xref: /freebsd/usr.bin/gprof/arcs.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1983, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #if 0
33 #ifndef lint
34 static char sccsid[] = "@(#)arcs.c	8.1 (Berkeley) 6/6/93";
35 #endif /* not lint */
36 #endif
37 
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 #include <err.h>
42 #include "gprof.h"
43 
44 #ifdef DEBUG
45 int visited;
46 int viable;
47 int newcycle;
48 int oldcycle;
49 #endif /* DEBUG */
50 
51 int topcmp(const void *, const void *);
52 
53     /*
54      *	add (or just increment) an arc
55      */
56 void
57 addarc(nltype *parentp, nltype *childp, long count)
58 {
59     arctype		*arcp;
60 
61 #   ifdef DEBUG
62 	if ( debug & TALLYDEBUG ) {
63 	    printf( "[addarc] %ld arcs from %s to %s\n" ,
64 		    count , parentp -> name , childp -> name );
65 	}
66 #   endif /* DEBUG */
67     arcp = arclookup( parentp , childp );
68     if ( arcp != 0 ) {
69 	    /*
70 	     *	a hit:  just increment the count.
71 	     */
72 #	ifdef DEBUG
73 	    if ( debug & TALLYDEBUG ) {
74 		printf( "[tally] hit %ld += %ld\n" ,
75 			arcp -> arc_count , count );
76 	    }
77 #	endif /* DEBUG */
78 	arcp -> arc_count += count;
79 	return;
80     }
81     arcp = (arctype *)calloc( 1 , sizeof *arcp );
82     if (arcp == NULL)
83 	errx( 1 , "malloc failed" );
84     arcp -> arc_parentp = parentp;
85     arcp -> arc_childp = childp;
86     arcp -> arc_count = count;
87 	/*
88 	 *	prepend this child to the children of this parent
89 	 */
90     arcp -> arc_childlist = parentp -> children;
91     parentp -> children = arcp;
92 	/*
93 	 *	prepend this parent to the parents of this child
94 	 */
95     arcp -> arc_parentlist = childp -> parents;
96     childp -> parents = arcp;
97 }
98 
99     /*
100      *	the code below topologically sorts the graph (collapsing cycles),
101      *	and propagates time bottom up and flags top down.
102      */
103 
104     /*
105      *	the topologically sorted name list pointers
106      */
107 nltype	**topsortnlp;
108 
109 int
110 topcmp(const void *v1, const void *v2)
111 {
112     const nltype **npp1 = (const nltype **)v1;
113     const nltype **npp2 = (const nltype **)v2;
114 
115     return (*npp1) -> toporder - (*npp2) -> toporder;
116 }
117 
118 nltype **
119 doarcs(void)
120 {
121     nltype	*parentp, **timesortnlp;
122     arctype	*arcp;
123     long	index;
124     long	pass;
125 
126 	/*
127 	 *	initialize various things:
128 	 *	    zero out child times.
129 	 *	    count self-recursive calls.
130 	 *	    indicate that nothing is on cycles.
131 	 */
132     for ( parentp = nl ; parentp < npe ; parentp++ ) {
133 	parentp -> childtime = 0.0;
134 	arcp = arclookup( parentp , parentp );
135 	if ( arcp != 0 ) {
136 	    parentp -> ncall -= arcp -> arc_count;
137 	    parentp -> selfcalls = arcp -> arc_count;
138 	} else {
139 	    parentp -> selfcalls = 0;
140 	}
141 	parentp -> npropcall = parentp -> ncall;
142 	parentp -> propfraction = 0.0;
143 	parentp -> propself = 0.0;
144 	parentp -> propchild = 0.0;
145 	parentp -> printflag = FALSE;
146 	parentp -> toporder = DFN_NAN;
147 	parentp -> cycleno = 0;
148 	parentp -> cyclehead = parentp;
149 	parentp -> cnext = 0;
150     }
151     for ( pass = 1 ; ; pass++ ) {
152 	    /*
153 	     *	topologically order things
154 	     *	if any node is unnumbered,
155 	     *	    number it and any of its descendents.
156 	     */
157 	for ( dfn_init() , parentp = nl ; parentp < npe ; parentp++ ) {
158 	    if ( parentp -> toporder == DFN_NAN ) {
159 		dfn( parentp );
160 	    }
161 	}
162 	    /*
163 	     *	link together nodes on the same cycle
164 	     */
165 	cyclelink();
166 	    /*
167 	     *	if no cycles to break up, proceed
168 	     */
169 	if ( ! Cflag )
170 	    break;
171 	    /*
172 	     *	analyze cycles to determine breakup
173 	     */
174 #	ifdef DEBUG
175 	    if ( debug & BREAKCYCLE ) {
176 		printf("[doarcs] pass %ld, cycle(s) %d\n" , pass , ncycle );
177 	    }
178 #	endif /* DEBUG */
179 	if ( pass == 1 ) {
180 	    printf( "\n\n%s %s\n%s %d:\n" ,
181 		"The following arcs were deleted" ,
182 		"from the propagation calculation" ,
183 		"to reduce the maximum cycle size to", cyclethreshold );
184 	}
185 	if ( cycleanalyze() )
186 	    break;
187 	free ( cyclenl );
188 	ncycle = 0;
189 	for ( parentp = nl ; parentp < npe ; parentp++ ) {
190 	    parentp -> toporder = DFN_NAN;
191 	    parentp -> cycleno = 0;
192 	    parentp -> cyclehead = parentp;
193 	    parentp -> cnext = 0;
194 	}
195     }
196     if ( pass > 1 ) {
197 	printf( "\f\n" );
198     } else {
199 	printf( "\tNone\n\n" );
200     }
201 	/*
202 	 *	Sort the symbol table in reverse topological order
203 	 */
204     topsortnlp = (nltype **) calloc( nname , sizeof(nltype *) );
205     if ( topsortnlp == (nltype **) 0 )
206 	errx( 1 , "[doarcs] ran out of memory for topo sorting" );
207     for ( index = 0 ; index < nname ; index += 1 ) {
208 	topsortnlp[ index ] = &nl[ index ];
209     }
210     qsort( topsortnlp , nname , sizeof(nltype *) , topcmp );
211 #   ifdef DEBUG
212 	if ( debug & DFNDEBUG ) {
213 	    printf( "[doarcs] topological sort listing\n" );
214 	    for ( index = 0 ; index < nname ; index += 1 ) {
215 		printf( "[doarcs] " );
216 		printf( "%d:" , topsortnlp[ index ] -> toporder );
217 		printname( topsortnlp[ index ] );
218 		printf( "\n" );
219 	    }
220 	}
221 #   endif /* DEBUG */
222 	/*
223 	 *	starting from the topological top,
224 	 *	propagate print flags to children.
225 	 *	also, calculate propagation fractions.
226 	 *	this happens before time propagation
227 	 *	since time propagation uses the fractions.
228 	 */
229     doflags();
230 	/*
231 	 *	starting from the topological bottom,
232 	 *	propagate children times up to parents.
233 	 */
234     dotime();
235 	/*
236 	 *	Now, sort by propself + propchild.
237 	 *	sorting both the regular function names
238 	 *	and cycle headers.
239 	 */
240     timesortnlp = (nltype **) calloc( nname + ncycle , sizeof(nltype *) );
241     if ( timesortnlp == (nltype **) 0 )
242 	errx( 1 , "ran out of memory for sorting" );
243     for ( index = 0 ; index < nname ; index++ ) {
244 	timesortnlp[index] = &nl[index];
245     }
246     for ( index = 1 ; index <= ncycle ; index++ ) {
247 	timesortnlp[nname+index-1] = &cyclenl[index];
248     }
249     qsort( timesortnlp , nname + ncycle , sizeof(nltype *) , totalcmp );
250     for ( index = 0 ; index < nname + ncycle ; index++ ) {
251 	timesortnlp[ index ] -> index = index + 1;
252     }
253     return( timesortnlp );
254 }
255 
256 void
257 dotime(void)
258 {
259     int	index;
260 
261     cycletime();
262     for ( index = 0 ; index < nname ; index += 1 ) {
263 	timepropagate( topsortnlp[ index ] );
264     }
265 }
266 
267 void
268 timepropagate(nltype *parentp)
269 {
270     arctype	*arcp;
271     nltype	*childp;
272     double	share;
273     double	propshare;
274 
275     if ( parentp -> propfraction == 0.0 ) {
276 	return;
277     }
278 	/*
279 	 *	gather time from children of this parent.
280 	 */
281     for ( arcp = parentp -> children ; arcp ; arcp = arcp -> arc_childlist ) {
282 	childp = arcp -> arc_childp;
283 	if ( arcp -> arc_flags & DEADARC ) {
284 	    continue;
285 	}
286 	if ( arcp -> arc_count == 0 ) {
287 	    continue;
288 	}
289 	if ( childp == parentp ) {
290 	    continue;
291 	}
292 	if ( childp -> propfraction == 0.0 ) {
293 	    continue;
294 	}
295 	if ( childp -> cyclehead != childp ) {
296 	    if ( parentp -> cycleno == childp -> cycleno ) {
297 		continue;
298 	    }
299 	    if ( parentp -> toporder <= childp -> toporder ) {
300 		fprintf( stderr , "[propagate] toporder botches\n" );
301 	    }
302 	    childp = childp -> cyclehead;
303 	} else {
304 	    if ( parentp -> toporder <= childp -> toporder ) {
305 		fprintf( stderr , "[propagate] toporder botches\n" );
306 		continue;
307 	    }
308 	}
309 	if ( childp -> npropcall == 0 ) {
310 	    continue;
311 	}
312 	    /*
313 	     *	distribute time for this arc
314 	     */
315 	arcp -> arc_time = childp -> time
316 			        * ( ( (double) arcp -> arc_count ) /
317 				    ( (double) childp -> npropcall ) );
318 	arcp -> arc_childtime = childp -> childtime
319 			        * ( ( (double) arcp -> arc_count ) /
320 				    ( (double) childp -> npropcall ) );
321 	share = arcp -> arc_time + arcp -> arc_childtime;
322 	parentp -> childtime += share;
323 	    /*
324 	     *	( 1 - propfraction ) gets lost along the way
325 	     */
326 	propshare = parentp -> propfraction * share;
327 	    /*
328 	     *	fix things for printing
329 	     */
330 	parentp -> propchild += propshare;
331 	arcp -> arc_time *= parentp -> propfraction;
332 	arcp -> arc_childtime *= parentp -> propfraction;
333 	    /*
334 	     *	add this share to the parent's cycle header, if any.
335 	     */
336 	if ( parentp -> cyclehead != parentp ) {
337 	    parentp -> cyclehead -> childtime += share;
338 	    parentp -> cyclehead -> propchild += propshare;
339 	}
340 #	ifdef DEBUG
341 	    if ( debug & PROPDEBUG ) {
342 		printf( "[dotime] child \t" );
343 		printname( childp );
344 		printf( " with %f %f %ld/%ld\n" ,
345 			childp -> time , childp -> childtime ,
346 			arcp -> arc_count , childp -> npropcall );
347 		printf( "[dotime] parent\t" );
348 		printname( parentp );
349 		printf( "\n[dotime] share %f\n" , share );
350 	    }
351 #	endif /* DEBUG */
352     }
353 }
354 
355 void
356 cyclelink(void)
357 {
358     register nltype	*nlp;
359     register nltype	*cyclenlp;
360     int			cycle;
361     nltype		*memberp;
362     arctype		*arcp;
363 
364 	/*
365 	 *	Count the number of cycles, and initialize the cycle lists
366 	 */
367     ncycle = 0;
368     for ( nlp = nl ; nlp < npe ; nlp++ ) {
369 	    /*
370 	     *	this is how you find unattached cycles
371 	     */
372 	if ( nlp -> cyclehead == nlp && nlp -> cnext != 0 ) {
373 	    ncycle += 1;
374 	}
375     }
376 	/*
377 	 *	cyclenl is indexed by cycle number:
378 	 *	i.e. it is origin 1, not origin 0.
379 	 */
380     cyclenl = (nltype *) calloc( ncycle + 1 , sizeof( nltype ) );
381     if ( cyclenl == NULL )
382 	errx( 1 , "no room for %zu bytes of cycle headers" ,
383 		   ( ncycle + 1 ) * sizeof( nltype ) );
384 	/*
385 	 *	now link cycles to true cycleheads,
386 	 *	number them, accumulate the data for the cycle
387 	 */
388     cycle = 0;
389     for ( nlp = nl ; nlp < npe ; nlp++ ) {
390 	if ( !( nlp -> cyclehead == nlp && nlp -> cnext != 0 ) ) {
391 	    continue;
392 	}
393 	cycle += 1;
394 	cyclenlp = &cyclenl[cycle];
395         cyclenlp -> name = 0;		/* the name */
396         cyclenlp -> value = 0;		/* the pc entry point */
397         cyclenlp -> time = 0.0;		/* ticks in this routine */
398         cyclenlp -> childtime = 0.0;	/* cumulative ticks in children */
399 	cyclenlp -> ncall = 0;		/* how many times called */
400 	cyclenlp -> selfcalls = 0;	/* how many calls to self */
401 	cyclenlp -> propfraction = 0.0;	/* what % of time propagates */
402 	cyclenlp -> propself = 0.0;	/* how much self time propagates */
403 	cyclenlp -> propchild = 0.0;	/* how much child time propagates */
404 	cyclenlp -> printflag = TRUE;	/* should this be printed? */
405 	cyclenlp -> index = 0;		/* index in the graph list */
406 	cyclenlp -> toporder = DFN_NAN;	/* graph call chain top-sort order */
407 	cyclenlp -> cycleno = cycle;	/* internal number of cycle on */
408 	cyclenlp -> cyclehead = cyclenlp;	/* pointer to head of cycle */
409 	cyclenlp -> cnext = nlp;	/* pointer to next member of cycle */
410 	cyclenlp -> parents = 0;	/* list of caller arcs */
411 	cyclenlp -> children = 0;	/* list of callee arcs */
412 #	ifdef DEBUG
413 	    if ( debug & CYCLEDEBUG ) {
414 		printf( "[cyclelink] " );
415 		printname( nlp );
416 		printf( " is the head of cycle %d\n" , cycle );
417 	    }
418 #	endif /* DEBUG */
419 	    /*
420 	     *	link members to cycle header
421 	     */
422 	for ( memberp = nlp ; memberp ; memberp = memberp -> cnext ) {
423 	    memberp -> cycleno = cycle;
424 	    memberp -> cyclehead = cyclenlp;
425 	}
426 	    /*
427 	     *	count calls from outside the cycle
428 	     *	and those among cycle members
429 	     */
430 	for ( memberp = nlp ; memberp ; memberp = memberp -> cnext ) {
431 	    for ( arcp=memberp->parents ; arcp ; arcp=arcp->arc_parentlist ) {
432 		if ( arcp -> arc_parentp == memberp ) {
433 		    continue;
434 		}
435 		if ( arcp -> arc_parentp -> cycleno == cycle ) {
436 		    cyclenlp -> selfcalls += arcp -> arc_count;
437 		} else {
438 		    cyclenlp -> npropcall += arcp -> arc_count;
439 		}
440 	    }
441 	}
442     }
443 }
444 
445     /*
446      *	analyze cycles to determine breakup
447      */
448 bool
449 cycleanalyze(void)
450 {
451     arctype	**cyclestack;
452     arctype	**stkp;
453     arctype	**arcpp;
454     arctype	**endlist;
455     arctype	*arcp;
456     nltype	*nlp;
457     cltype	*clp;
458     bool	ret;
459     bool	done;
460     int		size;
461     int		cycleno;
462 
463 	/*
464 	 *	calculate the size of the cycle, and find nodes that
465 	 *	exit the cycle as they are desirable targets to cut
466 	 *	some of their parents
467 	 */
468     for ( done = TRUE , cycleno = 1 ; cycleno <= ncycle ; cycleno++ ) {
469 	size = 0;
470 	for (nlp = cyclenl[ cycleno ] . cnext; nlp; nlp = nlp -> cnext) {
471 	    size += 1;
472 	    nlp -> parentcnt = 0;
473 	    nlp -> flags &= ~HASCYCLEXIT;
474 	    for ( arcp = nlp -> parents; arcp; arcp = arcp -> arc_parentlist ) {
475 		nlp -> parentcnt += 1;
476 		if ( arcp -> arc_parentp -> cycleno != cycleno )
477 		    nlp -> flags |= HASCYCLEXIT;
478 	    }
479 	}
480 	if ( size <= cyclethreshold )
481 	    continue;
482 	done = FALSE;
483         cyclestack = (arctype **) calloc( size + 1 , sizeof( arctype *) );
484 	if ( cyclestack == NULL )
485 	    errx( 1, "no room for %zu bytes of cycle stack" ,
486 			   ( size + 1 ) * sizeof( arctype * ) );
487 #	ifdef DEBUG
488 	    if ( debug & BREAKCYCLE ) {
489 		printf( "[cycleanalyze] starting cycle %d of %d, size %d\n" ,
490 		    cycleno , ncycle , size );
491 	    }
492 #	endif /* DEBUG */
493 	for ( nlp = cyclenl[ cycleno ] . cnext ; nlp ; nlp = nlp -> cnext ) {
494 	    stkp = &cyclestack[0];
495 	    nlp -> flags |= CYCLEHEAD;
496 	    ret = descend ( nlp , cyclestack , stkp );
497 	    nlp -> flags &= ~CYCLEHEAD;
498 	    if ( ret == FALSE )
499 		break;
500 	}
501 	free( cyclestack );
502 	if ( cyclecnt > 0 ) {
503 	    compresslist();
504 	    for ( clp = cyclehead ; clp ; ) {
505 		endlist = &clp -> list[ clp -> size ];
506 		for ( arcpp = clp -> list ; arcpp < endlist ; arcpp++ )
507 		    (*arcpp) -> arc_cyclecnt--;
508 		cyclecnt--;
509 		clp = clp -> next;
510 		free( clp );
511 	    }
512 	    cyclehead = 0;
513 	}
514     }
515 #   ifdef DEBUG
516 	if ( debug & BREAKCYCLE ) {
517 	    printf("%s visited %d, viable %d, newcycle %d, oldcycle %d\n",
518 		"[doarcs]" , visited , viable , newcycle , oldcycle);
519 	}
520 #   endif /* DEBUG */
521     return( done );
522 }
523 
524 bool
525 descend(nltype *node, arctype **stkstart, arctype **stkp)
526 {
527     arctype	*arcp;
528     bool	ret;
529 
530     for ( arcp = node -> children ; arcp ; arcp = arcp -> arc_childlist ) {
531 #	ifdef DEBUG
532 	    visited++;
533 #	endif /* DEBUG */
534 	if ( arcp -> arc_childp -> cycleno != node -> cycleno
535 	    || ( arcp -> arc_childp -> flags & VISITED )
536 	    || ( arcp -> arc_flags & DEADARC ) )
537 	    continue;
538 #	ifdef DEBUG
539 	    viable++;
540 #	endif /* DEBUG */
541 	*stkp = arcp;
542 	if ( arcp -> arc_childp -> flags & CYCLEHEAD ) {
543 	    if ( addcycle( stkstart , stkp ) == FALSE )
544 		return( FALSE );
545 	    continue;
546 	}
547 	arcp -> arc_childp -> flags |= VISITED;
548 	ret = descend( arcp -> arc_childp , stkstart , stkp + 1 );
549 	arcp -> arc_childp -> flags &= ~VISITED;
550 	if ( ret == FALSE )
551 	    return( FALSE );
552     }
553     return( TRUE );
554 }
555 
556 bool
557 addcycle(arctype **stkstart, arctype **stkend)
558 {
559     arctype	**arcpp;
560     arctype	**stkloc;
561     arctype	**stkp;
562     arctype	**endlist;
563     arctype	*minarc;
564     arctype	*arcp;
565     cltype	*clp;
566     int		size;
567 
568     size = stkend - stkstart + 1;
569     if ( size <= 1 )
570 	return( TRUE );
571     for ( arcpp = stkstart , minarc = *arcpp ; arcpp <= stkend ; arcpp++ ) {
572 	if ( *arcpp > minarc )
573 	    continue;
574 	minarc = *arcpp;
575 	stkloc = arcpp;
576     }
577     for ( clp = cyclehead ; clp ; clp = clp -> next ) {
578 	if ( clp -> size != size )
579 	    continue;
580 	stkp = stkloc;
581 	endlist = &clp -> list[ size ];
582 	for ( arcpp = clp -> list ; arcpp < endlist ; arcpp++ ) {
583 	    if ( *stkp++ != *arcpp )
584 		break;
585 	    if ( stkp > stkend )
586 		stkp = stkstart;
587 	}
588 	if ( arcpp == endlist ) {
589 #	    ifdef DEBUG
590 		oldcycle++;
591 #	    endif /* DEBUG */
592 	    return( TRUE );
593 	}
594     }
595     clp = (cltype *)
596 	calloc( 1 , sizeof ( cltype ) + ( size - 1 ) * sizeof( arctype * ) );
597     if ( clp == NULL ) {
598 	warnx( "no room for %zu bytes of subcycle storage" ,
599 	    sizeof ( cltype ) + ( size - 1 ) * sizeof( arctype * ) );
600 	return( FALSE );
601     }
602     stkp = stkloc;
603     endlist = &clp -> list[ size ];
604     for ( arcpp = clp -> list ; arcpp < endlist ; arcpp++ ) {
605 	arcp = *arcpp = *stkp++;
606 	if ( stkp > stkend )
607 	    stkp = stkstart;
608 	arcp -> arc_cyclecnt++;
609 	if ( ( arcp -> arc_flags & ONLIST ) == 0 ) {
610 	    arcp -> arc_flags |= ONLIST;
611 	    arcp -> arc_next = archead;
612 	    archead = arcp;
613 	}
614     }
615     clp -> size = size;
616     clp -> next = cyclehead;
617     cyclehead = clp;
618 #   ifdef DEBUG
619 	newcycle++;
620 	if ( debug & SUBCYCLELIST ) {
621 	    printsubcycle( clp );
622 	}
623 #   endif /* DEBUG */
624     cyclecnt++;
625     if ( cyclecnt >= CYCLEMAX )
626 	return( FALSE );
627     return( TRUE );
628 }
629 
630 void
631 compresslist(void)
632 {
633     cltype	*clp;
634     cltype	**prev;
635     arctype	**arcpp;
636     arctype	**endlist;
637     arctype	*arcp;
638     arctype	*maxarcp;
639     arctype	*maxexitarcp;
640     arctype	*maxwithparentarcp;
641     arctype	*maxnoparentarcp;
642     int		maxexitcnt;
643     int		maxwithparentcnt;
644     int		maxnoparentcnt;
645 #   ifdef DEBUG
646 	const char	*type;
647 #   endif /* DEBUG */
648 
649     maxexitcnt = 0;
650     maxwithparentcnt = 0;
651     maxnoparentcnt = 0;
652     for ( endlist = &archead , arcp = archead ; arcp ; ) {
653 	if ( arcp -> arc_cyclecnt == 0 ) {
654 	    arcp -> arc_flags &= ~ONLIST;
655 	    *endlist = arcp -> arc_next;
656 	    arcp -> arc_next = 0;
657 	    arcp = *endlist;
658 	    continue;
659 	}
660 	if ( arcp -> arc_childp -> flags & HASCYCLEXIT ) {
661 	    if ( arcp -> arc_cyclecnt > maxexitcnt ||
662 		( arcp -> arc_cyclecnt == maxexitcnt &&
663 		arcp -> arc_cyclecnt < maxexitarcp -> arc_count ) ) {
664 		maxexitcnt = arcp -> arc_cyclecnt;
665 		maxexitarcp = arcp;
666 	    }
667 	} else if ( arcp -> arc_childp -> parentcnt > 1 ) {
668 	    if ( arcp -> arc_cyclecnt > maxwithparentcnt ||
669 		( arcp -> arc_cyclecnt == maxwithparentcnt &&
670 		arcp -> arc_cyclecnt < maxwithparentarcp -> arc_count ) ) {
671 		maxwithparentcnt = arcp -> arc_cyclecnt;
672 		maxwithparentarcp = arcp;
673 	    }
674 	} else {
675 	    if ( arcp -> arc_cyclecnt > maxnoparentcnt ||
676 		( arcp -> arc_cyclecnt == maxnoparentcnt &&
677 		arcp -> arc_cyclecnt < maxnoparentarcp -> arc_count ) ) {
678 		maxnoparentcnt = arcp -> arc_cyclecnt;
679 		maxnoparentarcp = arcp;
680 	    }
681 	}
682 	endlist = &arcp -> arc_next;
683 	arcp = arcp -> arc_next;
684     }
685     if ( maxexitcnt > 0 ) {
686 	/*
687 	 *	first choice is edge leading to node with out-of-cycle parent
688 	 */
689 	maxarcp = maxexitarcp;
690 #	ifdef DEBUG
691 	    type = "exit";
692 #	endif /* DEBUG */
693     } else if ( maxwithparentcnt > 0 ) {
694 	/*
695 	 *	second choice is edge leading to node with at least one
696 	 *	other in-cycle parent
697 	 */
698 	maxarcp = maxwithparentarcp;
699 #	ifdef DEBUG
700 	    type = "internal";
701 #	endif /* DEBUG */
702     } else {
703 	/*
704 	 *	last choice is edge leading to node with only this arc as
705 	 *	a parent (as it will now be orphaned)
706 	 */
707 	maxarcp = maxnoparentarcp;
708 #	ifdef DEBUG
709 	    type = "orphan";
710 #	endif /* DEBUG */
711     }
712     maxarcp -> arc_flags |= DEADARC;
713     maxarcp -> arc_childp -> parentcnt -= 1;
714     maxarcp -> arc_childp -> npropcall -= maxarcp -> arc_count;
715 #   ifdef DEBUG
716 	if ( debug & BREAKCYCLE ) {
717 	    printf( "%s delete %s arc: %s (%ld) -> %s from %u cycle(s)\n" ,
718 		"[compresslist]" , type , maxarcp -> arc_parentp -> name ,
719 		maxarcp -> arc_count , maxarcp -> arc_childp -> name ,
720 		maxarcp -> arc_cyclecnt );
721 	}
722 #   endif /* DEBUG */
723     printf( "\t%s to %s with %ld calls\n" , maxarcp -> arc_parentp -> name ,
724 	maxarcp -> arc_childp -> name , maxarcp -> arc_count );
725     prev = &cyclehead;
726     for ( clp = cyclehead ; clp ; ) {
727 	endlist = &clp -> list[ clp -> size ];
728 	for ( arcpp = clp -> list ; arcpp < endlist ; arcpp++ )
729 	    if ( (*arcpp) -> arc_flags & DEADARC )
730 		break;
731 	if ( arcpp == endlist ) {
732 	    prev = &clp -> next;
733 	    clp = clp -> next;
734 	    continue;
735 	}
736 	for ( arcpp = clp -> list ; arcpp < endlist ; arcpp++ )
737 	    (*arcpp) -> arc_cyclecnt--;
738 	cyclecnt--;
739 	*prev = clp -> next;
740 	clp = clp -> next;
741 	free( clp );
742     }
743 }
744 
745 #ifdef DEBUG
746 void
747 printsubcycle(cltype *clp)
748 {
749     arctype	**arcpp;
750     arctype	**endlist;
751 
752     arcpp = clp -> list;
753     printf( "%s <cycle %d>\n" , (*arcpp) -> arc_parentp -> name ,
754 	(*arcpp) -> arc_parentp -> cycleno ) ;
755     for ( endlist = &clp -> list[ clp -> size ]; arcpp < endlist ; arcpp++ )
756 	printf( "\t(%ld) -> %s\n" , (*arcpp) -> arc_count ,
757 	    (*arcpp) -> arc_childp -> name ) ;
758 }
759 #endif /* DEBUG */
760 
761 void
762 cycletime(void)
763 {
764     int			cycle;
765     nltype		*cyclenlp;
766     nltype		*childp;
767 
768     for ( cycle = 1 ; cycle <= ncycle ; cycle += 1 ) {
769 	cyclenlp = &cyclenl[ cycle ];
770 	for ( childp = cyclenlp -> cnext ; childp ; childp = childp -> cnext ) {
771 	    if ( childp -> propfraction == 0.0 ) {
772 		    /*
773 		     * all members have the same propfraction except those
774 		     *	that were excluded with -E
775 		     */
776 		continue;
777 	    }
778 	    cyclenlp -> time += childp -> time;
779 	}
780 	cyclenlp -> propself = cyclenlp -> propfraction * cyclenlp -> time;
781     }
782 }
783 
784     /*
785      *	in one top to bottom pass over the topologically sorted namelist
786      *	propagate:
787      *		printflag as the union of parents' printflags
788      *		propfraction as the sum of fractional parents' propfractions
789      *	and while we're here, sum time for functions.
790      */
791 void
792 doflags(void)
793 {
794     int		index;
795     nltype	*childp;
796     nltype	*oldhead;
797 
798     oldhead = 0;
799     for ( index = nname-1 ; index >= 0 ; index -= 1 ) {
800 	childp = topsortnlp[ index ];
801 	    /*
802 	     *	if we haven't done this function or cycle,
803 	     *	inherit things from parent.
804 	     *	this way, we are linear in the number of arcs
805 	     *	since we do all members of a cycle (and the cycle itself)
806 	     *	as we hit the first member of the cycle.
807 	     */
808 	if ( childp -> cyclehead != oldhead ) {
809 	    oldhead = childp -> cyclehead;
810 	    inheritflags( childp );
811 	}
812 #	ifdef DEBUG
813 	    if ( debug & PROPDEBUG ) {
814 		printf( "[doflags] " );
815 		printname( childp );
816 		printf( " inherits printflag %d and propfraction %f\n" ,
817 			childp -> printflag , childp -> propfraction );
818 	    }
819 #	endif /* DEBUG */
820 	if ( ! childp -> printflag ) {
821 		/*
822 		 *	printflag is off
823 		 *	it gets turned on by
824 		 *	being on -f list,
825 		 *	or there not being any -f list and not being on -e list.
826 		 */
827 	    if (   onlist( flist , childp -> name )
828 		|| ( !fflag && !onlist( elist , childp -> name ) ) ) {
829 		childp -> printflag = TRUE;
830 	    }
831 	} else {
832 		/*
833 		 *	this function has printing parents:
834 		 *	maybe someone wants to shut it up
835 		 *	by putting it on -e list.  (but favor -f over -e)
836 		 */
837 	    if (  ( !onlist( flist , childp -> name ) )
838 		&& onlist( elist , childp -> name ) ) {
839 		childp -> printflag = FALSE;
840 	    }
841 	}
842 	if ( childp -> propfraction == 0.0 ) {
843 		/*
844 		 *	no parents to pass time to.
845 		 *	collect time from children if
846 		 *	its on -F list,
847 		 *	or there isn't any -F list and its not on -E list.
848 		 */
849 	    if ( onlist( Flist , childp -> name )
850 		|| ( !Fflag && !onlist( Elist , childp -> name ) ) ) {
851 		    childp -> propfraction = 1.0;
852 	    }
853 	} else {
854 		/*
855 		 *	it has parents to pass time to,
856 		 *	but maybe someone wants to shut it up
857 		 *	by putting it on -E list.  (but favor -F over -E)
858 		 */
859 	    if (  !onlist( Flist , childp -> name )
860 		&& onlist( Elist , childp -> name ) ) {
861 		childp -> propfraction = 0.0;
862 	    }
863 	}
864 	childp -> propself = childp -> time * childp -> propfraction;
865 	printtime += childp -> propself;
866 #	ifdef DEBUG
867 	    if ( debug & PROPDEBUG ) {
868 		printf( "[doflags] " );
869 		printname( childp );
870 		printf( " ends up with printflag %d and propfraction %f\n" ,
871 			childp -> printflag , childp -> propfraction );
872 		printf( "time %f propself %f printtime %f\n" ,
873 			childp -> time , childp -> propself , printtime );
874 	    }
875 #	endif /* DEBUG */
876     }
877 }
878 
879     /*
880      *	check if any parent of this child
881      *	(or outside parents of this cycle)
882      *	have their print flags on and set the
883      *	print flag of the child (cycle) appropriately.
884      *	similarly, deal with propagation fractions from parents.
885      */
886 void
887 inheritflags(nltype *childp)
888 {
889     nltype	*headp;
890     arctype	*arcp;
891     nltype	*parentp;
892     nltype	*memp;
893 
894     headp = childp -> cyclehead;
895     if ( childp == headp ) {
896 	    /*
897 	     *	just a regular child, check its parents
898 	     */
899 	childp -> printflag = FALSE;
900 	childp -> propfraction = 0.0;
901 	for (arcp = childp -> parents ; arcp ; arcp = arcp -> arc_parentlist) {
902 	    parentp = arcp -> arc_parentp;
903 	    if ( childp == parentp ) {
904 		continue;
905 	    }
906 	    childp -> printflag |= parentp -> printflag;
907 		/*
908 		 *	if the child was never actually called
909 		 *	(e.g. this arc is static (and all others are, too))
910 		 *	no time propagates along this arc.
911 		 */
912 	    if ( arcp -> arc_flags & DEADARC ) {
913 		continue;
914 	    }
915 	    if ( childp -> npropcall ) {
916 		childp -> propfraction += parentp -> propfraction
917 					* ( ( (double) arcp -> arc_count )
918 					  / ( (double) childp -> npropcall ) );
919 	    }
920 	}
921     } else {
922 	    /*
923 	     *	its a member of a cycle, look at all parents from
924 	     *	outside the cycle
925 	     */
926 	headp -> printflag = FALSE;
927 	headp -> propfraction = 0.0;
928 	for ( memp = headp -> cnext ; memp ; memp = memp -> cnext ) {
929 	    for (arcp = memp->parents ; arcp ; arcp = arcp->arc_parentlist) {
930 		if ( arcp -> arc_parentp -> cyclehead == headp ) {
931 		    continue;
932 		}
933 		parentp = arcp -> arc_parentp;
934 		headp -> printflag |= parentp -> printflag;
935 		    /*
936 		     *	if the cycle was never actually called
937 		     *	(e.g. this arc is static (and all others are, too))
938 		     *	no time propagates along this arc.
939 		     */
940 		if ( arcp -> arc_flags & DEADARC ) {
941 		    continue;
942 		}
943 		if ( headp -> npropcall ) {
944 		    headp -> propfraction += parentp -> propfraction
945 					* ( ( (double) arcp -> arc_count )
946 					  / ( (double) headp -> npropcall ) );
947 		}
948 	    }
949 	}
950 	for ( memp = headp ; memp ; memp = memp -> cnext ) {
951 	    memp -> printflag = headp -> printflag;
952 	    memp -> propfraction = headp -> propfraction;
953 	}
954     }
955 }
956