VAX83D.TIMING]AAAREADME.TXT

                              SAMPLING SOFTWARE

        This directory contains SAMPLE.OLB (the CP timing library) and
   PROBE.EXE (the program that automatically places calls to SAMPLE
   routines into a FORTRAN program).  As a precaution, the FORTRAN sources
   for SAMPLE and PROBE are included.  The following instructions assume
   that these files are copyied to the directory [misc], and corresponding
   symbols are defined:

             SLIB:==SYS$USR:[MISC]SAMPLE/L
             PROBE:==$SYS$USR:[MISC]PROBE

        The program LLFORM.FOR is timed in the following example session.
   User input is shown in upper case.

   $ PROBE
   file name, unit (a9,a8): LLFORM,59
         (program .main)
         subroutine nxtchr
      1   0   1   0
   $ FOR LLFORM
   $ LINK LLFORM,'SLIB'
   $ RUN LLFORM
   estimated original execution time       0.17
   interval   samples   %    count

   .main             8 46          1
   nxtchr           20 54        134
   $

        PROBE is told that the input file is LLFORM.FOR and that the
   timing summary is to be written to unit 59, which is SYS$OUTPUT in this
   case.  The next two lines report the code blocks found (the first block
   is a program with no PROGRAM statement), and the last line summarizes:
   one program, no functions, one subroutine, and no ENTRY statements.

        The timing summary, displayed at the end of LLFORM's execution,
   shows the estimated CP time (in seconds).  For each program unit, the
   CP time charged (in 10-ms ticks) and estimated percent CP time used are
   reported, together with the number of invocations.

                                    -2-

                              THE SAMPLE LIBRARY

        The following description is given for those who may wish to use
   the SAMPLE library directly.

        The routines below use the common block /SAMPBK/, whose length, in
   longwords, must be at least five times the number of sections to be
   timed.

        SAMPIN(mx) must be called to initialize storage.  The argument is
   an upper limit on the number of sections to be timed.

        SAMPON(name) is called to indicate nesting of a new section in the
   current one; SAMPON would be called, for example, at the beginning of a
   subroutine.  The argument is the (logical*8) name of the new section.

        SAMPOF is called to indicate the end of a section; SAMPOF would be
   called, for example, before a RETURN statement.  There is no argument.

        SAMPSW(name) is called to indicate the switch from one interval to
   another; for example, at the end of initialization.  The argument is
   the (logical*8) name of the new section.

        SAMPDI(lu) is called to terminate timing and display the results.
   The argument is the integer logical unit number to which the data will
   be written.