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GPROF !!!GPROF NAME SYNOPSIS DESCRIPTION OPTIONS FILES BUGS SEE ALSO COPYRIGHT ---- !!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 versions 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. If you use gcc 2.95.x or 3.0 to compile your binaries, you may need to add the __-fprofile-arcs__ to the compile command line in order for the call graphs to be properly stored in gmon.out. Gprof calculates the amount of time spent in each routine. Next, these times are propagated 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 eliminate function calls that use a lot of time. The ''annotated source'' listing is a copy of the program's source code, labeled with the number 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 specified, 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 determined 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 specified, 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 specified, 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 specified, 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 arbitrary 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 output. 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 functions 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 identified 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 ''function_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 indicated 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 ''function_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 percentages-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 function 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; Proceedings 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''. ----
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gprof(1)
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Man1g
profil(3)
Profiling
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