xref: /freebsd/usr.bin/gprof/arcs.c (revision 7431dfd4580e850375fe5478d92ec770344db098)
1 /*
2  * Copyright (c) 1983, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #if 0
31 #ifndef lint
32 static char sccsid[] = "@(#)arcs.c	8.1 (Berkeley) 6/6/93";
33 #endif /* not lint */
34 #endif
35 
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38 
39 #include <err.h>
40 #include "gprof.h"
41 
42 #ifdef DEBUG
43 int visited;
44 int viable;
45 int newcycle;
46 int oldcycle;
47 #endif /* DEBUG */
48 
49 int topcmp(const void *, const void *);
50 
51     /*
52      *	add (or just increment) an arc
53      */
54 void
55 addarc(nltype *parentp, nltype *childp, long count)
56 {
57     arctype		*arcp;
58 
59 #   ifdef DEBUG
60 	if ( debug & TALLYDEBUG ) {
61 	    printf( "[addarc] %ld arcs from %s to %s\n" ,
62 		    count , parentp -> name , childp -> name );
63 	}
64 #   endif /* DEBUG */
65     arcp = arclookup( parentp , childp );
66     if ( arcp != 0 ) {
67 	    /*
68 	     *	a hit:  just increment the count.
69 	     */
70 #	ifdef DEBUG
71 	    if ( debug & TALLYDEBUG ) {
72 		printf( "[tally] hit %ld += %ld\n" ,
73 			arcp -> arc_count , count );
74 	    }
75 #	endif /* DEBUG */
76 	arcp -> arc_count += count;
77 	return;
78     }
79     arcp = (arctype *)calloc( 1 , sizeof *arcp );
80     if (arcp == NULL)
81 	errx( 1 , "malloc failed" );
82     arcp -> arc_parentp = parentp;
83     arcp -> arc_childp = childp;
84     arcp -> arc_count = count;
85 	/*
86 	 *	prepend this child to the children of this parent
87 	 */
88     arcp -> arc_childlist = parentp -> children;
89     parentp -> children = arcp;
90 	/*
91 	 *	prepend this parent to the parents of this child
92 	 */
93     arcp -> arc_parentlist = childp -> parents;
94     childp -> parents = arcp;
95 }
96 
97     /*
98      *	the code below topologically sorts the graph (collapsing cycles),
99      *	and propagates time bottom up and flags top down.
100      */
101 
102     /*
103      *	the topologically sorted name list pointers
104      */
105 nltype	**topsortnlp;
106 
107 int
108 topcmp(const void *v1, const void *v2)
109 {
110     const nltype **npp1 = (const nltype **)v1;
111     const nltype **npp2 = (const nltype **)v2;
112 
113     return (*npp1) -> toporder - (*npp2) -> toporder;
114 }
115 
116 nltype **
117 doarcs(void)
118 {
119     nltype	*parentp, **timesortnlp;
120     arctype	*arcp;
121     long	index;
122     long	pass;
123 
124 	/*
125 	 *	initialize various things:
126 	 *	    zero out child times.
127 	 *	    count self-recursive calls.
128 	 *	    indicate that nothing is on cycles.
129 	 */
130     for ( parentp = nl ; parentp < npe ; parentp++ ) {
131 	parentp -> childtime = 0.0;
132 	arcp = arclookup( parentp , parentp );
133 	if ( arcp != 0 ) {
134 	    parentp -> ncall -= arcp -> arc_count;
135 	    parentp -> selfcalls = arcp -> arc_count;
136 	} else {
137 	    parentp -> selfcalls = 0;
138 	}
139 	parentp -> npropcall = parentp -> ncall;
140 	parentp -> propfraction = 0.0;
141 	parentp -> propself = 0.0;
142 	parentp -> propchild = 0.0;
143 	parentp -> printflag = FALSE;
144 	parentp -> toporder = DFN_NAN;
145 	parentp -> cycleno = 0;
146 	parentp -> cyclehead = parentp;
147 	parentp -> cnext = 0;
148     }
149     for ( pass = 1 ; ; pass++ ) {
150 	    /*
151 	     *	topologically order things
152 	     *	if any node is unnumbered,
153 	     *	    number it and any of its descendents.
154 	     */
155 	for ( dfn_init() , parentp = nl ; parentp < npe ; parentp++ ) {
156 	    if ( parentp -> toporder == DFN_NAN ) {
157 		dfn( parentp );
158 	    }
159 	}
160 	    /*
161 	     *	link together nodes on the same cycle
162 	     */
163 	cyclelink();
164 	    /*
165 	     *	if no cycles to break up, proceed
166 	     */
167 	if ( ! Cflag )
168 	    break;
169 	    /*
170 	     *	analyze cycles to determine breakup
171 	     */
172 #	ifdef DEBUG
173 	    if ( debug & BREAKCYCLE ) {
174 		printf("[doarcs] pass %ld, cycle(s) %d\n" , pass , ncycle );
175 	    }
176 #	endif /* DEBUG */
177 	if ( pass == 1 ) {
178 	    printf( "\n\n%s %s\n%s %d:\n" ,
179 		"The following arcs were deleted" ,
180 		"from the propagation calculation" ,
181 		"to reduce the maximum cycle size to", cyclethreshold );
182 	}
183 	if ( cycleanalyze() )
184 	    break;
185 	free ( cyclenl );
186 	ncycle = 0;
187 	for ( parentp = nl ; parentp < npe ; parentp++ ) {
188 	    parentp -> toporder = DFN_NAN;
189 	    parentp -> cycleno = 0;
190 	    parentp -> cyclehead = parentp;
191 	    parentp -> cnext = 0;
192 	}
193     }
194     if ( pass > 1 ) {
195 	printf( "\f\n" );
196     } else {
197 	printf( "\tNone\n\n" );
198     }
199 	/*
200 	 *	Sort the symbol table in reverse topological order
201 	 */
202     topsortnlp = (nltype **) calloc( nname , sizeof(nltype *) );
203     if ( topsortnlp == (nltype **) 0 )
204 	errx( 1 , "[doarcs] ran out of memory for topo sorting" );
205     for ( index = 0 ; index < nname ; index += 1 ) {
206 	topsortnlp[ index ] = &nl[ index ];
207     }
208     qsort( topsortnlp , nname , sizeof(nltype *) , topcmp );
209 #   ifdef DEBUG
210 	if ( debug & DFNDEBUG ) {
211 	    printf( "[doarcs] topological sort listing\n" );
212 	    for ( index = 0 ; index < nname ; index += 1 ) {
213 		printf( "[doarcs] " );
214 		printf( "%d:" , topsortnlp[ index ] -> toporder );
215 		printname( topsortnlp[ index ] );
216 		printf( "\n" );
217 	    }
218 	}
219 #   endif /* DEBUG */
220 	/*
221 	 *	starting from the topological top,
222 	 *	propagate print flags to children.
223 	 *	also, calculate propagation fractions.
224 	 *	this happens before time propagation
225 	 *	since time propagation uses the fractions.
226 	 */
227     doflags();
228 	/*
229 	 *	starting from the topological bottom,
230 	 *	propagate children times up to parents.
231 	 */
232     dotime();
233 	/*
234 	 *	Now, sort by propself + propchild.
235 	 *	sorting both the regular function names
236 	 *	and cycle headers.
237 	 */
238     timesortnlp = (nltype **) calloc( nname + ncycle , sizeof(nltype *) );
239     if ( timesortnlp == (nltype **) 0 )
240 	errx( 1 , "ran out of memory for sorting" );
241     for ( index = 0 ; index < nname ; index++ ) {
242 	timesortnlp[index] = &nl[index];
243     }
244     for ( index = 1 ; index <= ncycle ; index++ ) {
245 	timesortnlp[nname+index-1] = &cyclenl[index];
246     }
247     qsort( timesortnlp , nname + ncycle , sizeof(nltype *) , totalcmp );
248     for ( index = 0 ; index < nname + ncycle ; index++ ) {
249 	timesortnlp[ index ] -> index = index + 1;
250     }
251     return( timesortnlp );
252 }
253 
254 void
255 dotime(void)
256 {
257     int	index;
258 
259     cycletime();
260     for ( index = 0 ; index < nname ; index += 1 ) {
261 	timepropagate( topsortnlp[ index ] );
262     }
263 }
264 
265 void
266 timepropagate(nltype *parentp)
267 {
268     arctype	*arcp;
269     nltype	*childp;
270     double	share;
271     double	propshare;
272 
273     if ( parentp -> propfraction == 0.0 ) {
274 	return;
275     }
276 	/*
277 	 *	gather time from children of this parent.
278 	 */
279     for ( arcp = parentp -> children ; arcp ; arcp = arcp -> arc_childlist ) {
280 	childp = arcp -> arc_childp;
281 	if ( arcp -> arc_flags & DEADARC ) {
282 	    continue;
283 	}
284 	if ( arcp -> arc_count == 0 ) {
285 	    continue;
286 	}
287 	if ( childp == parentp ) {
288 	    continue;
289 	}
290 	if ( childp -> propfraction == 0.0 ) {
291 	    continue;
292 	}
293 	if ( childp -> cyclehead != childp ) {
294 	    if ( parentp -> cycleno == childp -> cycleno ) {
295 		continue;
296 	    }
297 	    if ( parentp -> toporder <= childp -> toporder ) {
298 		fprintf( stderr , "[propagate] toporder botches\n" );
299 	    }
300 	    childp = childp -> cyclehead;
301 	} else {
302 	    if ( parentp -> toporder <= childp -> toporder ) {
303 		fprintf( stderr , "[propagate] toporder botches\n" );
304 		continue;
305 	    }
306 	}
307 	if ( childp -> npropcall == 0 ) {
308 	    continue;
309 	}
310 	    /*
311 	     *	distribute time for this arc
312 	     */
313 	arcp -> arc_time = childp -> time
314 			        * ( ( (double) arcp -> arc_count ) /
315 				    ( (double) childp -> npropcall ) );
316 	arcp -> arc_childtime = childp -> childtime
317 			        * ( ( (double) arcp -> arc_count ) /
318 				    ( (double) childp -> npropcall ) );
319 	share = arcp -> arc_time + arcp -> arc_childtime;
320 	parentp -> childtime += share;
321 	    /*
322 	     *	( 1 - propfraction ) gets lost along the way
323 	     */
324 	propshare = parentp -> propfraction * share;
325 	    /*
326 	     *	fix things for printing
327 	     */
328 	parentp -> propchild += propshare;
329 	arcp -> arc_time *= parentp -> propfraction;
330 	arcp -> arc_childtime *= parentp -> propfraction;
331 	    /*
332 	     *	add this share to the parent's cycle header, if any.
333 	     */
334 	if ( parentp -> cyclehead != parentp ) {
335 	    parentp -> cyclehead -> childtime += share;
336 	    parentp -> cyclehead -> propchild += propshare;
337 	}
338 #	ifdef DEBUG
339 	    if ( debug & PROPDEBUG ) {
340 		printf( "[dotime] child \t" );
341 		printname( childp );
342 		printf( " with %f %f %ld/%ld\n" ,
343 			childp -> time , childp -> childtime ,
344 			arcp -> arc_count , childp -> npropcall );
345 		printf( "[dotime] parent\t" );
346 		printname( parentp );
347 		printf( "\n[dotime] share %f\n" , share );
348 	    }
349 #	endif /* DEBUG */
350     }
351 }
352 
353 void
354 cyclelink(void)
355 {
356     register nltype	*nlp;
357     register nltype	*cyclenlp;
358     int			cycle;
359     nltype		*memberp;
360     arctype		*arcp;
361 
362 	/*
363 	 *	Count the number of cycles, and initialize the cycle lists
364 	 */
365     ncycle = 0;
366     for ( nlp = nl ; nlp < npe ; nlp++ ) {
367 	    /*
368 	     *	this is how you find unattached cycles
369 	     */
370 	if ( nlp -> cyclehead == nlp && nlp -> cnext != 0 ) {
371 	    ncycle += 1;
372 	}
373     }
374 	/*
375 	 *	cyclenl is indexed by cycle number:
376 	 *	i.e. it is origin 1, not origin 0.
377 	 */
378     cyclenl = (nltype *) calloc( ncycle + 1 , sizeof( nltype ) );
379     if ( cyclenl == 0 )
380 	errx( 1 , "no room for %zu bytes of cycle headers" ,
381 		   ( ncycle + 1 ) * sizeof( nltype ) );
382 	/*
383 	 *	now link cycles to true cycleheads,
384 	 *	number them, accumulate the data for the cycle
385 	 */
386     cycle = 0;
387     for ( nlp = nl ; nlp < npe ; nlp++ ) {
388 	if ( !( nlp -> cyclehead == nlp && nlp -> cnext != 0 ) ) {
389 	    continue;
390 	}
391 	cycle += 1;
392 	cyclenlp = &cyclenl[cycle];
393         cyclenlp -> name = 0;		/* the name */
394         cyclenlp -> value = 0;		/* the pc entry point */
395         cyclenlp -> time = 0.0;		/* ticks in this routine */
396         cyclenlp -> childtime = 0.0;	/* cumulative ticks in children */
397 	cyclenlp -> ncall = 0;		/* how many times called */
398 	cyclenlp -> selfcalls = 0;	/* how many calls to self */
399 	cyclenlp -> propfraction = 0.0;	/* what % of time propagates */
400 	cyclenlp -> propself = 0.0;	/* how much self time propagates */
401 	cyclenlp -> propchild = 0.0;	/* how much child time propagates */
402 	cyclenlp -> printflag = TRUE;	/* should this be printed? */
403 	cyclenlp -> index = 0;		/* index in the graph list */
404 	cyclenlp -> toporder = DFN_NAN;	/* graph call chain top-sort order */
405 	cyclenlp -> cycleno = cycle;	/* internal number of cycle on */
406 	cyclenlp -> cyclehead = cyclenlp;	/* pointer to head of cycle */
407 	cyclenlp -> cnext = nlp;	/* pointer to next member of cycle */
408 	cyclenlp -> parents = 0;	/* list of caller arcs */
409 	cyclenlp -> children = 0;	/* list of callee arcs */
410 #	ifdef DEBUG
411 	    if ( debug & CYCLEDEBUG ) {
412 		printf( "[cyclelink] " );
413 		printname( nlp );
414 		printf( " is the head of cycle %d\n" , cycle );
415 	    }
416 #	endif /* DEBUG */
417 	    /*
418 	     *	link members to cycle header
419 	     */
420 	for ( memberp = nlp ; memberp ; memberp = memberp -> cnext ) {
421 	    memberp -> cycleno = cycle;
422 	    memberp -> cyclehead = cyclenlp;
423 	}
424 	    /*
425 	     *	count calls from outside the cycle
426 	     *	and those among cycle members
427 	     */
428 	for ( memberp = nlp ; memberp ; memberp = memberp -> cnext ) {
429 	    for ( arcp=memberp->parents ; arcp ; arcp=arcp->arc_parentlist ) {
430 		if ( arcp -> arc_parentp == memberp ) {
431 		    continue;
432 		}
433 		if ( arcp -> arc_parentp -> cycleno == cycle ) {
434 		    cyclenlp -> selfcalls += arcp -> arc_count;
435 		} else {
436 		    cyclenlp -> npropcall += arcp -> arc_count;
437 		}
438 	    }
439 	}
440     }
441 }
442 
443     /*
444      *	analyze cycles to determine breakup
445      */
446 bool
447 cycleanalyze(void)
448 {
449     arctype	**cyclestack;
450     arctype	**stkp;
451     arctype	**arcpp;
452     arctype	**endlist;
453     arctype	*arcp;
454     nltype	*nlp;
455     cltype	*clp;
456     bool	ret;
457     bool	done;
458     int		size;
459     int		cycleno;
460 
461 	/*
462 	 *	calculate the size of the cycle, and find nodes that
463 	 *	exit the cycle as they are desirable targets to cut
464 	 *	some of their parents
465 	 */
466     for ( done = TRUE , cycleno = 1 ; cycleno <= ncycle ; cycleno++ ) {
467 	size = 0;
468 	for (nlp = cyclenl[ cycleno ] . cnext; nlp; nlp = nlp -> cnext) {
469 	    size += 1;
470 	    nlp -> parentcnt = 0;
471 	    nlp -> flags &= ~HASCYCLEXIT;
472 	    for ( arcp = nlp -> parents; arcp; arcp = arcp -> arc_parentlist ) {
473 		nlp -> parentcnt += 1;
474 		if ( arcp -> arc_parentp -> cycleno != cycleno )
475 		    nlp -> flags |= HASCYCLEXIT;
476 	    }
477 	}
478 	if ( size <= cyclethreshold )
479 	    continue;
480 	done = FALSE;
481         cyclestack = (arctype **) calloc( size + 1 , sizeof( arctype *) );
482 	if ( cyclestack == 0 )
483 	    errx( 1, "no room for %zu bytes of cycle stack" ,
484 			   ( size + 1 ) * sizeof( arctype * ) );
485 #	ifdef DEBUG
486 	    if ( debug & BREAKCYCLE ) {
487 		printf( "[cycleanalyze] starting cycle %d of %d, size %d\n" ,
488 		    cycleno , ncycle , size );
489 	    }
490 #	endif /* DEBUG */
491 	for ( nlp = cyclenl[ cycleno ] . cnext ; nlp ; nlp = nlp -> cnext ) {
492 	    stkp = &cyclestack[0];
493 	    nlp -> flags |= CYCLEHEAD;
494 	    ret = descend ( nlp , cyclestack , stkp );
495 	    nlp -> flags &= ~CYCLEHEAD;
496 	    if ( ret == FALSE )
497 		break;
498 	}
499 	free( cyclestack );
500 	if ( cyclecnt > 0 ) {
501 	    compresslist();
502 	    for ( clp = cyclehead ; clp ; ) {
503 		endlist = &clp -> list[ clp -> size ];
504 		for ( arcpp = clp -> list ; arcpp < endlist ; arcpp++ )
505 		    (*arcpp) -> arc_cyclecnt--;
506 		cyclecnt--;
507 		clp = clp -> next;
508 		free( clp );
509 	    }
510 	    cyclehead = 0;
511 	}
512     }
513 #   ifdef DEBUG
514 	if ( debug & BREAKCYCLE ) {
515 	    printf("%s visited %d, viable %d, newcycle %d, oldcycle %d\n",
516 		"[doarcs]" , visited , viable , newcycle , oldcycle);
517 	}
518 #   endif /* DEBUG */
519     return( done );
520 }
521 
522 bool
523 descend(nltype *node, arctype **stkstart, arctype **stkp)
524 {
525     arctype	*arcp;
526     bool	ret;
527 
528     for ( arcp = node -> children ; arcp ; arcp = arcp -> arc_childlist ) {
529 #	ifdef DEBUG
530 	    visited++;
531 #	endif /* DEBUG */
532 	if ( arcp -> arc_childp -> cycleno != node -> cycleno
533 	    || ( arcp -> arc_childp -> flags & VISITED )
534 	    || ( arcp -> arc_flags & DEADARC ) )
535 	    continue;
536 #	ifdef DEBUG
537 	    viable++;
538 #	endif /* DEBUG */
539 	*stkp = arcp;
540 	if ( arcp -> arc_childp -> flags & CYCLEHEAD ) {
541 	    if ( addcycle( stkstart , stkp ) == FALSE )
542 		return( FALSE );
543 	    continue;
544 	}
545 	arcp -> arc_childp -> flags |= VISITED;
546 	ret = descend( arcp -> arc_childp , stkstart , stkp + 1 );
547 	arcp -> arc_childp -> flags &= ~VISITED;
548 	if ( ret == FALSE )
549 	    return( FALSE );
550     }
551     return( TRUE );
552 }
553 
554 bool
555 addcycle(arctype **stkstart, arctype **stkend)
556 {
557     arctype	**arcpp;
558     arctype	**stkloc;
559     arctype	**stkp;
560     arctype	**endlist;
561     arctype	*minarc;
562     arctype	*arcp;
563     cltype	*clp;
564     int		size;
565 
566     size = stkend - stkstart + 1;
567     if ( size <= 1 )
568 	return( TRUE );
569     for ( arcpp = stkstart , minarc = *arcpp ; arcpp <= stkend ; arcpp++ ) {
570 	if ( *arcpp > minarc )
571 	    continue;
572 	minarc = *arcpp;
573 	stkloc = arcpp;
574     }
575     for ( clp = cyclehead ; clp ; clp = clp -> next ) {
576 	if ( clp -> size != size )
577 	    continue;
578 	stkp = stkloc;
579 	endlist = &clp -> list[ size ];
580 	for ( arcpp = clp -> list ; arcpp < endlist ; arcpp++ ) {
581 	    if ( *stkp++ != *arcpp )
582 		break;
583 	    if ( stkp > stkend )
584 		stkp = stkstart;
585 	}
586 	if ( arcpp == endlist ) {
587 #	    ifdef DEBUG
588 		oldcycle++;
589 #	    endif /* DEBUG */
590 	    return( TRUE );
591 	}
592     }
593     clp = (cltype *)
594 	calloc( 1 , sizeof ( cltype ) + ( size - 1 ) * sizeof( arctype * ) );
595     if ( clp == 0 ) {
596 	warnx( "no room for %zu bytes of subcycle storage" ,
597 	    sizeof ( cltype ) + ( size - 1 ) * sizeof( arctype * ) );
598 	return( FALSE );
599     }
600     stkp = stkloc;
601     endlist = &clp -> list[ size ];
602     for ( arcpp = clp -> list ; arcpp < endlist ; arcpp++ ) {
603 	arcp = *arcpp = *stkp++;
604 	if ( stkp > stkend )
605 	    stkp = stkstart;
606 	arcp -> arc_cyclecnt++;
607 	if ( ( arcp -> arc_flags & ONLIST ) == 0 ) {
608 	    arcp -> arc_flags |= ONLIST;
609 	    arcp -> arc_next = archead;
610 	    archead = arcp;
611 	}
612     }
613     clp -> size = size;
614     clp -> next = cyclehead;
615     cyclehead = clp;
616 #   ifdef DEBUG
617 	newcycle++;
618 	if ( debug & SUBCYCLELIST ) {
619 	    printsubcycle( clp );
620 	}
621 #   endif /* DEBUG */
622     cyclecnt++;
623     if ( cyclecnt >= CYCLEMAX )
624 	return( FALSE );
625     return( TRUE );
626 }
627 
628 void
629 compresslist(void)
630 {
631     cltype	*clp;
632     cltype	**prev;
633     arctype	**arcpp;
634     arctype	**endlist;
635     arctype	*arcp;
636     arctype	*maxarcp;
637     arctype	*maxexitarcp;
638     arctype	*maxwithparentarcp;
639     arctype	*maxnoparentarcp;
640     int		maxexitcnt;
641     int		maxwithparentcnt;
642     int		maxnoparentcnt;
643 #   ifdef DEBUG
644 	const char	*type;
645 #   endif /* DEBUG */
646 
647     maxexitcnt = 0;
648     maxwithparentcnt = 0;
649     maxnoparentcnt = 0;
650     for ( endlist = &archead , arcp = archead ; arcp ; ) {
651 	if ( arcp -> arc_cyclecnt == 0 ) {
652 	    arcp -> arc_flags &= ~ONLIST;
653 	    *endlist = arcp -> arc_next;
654 	    arcp -> arc_next = 0;
655 	    arcp = *endlist;
656 	    continue;
657 	}
658 	if ( arcp -> arc_childp -> flags & HASCYCLEXIT ) {
659 	    if ( arcp -> arc_cyclecnt > maxexitcnt ||
660 		( arcp -> arc_cyclecnt == maxexitcnt &&
661 		arcp -> arc_cyclecnt < maxexitarcp -> arc_count ) ) {
662 		maxexitcnt = arcp -> arc_cyclecnt;
663 		maxexitarcp = arcp;
664 	    }
665 	} else if ( arcp -> arc_childp -> parentcnt > 1 ) {
666 	    if ( arcp -> arc_cyclecnt > maxwithparentcnt ||
667 		( arcp -> arc_cyclecnt == maxwithparentcnt &&
668 		arcp -> arc_cyclecnt < maxwithparentarcp -> arc_count ) ) {
669 		maxwithparentcnt = arcp -> arc_cyclecnt;
670 		maxwithparentarcp = arcp;
671 	    }
672 	} else {
673 	    if ( arcp -> arc_cyclecnt > maxnoparentcnt ||
674 		( arcp -> arc_cyclecnt == maxnoparentcnt &&
675 		arcp -> arc_cyclecnt < maxnoparentarcp -> arc_count ) ) {
676 		maxnoparentcnt = arcp -> arc_cyclecnt;
677 		maxnoparentarcp = arcp;
678 	    }
679 	}
680 	endlist = &arcp -> arc_next;
681 	arcp = arcp -> arc_next;
682     }
683     if ( maxexitcnt > 0 ) {
684 	/*
685 	 *	first choice is edge leading to node with out-of-cycle parent
686 	 */
687 	maxarcp = maxexitarcp;
688 #	ifdef DEBUG
689 	    type = "exit";
690 #	endif /* DEBUG */
691     } else if ( maxwithparentcnt > 0 ) {
692 	/*
693 	 *	second choice is edge leading to node with at least one
694 	 *	other in-cycle parent
695 	 */
696 	maxarcp = maxwithparentarcp;
697 #	ifdef DEBUG
698 	    type = "internal";
699 #	endif /* DEBUG */
700     } else {
701 	/*
702 	 *	last choice is edge leading to node with only this arc as
703 	 *	a parent (as it will now be orphaned)
704 	 */
705 	maxarcp = maxnoparentarcp;
706 #	ifdef DEBUG
707 	    type = "orphan";
708 #	endif /* DEBUG */
709     }
710     maxarcp -> arc_flags |= DEADARC;
711     maxarcp -> arc_childp -> parentcnt -= 1;
712     maxarcp -> arc_childp -> npropcall -= maxarcp -> arc_count;
713 #   ifdef DEBUG
714 	if ( debug & BREAKCYCLE ) {
715 	    printf( "%s delete %s arc: %s (%ld) -> %s from %u cycle(s)\n" ,
716 		"[compresslist]" , type , maxarcp -> arc_parentp -> name ,
717 		maxarcp -> arc_count , maxarcp -> arc_childp -> name ,
718 		maxarcp -> arc_cyclecnt );
719 	}
720 #   endif /* DEBUG */
721     printf( "\t%s to %s with %ld calls\n" , maxarcp -> arc_parentp -> name ,
722 	maxarcp -> arc_childp -> name , maxarcp -> arc_count );
723     prev = &cyclehead;
724     for ( clp = cyclehead ; clp ; ) {
725 	endlist = &clp -> list[ clp -> size ];
726 	for ( arcpp = clp -> list ; arcpp < endlist ; arcpp++ )
727 	    if ( (*arcpp) -> arc_flags & DEADARC )
728 		break;
729 	if ( arcpp == endlist ) {
730 	    prev = &clp -> next;
731 	    clp = clp -> next;
732 	    continue;
733 	}
734 	for ( arcpp = clp -> list ; arcpp < endlist ; arcpp++ )
735 	    (*arcpp) -> arc_cyclecnt--;
736 	cyclecnt--;
737 	*prev = clp -> next;
738 	clp = clp -> next;
739 	free( clp );
740     }
741 }
742 
743 #ifdef DEBUG
744 void
745 printsubcycle(cltype *clp)
746 {
747     arctype	**arcpp;
748     arctype	**endlist;
749 
750     arcpp = clp -> list;
751     printf( "%s <cycle %d>\n" , (*arcpp) -> arc_parentp -> name ,
752 	(*arcpp) -> arc_parentp -> cycleno ) ;
753     for ( endlist = &clp -> list[ clp -> size ]; arcpp < endlist ; arcpp++ )
754 	printf( "\t(%ld) -> %s\n" , (*arcpp) -> arc_count ,
755 	    (*arcpp) -> arc_childp -> name ) ;
756 }
757 #endif /* DEBUG */
758 
759 void
760 cycletime(void)
761 {
762     int			cycle;
763     nltype		*cyclenlp;
764     nltype		*childp;
765 
766     for ( cycle = 1 ; cycle <= ncycle ; cycle += 1 ) {
767 	cyclenlp = &cyclenl[ cycle ];
768 	for ( childp = cyclenlp -> cnext ; childp ; childp = childp -> cnext ) {
769 	    if ( childp -> propfraction == 0.0 ) {
770 		    /*
771 		     * all members have the same propfraction except those
772 		     *	that were excluded with -E
773 		     */
774 		continue;
775 	    }
776 	    cyclenlp -> time += childp -> time;
777 	}
778 	cyclenlp -> propself = cyclenlp -> propfraction * cyclenlp -> time;
779     }
780 }
781 
782     /*
783      *	in one top to bottom pass over the topologically sorted namelist
784      *	propagate:
785      *		printflag as the union of parents' printflags
786      *		propfraction as the sum of fractional parents' propfractions
787      *	and while we're here, sum time for functions.
788      */
789 void
790 doflags(void)
791 {
792     int		index;
793     nltype	*childp;
794     nltype	*oldhead;
795 
796     oldhead = 0;
797     for ( index = nname-1 ; index >= 0 ; index -= 1 ) {
798 	childp = topsortnlp[ index ];
799 	    /*
800 	     *	if we haven't done this function or cycle,
801 	     *	inherit things from parent.
802 	     *	this way, we are linear in the number of arcs
803 	     *	since we do all members of a cycle (and the cycle itself)
804 	     *	as we hit the first member of the cycle.
805 	     */
806 	if ( childp -> cyclehead != oldhead ) {
807 	    oldhead = childp -> cyclehead;
808 	    inheritflags( childp );
809 	}
810 #	ifdef DEBUG
811 	    if ( debug & PROPDEBUG ) {
812 		printf( "[doflags] " );
813 		printname( childp );
814 		printf( " inherits printflag %d and propfraction %f\n" ,
815 			childp -> printflag , childp -> propfraction );
816 	    }
817 #	endif /* DEBUG */
818 	if ( ! childp -> printflag ) {
819 		/*
820 		 *	printflag is off
821 		 *	it gets turned on by
822 		 *	being on -f list,
823 		 *	or there not being any -f list and not being on -e list.
824 		 */
825 	    if (   onlist( flist , childp -> name )
826 		|| ( !fflag && !onlist( elist , childp -> name ) ) ) {
827 		childp -> printflag = TRUE;
828 	    }
829 	} else {
830 		/*
831 		 *	this function has printing parents:
832 		 *	maybe someone wants to shut it up
833 		 *	by putting it on -e list.  (but favor -f over -e)
834 		 */
835 	    if (  ( !onlist( flist , childp -> name ) )
836 		&& onlist( elist , childp -> name ) ) {
837 		childp -> printflag = FALSE;
838 	    }
839 	}
840 	if ( childp -> propfraction == 0.0 ) {
841 		/*
842 		 *	no parents to pass time to.
843 		 *	collect time from children if
844 		 *	its on -F list,
845 		 *	or there isn't any -F list and its not on -E list.
846 		 */
847 	    if ( onlist( Flist , childp -> name )
848 		|| ( !Fflag && !onlist( Elist , childp -> name ) ) ) {
849 		    childp -> propfraction = 1.0;
850 	    }
851 	} else {
852 		/*
853 		 *	it has parents to pass time to,
854 		 *	but maybe someone wants to shut it up
855 		 *	by putting it on -E list.  (but favor -F over -E)
856 		 */
857 	    if (  !onlist( Flist , childp -> name )
858 		&& onlist( Elist , childp -> name ) ) {
859 		childp -> propfraction = 0.0;
860 	    }
861 	}
862 	childp -> propself = childp -> time * childp -> propfraction;
863 	printtime += childp -> propself;
864 #	ifdef DEBUG
865 	    if ( debug & PROPDEBUG ) {
866 		printf( "[doflags] " );
867 		printname( childp );
868 		printf( " ends up with printflag %d and propfraction %f\n" ,
869 			childp -> printflag , childp -> propfraction );
870 		printf( "time %f propself %f printtime %f\n" ,
871 			childp -> time , childp -> propself , printtime );
872 	    }
873 #	endif /* DEBUG */
874     }
875 }
876 
877     /*
878      *	check if any parent of this child
879      *	(or outside parents of this cycle)
880      *	have their print flags on and set the
881      *	print flag of the child (cycle) appropriately.
882      *	similarly, deal with propagation fractions from parents.
883      */
884 void
885 inheritflags(nltype *childp)
886 {
887     nltype	*headp;
888     arctype	*arcp;
889     nltype	*parentp;
890     nltype	*memp;
891 
892     headp = childp -> cyclehead;
893     if ( childp == headp ) {
894 	    /*
895 	     *	just a regular child, check its parents
896 	     */
897 	childp -> printflag = FALSE;
898 	childp -> propfraction = 0.0;
899 	for (arcp = childp -> parents ; arcp ; arcp = arcp -> arc_parentlist) {
900 	    parentp = arcp -> arc_parentp;
901 	    if ( childp == parentp ) {
902 		continue;
903 	    }
904 	    childp -> printflag |= parentp -> printflag;
905 		/*
906 		 *	if the child was never actually called
907 		 *	(e.g. this arc is static (and all others are, too))
908 		 *	no time propagates along this arc.
909 		 */
910 	    if ( arcp -> arc_flags & DEADARC ) {
911 		continue;
912 	    }
913 	    if ( childp -> npropcall ) {
914 		childp -> propfraction += parentp -> propfraction
915 					* ( ( (double) arcp -> arc_count )
916 					  / ( (double) childp -> npropcall ) );
917 	    }
918 	}
919     } else {
920 	    /*
921 	     *	its a member of a cycle, look at all parents from
922 	     *	outside the cycle
923 	     */
924 	headp -> printflag = FALSE;
925 	headp -> propfraction = 0.0;
926 	for ( memp = headp -> cnext ; memp ; memp = memp -> cnext ) {
927 	    for (arcp = memp->parents ; arcp ; arcp = arcp->arc_parentlist) {
928 		if ( arcp -> arc_parentp -> cyclehead == headp ) {
929 		    continue;
930 		}
931 		parentp = arcp -> arc_parentp;
932 		headp -> printflag |= parentp -> printflag;
933 		    /*
934 		     *	if the cycle was never actually called
935 		     *	(e.g. this arc is static (and all others are, too))
936 		     *	no time propagates along this arc.
937 		     */
938 		if ( arcp -> arc_flags & DEADARC ) {
939 		    continue;
940 		}
941 		if ( headp -> npropcall ) {
942 		    headp -> propfraction += parentp -> propfraction
943 					* ( ( (double) arcp -> arc_count )
944 					  / ( (double) headp -> npropcall ) );
945 		}
946 	    }
947 	}
948 	for ( memp = headp ; memp ; memp = memp -> cnext ) {
949 	    memp -> printflag = headp -> printflag;
950 	    memp -> propfraction = headp -> propfraction;
951 	}
952     }
953 }
954