1 /****************************************************************************
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3  *                                                                          *
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14  *                                                                          *
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22  *                                                                          *
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28 
29 /****************************************************************************
30  *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
31  *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
32  *     and: Thomas E. Dickey                        1996-on                 *
33  *     and: Juergen Pfeifer                         2009                    *
34  ****************************************************************************/
35 
36 /*
37 **	lib_mvcur.c
38 **
39 **	The routines for moving the physical cursor and scrolling:
40 **
41 **		void _nc_mvcur_init(void)
42 **
43 **		void _nc_mvcur_resume(void)
44 **
45 **		int mvcur(int old_y, int old_x, int new_y, int new_x)
46 **
47 **		void _nc_mvcur_wrap(void)
48 **
49 ** Comparisons with older movement optimizers:
50 **    SVr3 curses mvcur() can't use cursor_to_ll or auto_left_margin.
51 **    4.4BSD curses can't use cuu/cud/cuf/cub/hpa/vpa/tab/cbt for local
52 ** motions.  It doesn't use tactics based on auto_left_margin.  Weirdly
53 ** enough, it doesn't use its own hardware-scrolling routine to scroll up
54 ** destination lines for out-of-bounds addresses!
55 **    old ncurses optimizer: less accurate cost computations (in fact,
56 ** it was broken and had to be commented out!).
57 **
58 ** Compile with -DMAIN to build an interactive tester/timer for the movement
59 ** optimizer.  You can use it to investigate the optimizer's behavior.
60 ** You can also use it for tuning the formulas used to determine whether
61 ** or not full optimization is attempted.
62 **
63 ** This code has a nasty tendency to find bugs in terminfo entries, because it
64 ** exercises the non-cup movement capabilities heavily.  If you think you've
65 ** found a bug, try deleting subsets of the following capabilities (arranged
66 ** in decreasing order of suspiciousness): it, tab, cbt, hpa, vpa, cuu, cud,
67 ** cuf, cub, cuu1, cud1, cuf1, cub1.  It may be that one or more are wrong.
68 **
69 ** Note: you should expect this code to look like a resource hog in a profile.
70 ** That's because it does a lot of I/O, through the tputs() calls.  The I/O
71 ** cost swamps the computation overhead (and as machines get faster, this
72 ** will become even more true).  Comments in the test exerciser at the end
73 ** go into detail about tuning and how you can gauge the optimizer's
74 ** effectiveness.
75 **/
76 
77 /****************************************************************************
78  *
79  * Constants and macros for optimizer tuning.
80  *
81  ****************************************************************************/
82 
83 /*
84  * The average overhead of a full optimization computation in character
85  * transmission times.  If it's too high, the algorithm will be a bit
86  * over-biased toward using cup rather than local motions; if it's too
87  * low, the algorithm may spend more time than is strictly optimal
88  * looking for non-cup motions.  Profile the optimizer using the `t'
89  * command of the exerciser (see below), and round to the nearest integer.
90  *
91  * Yes, I (esr) thought about computing expected overhead dynamically, say
92  * by derivation from a running average of optimizer times.  But the
93  * whole point of this optimization is to *decrease* the frequency of
94  * system calls. :-)
95  */
96 #define COMPUTE_OVERHEAD	1	/* I use a 90MHz Pentium @ 9.6Kbps */
97 
98 /*
99  * LONG_DIST is the distance we consider to be just as costly to move over as a
100  * cup sequence is to emit.  In other words, it's the length of a cup sequence
101  * adjusted for average computation overhead.  The magic number is the length
102  * of "\033[yy;xxH", the typical cup sequence these days.
103  */
104 #define LONG_DIST		(8 - COMPUTE_OVERHEAD)
105 
106 /*
107  * Tell whether a motion is optimizable by local motions.  Needs to be cheap to
108  * compute. In general, all the fast moves go to either the right or left edge
109  * of the screen.  So any motion to a location that is (a) further away than
110  * LONG_DIST and (b) further inward from the right or left edge than LONG_DIST,
111  * we'll consider nonlocal.
112  */
113 #define NOT_LOCAL(sp, fy, fx, ty, tx)	((tx > LONG_DIST) \
114 		 && (tx < screen_columns(sp) - 1 - LONG_DIST) \
115 		 && (abs(ty-fy) + abs(tx-fx) > LONG_DIST))
116 
117 /****************************************************************************
118  *
119  * External interfaces
120  *
121  ****************************************************************************/
122 
123 /*
124  * For this code to work OK, the following components must live in the
125  * screen structure:
126  *
127  *	int		_char_padding;	// cost of character put
128  *	int		_cr_cost;	// cost of (carriage_return)
129  *	int		_cup_cost;	// cost of (cursor_address)
130  *	int		_home_cost;	// cost of (cursor_home)
131  *	int		_ll_cost;	// cost of (cursor_to_ll)
132  *#if USE_HARD_TABS
133  *	int		_ht_cost;	// cost of (tab)
134  *	int		_cbt_cost;	// cost of (back_tab)
135  *#endif USE_HARD_TABS
136  *	int		_cub1_cost;	// cost of (cursor_left)
137  *	int		_cuf1_cost;	// cost of (cursor_right)
138  *	int		_cud1_cost;	// cost of (cursor_down)
139  *	int		_cuu1_cost;	// cost of (cursor_up)
140  *	int		_cub_cost;	// cost of (parm_cursor_left)
141  *	int		_cuf_cost;	// cost of (parm_cursor_right)
142  *	int		_cud_cost;	// cost of (parm_cursor_down)
143  *	int		_cuu_cost;	// cost of (parm_cursor_up)
144  *	int		_hpa_cost;	// cost of (column_address)
145  *	int		_vpa_cost;	// cost of (row_address)
146  *	int		_ech_cost;	// cost of (erase_chars)
147  *	int		_rep_cost;	// cost of (repeat_char)
148  *
149  * The USE_HARD_TABS switch controls whether it is reliable to use tab/backtabs
150  * for local motions.  On many systems, it's not, due to uncertainties about
151  * tab delays and whether or not tabs will be expanded in raw mode.  If you
152  * have parm_right_cursor, tab motions don't win you a lot anyhow.
153  */
154 
155 #include <curses.priv.h>
156 #include <ctype.h>
157 
158 #ifndef CUR
159 #define CUR SP_TERMTYPE
160 #endif
161 
162 MODULE_ID("$Id: lib_mvcur.c,v 1.126 2011/01/22 19:48:21 tom Exp $")
163 
164 #define WANT_CHAR(sp, y, x) NewScreen(sp)->_line[y].text[x]	/* desired state */
165 
166 #if NCURSES_SP_FUNCS
167 #define BAUDRATE(sp)	sp->_term->_baudrate	/* bits per second */
168 #else
169 #define BAUDRATE(sp)	cur_term->_baudrate	/* bits per second */
170 #endif
171 
172 #if defined(MAIN) || defined(NCURSES_TEST)
173 #include <sys/time.h>
174 
175 static bool profiling = FALSE;
176 static float diff;
177 #endif /* MAIN */
178 
179 #define OPT_SIZE 512
180 
181 static int normalized_cost(NCURSES_SP_DCLx const char *const cap, int affcnt);
182 
183 /****************************************************************************
184  *
185  * Initialization/wrapup (including cost pre-computation)
186  *
187  ****************************************************************************/
188 
189 #ifdef TRACE
190 static int
191 trace_cost_of(NCURSES_SP_DCLx const char *capname, const char *cap, int affcnt)
192 {
193     int result = NCURSES_SP_NAME(_nc_msec_cost) (NCURSES_SP_ARGx cap, affcnt);
194     TR(TRACE_CHARPUT | TRACE_MOVE,
195        ("CostOf %s %d %s", capname, result, _nc_visbuf(cap)));
196     return result;
197 }
198 #define CostOf(cap,affcnt) trace_cost_of(NCURSES_SP_ARGx #cap, cap, affcnt)
199 
200 static int
201 trace_normalized_cost(NCURSES_SP_DCLx const char *capname, const char *cap, int affcnt)
202 {
203     int result = normalized_cost(NCURSES_SP_ARGx cap, affcnt);
204     TR(TRACE_CHARPUT | TRACE_MOVE,
205        ("NormalizedCost %s %d %s", capname, result, _nc_visbuf(cap)));
206     return result;
207 }
208 #define NormalizedCost(cap,affcnt) trace_normalized_cost(NCURSES_SP_ARGx #cap, cap, affcnt)
209 
210 #else
211 
212 #define CostOf(cap,affcnt) NCURSES_SP_NAME(_nc_msec_cost)(NCURSES_SP_ARGx cap, affcnt)
213 #define NormalizedCost(cap,affcnt) normalized_cost(NCURSES_SP_ARGx cap, affcnt)
214 
215 #endif
216 
217 NCURSES_EXPORT(int)
218 NCURSES_SP_NAME(_nc_msec_cost) (NCURSES_SP_DCLx const char *const cap, int affcnt)
219 /* compute the cost of a given operation */
220 {
221     if (cap == 0)
222 	return (INFINITY);
223     else {
224 	const char *cp;
225 	float cum_cost = 0.0;
226 
227 	for (cp = cap; *cp; cp++) {
228 	    /* extract padding, either mandatory or required */
229 	    if (cp[0] == '$' && cp[1] == '<' && strchr(cp, '>')) {
230 		float number = 0.0;
231 
232 		for (cp += 2; *cp != '>'; cp++) {
233 		    if (isdigit(UChar(*cp)))
234 			number = number * 10 + (float) (*cp - '0');
235 		    else if (*cp == '*')
236 			number *= (float) affcnt;
237 		    else if (*cp == '.' && (*++cp != '>') && isdigit(UChar(*cp)))
238 			number += (float) ((*cp - '0') / 10.0);
239 		}
240 
241 #if NCURSES_NO_PADDING
242 		if (!GetNoPadding(SP_PARM))
243 #endif
244 		    cum_cost += number * 10;
245 	    } else if (SP_PARM) {
246 		cum_cost += (float) SP_PARM->_char_padding;
247 	    }
248 	}
249 
250 	return ((int) cum_cost);
251     }
252 }
253 
254 #if NCURSES_SP_FUNCS
255 NCURSES_EXPORT(int)
256 _nc_msec_cost(const char *const cap, int affcnt)
257 {
258     return NCURSES_SP_NAME(_nc_msec_cost) (CURRENT_SCREEN, cap, affcnt);
259 }
260 #endif
261 
262 static int
263 normalized_cost(NCURSES_SP_DCLx const char *const cap, int affcnt)
264 /* compute the effective character-count for an operation (round up) */
265 {
266     int cost = NCURSES_SP_NAME(_nc_msec_cost) (NCURSES_SP_ARGx cap, affcnt);
267     if (cost != INFINITY)
268 	cost = (cost + SP_PARM->_char_padding - 1) / SP_PARM->_char_padding;
269     return cost;
270 }
271 
272 static void
273 reset_scroll_region(NCURSES_SP_DCL0)
274 /* Set the scroll-region to a known state (the default) */
275 {
276     if (change_scroll_region) {
277 	NCURSES_SP_NAME(_nc_putp) (NCURSES_SP_ARGx
278 				   "change_scroll_region",
279 				   TPARM_2(change_scroll_region,
280 					   0, screen_lines(SP_PARM) - 1));
281     }
282 }
283 
284 NCURSES_EXPORT(void)
285 NCURSES_SP_NAME(_nc_mvcur_resume) (NCURSES_SP_DCL0)
286 /* what to do at initialization time and after each shellout */
287 {
288     if (SP_PARM && !IsTermInfo(SP_PARM))
289 	return;
290 
291     /* initialize screen for cursor access */
292     if (enter_ca_mode) {
293 	NCURSES_SP_NAME(_nc_putp) (NCURSES_SP_ARGx
294 				   "enter_ca_mode",
295 				   enter_ca_mode);
296     }
297 
298     /*
299      * Doing this here rather than in _nc_mvcur_wrap() ensures that
300      * ncurses programs will see a reset scroll region even if a
301      * program that messed with it died ungracefully.
302      *
303      * This also undoes the effects of terminal init strings that assume
304      * they know the screen size.  This is useful when you're running
305      * a vt100 emulation through xterm.
306      */
307     reset_scroll_region(NCURSES_SP_ARG);
308     SP_PARM->_cursrow = SP_PARM->_curscol = -1;
309 
310     /* restore cursor shape */
311     if (SP_PARM->_cursor != -1) {
312 	int cursor = SP_PARM->_cursor;
313 	SP_PARM->_cursor = -1;
314 	NCURSES_SP_NAME(curs_set) (NCURSES_SP_ARGx cursor);
315     }
316 }
317 
318 #if NCURSES_SP_FUNCS
319 NCURSES_EXPORT(void)
320 _nc_mvcur_resume(void)
321 {
322     NCURSES_SP_NAME(_nc_mvcur_resume) (CURRENT_SCREEN);
323 }
324 #endif
325 
326 NCURSES_EXPORT(void)
327 NCURSES_SP_NAME(_nc_mvcur_init) (NCURSES_SP_DCL0)
328 /* initialize the cost structure */
329 {
330     if (SP_PARM->_ofp && isatty(fileno(SP_PARM->_ofp)))
331 	SP_PARM->_char_padding = ((BAUDBYTE * 1000 * 10)
332 				  / (BAUDRATE(SP_PARM) > 0
333 				     ? BAUDRATE(SP_PARM)
334 				     : 9600));
335     else
336 	SP_PARM->_char_padding = 1;	/* must be nonzero */
337     if (SP_PARM->_char_padding <= 0)
338 	SP_PARM->_char_padding = 1;	/* must be nonzero */
339     TR(TRACE_CHARPUT | TRACE_MOVE, ("char_padding %d msecs", SP_PARM->_char_padding));
340 
341     /* non-parameterized local-motion strings */
342     SP_PARM->_cr_cost = CostOf(carriage_return, 0);
343     SP_PARM->_home_cost = CostOf(cursor_home, 0);
344     SP_PARM->_ll_cost = CostOf(cursor_to_ll, 0);
345 #if USE_HARD_TABS
346     if (getenv("NCURSES_NO_HARD_TABS") == 0) {
347 	SP_PARM->_ht_cost = CostOf(tab, 0);
348 	SP_PARM->_cbt_cost = CostOf(back_tab, 0);
349     } else {
350 	SP_PARM->_ht_cost = INFINITY;
351 	SP_PARM->_cbt_cost = INFINITY;
352     }
353 #endif /* USE_HARD_TABS */
354     SP_PARM->_cub1_cost = CostOf(cursor_left, 0);
355     SP_PARM->_cuf1_cost = CostOf(cursor_right, 0);
356     SP_PARM->_cud1_cost = CostOf(cursor_down, 0);
357     SP_PARM->_cuu1_cost = CostOf(cursor_up, 0);
358 
359     SP_PARM->_smir_cost = CostOf(enter_insert_mode, 0);
360     SP_PARM->_rmir_cost = CostOf(exit_insert_mode, 0);
361     SP_PARM->_ip_cost = 0;
362     if (insert_padding) {
363 	SP_PARM->_ip_cost = CostOf(insert_padding, 0);
364     }
365 
366     /*
367      * Assumption: if the terminal has memory_relative addressing, the
368      * initialization strings or smcup will set single-page mode so we
369      * can treat it like absolute screen addressing.  This seems to be true
370      * for all cursor_mem_address terminal types in the terminfo database.
371      */
372     SP_PARM->_address_cursor = cursor_address ? cursor_address : cursor_mem_address;
373 
374     /*
375      * Parametrized local-motion strings.  This static cost computation
376      * depends on the following assumptions:
377      *
378      * (1) They never have * padding.  In the entire master terminfo database
379      *     as of March 1995, only the obsolete Zenith Z-100 pc violates this.
380      *     (Proportional padding is found mainly in insert, delete and scroll
381      *     capabilities).
382      *
383      * (2) The average case of cup has two two-digit parameters.  Strictly,
384      *     the average case for a 24 * 80 screen has ((10*10*(1 + 1)) +
385      *     (14*10*(1 + 2)) + (10*70*(2 + 1)) + (14*70*4)) / (24*80) = 3.458
386      *     digits of parameters.  On a 25x80 screen the average is 3.6197.
387      *     On larger screens the value gets much closer to 4.
388      *
389      * (3) The average case of cub/cuf/hpa/ech/rep has 2 digits of parameters
390      *     (strictly, (((10 * 1) + (70 * 2)) / 80) = 1.8750).
391      *
392      * (4) The average case of cud/cuu/vpa has 2 digits of parameters
393      *     (strictly, (((10 * 1) + (14 * 2)) / 24) = 1.5833).
394      *
395      * All these averages depend on the assumption that all parameter values
396      * are equally probable.
397      */
398     SP_PARM->_cup_cost = CostOf(TPARM_2(SP_PARM->_address_cursor, 23, 23), 1);
399     SP_PARM->_cub_cost = CostOf(TPARM_1(parm_left_cursor, 23), 1);
400     SP_PARM->_cuf_cost = CostOf(TPARM_1(parm_right_cursor, 23), 1);
401     SP_PARM->_cud_cost = CostOf(TPARM_1(parm_down_cursor, 23), 1);
402     SP_PARM->_cuu_cost = CostOf(TPARM_1(parm_up_cursor, 23), 1);
403     SP_PARM->_hpa_cost = CostOf(TPARM_1(column_address, 23), 1);
404     SP_PARM->_vpa_cost = CostOf(TPARM_1(row_address, 23), 1);
405 
406     /* non-parameterized screen-update strings */
407     SP_PARM->_ed_cost = NormalizedCost(clr_eos, 1);
408     SP_PARM->_el_cost = NormalizedCost(clr_eol, 1);
409     SP_PARM->_el1_cost = NormalizedCost(clr_bol, 1);
410     SP_PARM->_dch1_cost = NormalizedCost(delete_character, 1);
411     SP_PARM->_ich1_cost = NormalizedCost(insert_character, 1);
412 
413     /*
414      * If this is a bce-terminal, we want to bias the choice so we use clr_eol
415      * rather than spaces at the end of a line.
416      */
417     if (back_color_erase)
418 	SP_PARM->_el_cost = 0;
419 
420     /* parameterized screen-update strings */
421     SP_PARM->_dch_cost = NormalizedCost(TPARM_1(parm_dch, 23), 1);
422     SP_PARM->_ich_cost = NormalizedCost(TPARM_1(parm_ich, 23), 1);
423     SP_PARM->_ech_cost = NormalizedCost(TPARM_1(erase_chars, 23), 1);
424     SP_PARM->_rep_cost = NormalizedCost(TPARM_2(repeat_char, ' ', 23), 1);
425 
426     SP_PARM->_cup_ch_cost = NormalizedCost(
427 					      TPARM_2(SP_PARM->_address_cursor,
428 						      23, 23),
429 					      1);
430     SP_PARM->_hpa_ch_cost = NormalizedCost(TPARM_1(column_address, 23), 1);
431     SP_PARM->_cuf_ch_cost = NormalizedCost(TPARM_1(parm_right_cursor, 23), 1);
432     SP_PARM->_inline_cost = min(SP_PARM->_cup_ch_cost,
433 				min(SP_PARM->_hpa_ch_cost,
434 				    SP_PARM->_cuf_ch_cost));
435 
436     /*
437      * If save_cursor is used within enter_ca_mode, we should not use it for
438      * scrolling optimization, since the corresponding restore_cursor is not
439      * nested on the various terminals (vt100, xterm, etc.) which use this
440      * feature.
441      */
442     if (save_cursor != 0
443 	&& enter_ca_mode != 0
444 	&& strstr(enter_ca_mode, save_cursor) != 0) {
445 	T(("...suppressed sc/rc capability due to conflict with smcup/rmcup"));
446 	save_cursor = 0;
447 	restore_cursor = 0;
448     }
449 
450     /*
451      * A different, possibly better way to arrange this would be to set the
452      * SCREEN's _endwin to TRUE at window initialization time and let this be
453      * called by doupdate's return-from-shellout code.
454      */
455     NCURSES_SP_NAME(_nc_mvcur_resume) (NCURSES_SP_ARG);
456 }
457 
458 #if NCURSES_SP_FUNCS
459 NCURSES_EXPORT(void)
460 _nc_mvcur_init(void)
461 {
462     NCURSES_SP_NAME(_nc_mvcur_init) (CURRENT_SCREEN);
463 }
464 #endif
465 
466 NCURSES_EXPORT(void)
467 NCURSES_SP_NAME(_nc_mvcur_wrap) (NCURSES_SP_DCL0)
468 /* wrap up cursor-addressing mode */
469 {
470     /* leave cursor at screen bottom */
471     TINFO_MVCUR(NCURSES_SP_ARGx -1, -1, screen_lines(SP_PARM) - 1, 0);
472 
473     if (!SP_PARM || !IsTermInfo(SP_PARM))
474 	return;
475 
476     /* set cursor to normal mode */
477     if (SP_PARM->_cursor != -1) {
478 	int cursor = SP_PARM->_cursor;
479 	NCURSES_SP_NAME(curs_set) (NCURSES_SP_ARGx 1);
480 	SP_PARM->_cursor = cursor;
481     }
482 
483     if (exit_ca_mode) {
484 	NCURSES_SP_NAME(_nc_putp) (NCURSES_SP_ARGx
485 				   "exit_ca_mode",
486 				   exit_ca_mode);
487     }
488     /*
489      * Reset terminal's tab counter.  There's a long-time bug that
490      * if you exit a "curses" program such as vi or more, tab
491      * forward, and then backspace, the cursor doesn't go to the
492      * right place.  The problem is that the kernel counts the
493      * escape sequences that reset things as column positions.
494      * Utter a \r to reset this invisibly.
495      */
496     NCURSES_SP_NAME(_nc_outch) (NCURSES_SP_ARGx '\r');
497 }
498 
499 #if NCURSES_SP_FUNCS
500 NCURSES_EXPORT(void)
501 _nc_mvcur_wrap(void)
502 {
503     NCURSES_SP_NAME(_nc_mvcur_wrap) (CURRENT_SCREEN);
504 }
505 #endif
506 
507 /****************************************************************************
508  *
509  * Optimized cursor movement
510  *
511  ****************************************************************************/
512 
513 /*
514  * Perform repeated-append, returning cost
515  */
516 static NCURSES_INLINE int
517 repeated_append(string_desc * target, int total, int num, int repeat, const char *src)
518 {
519     size_t need = (size_t) repeat * strlen(src);
520 
521     if (need < target->s_size) {
522 	while (repeat-- > 0) {
523 	    if (_nc_safe_strcat(target, src)) {
524 		total += num;
525 	    } else {
526 		total = INFINITY;
527 		break;
528 	    }
529 	}
530     } else {
531 	total = INFINITY;
532     }
533     return total;
534 }
535 
536 #ifndef NO_OPTIMIZE
537 #define NEXTTAB(fr)	(fr + init_tabs - (fr % init_tabs))
538 
539 /*
540  * Assume back_tab (CBT) does not wrap backwards at the left margin, return
541  * a negative value at that point to simplify the loop.
542  */
543 #define LASTTAB(fr)	((fr > 0) ? ((fr - 1) / init_tabs) * init_tabs : -1)
544 
545 static int
546 relative_move(NCURSES_SP_DCLx
547 	      string_desc * target,
548 	      int from_y,
549 	      int from_x,
550 	      int to_y,
551 	      int to_x,
552 	      bool ovw)
553 /* move via local motions (cuu/cuu1/cud/cud1/cub1/cub/cuf1/cuf/vpa/hpa) */
554 {
555     string_desc save;
556     int n, vcost = 0, hcost = 0;
557 
558     (void) _nc_str_copy(&save, target);
559 
560     if (to_y != from_y) {
561 	vcost = INFINITY;
562 
563 	if (row_address != 0
564 	    && _nc_safe_strcat(target, TPARM_1(row_address, to_y))) {
565 	    vcost = SP_PARM->_vpa_cost;
566 	}
567 
568 	if (to_y > from_y) {
569 	    n = (to_y - from_y);
570 
571 	    if (parm_down_cursor
572 		&& SP_PARM->_cud_cost < vcost
573 		&& _nc_safe_strcat(_nc_str_copy(target, &save),
574 				   TPARM_1(parm_down_cursor, n))) {
575 		vcost = SP_PARM->_cud_cost;
576 	    }
577 
578 	    if (cursor_down
579 		&& (*cursor_down != '\n' || SP_PARM->_nl)
580 		&& (n * SP_PARM->_cud1_cost < vcost)) {
581 		vcost = repeated_append(_nc_str_copy(target, &save), 0,
582 					SP_PARM->_cud1_cost, n, cursor_down);
583 	    }
584 	} else {		/* (to_y < from_y) */
585 	    n = (from_y - to_y);
586 
587 	    if (parm_up_cursor
588 		&& SP_PARM->_cuu_cost < vcost
589 		&& _nc_safe_strcat(_nc_str_copy(target, &save),
590 				   TPARM_1(parm_up_cursor, n))) {
591 		vcost = SP_PARM->_cuu_cost;
592 	    }
593 
594 	    if (cursor_up && (n * SP_PARM->_cuu1_cost < vcost)) {
595 		vcost = repeated_append(_nc_str_copy(target, &save), 0,
596 					SP_PARM->_cuu1_cost, n, cursor_up);
597 	    }
598 	}
599 
600 	if (vcost == INFINITY)
601 	    return (INFINITY);
602     }
603 
604     save = *target;
605 
606     if (to_x != from_x) {
607 	char str[OPT_SIZE];
608 	string_desc check;
609 
610 	hcost = INFINITY;
611 
612 	if (column_address
613 	    && _nc_safe_strcat(_nc_str_copy(target, &save),
614 			       TPARM_1(column_address, to_x))) {
615 	    hcost = SP_PARM->_hpa_cost;
616 	}
617 
618 	if (to_x > from_x) {
619 	    n = to_x - from_x;
620 
621 	    if (parm_right_cursor
622 		&& SP_PARM->_cuf_cost < hcost
623 		&& _nc_safe_strcat(_nc_str_copy(target, &save),
624 				   TPARM_1(parm_right_cursor, n))) {
625 		hcost = SP_PARM->_cuf_cost;
626 	    }
627 
628 	    if (cursor_right) {
629 		int lhcost = 0;
630 
631 		(void) _nc_str_init(&check, str, sizeof(str));
632 
633 #if USE_HARD_TABS
634 		/* use hard tabs, if we have them, to do as much as possible */
635 		if (init_tabs > 0 && tab) {
636 		    int nxt, fr;
637 
638 		    for (fr = from_x; (nxt = NEXTTAB(fr)) <= to_x; fr = nxt) {
639 			lhcost = repeated_append(&check, lhcost,
640 						 SP_PARM->_ht_cost, 1, tab);
641 			if (lhcost == INFINITY)
642 			    break;
643 		    }
644 
645 		    n = to_x - fr;
646 		    from_x = fr;
647 		}
648 #endif /* USE_HARD_TABS */
649 
650 		if (n <= 0 || n >= (int) check.s_size)
651 		    ovw = FALSE;
652 #if BSD_TPUTS
653 		/*
654 		 * If we're allowing BSD-style padding in tputs, don't generate
655 		 * a string with a leading digit.  Otherwise, that will be
656 		 * interpreted as a padding value rather than sent to the
657 		 * screen.
658 		 */
659 		if (ovw
660 		    && n > 0
661 		    && n < (int) check.s_size
662 		    && vcost == 0
663 		    && str[0] == '\0') {
664 		    int wanted = CharOf(WANT_CHAR(SP_PARM, to_y, from_x));
665 		    if (is8bits(wanted) && isdigit(wanted))
666 			ovw = FALSE;
667 		}
668 #endif
669 		/*
670 		 * If we have no attribute changes, overwrite is cheaper.
671 		 * Note: must suppress this by passing in ovw = FALSE whenever
672 		 * WANT_CHAR would return invalid data.  In particular, this
673 		 * is true between the time a hardware scroll has been done
674 		 * and the time the structure WANT_CHAR would access has been
675 		 * updated.
676 		 */
677 		if (ovw) {
678 		    int i;
679 
680 		    for (i = 0; i < n; i++) {
681 			NCURSES_CH_T ch = WANT_CHAR(SP_PARM, to_y, from_x + i);
682 			if (!SameAttrOf(ch, SCREEN_ATTRS(SP_PARM))
683 #if USE_WIDEC_SUPPORT
684 			    || !Charable(ch)
685 #endif
686 			    ) {
687 			    ovw = FALSE;
688 			    break;
689 			}
690 		    }
691 		}
692 		if (ovw) {
693 		    int i;
694 
695 		    for (i = 0; i < n; i++)
696 			*check.s_tail++ = (char) CharOf(WANT_CHAR(SP_PARM, to_y,
697 								  from_x + i));
698 		    *check.s_tail = '\0';
699 		    check.s_size -= (size_t) n;
700 		    lhcost += n * SP_PARM->_char_padding;
701 		} else {
702 		    lhcost = repeated_append(&check, lhcost, SP_PARM->_cuf1_cost,
703 					     n, cursor_right);
704 		}
705 
706 		if (lhcost < hcost
707 		    && _nc_safe_strcat(_nc_str_copy(target, &save), str)) {
708 		    hcost = lhcost;
709 		}
710 	    }
711 	} else {		/* (to_x < from_x) */
712 	    n = from_x - to_x;
713 
714 	    if (parm_left_cursor
715 		&& SP_PARM->_cub_cost < hcost
716 		&& _nc_safe_strcat(_nc_str_copy(target, &save),
717 				   TPARM_1(parm_left_cursor, n))) {
718 		hcost = SP_PARM->_cub_cost;
719 	    }
720 
721 	    if (cursor_left) {
722 		int lhcost = 0;
723 
724 		(void) _nc_str_init(&check, str, sizeof(str));
725 
726 #if USE_HARD_TABS
727 		if (init_tabs > 0 && back_tab) {
728 		    int nxt, fr;
729 
730 		    for (fr = from_x; (nxt = LASTTAB(fr)) >= to_x; fr = nxt) {
731 			lhcost = repeated_append(&check, lhcost,
732 						 SP_PARM->_cbt_cost,
733 						 1, back_tab);
734 			if (lhcost == INFINITY)
735 			    break;
736 		    }
737 
738 		    n = fr - to_x;
739 		}
740 #endif /* USE_HARD_TABS */
741 
742 		lhcost = repeated_append(&check, lhcost,
743 					 SP_PARM->_cub1_cost,
744 					 n, cursor_left);
745 
746 		if (lhcost < hcost
747 		    && _nc_safe_strcat(_nc_str_copy(target, &save), str)) {
748 		    hcost = lhcost;
749 		}
750 	    }
751 	}
752 
753 	if (hcost == INFINITY)
754 	    return (INFINITY);
755     }
756 
757     return (vcost + hcost);
758 }
759 #endif /* !NO_OPTIMIZE */
760 
761 /*
762  * With the machinery set up above, it's conceivable that
763  * onscreen_mvcur could be modified into a recursive function that does
764  * an alpha-beta search of motion space, as though it were a chess
765  * move tree, with the weight function being boolean and the search
766  * depth equated to length of string.  However, this would jack up the
767  * computation cost a lot, especially on terminals without a cup
768  * capability constraining the search tree depth.  So we settle for
769  * the simpler method below.
770  */
771 
772 static NCURSES_INLINE int
773 onscreen_mvcur(NCURSES_SP_DCLx int yold, int xold, int ynew, int xnew, bool ovw)
774 /* onscreen move from (yold, xold) to (ynew, xnew) */
775 {
776     string_desc result;
777     char buffer[OPT_SIZE];
778     int tactic = 0, newcost, usecost = INFINITY;
779     int t5_cr_cost;
780 
781 #if defined(MAIN) || defined(NCURSES_TEST)
782     struct timeval before, after;
783 
784     gettimeofday(&before, NULL);
785 #endif /* MAIN */
786 
787 #define NullResult _nc_str_null(&result, sizeof(buffer))
788 #define InitResult _nc_str_init(&result, buffer, sizeof(buffer))
789 
790     /* tactic #0: use direct cursor addressing */
791     if (_nc_safe_strcpy(InitResult, TPARM_2(SP_PARM->_address_cursor, ynew, xnew))) {
792 	tactic = 0;
793 	usecost = SP_PARM->_cup_cost;
794 
795 #if defined(TRACE) || defined(NCURSES_TEST)
796 	if (!(_nc_optimize_enable & OPTIMIZE_MVCUR))
797 	    goto nonlocal;
798 #endif /* TRACE */
799 
800 	/*
801 	 * We may be able to tell in advance that the full optimization
802 	 * will probably not be worth its overhead.  Also, don't try to
803 	 * use local movement if the current attribute is anything but
804 	 * A_NORMAL...there are just too many ways this can screw up
805 	 * (like, say, local-movement \n getting mapped to some obscure
806 	 * character because A_ALTCHARSET is on).
807 	 */
808 	if (yold == -1 || xold == -1 || NOT_LOCAL(SP_PARM, yold, xold, ynew, xnew)) {
809 #if defined(MAIN) || defined(NCURSES_TEST)
810 	    if (!profiling) {
811 		(void) fputs("nonlocal\n", stderr);
812 		goto nonlocal;	/* always run the optimizer if profiling */
813 	    }
814 #else
815 	    goto nonlocal;
816 #endif /* MAIN */
817 	}
818     }
819 #ifndef NO_OPTIMIZE
820     /* tactic #1: use local movement */
821     if (yold != -1 && xold != -1
822 	&& ((newcost = relative_move(NCURSES_SP_ARGx
823 				     NullResult,
824 				     yold, xold,
825 				     ynew, xnew, ovw)) != INFINITY)
826 	&& newcost < usecost) {
827 	tactic = 1;
828 	usecost = newcost;
829     }
830 
831     /* tactic #2: use carriage-return + local movement */
832     if (yold != -1 && carriage_return
833 	&& ((newcost = relative_move(NCURSES_SP_ARGx
834 				     NullResult,
835 				     yold, 0,
836 				     ynew, xnew, ovw)) != INFINITY)
837 	&& SP_PARM->_cr_cost + newcost < usecost) {
838 	tactic = 2;
839 	usecost = SP_PARM->_cr_cost + newcost;
840     }
841 
842     /* tactic #3: use home-cursor + local movement */
843     if (cursor_home
844 	&& ((newcost = relative_move(NCURSES_SP_ARGx
845 				     NullResult,
846 				     0, 0,
847 				     ynew, xnew, ovw)) != INFINITY)
848 	&& SP_PARM->_home_cost + newcost < usecost) {
849 	tactic = 3;
850 	usecost = SP_PARM->_home_cost + newcost;
851     }
852 
853     /* tactic #4: use home-down + local movement */
854     if (cursor_to_ll
855 	&& ((newcost = relative_move(NCURSES_SP_ARGx
856 				     NullResult,
857 				     screen_lines(SP_PARM) - 1, 0,
858 				     ynew, xnew, ovw)) != INFINITY)
859 	&& SP_PARM->_ll_cost + newcost < usecost) {
860 	tactic = 4;
861 	usecost = SP_PARM->_ll_cost + newcost;
862     }
863 
864     /*
865      * tactic #5: use left margin for wrap to right-hand side,
866      * unless strange wrap behavior indicated by xenl might hose us.
867      */
868     t5_cr_cost = (xold > 0 ? SP_PARM->_cr_cost : 0);
869     if (auto_left_margin && !eat_newline_glitch
870 	&& yold > 0 && cursor_left
871 	&& ((newcost = relative_move(NCURSES_SP_ARGx
872 				     NullResult,
873 				     yold - 1, screen_columns(SP_PARM) - 1,
874 				     ynew, xnew, ovw)) != INFINITY)
875 	&& t5_cr_cost + SP_PARM->_cub1_cost + newcost < usecost) {
876 	tactic = 5;
877 	usecost = t5_cr_cost + SP_PARM->_cub1_cost + newcost;
878     }
879 
880     /*
881      * These cases are ordered by estimated relative frequency.
882      */
883     if (tactic)
884 	InitResult;
885     switch (tactic) {
886     case 1:
887 	(void) relative_move(NCURSES_SP_ARGx
888 			     &result,
889 			     yold, xold,
890 			     ynew, xnew, ovw);
891 	break;
892     case 2:
893 	(void) _nc_safe_strcpy(&result, carriage_return);
894 	(void) relative_move(NCURSES_SP_ARGx
895 			     &result,
896 			     yold, 0,
897 			     ynew, xnew, ovw);
898 	break;
899     case 3:
900 	(void) _nc_safe_strcpy(&result, cursor_home);
901 	(void) relative_move(NCURSES_SP_ARGx
902 			     &result, 0, 0,
903 			     ynew, xnew, ovw);
904 	break;
905     case 4:
906 	(void) _nc_safe_strcpy(&result, cursor_to_ll);
907 	(void) relative_move(NCURSES_SP_ARGx
908 			     &result,
909 			     screen_lines(SP_PARM) - 1, 0,
910 			     ynew, xnew, ovw);
911 	break;
912     case 5:
913 	if (xold > 0)
914 	    (void) _nc_safe_strcat(&result, carriage_return);
915 	(void) _nc_safe_strcat(&result, cursor_left);
916 	(void) relative_move(NCURSES_SP_ARGx
917 			     &result,
918 			     yold - 1, screen_columns(SP_PARM) - 1,
919 			     ynew, xnew, ovw);
920 	break;
921     }
922 #endif /* !NO_OPTIMIZE */
923 
924   nonlocal:
925 #if defined(MAIN) || defined(NCURSES_TEST)
926     gettimeofday(&after, NULL);
927     diff = after.tv_usec - before.tv_usec
928 	+ (after.tv_sec - before.tv_sec) * 1000000;
929     if (!profiling)
930 	(void) fprintf(stderr,
931 		       "onscreen: %d microsec, %f 28.8Kbps char-equivalents\n",
932 		       (int) diff, diff / 288);
933 #endif /* MAIN */
934 
935     if (usecost != INFINITY) {
936 	TPUTS_TRACE("mvcur");
937 	NCURSES_SP_NAME(tputs) (NCURSES_SP_ARGx
938 				buffer, 1, NCURSES_SP_NAME(_nc_outch));
939 	SP_PARM->_cursrow = ynew;
940 	SP_PARM->_curscol = xnew;
941 	return (OK);
942     } else
943 	return (ERR);
944 }
945 
946 NCURSES_EXPORT(int)
947 TINFO_MVCUR(NCURSES_SP_DCLx int yold, int xold, int ynew, int xnew)
948 /* optimized cursor move from (yold, xold) to (ynew, xnew) */
949 {
950     NCURSES_CH_T oldattr;
951     int code;
952 
953     TR(TRACE_CALLS | TRACE_MOVE, (T_CALLED("_nc_tinfo_mvcur(%p,%d,%d,%d,%d)"),
954 				  (void *) SP_PARM, yold, xold, ynew, xnew));
955 
956     if (SP_PARM == 0) {
957 	code = ERR;
958     } else if (yold == ynew && xold == xnew) {
959 	code = OK;
960     } else {
961 
962 	/*
963 	 * Most work here is rounding for terminal boundaries getting the
964 	 * column position implied by wraparound or the lack thereof and
965 	 * rolling up the screen to get ynew on the screen.
966 	 */
967 	if (xnew >= screen_columns(SP_PARM)) {
968 	    ynew += xnew / screen_columns(SP_PARM);
969 	    xnew %= screen_columns(SP_PARM);
970 	}
971 
972 	/*
973 	 * Force restore even if msgr is on when we're in an alternate
974 	 * character set -- these have a strong tendency to screw up the CR &
975 	 * LF used for local character motions!
976 	 */
977 	oldattr = SCREEN_ATTRS(SP_PARM);
978 	if ((AttrOf(oldattr) & A_ALTCHARSET)
979 	    || (AttrOf(oldattr) && !move_standout_mode)) {
980 	    TR(TRACE_CHARPUT, ("turning off (%#lx) %s before move",
981 			       (unsigned long) AttrOf(oldattr),
982 			       _traceattr(AttrOf(oldattr))));
983 	    (void) VIDATTR(SP_PARM, A_NORMAL, 0);
984 	}
985 
986 	if (xold >= screen_columns(SP_PARM)) {
987 	    int l;
988 
989 	    if (SP_PARM->_nl) {
990 		l = (xold + 1) / screen_columns(SP_PARM);
991 		yold += l;
992 		if (yold >= screen_lines(SP_PARM))
993 		    l -= (yold - screen_lines(SP_PARM) - 1);
994 
995 		if (l > 0) {
996 		    if (carriage_return) {
997 			NCURSES_SP_NAME(_nc_putp) (NCURSES_SP_ARGx
998 						   "carriage_return",
999 						   carriage_return);
1000 		    } else
1001 			NCURSES_SP_NAME(_nc_outch) (NCURSES_SP_ARGx '\r');
1002 		    xold = 0;
1003 
1004 		    while (l > 0) {
1005 			if (newline) {
1006 			    NCURSES_SP_NAME(_nc_putp) (NCURSES_SP_ARGx
1007 						       "newline",
1008 						       newline);
1009 			} else
1010 			    NCURSES_SP_NAME(_nc_outch) (NCURSES_SP_ARGx '\n');
1011 			l--;
1012 		    }
1013 		}
1014 	    } else {
1015 		/*
1016 		 * If caller set nonl(), we cannot really use newlines to
1017 		 * position to the next row.
1018 		 */
1019 		xold = -1;
1020 		yold = -1;
1021 	    }
1022 	}
1023 
1024 	if (yold > screen_lines(SP_PARM) - 1)
1025 	    yold = screen_lines(SP_PARM) - 1;
1026 	if (ynew > screen_lines(SP_PARM) - 1)
1027 	    ynew = screen_lines(SP_PARM) - 1;
1028 
1029 	/* destination location is on screen now */
1030 	code = onscreen_mvcur(NCURSES_SP_ARGx yold, xold, ynew, xnew, TRUE);
1031 
1032 	/*
1033 	 * Restore attributes if we disabled them before moving.
1034 	 */
1035 	if (!SameAttrOf(oldattr, SCREEN_ATTRS(SP_PARM))) {
1036 	    TR(TRACE_CHARPUT, ("turning on (%#lx) %s after move",
1037 			       (unsigned long) AttrOf(oldattr),
1038 			       _traceattr(AttrOf(oldattr))));
1039 	    (void) VIDATTR(SP_PARM, AttrOf(oldattr), GetPair(oldattr));
1040 	}
1041     }
1042     returnCode(code);
1043 }
1044 
1045 #if NCURSES_SP_FUNCS && !defined(USE_TERM_DRIVER)
1046 NCURSES_EXPORT(int)
1047 mvcur(int yold, int xold, int ynew, int xnew)
1048 {
1049     return NCURSES_SP_NAME(mvcur) (CURRENT_SCREEN, yold, xold, ynew, xnew);
1050 }
1051 #endif
1052 
1053 #if defined(TRACE) || defined(NCURSES_TEST)
1054 NCURSES_EXPORT_VAR(int) _nc_optimize_enable = OPTIMIZE_ALL;
1055 #endif
1056 
1057 #if defined(MAIN) || defined(NCURSES_TEST)
1058 /****************************************************************************
1059  *
1060  * Movement optimizer test code
1061  *
1062  ****************************************************************************/
1063 
1064 #include <tic.h>
1065 #include <dump_entry.h>
1066 #include <time.h>
1067 
1068 NCURSES_EXPORT_VAR(const char *) _nc_progname = "mvcur";
1069 
1070 static unsigned long xmits;
1071 
1072 /* these override lib_tputs.c */
1073 NCURSES_EXPORT(int)
1074 tputs(const char *string, int affcnt GCC_UNUSED, int (*outc) (int) GCC_UNUSED)
1075 /* stub tputs() that dumps sequences in a visible form */
1076 {
1077     if (profiling)
1078 	xmits += strlen(string);
1079     else
1080 	(void) fputs(_nc_visbuf(string), stdout);
1081     return (OK);
1082 }
1083 
1084 NCURSES_EXPORT(int)
1085 putp(const char *string)
1086 {
1087     return (tputs(string, 1, _nc_outch));
1088 }
1089 
1090 NCURSES_EXPORT(int)
1091 _nc_outch(int ch)
1092 {
1093     putc(ch, stdout);
1094     return OK;
1095 }
1096 
1097 NCURSES_EXPORT(int)
1098 delay_output(int ms GCC_UNUSED)
1099 {
1100     return OK;
1101 }
1102 
1103 static char tname[PATH_MAX];
1104 
1105 static void
1106 load_term(void)
1107 {
1108     (void) setupterm(tname, STDOUT_FILENO, NULL);
1109 }
1110 
1111 static int
1112 roll(int n)
1113 {
1114     int i, j;
1115 
1116     i = (RAND_MAX / n) * n;
1117     while ((j = rand()) >= i)
1118 	continue;
1119     return (j % n);
1120 }
1121 
1122 int
1123 main(int argc GCC_UNUSED, char *argv[]GCC_UNUSED)
1124 {
1125     strcpy(tname, getenv("TERM"));
1126     load_term();
1127     _nc_setupscreen(lines, columns, stdout, FALSE, 0);
1128     baudrate();
1129 
1130     _nc_mvcur_init();
1131     NC_BUFFERED(FALSE);
1132 
1133     (void) puts("The mvcur tester.  Type ? for help");
1134 
1135     fputs("smcup:", stdout);
1136     putchar('\n');
1137 
1138     for (;;) {
1139 	int fy, fx, ty, tx, n, i;
1140 	char buf[BUFSIZ], capname[BUFSIZ];
1141 
1142 	(void) fputs("> ", stdout);
1143 	(void) fgets(buf, sizeof(buf), stdin);
1144 
1145 	if (buf[0] == '?') {
1146 	    (void) puts("?                -- display this help message");
1147 	    (void)
1148 		puts("fy fx ty tx      -- (4 numbers) display (fy,fx)->(ty,tx) move");
1149 	    (void) puts("s[croll] n t b m -- display scrolling sequence");
1150 	    (void)
1151 		printf("r[eload]         -- reload terminal info for %s\n",
1152 		       termname());
1153 	    (void)
1154 		puts("l[oad] <term>    -- load terminal info for type <term>");
1155 	    (void) puts("d[elete] <cap>   -- delete named capability");
1156 	    (void) puts("i[nspect]        -- display terminal capabilities");
1157 	    (void)
1158 		puts("c[ost]           -- dump cursor-optimization cost table");
1159 	    (void) puts("o[optimize]      -- toggle movement optimization");
1160 	    (void)
1161 		puts("t[orture] <num>  -- torture-test with <num> random moves");
1162 	    (void) puts("q[uit]           -- quit the program");
1163 	} else if (sscanf(buf, "%d %d %d %d", &fy, &fx, &ty, &tx) == 4) {
1164 	    struct timeval before, after;
1165 
1166 	    putchar('"');
1167 
1168 	    gettimeofday(&before, NULL);
1169 	    mvcur(fy, fx, ty, tx);
1170 	    gettimeofday(&after, NULL);
1171 
1172 	    printf("\" (%ld msec)\n",
1173 		   (long) (after.tv_usec - before.tv_usec
1174 			   + (after.tv_sec - before.tv_sec)
1175 			   * 1000000));
1176 	} else if (sscanf(buf, "s %d %d %d %d", &fy, &fx, &ty, &tx) == 4) {
1177 	    struct timeval before, after;
1178 
1179 	    putchar('"');
1180 
1181 	    gettimeofday(&before, NULL);
1182 	    _nc_scrolln(fy, fx, ty, tx);
1183 	    gettimeofday(&after, NULL);
1184 
1185 	    printf("\" (%ld msec)\n",
1186 		   (long) (after.tv_usec - before.tv_usec + (after.tv_sec -
1187 							     before.tv_sec)
1188 			   * 1000000));
1189 	} else if (buf[0] == 'r') {
1190 	    (void) strcpy(tname, termname());
1191 	    load_term();
1192 	} else if (sscanf(buf, "l %s", tname) == 1) {
1193 	    load_term();
1194 	} else if (sscanf(buf, "d %s", capname) == 1) {
1195 	    struct name_table_entry const *np = _nc_find_entry(capname,
1196 							       _nc_get_hash_table(FALSE));
1197 
1198 	    if (np == NULL)
1199 		(void) printf("No such capability as \"%s\"\n", capname);
1200 	    else {
1201 		switch (np->nte_type) {
1202 		case BOOLEAN:
1203 		    cur_term->type.Booleans[np->nte_index] = FALSE;
1204 		    (void)
1205 			printf("Boolean capability `%s' (%d) turned off.\n",
1206 			       np->nte_name, np->nte_index);
1207 		    break;
1208 
1209 		case NUMBER:
1210 		    cur_term->type.Numbers[np->nte_index] = ABSENT_NUMERIC;
1211 		    (void) printf("Number capability `%s' (%d) set to -1.\n",
1212 				  np->nte_name, np->nte_index);
1213 		    break;
1214 
1215 		case STRING:
1216 		    cur_term->type.Strings[np->nte_index] = ABSENT_STRING;
1217 		    (void) printf("String capability `%s' (%d) deleted.\n",
1218 				  np->nte_name, np->nte_index);
1219 		    break;
1220 		}
1221 	    }
1222 	} else if (buf[0] == 'i') {
1223 	    dump_init((char *) NULL, F_TERMINFO, S_TERMINFO, 70, 0, FALSE);
1224 	    dump_entry(&cur_term->type, FALSE, TRUE, 0, 0);
1225 	    putchar('\n');
1226 	} else if (buf[0] == 'o') {
1227 	    if (_nc_optimize_enable & OPTIMIZE_MVCUR) {
1228 		_nc_optimize_enable &= ~OPTIMIZE_MVCUR;
1229 		(void) puts("Optimization is now off.");
1230 	    } else {
1231 		_nc_optimize_enable |= OPTIMIZE_MVCUR;
1232 		(void) puts("Optimization is now on.");
1233 	    }
1234 	}
1235 	/*
1236 	 * You can use the `t' test to profile and tune the movement
1237 	 * optimizer.  Use iteration values in three digits or more.
1238 	 * At above 5000 iterations the profile timing averages are stable
1239 	 * to within a millisecond or three.
1240 	 *
1241 	 * The `overhead' field of the report will help you pick a
1242 	 * COMPUTE_OVERHEAD figure appropriate for your processor and
1243 	 * expected line speed.  The `total estimated time' is
1244 	 * computation time plus a character-transmission time
1245 	 * estimate computed from the number of transmits and the baud
1246 	 * rate.
1247 	 *
1248 	 * Use this together with the `o' command to get a read on the
1249 	 * optimizer's effectiveness.  Compare the total estimated times
1250 	 * for `t' runs of the same length in both optimized and un-optimized
1251 	 * modes.  As long as the optimized times are less, the optimizer
1252 	 * is winning.
1253 	 */
1254 	else if (sscanf(buf, "t %d", &n) == 1) {
1255 	    float cumtime = 0.0, perchar;
1256 	    int speeds[] =
1257 	    {2400, 9600, 14400, 19200, 28800, 38400, 0};
1258 
1259 	    srand((unsigned) (getpid() + time((time_t *) 0)));
1260 	    profiling = TRUE;
1261 	    xmits = 0;
1262 	    for (i = 0; i < n; i++) {
1263 		/*
1264 		 * This does a move test between two random locations,
1265 		 * Random moves probably short-change the optimizer,
1266 		 * which will work better on the short moves probably
1267 		 * typical of doupdate()'s usage pattern.  Still,
1268 		 * until we have better data...
1269 		 */
1270 #ifdef FIND_COREDUMP
1271 		int from_y = roll(lines);
1272 		int to_y = roll(lines);
1273 		int from_x = roll(columns);
1274 		int to_x = roll(columns);
1275 
1276 		printf("(%d,%d) -> (%d,%d)\n", from_y, from_x, to_y, to_x);
1277 		mvcur(from_y, from_x, to_y, to_x);
1278 #else
1279 		mvcur(roll(lines), roll(columns), roll(lines), roll(columns));
1280 #endif /* FIND_COREDUMP */
1281 		if (diff)
1282 		    cumtime += diff;
1283 	    }
1284 	    profiling = FALSE;
1285 
1286 	    /*
1287 	     * Average milliseconds per character optimization time.
1288 	     * This is the key figure to watch when tuning the optimizer.
1289 	     */
1290 	    perchar = cumtime / n;
1291 
1292 	    (void) printf("%d moves (%ld chars) in %d msec, %f msec each:\n",
1293 			  n, xmits, (int) cumtime, perchar);
1294 
1295 	    for (i = 0; speeds[i]; i++) {
1296 		/*
1297 		 * Total estimated time for the moves, computation and
1298 		 * transmission both. Transmission time is an estimate
1299 		 * assuming 9 bits/char, 8 bits + 1 stop bit.
1300 		 */
1301 		float totalest = cumtime + xmits * 9 * 1e6 / speeds[i];
1302 
1303 		/*
1304 		 * Per-character optimization overhead in character transmits
1305 		 * at the current speed.  Round this to the nearest integer
1306 		 * to figure COMPUTE_OVERHEAD for the speed.
1307 		 */
1308 		float overhead = speeds[i] * perchar / 1e6;
1309 
1310 		(void)
1311 		    printf("%6d bps: %3.2f char-xmits overhead; total estimated time %15.2f\n",
1312 			   speeds[i], overhead, totalest);
1313 	    }
1314 	} else if (buf[0] == 'c') {
1315 	    (void) printf("char padding: %d\n", CURRENT_SCREEN->_char_padding);
1316 	    (void) printf("cr cost: %d\n", CURRENT_SCREEN->_cr_cost);
1317 	    (void) printf("cup cost: %d\n", CURRENT_SCREEN->_cup_cost);
1318 	    (void) printf("home cost: %d\n", CURRENT_SCREEN->_home_cost);
1319 	    (void) printf("ll cost: %d\n", CURRENT_SCREEN->_ll_cost);
1320 #if USE_HARD_TABS
1321 	    (void) printf("ht cost: %d\n", CURRENT_SCREEN->_ht_cost);
1322 	    (void) printf("cbt cost: %d\n", CURRENT_SCREEN->_cbt_cost);
1323 #endif /* USE_HARD_TABS */
1324 	    (void) printf("cub1 cost: %d\n", CURRENT_SCREEN->_cub1_cost);
1325 	    (void) printf("cuf1 cost: %d\n", CURRENT_SCREEN->_cuf1_cost);
1326 	    (void) printf("cud1 cost: %d\n", CURRENT_SCREEN->_cud1_cost);
1327 	    (void) printf("cuu1 cost: %d\n", CURRENT_SCREEN->_cuu1_cost);
1328 	    (void) printf("cub cost: %d\n", CURRENT_SCREEN->_cub_cost);
1329 	    (void) printf("cuf cost: %d\n", CURRENT_SCREEN->_cuf_cost);
1330 	    (void) printf("cud cost: %d\n", CURRENT_SCREEN->_cud_cost);
1331 	    (void) printf("cuu cost: %d\n", CURRENT_SCREEN->_cuu_cost);
1332 	    (void) printf("hpa cost: %d\n", CURRENT_SCREEN->_hpa_cost);
1333 	    (void) printf("vpa cost: %d\n", CURRENT_SCREEN->_vpa_cost);
1334 	} else if (buf[0] == 'x' || buf[0] == 'q')
1335 	    break;
1336 	else
1337 	    (void) puts("Invalid command.");
1338     }
1339 
1340     (void) fputs("rmcup:", stdout);
1341     _nc_mvcur_wrap();
1342     putchar('\n');
1343 
1344     return (0);
1345 }
1346 
1347 #endif /* MAIN */
1348 
1349 /* lib_mvcur.c ends here */
1350