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diff --git a/doc/gawk.texi b/doc/gawk.texi index 476c3717..d0832b5c 100644 --- a/doc/gawk.texi +++ b/doc/gawk.texi @@ -1031,6 +1031,7 @@ particular records in a file and perform operations upon them. * Unix Installation:: Installing @command{gawk} under various versions of Unix. * Quick Installation:: Compiling @command{gawk} under Unix. +* Compiling with MPFR:: Building with MPFR. * Shell Startup Files:: Shell convenience functions. * Additional Configuration Options:: Other compile-time options. * Configuration Philosophy:: How it's all supposed to work. @@ -1060,6 +1061,7 @@ particular records in a file and perform operations upon them. * Bugs:: Reporting Problems and Bugs. * Bug address:: Where to send reports to. * Usenet:: Where not to send reports to. +* Performance bugs:: What to do if you think there is a performance issue. * Maintainers:: Maintainers of non-*nix ports. * Other Versions:: Other freely available @command{awk} implementations. @@ -42186,6 +42188,10 @@ to configure @command{gawk} for your system yourself. @node Quick Installation @appendixsubsec Compiling @command{gawk} for Unix-Like Systems +@menu +* Compiling with MPFR:: Building with MPFR. +@end menu + The normal installation steps should work on all modern commercial Unix-derived systems, GNU/Linux, BSD-based systems, and the Cygwin environment for MS-Windows. @@ -42259,6 +42265,24 @@ is likely that you will be asked for your password, and you will have to have been set up previously as a user who is allowed to run the @command{sudo} command. + +@node Compiling with MPFR +@appendixsubsubsec Building With MPFR + +@cindex MPFR library, building with +Use of the MPFR library with @command{gawk} +is an optional feature: if you have the MPFR and GMP libraries already installed +when you configure and build @command{gawk}, +@command{gawk} automatically will be able to use them. + +You can install these libraries from source code by fetching them +from the GNU distribution site at @code{ftp.gnu.org}. + +Most modern systems provide package managers which save you the trouble +of building from source. They fetch and install the library header files +and binaries for you. You will need to research how to do this for +your particular system. + @node Shell Startup Files @appendixsubsec Shell Startup Files @@ -43055,6 +43079,7 @@ but we might well want to fix it. @menu * Bug address:: Where to send reports to. * Usenet:: Where not to send reports to. +* Performance bugs:: What to do if you think there is a performance issue. * Maintainers:: Maintainers of non-*nix ports. @end menu @@ -43164,6 +43189,88 @@ and run to another section of the playground. Then, if you like mixing metaphors, you can throw rocks from there." @end ignore +@node Performance bugs +@appendixsubsec What To Do If You Think There Is A Performance Issue + +@cindex performance, checking issues +@cindex profiling, compiling @command{gawk} for +If you think that @command{gawk} is too slow at doing a particular task, +you should investigate before sending in a bug report. Here are the steps +to follow: + +@enumerate 1 +@item +Run @command{gawk} with the @option{--profile} option (@pxref{Options}) +to see what your +program is doing. It may be that you have written it in an inefficient manner. +For example, you may be doing something for every record that could be done +just once, for every file. +(Use a @code{BEGINFILE} rule; @pxref{BEGINFILE/ENDFILE}.) +Or you may be doing something for every file that only needs to be done +once per run of the program. +(Use a @code{BEGIN} rule; @pxref{BEGIN/END}.) + +@item +If profiling at the @command{awk} level doesn't help, then you will +need to compile @command{gawk} itself for profiling at the C language level. + +To do that, start with the latest released version of +@command{gawk}. Unpack the source code in a new directory, and configure +it: + +@example +$ @kbd{tar -xpzvf gawk-X.Y.Z.tar.gz} +@print{} @dots{} @ii{Output ommited} +$ @kbd{cd gawk-X.Y.Z} +$ @kbd{./configure} +@print{} @dots{} @ii{Output ommited} +@end example + +@item +Edit the files @file{Makefile} and @file{support/Makefile}. +Change every instance of @option{-O2} or @option{-O} to @option{-pg}. +This causes @command{gawk} to be compiled for profiling. + +@item +Compile the program by running the @command{make} command: + +@example +@group +$ @kbd{make} +@print{} @dots{} @ii{Output ommited} +@end group +@end example + +@item +Run the freshly compiled @command{gawk} on a @emph{real} program, +using @emph{real} data. Using an artificial program to try to time one +particular feature of @command{gawk} is useless; real @command{awk} programs +generally spend most of their time doing I/O, not computing. If you want to prove +that something is slow, it @emph{must} be done using a real program and real data. + +Use a data file that is large enough for the statistical profiling to measure +where @command{gawk} spends its time. It should be at least 100 megabytes in size. + +@item +When done, you should have a file in the current directory named @file{gmon.out}. +Run the command @samp{gprof gawk gmon.out > gprof.out}. + +@item +Submit a bug report explaining what you think is slow. Include the @file{gprof.out} +file with it. + +Preferably, you should also submit the program and the data, or else indicate where to +get the data if the file is large. + +@item +If you have not submitted your program and data, be prepared to apply patches and +rerun the profiling in order to see if the patches were effective. + +@end enumerate + +If you are incapable or unwilling to do the steps listed above, then you will +just have to live with @command{gawk} as it is. + @node Maintainers @appendixsubsec Reporting Problems with Non-Unix Ports |