:
+      case BACKREF + 3:
+      case BACKREF + 4:
+      case BACKREF + 5:
+      case BACKREF + 6:
+      case BACKREF + 7:
+      case BACKREF + 8:
+      case BACKREF + 9:
+	sprintf(buf + STRLEN(buf), "BACKREF%d", OP(op) - BACKREF);
+	p = NULL;
+	break;
+      case NOPEN:
+	p = "NOPEN";
+	break;
+      case NCLOSE:
+	p = "NCLOSE";
+	break;
+#ifdef FEAT_SYN_HL
+      case ZOPEN + 1:
+      case ZOPEN + 2:
+      case ZOPEN + 3:
+      case ZOPEN + 4:
+      case ZOPEN + 5:
+      case ZOPEN + 6:
+      case ZOPEN + 7:
+      case ZOPEN + 8:
+      case ZOPEN + 9:
+	sprintf(buf + STRLEN(buf), "ZOPEN%d", OP(op) - ZOPEN);
+	p = NULL;
+	break;
+      case ZCLOSE + 1:
+      case ZCLOSE + 2:
+      case ZCLOSE + 3:
+      case ZCLOSE + 4:
+      case ZCLOSE + 5:
+      case ZCLOSE + 6:
+      case ZCLOSE + 7:
+      case ZCLOSE + 8:
+      case ZCLOSE + 9:
+	sprintf(buf + STRLEN(buf), "ZCLOSE%d", OP(op) - ZCLOSE);
+	p = NULL;
+	break;
+      case ZREF + 1:
+      case ZREF + 2:
+      case ZREF + 3:
+      case ZREF + 4:
+      case ZREF + 5:
+      case ZREF + 6:
+      case ZREF + 7:
+      case ZREF + 8:
+      case ZREF + 9:
+	sprintf(buf + STRLEN(buf), "ZREF%d", OP(op) - ZREF);
+	p = NULL;
+	break;
+#endif
+      case STAR:
+	p = "STAR";
+	break;
+      case PLUS:
+	p = "PLUS";
+	break;
+      case NOMATCH:
+	p = "NOMATCH";
+	break;
+      case MATCH:
+	p = "MATCH";
+	break;
+      case BEHIND:
+	p = "BEHIND";
+	break;
+      case NOBEHIND:
+	p = "NOBEHIND";
+	break;
+      case SUBPAT:
+	p = "SUBPAT";
+	break;
+      case BRACE_LIMITS:
+	p = "BRACE_LIMITS";
+	break;
+      case BRACE_SIMPLE:
+	p = "BRACE_SIMPLE";
+	break;
+      case BRACE_COMPLEX + 0:
+      case BRACE_COMPLEX + 1:
+      case BRACE_COMPLEX + 2:
+      case BRACE_COMPLEX + 3:
+      case BRACE_COMPLEX + 4:
+      case BRACE_COMPLEX + 5:
+      case BRACE_COMPLEX + 6:
+      case BRACE_COMPLEX + 7:
+      case BRACE_COMPLEX + 8:
+      case BRACE_COMPLEX + 9:
+	sprintf(buf + STRLEN(buf), "BRACE_COMPLEX%d", OP(op) - BRACE_COMPLEX);
+	p = NULL;
+	break;
+      case MULTIBYTECODE:
+	p = "MULTIBYTECODE";
+	break;
+      case NEWL:
+	p = "NEWL";
+	break;
+      default:
+	sprintf(buf + STRLEN(buf), "corrupt %d", OP(op));
+	p = NULL;
+	break;
+    }
+    if (p != NULL)
+	STRCAT(buf, p);
+    return (char_u *)buf;
+}
+#endif	    // DEBUG
-- 
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