xref: /openbsd-src/gnu/usr.bin/binutils/gprof/hist.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /*
2  * Histogram related operations.
3  */
4 #include <stdio.h>
5 #include "libiberty.h"
6 #include "gprof.h"
7 #include "corefile.h"
8 #include "gmon_io.h"
9 #include "gmon_out.h"
10 #include "hist.h"
11 #include "symtab.h"
12 #include "sym_ids.h"
13 #include "utils.h"
14 
15 #define UNITS_TO_CODE (offset_to_code / sizeof(UNIT))
16 
17 static void scale_and_align_entries PARAMS ((void));
18 
19 /* declarations of automatically generated functions to output blurbs: */
20 extern void flat_blurb PARAMS ((FILE * fp));
21 
22 bfd_vma s_lowpc;		/* lowest address in .text */
23 bfd_vma s_highpc = 0;		/* highest address in .text */
24 bfd_vma lowpc, highpc;		/* same, but expressed in UNITs */
25 int hist_num_bins = 0;		/* number of histogram samples */
26 int *hist_sample = 0;		/* histogram samples (shorts in the file!) */
27 double hist_scale;
28 char hist_dimension[sizeof (((struct gmon_hist_hdr *) 0)->dimen) + 1] =
29   "seconds";
30 char hist_dimension_abbrev = 's';
31 
32 static double accum_time;	/* accumulated time so far for print_line() */
33 static double total_time;	/* total time for all routines */
34 /*
35  * Table of SI prefixes for powers of 10 (used to automatically
36  * scale some of the values in the flat profile).
37  */
38 const struct
39   {
40     char prefix;
41     double scale;
42   }
43 SItab[] =
44 {
45   {
46     'T', 1e-12
47   }
48   ,				/* tera */
49   {
50     'G', 1e-09
51   }
52   ,				/* giga */
53   {
54     'M', 1e-06
55   }
56   ,				/* mega */
57   {
58     'K', 1e-03
59   }
60   ,				/* kilo */
61   {
62     ' ', 1e-00
63   }
64   ,
65   {
66     'm', 1e+03
67   }
68   ,				/* milli */
69   {
70     'u', 1e+06
71   }
72   ,				/* micro */
73   {
74     'n', 1e+09
75   }
76   ,				/* nano */
77   {
78     'p', 1e+12
79   }
80   ,				/* pico */
81   {
82     'f', 1e+15
83   }
84   ,				/* femto */
85   {
86     'a', 1e+18
87   }
88   ,				/* ato */
89 };
90 
91 /*
92  * Read the histogram from file IFP.  FILENAME is the name of IFP and
93  * is provided for formatting error messages only.
94  */
95 void
96 DEFUN (hist_read_rec, (ifp, filename), FILE * ifp AND const char *filename)
97 {
98   struct gmon_hist_hdr hdr;
99   bfd_vma n_lowpc, n_highpc;
100   int i, ncnt, profrate;
101   UNIT count;
102 
103   if (fread (&hdr, sizeof (hdr), 1, ifp) != 1)
104     {
105       fprintf (stderr, _("%s: %s: unexpected end of file\n"),
106 	       whoami, filename);
107       done (1);
108     }
109 
110   n_lowpc = (bfd_vma) get_vma (core_bfd, (bfd_byte *) hdr.low_pc);
111   n_highpc = (bfd_vma) get_vma (core_bfd, (bfd_byte *) hdr.high_pc);
112   ncnt = bfd_get_32 (core_bfd, (bfd_byte *) hdr.hist_size);
113   profrate = bfd_get_32 (core_bfd, (bfd_byte *) hdr.prof_rate);
114   strncpy (hist_dimension, hdr.dimen, sizeof (hdr.dimen));
115   hist_dimension[sizeof (hdr.dimen)] = '\0';
116   hist_dimension_abbrev = hdr.dimen_abbrev;
117 
118   if (!s_highpc)
119     {
120 
121       /* this is the first histogram record: */
122 
123       s_lowpc = n_lowpc;
124       s_highpc = n_highpc;
125       lowpc = (bfd_vma) n_lowpc / sizeof (UNIT);
126       highpc = (bfd_vma) n_highpc / sizeof (UNIT);
127       hist_num_bins = ncnt;
128       hz = profrate;
129     }
130 
131   DBG (SAMPLEDEBUG,
132        printf ("[hist_read_rec] n_lowpc 0x%lx n_highpc 0x%lx ncnt %d\n",
133 	       (unsigned long) n_lowpc, (unsigned long) n_highpc, ncnt);
134        printf ("[hist_read_rec] s_lowpc 0x%lx s_highpc 0x%lx nsamples %d\n",
135 	       (unsigned long) s_lowpc, (unsigned long) s_highpc,
136 	       hist_num_bins);
137        printf ("[hist_read_rec]   lowpc 0x%lx   highpc 0x%lx\n",
138 	       (unsigned long) lowpc, (unsigned long) highpc));
139 
140   if (n_lowpc != s_lowpc || n_highpc != s_highpc
141       || ncnt != hist_num_bins || hz != profrate)
142     {
143       fprintf (stderr, _("%s: `%s' is incompatible with first gmon file\n"),
144 	       whoami, filename);
145       done (1);
146     }
147 
148   if (!hist_sample)
149     {
150       hist_sample = (int *) xmalloc (hist_num_bins * sizeof (hist_sample[0]));
151       memset (hist_sample, 0, hist_num_bins * sizeof (hist_sample[0]));
152     }
153 
154   for (i = 0; i < hist_num_bins; ++i)
155     {
156       if (fread (&count[0], sizeof (count), 1, ifp) != 1)
157 	{
158 	  fprintf (stderr,
159 		   _("%s: %s: unexpected EOF after reading %d of %d samples\n"),
160 		   whoami, filename, i, hist_num_bins);
161 	  done (1);
162 	}
163       hist_sample[i] += bfd_get_16 (core_bfd, (bfd_byte *) & count[0]);
164     }
165 }
166 
167 
168 /*
169  * Write execution histogram to file OFP.  FILENAME is the name
170  * of OFP and is provided for formatting error-messages only.
171  */
172 void
173 DEFUN (hist_write_hist, (ofp, filename), FILE * ofp AND const char *filename)
174 {
175   struct gmon_hist_hdr hdr;
176   unsigned char tag;
177   UNIT count;
178   int i;
179 
180   /* write header: */
181 
182   tag = GMON_TAG_TIME_HIST;
183   put_vma (core_bfd, s_lowpc, (bfd_byte *) hdr.low_pc);
184   put_vma (core_bfd, s_highpc, (bfd_byte *) hdr.high_pc);
185   bfd_put_32 (core_bfd, hist_num_bins, (bfd_byte *) hdr.hist_size);
186   bfd_put_32 (core_bfd, hz, (bfd_byte *) hdr.prof_rate);
187   strncpy (hdr.dimen, hist_dimension, sizeof (hdr.dimen));
188   hdr.dimen_abbrev = hist_dimension_abbrev;
189 
190   if (fwrite (&tag, sizeof (tag), 1, ofp) != 1
191       || fwrite (&hdr, sizeof (hdr), 1, ofp) != 1)
192     {
193       perror (filename);
194       done (1);
195     }
196 
197   for (i = 0; i < hist_num_bins; ++i)
198     {
199       bfd_put_16 (core_bfd, hist_sample[i], (bfd_byte *) & count[0]);
200       if (fwrite (&count[0], sizeof (count), 1, ofp) != 1)
201 	{
202 	  perror (filename);
203 	  done (1);
204 	}
205     }
206 }
207 
208 
209 /*
210  * Calculate scaled entry point addresses (to save time in
211  * hist_assign_samples), and, on architectures that have procedure
212  * entry masks at the start of a function, possibly push the scaled
213  * entry points over the procedure entry mask, if it turns out that
214  * the entry point is in one bin and the code for a routine is in the
215  * next bin.
216  */
217 static void
218 scale_and_align_entries ()
219 {
220   Sym *sym;
221   bfd_vma bin_of_entry;
222   bfd_vma bin_of_code;
223 
224   for (sym = symtab.base; sym < symtab.limit; sym++)
225     {
226       sym->hist.scaled_addr = sym->addr / sizeof (UNIT);
227       bin_of_entry = (sym->hist.scaled_addr - lowpc) / hist_scale;
228       bin_of_code = (sym->hist.scaled_addr + UNITS_TO_CODE - lowpc) / hist_scale;
229       if (bin_of_entry < bin_of_code)
230 	{
231 	  DBG (SAMPLEDEBUG,
232 	       printf ("[scale_and_align_entries] pushing 0x%lx to 0x%lx\n",
233 		       (unsigned long) sym->hist.scaled_addr,
234 		       (unsigned long) (sym->hist.scaled_addr
235 					+ UNITS_TO_CODE)));
236 	  sym->hist.scaled_addr += UNITS_TO_CODE;
237 	}
238     }
239 }
240 
241 
242 /*
243  * Assign samples to the symbol to which they belong.
244  *
245  * Histogram bin I covers some address range [BIN_LOWPC,BIN_HIGH_PC)
246  * which may overlap one more symbol address ranges.  If a symbol
247  * overlaps with the bin's address range by O percent, then O percent
248  * of the bin's count is credited to that symbol.
249  *
250  * There are three cases as to where BIN_LOW_PC and BIN_HIGH_PC can be
251  * with respect to the symbol's address range [SYM_LOW_PC,
252  * SYM_HIGH_PC) as shown in the following diagram.  OVERLAP computes
253  * the distance (in UNITs) between the arrows, the fraction of the
254  * sample that is to be credited to the symbol which starts at
255  * SYM_LOW_PC.
256  *
257  *        sym_low_pc                                      sym_high_pc
258  *             |                                               |
259  *             v                                               v
260  *
261  *             +-----------------------------------------------+
262  *             |                                               |
263  *        |  ->|    |<-         ->|         |<-         ->|    |<-  |
264  *        |         |             |         |             |         |
265  *        +---------+             +---------+             +---------+
266  *
267  *        ^         ^             ^         ^             ^         ^
268  *        |         |             |         |             |         |
269  *   bin_low_pc bin_high_pc  bin_low_pc bin_high_pc  bin_low_pc bin_high_pc
270  *
271  * For the VAX we assert that samples will never fall in the first two
272  * bytes of any routine, since that is the entry mask, thus we call
273  * scale_and_align_entries() to adjust the entry points if the entry
274  * mask falls in one bin but the code for the routine doesn't start
275  * until the next bin.  In conjunction with the alignment of routine
276  * addresses, this should allow us to have only one sample for every
277  * four bytes of text space and never have any overlap (the two end
278  * cases, above).
279  */
280 void
281 DEFUN_VOID (hist_assign_samples)
282 {
283   bfd_vma bin_low_pc, bin_high_pc;
284   bfd_vma sym_low_pc, sym_high_pc;
285   bfd_vma overlap, addr;
286   int bin_count, i;
287   unsigned int j;
288   double time, credit;
289 
290   /* read samples and assign to symbols: */
291   hist_scale = highpc - lowpc;
292   hist_scale /= hist_num_bins;
293   scale_and_align_entries ();
294 
295   /* iterate over all sample bins: */
296 
297   for (i = 0, j = 1; i < hist_num_bins; ++i)
298     {
299       bin_count = hist_sample[i];
300       if (!bin_count)
301 	{
302 	  continue;
303 	}
304       bin_low_pc = lowpc + (bfd_vma) (hist_scale * i);
305       bin_high_pc = lowpc + (bfd_vma) (hist_scale * (i + 1));
306       time = bin_count;
307       DBG (SAMPLEDEBUG,
308 	   printf (
309       "[assign_samples] bin_low_pc=0x%lx, bin_high_pc=0x%lx, bin_count=%d\n",
310 		    (unsigned long) (sizeof (UNIT) * bin_low_pc),
311 		    (unsigned long) (sizeof (UNIT) * bin_high_pc),
312 		    bin_count));
313       total_time += time;
314 
315       /* credit all symbols that are covered by bin I: */
316 
317       for (j = j - 1; j < symtab.len; ++j)
318 	{
319 	  sym_low_pc = symtab.base[j].hist.scaled_addr;
320 	  sym_high_pc = symtab.base[j + 1].hist.scaled_addr;
321 	  /*
322 	   * If high end of bin is below entry address, go for next
323 	   * bin:
324 	   */
325 	  if (bin_high_pc < sym_low_pc)
326 	    {
327 	      break;
328 	    }
329 	  /*
330 	   * If low end of bin is above high end of symbol, go for
331 	   * next symbol.
332 	   */
333 	  if (bin_low_pc >= sym_high_pc)
334 	    {
335 	      continue;
336 	    }
337 	  overlap =
338 	    MIN (bin_high_pc, sym_high_pc) - MAX (bin_low_pc, sym_low_pc);
339 	  if (overlap > 0)
340 	    {
341 	      DBG (SAMPLEDEBUG,
342 		   printf (
343 			    "[assign_samples] [0x%lx,0x%lx) %s gets %f ticks %ld overlap\n",
344 			    (unsigned long) symtab.base[j].addr,
345 			    (unsigned long) (sizeof (UNIT) * sym_high_pc),
346 			    symtab.base[j].name, overlap * time / hist_scale,
347 			    (long) overlap));
348 	      addr = symtab.base[j].addr;
349 	      credit = overlap * time / hist_scale;
350 	      /*
351 	       * Credit symbol if it appears in INCL_FLAT or that
352 	       * table is empty and it does not appear it in
353 	       * EXCL_FLAT.
354 	       */
355 	      if (sym_lookup (&syms[INCL_FLAT], addr)
356 		  || (syms[INCL_FLAT].len == 0
357 		      && !sym_lookup (&syms[EXCL_FLAT], addr)))
358 		{
359 		  symtab.base[j].hist.time += credit;
360 		}
361 	      else
362 		{
363 		  total_time -= credit;
364 		}
365 	    }
366 	}
367     }
368   DBG (SAMPLEDEBUG, printf ("[assign_samples] total_time %f\n",
369 			    total_time));
370 }
371 
372 
373 /*
374  * Print header for flag histogram profile:
375  */
376 static void
377 DEFUN (print_header, (prefix), const char prefix)
378 {
379   char unit[64];
380 
381   sprintf (unit, _("%c%c/call"), prefix, hist_dimension_abbrev);
382 
383   if (bsd_style_output)
384     {
385       printf (_("\ngranularity: each sample hit covers %ld byte(s)"),
386 	      (long) hist_scale * sizeof (UNIT));
387       if (total_time > 0.0)
388 	{
389 	  printf (_(" for %.2f%% of %.2f %s\n\n"),
390 		  100.0 / total_time, total_time / hz, hist_dimension);
391 	}
392     }
393   else
394     {
395       printf (_("\nEach sample counts as %g %s.\n"), 1.0 / hz, hist_dimension);
396     }
397 
398   if (total_time <= 0.0)
399     {
400       printf (_(" no time accumulated\n\n"));
401       /* this doesn't hurt since all the numerators will be zero: */
402       total_time = 1.0;
403     }
404 
405   printf ("%5.5s %10.10s %8.8s %8.8s %8.8s %8.8s  %-8.8s\n",
406 	  "%  ", _("cumulative"), _("self  "), "", _("self  "), _("total "), "");
407   printf ("%5.5s %9.9s  %8.8s %8.8s %8.8s %8.8s  %-8.8s\n",
408 	  _("time"), hist_dimension, hist_dimension, _("calls"), unit, unit,
409 	  _("name"));
410 }
411 
412 
413 static void
414 DEFUN (print_line, (sym, scale), Sym * sym AND double scale)
415 {
416   if (ignore_zeros && sym->ncalls == 0 && sym->hist.time == 0)
417     {
418       return;
419     }
420 
421   accum_time += sym->hist.time;
422   if (bsd_style_output)
423     {
424       printf ("%5.1f %10.2f %8.2f",
425 	      total_time > 0.0 ? 100 * sym->hist.time / total_time : 0.0,
426 	      accum_time / hz, sym->hist.time / hz);
427     }
428   else
429     {
430       printf ("%6.2f %9.2f %8.2f",
431 	      total_time > 0.0 ? 100 * sym->hist.time / total_time : 0.0,
432 	      accum_time / hz, sym->hist.time / hz);
433     }
434   if (sym->ncalls != 0)
435     {
436       printf (" %8lu %8.2f %8.2f  ",
437 	      sym->ncalls, scale * sym->hist.time / hz / sym->ncalls,
438 	  scale * (sym->hist.time + sym->cg.child_time) / hz / sym->ncalls);
439     }
440   else
441     {
442       printf (" %8.8s %8.8s %8.8s  ", "", "", "");
443     }
444   if (bsd_style_output)
445     {
446       print_name (sym);
447     }
448   else
449     {
450       print_name_only (sym);
451     }
452   printf ("\n");
453 }
454 
455 
456 /*
457  * Compare LP and RP.  The primary comparison key is execution time,
458  * the secondary is number of invocation, and the tertiary is the
459  * lexicographic order of the function names.
460  */
461 static int
462 DEFUN (cmp_time, (lp, rp), const PTR lp AND const PTR rp)
463 {
464   const Sym *left = *(const Sym **) lp;
465   const Sym *right = *(const Sym **) rp;
466   double time_diff;
467 
468   time_diff = right->hist.time - left->hist.time;
469   if (time_diff > 0.0)
470     {
471       return 1;
472     }
473   if (time_diff < 0.0)
474     {
475       return -1;
476     }
477 
478   if (right->ncalls > left->ncalls)
479     {
480       return 1;
481     }
482   if (right->ncalls < left->ncalls)
483     {
484       return -1;
485     }
486 
487   return strcmp (left->name, right->name);
488 }
489 
490 
491 /*
492  * Print the flat histogram profile.
493  */
494 void
495 DEFUN_VOID (hist_print)
496 {
497   Sym **time_sorted_syms, *top_dog, *sym;
498   unsigned int index;
499   int log_scale;
500   double top_time, time;
501   bfd_vma addr;
502 
503   if (first_output)
504     {
505       first_output = FALSE;
506     }
507   else
508     {
509       printf ("\f\n");
510     }
511 
512   accum_time = 0.0;
513   if (bsd_style_output)
514     {
515       if (print_descriptions)
516 	{
517 	  printf (_("\n\n\nflat profile:\n"));
518 	  flat_blurb (stdout);
519 	}
520     }
521   else
522     {
523       printf (_("Flat profile:\n"));
524     }
525   /*
526    * Sort the symbol table by time (call-count and name as secondary
527    * and tertiary keys):
528    */
529   time_sorted_syms = (Sym **) xmalloc (symtab.len * sizeof (Sym *));
530   for (index = 0; index < symtab.len; ++index)
531     {
532       time_sorted_syms[index] = &symtab.base[index];
533     }
534   qsort (time_sorted_syms, symtab.len, sizeof (Sym *), cmp_time);
535 
536   if (bsd_style_output)
537     {
538       log_scale = 5;		/* milli-seconds is BSD-default */
539     }
540   else
541     {
542       /*
543        * Search for symbol with highest per-call execution time and
544        * scale accordingly:
545        */
546       log_scale = 0;
547       top_dog = 0;
548       top_time = 0.0;
549       for (index = 0; index < symtab.len; ++index)
550 	{
551 	  sym = time_sorted_syms[index];
552 	  if (sym->ncalls != 0)
553 	    {
554 	      time = (sym->hist.time + sym->cg.child_time) / sym->ncalls;
555 	      if (time > top_time)
556 		{
557 		  top_dog = sym;
558 		  top_time = time;
559 		}
560 	    }
561 	}
562       if (top_dog && top_dog->ncalls != 0 && top_time > 0.0)
563 	{
564 	  top_time /= hz;
565 	  while (SItab[log_scale].scale * top_time < 1000.0
566 		 && ((size_t) log_scale
567 		     < sizeof (SItab) / sizeof (SItab[0]) - 1))
568 	    {
569 	      ++log_scale;
570 	    }
571 	}
572     }
573 
574   /*
575    * For now, the dimension is always seconds.  In the future, we
576    * may also want to support other (pseudo-)dimensions (such as
577    * I-cache misses etc.).
578    */
579   print_header (SItab[log_scale].prefix);
580   for (index = 0; index < symtab.len; ++index)
581     {
582       addr = time_sorted_syms[index]->addr;
583       /*
584        * Print symbol if its in INCL_FLAT table or that table
585        * is empty and the symbol is not in EXCL_FLAT.
586        */
587       if (sym_lookup (&syms[INCL_FLAT], addr)
588 	  || (syms[INCL_FLAT].len == 0
589 	      && !sym_lookup (&syms[EXCL_FLAT], addr)))
590 	{
591 	  print_line (time_sorted_syms[index], SItab[log_scale].scale);
592 	}
593     }
594   free (time_sorted_syms);
595 
596   if (print_descriptions && !bsd_style_output)
597     {
598       flat_blurb (stdout);
599     }
600 }
601