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Diffstat (limited to 'gprof/hist.c')
| -rw-r--r-- | gprof/hist.c | 754 |
1 files changed, 754 insertions, 0 deletions
diff --git a/gprof/hist.c b/gprof/hist.c new file mode 100644 index 0000000..9043020 --- /dev/null +++ b/gprof/hist.c @@ -0,0 +1,754 @@ +/* hist.c - Histogram related operations. + + Copyright (C) 1999-2014 Free Software Foundation, Inc. + + This file is part of GNU Binutils. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA + 02110-1301, USA. */ + +#include "gprof.h" +#include "libiberty.h" +#include "search_list.h" +#include "source.h" +#include "symtab.h" +#include "corefile.h" +#include "gmon_io.h" +#include "gmon_out.h" +#include "hist.h" +#include "sym_ids.h" +#include "utils.h" +#include "math.h" +#include "stdio.h" +#include "stdlib.h" + +#define UNITS_TO_CODE (offset_to_code / sizeof(UNIT)) + +static void scale_and_align_entries (void); +static void print_header (int); +static void print_line (Sym *, double); +static int cmp_time (const PTR, const PTR); + +/* Declarations of automatically generated functions to output blurbs. */ +extern void flat_blurb (FILE * fp); + +static histogram *find_histogram (bfd_vma lowpc, bfd_vma highpc); +static histogram *find_histogram_for_pc (bfd_vma pc); + +histogram * histograms; +unsigned num_histograms; +double hist_scale; +static char hist_dimension[16] = "seconds"; +static char hist_dimension_abbrev = 's'; + +static double accum_time; /* Accumulated time so far for print_line(). */ +static double total_time; /* Total time for all routines. */ + +/* Table of SI prefixes for powers of 10 (used to automatically + scale some of the values in the flat profile). */ +const struct + { + char prefix; + double scale; + } +SItab[] = +{ + { 'T', 1e-12 }, /* tera */ + { 'G', 1e-09 }, /* giga */ + { 'M', 1e-06 }, /* mega */ + { 'K', 1e-03 }, /* kilo */ + { ' ', 1e-00 }, + { 'm', 1e+03 }, /* milli */ + { 'u', 1e+06 }, /* micro */ + { 'n', 1e+09 }, /* nano */ + { 'p', 1e+12 }, /* pico */ + { 'f', 1e+15 }, /* femto */ + { 'a', 1e+18 } /* ato */ +}; + +/* Reads just the header part of histogram record into + *RECORD from IFP. FILENAME is the name of IFP and + is provided for formatting error messages only. + + If FIRST is non-zero, sets global variables HZ, HIST_DIMENSION, + HIST_DIMENSION_ABBREV, HIST_SCALE. If FIRST is zero, checks + that the new histogram is compatible with already-set values + of those variables and emits an error if that's not so. */ +static void +read_histogram_header (histogram *record, + FILE *ifp, const char *filename, + int first) +{ + unsigned int profrate; + char n_hist_dimension[15]; + char n_hist_dimension_abbrev; + double n_hist_scale; + + if (gmon_io_read_vma (ifp, &record->lowpc) + || gmon_io_read_vma (ifp, &record->highpc) + || gmon_io_read_32 (ifp, &record->num_bins) + || gmon_io_read_32 (ifp, &profrate) + || gmon_io_read (ifp, n_hist_dimension, 15) + || gmon_io_read (ifp, &n_hist_dimension_abbrev, 1)) + { + fprintf (stderr, _("%s: %s: unexpected end of file\n"), + whoami, filename); + + done (1); + } + + n_hist_scale = (double)((record->highpc - record->lowpc) / sizeof (UNIT)) + / record->num_bins; + + if (first) + { + /* We don't try to veryfy profrate is the same for all histogram + records. If we have two histogram records for the same + address range and profiling samples is done as often + as possible as opposed on timer, then the actual profrate will + be slightly different. Most of the time the difference does not + matter and insisting that profiling rate is exactly the same + will only create inconvenient. */ + hz = profrate; + memcpy (hist_dimension, n_hist_dimension, 15); + hist_dimension_abbrev = n_hist_dimension_abbrev; + hist_scale = n_hist_scale; + } + else + { + if (strncmp (n_hist_dimension, hist_dimension, 15) != 0) + { + fprintf (stderr, + _("%s: dimension unit changed between histogram records\n" + "%s: from '%s'\n" + "%s: to '%s'\n"), + whoami, whoami, hist_dimension, whoami, n_hist_dimension); + done (1); + } + + if (n_hist_dimension_abbrev != hist_dimension_abbrev) + { + fprintf (stderr, + _("%s: dimension abbreviation changed between histogram records\n" + "%s: from '%c'\n" + "%s: to '%c'\n"), + whoami, whoami, hist_dimension_abbrev, whoami, n_hist_dimension_abbrev); + done (1); + } + + /* The only reason we require the same scale for histograms is that + there's code (notably printing code), that prints units, + and it would be very confusing to have one unit mean different + things for different functions. */ + if (fabs (hist_scale - n_hist_scale) > 0.000001) + { + fprintf (stderr, + _("%s: different scales in histogram records"), + whoami); + done (1); + } + } +} + +/* Read the histogram from file IFP. FILENAME is the name of IFP and + is provided for formatting error messages only. */ + +void +hist_read_rec (FILE * ifp, const char *filename) +{ + bfd_vma lowpc, highpc; + histogram n_record; + histogram *record, *existing_record; + unsigned i; + + /* 1. Read the header and see if there's existing record for the + same address range and that there are no overlapping records. */ + read_histogram_header (&n_record, ifp, filename, num_histograms == 0); + + existing_record = find_histogram (n_record.lowpc, n_record.highpc); + if (existing_record) + { + record = existing_record; + } + else + { + /* If this record overlaps, but does not completely match an existing + record, it's an error. */ + lowpc = n_record.lowpc; + highpc = n_record.highpc; + hist_clip_symbol_address (&lowpc, &highpc); + if (lowpc != highpc) + { + fprintf (stderr, + _("%s: overlapping histogram records\n"), + whoami); + done (1); + } + + /* This is new record. Add it to global array and allocate space for + the samples. */ + histograms = (struct histogram *) + xrealloc (histograms, sizeof (histogram) * (num_histograms + 1)); + memcpy (histograms + num_histograms, + &n_record, sizeof (histogram)); + record = &histograms[num_histograms]; + ++num_histograms; + + record->sample = (int *) xmalloc (record->num_bins + * sizeof (record->sample[0])); + memset (record->sample, 0, record->num_bins * sizeof (record->sample[0])); + } + + /* 2. We have either a new record (with zeroed histogram data), or an existing + record with some data in the histogram already. Read new data into the + record, adding hit counts. */ + + DBG (SAMPLEDEBUG, + printf ("[hist_read_rec] n_lowpc 0x%lx n_highpc 0x%lx ncnt %u\n", + (unsigned long) record->lowpc, (unsigned long) record->highpc, + record->num_bins)); + + for (i = 0; i < record->num_bins; ++i) + { + UNIT count; + if (fread (&count[0], sizeof (count), 1, ifp) != 1) + { + fprintf (stderr, + _("%s: %s: unexpected EOF after reading %u of %u samples\n"), + whoami, filename, i, record->num_bins); + done (1); + } + record->sample[i] += bfd_get_16 (core_bfd, (bfd_byte *) & count[0]); + DBG (SAMPLEDEBUG, + printf ("[hist_read_rec] 0x%lx: %u\n", + (unsigned long) (record->lowpc + + i * (record->highpc - record->lowpc) + / record->num_bins), + record->sample[i])); + } +} + + +/* Write all execution histograms file OFP. FILENAME is the name + of OFP and is provided for formatting error-messages only. */ + +void +hist_write_hist (FILE * ofp, const char *filename) +{ + UNIT count; + unsigned int i, r; + + for (r = 0; r < num_histograms; ++r) + { + histogram *record = &histograms[r]; + + /* Write header. */ + + if (gmon_io_write_8 (ofp, GMON_TAG_TIME_HIST) + || gmon_io_write_vma (ofp, record->lowpc) + || gmon_io_write_vma (ofp, record->highpc) + || gmon_io_write_32 (ofp, record->num_bins) + || gmon_io_write_32 (ofp, hz) + || gmon_io_write (ofp, hist_dimension, 15) + || gmon_io_write (ofp, &hist_dimension_abbrev, 1)) + { + perror (filename); + done (1); + } + + for (i = 0; i < record->num_bins; ++i) + { + bfd_put_16 (core_bfd, (bfd_vma) record->sample[i], (bfd_byte *) &count[0]); + + if (fwrite (&count[0], sizeof (count), 1, ofp) != 1) + { + perror (filename); + done (1); + } + } + } +} + +/* Calculate scaled entry point addresses (to save time in + hist_assign_samples), and, on architectures that have procedure + entry masks at the start of a function, possibly push the scaled + entry points over the procedure entry mask, if it turns out that + the entry point is in one bin and the code for a routine is in the + next bin. */ + +static void +scale_and_align_entries () +{ + Sym *sym; + bfd_vma bin_of_entry; + bfd_vma bin_of_code; + + for (sym = symtab.base; sym < symtab.limit; sym++) + { + histogram *r = find_histogram_for_pc (sym->addr); + + sym->hist.scaled_addr = sym->addr / sizeof (UNIT); + + if (r) + { + bin_of_entry = (sym->hist.scaled_addr - r->lowpc) / hist_scale; + bin_of_code = ((sym->hist.scaled_addr + UNITS_TO_CODE - r->lowpc) + / hist_scale); + if (bin_of_entry < bin_of_code) + { + DBG (SAMPLEDEBUG, + printf ("[scale_and_align_entries] pushing 0x%lx to 0x%lx\n", + (unsigned long) sym->hist.scaled_addr, + (unsigned long) (sym->hist.scaled_addr + + UNITS_TO_CODE))); + sym->hist.scaled_addr += UNITS_TO_CODE; + } + } + } +} + + +/* Assign samples to the symbol to which they belong. + + Histogram bin I covers some address range [BIN_LOWPC,BIN_HIGH_PC) + which may overlap one more symbol address ranges. If a symbol + overlaps with the bin's address range by O percent, then O percent + of the bin's count is credited to that symbol. + + There are three cases as to where BIN_LOW_PC and BIN_HIGH_PC can be + with respect to the symbol's address range [SYM_LOW_PC, + SYM_HIGH_PC) as shown in the following diagram. OVERLAP computes + the distance (in UNITs) between the arrows, the fraction of the + sample that is to be credited to the symbol which starts at + SYM_LOW_PC. + + sym_low_pc sym_high_pc + | | + v v + + +-----------------------------------------------+ + | | + | ->| |<- ->| |<- ->| |<- | + | | | | | | + +---------+ +---------+ +---------+ + + ^ ^ ^ ^ ^ ^ + | | | | | | + bin_low_pc bin_high_pc bin_low_pc bin_high_pc bin_low_pc bin_high_pc + + For the VAX we assert that samples will never fall in the first two + bytes of any routine, since that is the entry mask, thus we call + scale_and_align_entries() to adjust the entry points if the entry + mask falls in one bin but the code for the routine doesn't start + until the next bin. In conjunction with the alignment of routine + addresses, this should allow us to have only one sample for every + four bytes of text space and never have any overlap (the two end + cases, above). */ + +static void +hist_assign_samples_1 (histogram *r) +{ + bfd_vma bin_low_pc, bin_high_pc; + bfd_vma sym_low_pc, sym_high_pc; + bfd_vma overlap, addr; + unsigned int bin_count; + unsigned int i, j, k; + double count_time, credit; + + bfd_vma lowpc = r->lowpc / sizeof (UNIT); + + /* Iterate over all sample bins. */ + for (i = 0, k = 1; i < r->num_bins; ++i) + { + bin_count = r->sample[i]; + if (! bin_count) + continue; + + bin_low_pc = lowpc + (bfd_vma) (hist_scale * i); + bin_high_pc = lowpc + (bfd_vma) (hist_scale * (i + 1)); + count_time = bin_count; + + DBG (SAMPLEDEBUG, + printf ( + "[assign_samples] bin_low_pc=0x%lx, bin_high_pc=0x%lx, bin_count=%u\n", + (unsigned long) (sizeof (UNIT) * bin_low_pc), + (unsigned long) (sizeof (UNIT) * bin_high_pc), + bin_count)); + total_time += count_time; + + /* Credit all symbols that are covered by bin I. + + PR gprof/13325: Make sure that K does not get decremented + and J will never be less than 0. */ + for (j = k - 1; j < symtab.len; k = ++j) + { + sym_low_pc = symtab.base[j].hist.scaled_addr; + sym_high_pc = symtab.base[j + 1].hist.scaled_addr; + + /* If high end of bin is below entry address, + go for next bin. */ + if (bin_high_pc < sym_low_pc) + break; + + /* If low end of bin is above high end of symbol, + go for next symbol. */ + if (bin_low_pc >= sym_high_pc) + continue; + + overlap = + MIN (bin_high_pc, sym_high_pc) - MAX (bin_low_pc, sym_low_pc); + if (overlap > 0) + { + DBG (SAMPLEDEBUG, + printf ( + "[assign_samples] [0x%lx,0x%lx) %s gets %f ticks %ld overlap\n", + (unsigned long) symtab.base[j].addr, + (unsigned long) (sizeof (UNIT) * sym_high_pc), + symtab.base[j].name, overlap * count_time / hist_scale, + (long) overlap)); + + addr = symtab.base[j].addr; + credit = overlap * count_time / hist_scale; + + /* Credit symbol if it appears in INCL_FLAT or that + table is empty and it does not appear it in + EXCL_FLAT. */ + if (sym_lookup (&syms[INCL_FLAT], addr) + || (syms[INCL_FLAT].len == 0 + && !sym_lookup (&syms[EXCL_FLAT], addr))) + { + symtab.base[j].hist.time += credit; + } + else + { + total_time -= credit; + } + } + } + } + + DBG (SAMPLEDEBUG, printf ("[assign_samples] total_time %f\n", + total_time)); +} + +/* Calls 'hist_assign_sampes_1' for all histogram records read so far. */ +void +hist_assign_samples () +{ + unsigned i; + + scale_and_align_entries (); + + for (i = 0; i < num_histograms; ++i) + hist_assign_samples_1 (&histograms[i]); + +} + +/* Print header for flag histogram profile. */ + +static void +print_header (int prefix) +{ + char unit[64]; + + sprintf (unit, _("%c%c/call"), prefix, hist_dimension_abbrev); + + if (bsd_style_output) + { + printf (_("\ngranularity: each sample hit covers %ld byte(s)"), + (long) hist_scale * (long) sizeof (UNIT)); + if (total_time > 0.0) + { + printf (_(" for %.2f%% of %.2f %s\n\n"), + 100.0 / total_time, total_time / hz, hist_dimension); + } + } + else + { + printf (_("\nEach sample counts as %g %s.\n"), 1.0 / hz, hist_dimension); + } + + if (total_time <= 0.0) + { + printf (_(" no time accumulated\n\n")); + + /* This doesn't hurt since all the numerators will be zero. */ + total_time = 1.0; + } + + printf ("%5.5s %10.10s %8.8s %8.8s %8.8s %8.8s %-8.8s\n", + "% ", _("cumulative"), _("self "), "", _("self "), _("total "), + ""); + printf ("%5.5s %9.9s %8.8s %8.8s %8.8s %8.8s %-8.8s\n", + _("time"), hist_dimension, hist_dimension, _("calls"), unit, unit, + _("name")); +} + + +static void +print_line (Sym *sym, double scale) +{ + if (ignore_zeros && sym->ncalls == 0 && sym->hist.time == 0) + return; + + accum_time += sym->hist.time; + + if (bsd_style_output) + printf ("%5.1f %10.2f %8.2f", + total_time > 0.0 ? 100 * sym->hist.time / total_time : 0.0, + accum_time / hz, sym->hist.time / hz); + else + printf ("%6.2f %9.2f %8.2f", + total_time > 0.0 ? 100 * sym->hist.time / total_time : 0.0, + accum_time / hz, sym->hist.time / hz); + + if (sym->ncalls != 0) + printf (" %8lu %8.2f %8.2f ", + sym->ncalls, scale * sym->hist.time / hz / sym->ncalls, + scale * (sym->hist.time + sym->cg.child_time) / hz / sym->ncalls); + else + printf (" %8.8s %8.8s %8.8s ", "", "", ""); + + if (bsd_style_output) + print_name (sym); + else + print_name_only (sym); + + printf ("\n"); +} + + +/* Compare LP and RP. The primary comparison key is execution time, + the secondary is number of invocation, and the tertiary is the + lexicographic order of the function names. */ + +static int +cmp_time (const PTR lp, const PTR rp) +{ + const Sym *left = *(const Sym **) lp; + const Sym *right = *(const Sym **) rp; + double time_diff; + + time_diff = right->hist.time - left->hist.time; + + if (time_diff > 0.0) + return 1; + + if (time_diff < 0.0) + return -1; + + if (right->ncalls > left->ncalls) + return 1; + + if (right->ncalls < left->ncalls) + return -1; + + return strcmp (left->name, right->name); +} + + +/* Print the flat histogram profile. */ + +void +hist_print () +{ + Sym **time_sorted_syms, *top_dog, *sym; + unsigned int sym_index; + unsigned log_scale; + double top_time; + bfd_vma addr; + + if (first_output) + first_output = FALSE; + else + printf ("\f\n"); + + accum_time = 0.0; + + if (bsd_style_output) + { + if (print_descriptions) + { + printf (_("\n\n\nflat profile:\n")); + flat_blurb (stdout); + } + } + else + { + printf (_("Flat profile:\n")); + } + + /* Sort the symbol table by time (call-count and name as secondary + and tertiary keys). */ + time_sorted_syms = (Sym **) xmalloc (symtab.len * sizeof (Sym *)); + + for (sym_index = 0; sym_index < symtab.len; ++sym_index) + time_sorted_syms[sym_index] = &symtab.base[sym_index]; + + qsort (time_sorted_syms, symtab.len, sizeof (Sym *), cmp_time); + + if (bsd_style_output) + { + log_scale = 5; /* Milli-seconds is BSD-default. */ + } + else + { + /* Search for symbol with highest per-call + execution time and scale accordingly. */ + log_scale = 0; + top_dog = 0; + top_time = 0.0; + + for (sym_index = 0; sym_index < symtab.len; ++sym_index) + { + sym = time_sorted_syms[sym_index]; + + if (sym->ncalls != 0) + { + double call_time; + + call_time = (sym->hist.time + sym->cg.child_time) / sym->ncalls; + + if (call_time > top_time) + { + top_dog = sym; + top_time = call_time; + } + } + } + + if (top_dog && top_dog->ncalls != 0 && top_time > 0.0) + { + top_time /= hz; + + for (log_scale = 0; log_scale < ARRAY_SIZE (SItab); log_scale ++) + { + double scaled_value = SItab[log_scale].scale * top_time; + + if (scaled_value >= 1.0 && scaled_value < 1000.0) + break; + } + } + } + + /* For now, the dimension is always seconds. In the future, we + may also want to support other (pseudo-)dimensions (such as + I-cache misses etc.). */ + print_header (SItab[log_scale].prefix); + + for (sym_index = 0; sym_index < symtab.len; ++sym_index) + { + addr = time_sorted_syms[sym_index]->addr; + + /* Print symbol if its in INCL_FLAT table or that table + is empty and the symbol is not in EXCL_FLAT. */ + if (sym_lookup (&syms[INCL_FLAT], addr) + || (syms[INCL_FLAT].len == 0 + && !sym_lookup (&syms[EXCL_FLAT], addr))) + print_line (time_sorted_syms[sym_index], SItab[log_scale].scale); + } + + free (time_sorted_syms); + + if (print_descriptions && !bsd_style_output) + flat_blurb (stdout); +} + +int +hist_check_address (unsigned address) +{ + unsigned i; + + for (i = 0; i < num_histograms; ++i) + if (histograms[i].lowpc <= address && address < histograms[i].highpc) + return 1; + + return 0; +} + +#if ! defined(min) +#define min(a,b) (((a)<(b)) ? (a) : (b)) +#endif +#if ! defined(max) +#define max(a,b) (((a)>(b)) ? (a) : (b)) +#endif + +void +hist_clip_symbol_address (bfd_vma *p_lowpc, bfd_vma *p_highpc) +{ + unsigned i; + int found = 0; + + if (num_histograms == 0) + { + *p_highpc = *p_lowpc; + return; + } + + for (i = 0; i < num_histograms; ++i) + { + bfd_vma common_low, common_high; + common_low = max (histograms[i].lowpc, *p_lowpc); + common_high = min (histograms[i].highpc, *p_highpc); + + if (common_low < common_high) + { + if (found) + { + fprintf (stderr, + _("%s: found a symbol that covers " + "several histogram records"), + whoami); + done (1); + } + + found = 1; + *p_lowpc = common_low; + *p_highpc = common_high; + } + } + + if (!found) + *p_highpc = *p_lowpc; +} + +/* Find and return exising histogram record having the same lowpc and + highpc as passed via the parameters. Return NULL if nothing is found. + The return value is valid until any new histogram is read. */ +static histogram * +find_histogram (bfd_vma lowpc, bfd_vma highpc) +{ + unsigned i; + for (i = 0; i < num_histograms; ++i) + { + if (histograms[i].lowpc == lowpc && histograms[i].highpc == highpc) + return &histograms[i]; + } + return 0; +} + +/* Given a PC, return histogram record which address range include this PC. + Return NULL if there's no such record. */ +static histogram * +find_histogram_for_pc (bfd_vma pc) +{ + unsigned i; + for (i = 0; i < num_histograms; ++i) + { + if (histograms[i].lowpc <= pc && pc < histograms[i].highpc) + return &histograms[i]; + } + return 0; +} |