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RedHat 9 (Linux i386) - man page for gprof (redhat section 1)

GPROF(1)				       GNU					 GPROF(1)

NAME
       gprof - display call graph profile data

SYNOPSIS
       gprof [ -[abcDhilLsTvwxyz] ] [ -[ACeEfFJnNOpPqQZ][name] ]
	[ -I dirs ] [ -d[num] ] [ -k from/to ]
	[ -m min-count ] [ -t table-length ]
	[ --[no-]annotated-source[=name] ]
	[ --[no-]exec-counts[=name] ]
	[ --[no-]flat-profile[=name] ] [ --[no-]graph[=name] ]
	[ --[no-]time=name] [ --all-lines ] [ --brief ]
	[ --debug[=level] ] [ --function-ordering ]
	[ --file-ordering ] [ --directory-path=dirs ]
	[ --display-unused-functions ] [ --file-format=name ]
	[ --file-info ] [ --help ] [ --line ] [ --min-count=n ]
	[ --no-static ] [ --print-path ] [ --separate-files ]
	[ --static-call-graph ] [ --sum ] [ --table-length=len ]
	[ --traditional ] [ --version ] [ --width=n ]
	[ --ignore-non-functions ] [ --demangle[=STYLE] ]
	[ --no-demangle ] [ image-file ] [ profile-file ... ]

DESCRIPTION
       "gprof"	produces an execution profile of C, Pascal, or Fortran77 programs.  The effect of
       called routines is incorporated in the profile of each caller.  The profile data is  taken
       from  the call graph profile file (gmon.out default) which is created by programs that are
       compiled with the -pg option of "cc", "pc", and "f77".  The -pg option also links in  ver-
       sions  of  the  library routines that are compiled for profiling.  "Gprof" reads the given
       object file (the default is "a.out") and establishes the relation between its symbol table
       and the call graph profile from gmon.out.  If more than one profile file is specified, the
       "gprof" output shows the sum of the profile information in the given profile files.

       "Gprof" calculates the amount of time spent in each routine.  Next, these times are propa-
       gated  along  the  edges of the call graph.  Cycles are discovered, and calls into a cycle
       are made to share the time of the cycle.

       Several forms of output are available from the analysis.

       The flat profile shows how much time your program spent in each	function,  and	how  many
       times  that  function was called.  If you simply want to know which functions burn most of
       the cycles, it is stated concisely here.

       The call graph shows, for each function, which functions called it, which other	functions
       it  called,  and  how many times.  There is also an estimate of how much time was spent in
       the subroutines of each function.  This can suggest places where you might try  to  elimi-
       nate function calls that use a lot of time.

       The annotated source listing is a copy of the program's source code, labeled with the num-
       ber of times each line of the program was executed.

OPTIONS
       These options specify which of several output formats "gprof" should produce.

       Many of these options take an optional symspec to specify  functions  to  be  included  or
       excluded.   These  options  can	be  specified multiple times, with different symspecs, to
       include or exclude sets of symbols.

       Specifying any of these options overrides the default (-p -q), which prints a flat profile
       and call graph analysis for all functions.

       "-A[symspec]"
       "--annotated-source[=symspec]"
	   The -A option causes "gprof" to print annotated source code.  If symspec is specified,
	   print output only for matching symbols.

       "-b"
       "--brief"
	   If the -b option is given, "gprof" doesn't  print  the  verbose  blurbs  that  try  to
	   explain  the meaning of all of the fields in the tables.  This is useful if you intend
	   to print out the output, or are tired of seeing the blurbs.

       "-C[symspec]"
       "--exec-counts[=symspec]"
	   The -C option causes "gprof" to print a tally of functions and  the	number	of  times
	   each was called.  If symspec is specified, print tally only for matching symbols.

	   If the profile data file contains basic-block count records, specifying the -l option,
	   along with -C, will cause basic-block execution counts to be tallied and displayed.

       "-i"
       "--file-info"
	   The -i option causes "gprof" to display summary information	about  the  profile  data
	   file(s)  and  then  exit.   The number of histogram, call graph, and basic-block count
	   records is displayed.

       "-I dirs"
       "--directory-path=dirs"
	   The -I option specifies a list of search directories in which to  find  source  files.
	   Environment	variable  GPROF_PATH  can  also be used to convey this information.  Used
	   mostly for annotated source output.

       "-J[symspec]"
       "--no-annotated-source[=symspec]"
	   The -J option causes "gprof" not to print annotated source code.  If symspec is speci-
	   fied, "gprof" prints annotated source, but excludes matching symbols.

       "-L"
       "--print-path"
	   Normally,  source  filenames  are  printed with the path component suppressed.  The -L
	   option causes "gprof" to print the full pathname of source filenames, which is  deter-
	   mined  from	symbolic  debugging  information in the image file and is relative to the
	   directory in which the compiler was invoked.

       "-p[symspec]"
       "--flat-profile[=symspec]"
	   The -p option causes "gprof" to print a flat profile.  If symspec is specified,  print
	   flat profile only for matching symbols.

       "-P[symspec]"
       "--no-flat-profile[=symspec]"
	   The -P option causes "gprof" to suppress printing a flat profile.  If symspec is spec-
	   ified, "gprof" prints a flat profile, but excludes matching symbols.

       "-q[symspec]"
       "--graph[=symspec]"
	   The -q option causes "gprof" to print the call graph analysis.  If symspec  is  speci-
	   fied, print call graph only for matching symbols and their children.

       "-Q[symspec]"
       "--no-graph[=symspec]"
	   The -Q option causes "gprof" to suppress printing the call graph.  If symspec is spec-
	   ified, "gprof" prints a call graph, but excludes matching symbols.

       "-y"
       "--separate-files"
	   This option affects annotated source output only.  Normally, "gprof" prints	annotated
	   source  files to standard-output.  If this option is specified, annotated source for a
	   file named path/filename is generated in the file  filename-ann.   If  the  underlying
	   filesystem  would  truncate	filename-ann so that it overwrites the original filename,
	   "gprof" generates annotated source in the file filename.ann instead (if  the  original
	   file name has an extension, that extension is replaced with .ann).

       "-Z[symspec]"
       "--no-exec-counts[=symspec]"
	   The -Z option causes "gprof" not to print a tally of functions and the number of times
	   each was called.  If symspec is specified, print tally, but exclude matching symbols.

       "--function-ordering"
	   The --function-ordering option causes "gprof" to print a suggested  function  ordering
	   for	the  program based on profiling data.  This option suggests an ordering which may
	   improve paging, tlb and cache behavior for the program on systems which support  arbi-
	   trary ordering of functions in an executable.

	   The	exact details of how to force the linker to place functions in a particular order
	   is system dependent and out of the scope of this manual.

       "--file-ordering map_file"
	   The --file-ordering option causes "gprof" to print a suggested .o link  line  ordering
	   for	the  program based on profiling data.  This option suggests an ordering which may
	   improve paging, tlb and cache behavior for the program on systems which do not support
	   arbitrary ordering of functions in an executable.

	   Use of the -a argument is highly recommended with this option.

	   The	map_file  argument is a pathname to a file which provides function name to object
	   file mappings.  The format of the file is similar to the output of the program "nm".

		   c-parse.o:00000000 T yyparse
		   c-parse.o:00000004 C yyerrflag
		   c-lang.o:00000000 T maybe_objc_method_name
		   c-lang.o:00000000 T print_lang_statistics
		   c-lang.o:00000000 T recognize_objc_keyword
		   c-decl.o:00000000 T print_lang_identifier
		   c-decl.o:00000000 T print_lang_type
		   ...

	   To  create  a  map_file  with  GNU  "nm",  type  a  command	like  "nm   --extern-only
	   --defined-only -v --print-file-name program-name".

       "-T"
       "--traditional"
	   The -T option causes "gprof" to print its output in ``traditional'' BSD style.

       "-w width"
       "--width=width"
	   Sets  width	of output lines to width.  Currently only used when printing the function
	   index at the bottom of the call graph.

       "-x"
       "--all-lines"
	   This option affects annotated source output only.  By default, only the lines  at  the
	   beginning  of a basic-block are annotated.  If this option is specified, every line in
	   a basic-block is annotated by repeating the	annotation  for  the  first  line.   This
	   behavior is similar to "tcov"'s -a.

       "--demangle[=style]"
       "--no-demangle"
	   These  options control whether C++ symbol names should be demangled when printing out-
	   put.  The default is to demangle symbols.  The "--no-demangle" option may be  used  to
	   turn off demangling. Different compilers have different mangling styles.  The optional
	   demangling style argument can be used to choose an appropriate  demangling  style  for
	   your compiler.

       Analysis Options

       "-a"
       "--no-static"
	   The -a option causes "gprof" to suppress the printing of statically declared (private)
	   functions.  (These are functions whose names are not listed as global, and  which  are
	   not	visible  outside the file/function/block where they were defined.)  Time spent in
	   these functions, calls to/from them, etc, will all be attributed to the function  that
	   was	loaded	directly  before it in the executable file.  This option affects both the
	   flat profile and the call graph.

       "-c"
       "--static-call-graph"
	   The -c option causes the call graph of the program to  be  augmented  by  a	heuristic
	   which  examines the text space of the object file and identifies function calls in the
	   binary machine code.  Since normal call graph records are only  generated  when  func-
	   tions  are  entered,  this option identifies children that could have been called, but
	   never were.	Calls to functions that were not compiled with profiling enabled are also
	   identified,	but  only if symbol table entries are present for them.  Calls to dynamic
	   library routines are typically not found by this option.  Parents or children  identi-
	   fied via this heuristic are indicated in the call graph with call counts of 0.

       "-D"
       "--ignore-non-functions"
	   The	-D  option  causes "gprof" to ignore symbols which are not known to be functions.
	   This option will give more accurate profile data on	systems  where	it  is	supported
	   (Solaris and HPUX for example).

       "-k from/to"
	   The	-k option allows you to delete from the call graph any arcs from symbols matching
	   symspec from to those matching symspec to.

       "-l"
       "--line"
	   The -l option enables line-by-line  profiling,  which  causes  histogram  hits  to  be
	   charged  to	individual  source  code lines, instead of functions.  If the program was
	   compiled with basic-block counting enabled, this option will also  identify	how  many
	   times  each	line of code was executed.  While line-by-line profiling can help isolate
	   where in a large function a program	is  spending  its  time,  it  also  significantly
	   increases the running time of "gprof", and magnifies statistical inaccuracies.

       "-m num"
       "--min-count=num"
	   This  option affects execution count output only.  Symbols that are executed less than
	   num times are suppressed.

       "-n[symspec]"
       "--time[=symspec]"
	   The -n option causes "gprof", in its call graph analysis, to only propagate times  for
	   symbols matching symspec.

       "-N[symspec]"
       "--no-time[=symspec]"
	   The	-n  option causes "gprof", in its call graph analysis, not to propagate times for
	   symbols matching symspec.

       "-z"
       "--display-unused-functions"
	   If you give the -z option, "gprof" will mention all functions  in  the  flat  profile,
	   even those that were never called, and that had no time spent in them.  This is useful
	   in conjunction with the -c option for discovering which routines were never called.

       Miscellaneous Options

       "-d[num]"
       "--debug[=num]"
	   The -d num option specifies debugging options.  If num is not  specified,  enable  all
	   debugging.

       "-Oname"
       "--file-format=name"
	   Selects  the  format  of  the  profile  data  files.  Recognized formats are auto (the
	   default), bsd, 4.4bsd, magic, and prof (not yet supported).

       "-s"
       "--sum"
	   The -s option causes "gprof" to summarize the information in the profile data files it
	   read  in,  and  write  out a profile data file called gmon.sum, which contains all the
	   information from the profile data files that "gprof" read in.  The file  gmon.sum  may
	   be  one  of	the specified input files; the effect of this is to merge the data in the
	   other input files into gmon.sum.

	   Eventually you can run "gprof" again without -s to analyze the cumulative data in  the
	   file gmon.sum.

       "-v"
       "--version"
	   The -v flag causes "gprof" to print the current version number, and then exit.

       Deprecated Options

	   These options have been replaced with newer versions that use symspecs.

       "-e function_name"
	   The -e function option tells "gprof" to not print information about the function func-
	   tion_name (and its children...) in the call graph.  The function will still be  listed
	   as  a  child of any functions that call it, but its index number will be shown as [not
	   printed].  More than one -e option may be given; only one function_name may	be  indi-
	   cated with each -e option.

       "-E function_name"
	   The	"-E  function"	option works like the "-e" option, but time spent in the function
	   (and children who were not called from anywhere else), will not be used to compute the
	   percentages-of-time	for  the  call graph.  More than one -E option may be given; only
	   one function_name may be indicated with each -E option.

       "-f function_name"
	   The -f function option causes "gprof" to limit the call graph to  the  function  func-
	   tion_name  and  its	children (and their children...).  More than one -f option may be
	   given; only one function_name may be indicated with each -f option.

       "-F function_name"
	   The -F function option works like the "-f" option, but only time spent in the function
	   and its children (and their children...) will be used to determine total-time and per-
	   centages-of-time for the call graph.  More than one -F option may be given;	only  one
	   function_name  may  be  indicated with each -F option.  The -F option overrides the -E
	   option.

FILES
       "a.out"
	   the namelist and text space.

       "gmon.out"
	   dynamic call graph and profile.

       "gmon.sum"
	   summarized dynamic call graph and profile.

BUGS
       The granularity of the sampling is shown, but remains statistical at best.  We assume that
       the time for each execution of a function can be expressed by the total time for the func-
       tion divided by the number of times the function is  called.   Thus  the  time  propagated
       along the call graph arcs to the function's parents is directly proportional to the number
       of times that arc is traversed.

       Parents that are not themselves profiled will have the time  of	their  profiled  children
       propagated  to  them,  but  they will appear to be spontaneously invoked in the call graph
       listing, and will not have their time propagated  further.   Similarly,	signal	catchers,
       even  though  profiled, will appear to be spontaneous (although for more obscure reasons).
       Any profiled children of signal catchers should	have  their  times  propagated	properly,
       unless  the  signal  catcher was invoked during the execution of the profiling routine, in
       which case all is lost.

       The profiled program must call "exit"(2) or return normally for the profiling  information
       to be saved in the gmon.out file.

SEE ALSO
       monitor(3), profil(2), cc(1), prof(1), and the Info entry for gprof.

       ``An  Execution	Profiler  for  Modular Programs'', by S. Graham, P. Kessler, M. McKusick;
       Software - Practice and Experience, Vol. 13, pp. 671-685, 1983.

       ``gprof: A Call Graph Execution Profiler'', by S. Graham, P. Kessler,  M.  McKusick;  Pro-
       ceedings  of the SIGPLAN '82 Symposium on Compiler Construction, SIGPLAN Notices, Vol. 17,
       No  6, pp. 120-126, June 1982.

COPYRIGHT
       Copyright (C) 1988, 92, 97, 98, 99, 2000, 2001 Free Software Foundation, Inc.

       Permission is granted to copy, distribute and/or modify this document under the	terms  of
       the GNU Free Documentation License, Version 1.1 or any later version published by the Free
       Software Foundation; with no Invariant Sections, with no Front-Cover Texts,  and  with  no
       Back-Cover  Texts.   A  copy  of the license is included in the section entitled "GNU Free
       Documentation License".

binutils-2.13.90.0.18			    2003-02-24					 GPROF(1)


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