NAME
libppl_c - the C interface of the Parma Polyhedra Library
SYNOPSIS
#include <ppl_c.h>
cc file.c -lppl
DESCRIPTION
This is a short overview on how to use the Parma Polyhedra Library
(PPL) in your C programs on Unix-like operating systems. Note that the
PPL has interfaces also for C++, Java, OCaml and a number of Prolog
systems: look elsewhere for documentation on those. Note also that the
present document does not describe the library functionality, its
classes or its methods and functions: see The Parma Polyhedra Library
User's Manual (version 0.10.2) and The Parma Polyhedra Library C
Language Interface User's Manual (version 0.10.2) for this kind of
information.
INCLUDING THE HEADER FILE
The C interface of the PPL has only one header file, named ppl_c.h. So
your program should contain a directive of the form
#include <ppl_c.h>
Of course, you must make sure you installed the PPL in a place where
the compiler can find it, either by itself or with the help of a
suitable -Idir command line option (see the file INSTALL for
information on how to configure the library so that it is installed in
the place of your choice).
INITIALIZING AND FINALIZING THE LIBRARY
In order to initialize the Parma Polyhedra Library you must call the
function
int ppl_initialize(void)
before using any of its functionalities. It is also a good norm to
call the function
int ppl_finalize(void)
when you are done with the library.
USING THE LIBRARY
Keeping in mind that there is no substitute for a careful reading of
The Parma Polyhedra Library User's Manual (version 0.10.2) and The
Parma Polyhedra Library C Language Interface User's Manual (version
0.10.2) you can find examples of use in the directories
interfaces/C/tests and demos/ppl_lpsol of the source distribution.
LINKING WITH THE LIBRARY
Linking with the C interface of the Parma Polyhedra Library is best
done using the C compiler itself: usually, specifying the -lppl_c
command line option is enough. In fact, if you use a shared version of
the library, this automatically records the dependency from the PPL
core and the GMP libraries, something that the linker ought to deal
with gracefully. Otherwise you will have to add -lppl -lgmpxx -lgmp to
the command line. Things are more complex if you installed the PPL
into some nonstandard place. In this case you will have to use the
-Ldir option and, if you use a shared version of the library, possible
take further steps: see the documentation of your system for more
information on this subject (the Program Library HOWTO is especially
valuable for GNU/Linux users).
RETURN VALUES
All the PPL C interface functions return an int: a negative value means
that an error occurred. See The Parma Polyhedra Library C Language
Interface User's Manual (version 0.10.2) for the error codes.
IMPLEMENTING MEMORY-GUARDED COMPUTATIONS
One of the interesting features of the Parma Polyhedra Library is the
possibility to implement memory-guarded computations. The idea is that
you can limit the amount of virtual memory available to the process,
launch a PPL computation, and be ready to be returned a
PPL_ERROR_OUT_OF_MEMORY error code. You can then take the appropriate
corrective measures (e.g., simplify the polyhedra and/or select less
precise though less complex algorithms), and restart the computation.
In order to do that, you should define alternative memory allocation
functions for GMP that throw std::bad_alloc upon memory exhaustion.
See libppl(3) for instructions on how to do that.
USING NATIVE FLOATING POINT NUMBERS
At initialization time, the Parma Polyhedra Library sets the FPU
rounding mode in a way that allows its floating-point-based
computations to be conservative (i.e., possibly approximated but
correct) and reasonably efficient. In case your application itself
uses native floating point numbers and relies on a particular rounding
mode (if you are in doubt, assume that it does rely on round-to-nearest
to be in effect), you should use the function
int ppl_restore_pre_PPL_rounding()
after the PPL initialization and before using native floating point
numbers in the application. If your application does not use any
floating-point-based PPL abstraction, no further measure should be
taken. Otherwise, it is imperative to call the function
int ppl_set_rounding_for_PPL()
before invoking any PPL interface related to such abstractions.
SEE ALSO
ppl-config(1)
libppl(3)
Roberto Bagnara, Patricia M. Hill, and Enea Zaffanella. The Parma
Polyhedra Library User's Manual (version 0.10.2), available (in several
formats) at http://www.cs.unipr.it/ppl/ .
Roberto Bagnara, Patricia M. Hill, and Enea Zaffanella. The Parma
Polyhedra Library C Language Interface User's Manual (version 0.10.2),
available (in several formats) at http://www.cs.unipr.it/ppl/ .
David A. Wheeler. Program Library HOWTO, available (in several
formats) at http://www.dwheeler.com/program-library/ .
AVAILABILITY
The latest version of the Parma Polyhedra Library and all the
documentation is available at http://www.cs.unipr.it/ppl/ .
AUTHOR
See the file CREDITS in the source distribution or use the command
ppl-config --credits for a list of contributors.
REPORTING BUGS
Report bugs to <ppl-devel@cs.unipr.it>.
COPYRIGHT
Copyright (C) 2001-2009 Roberto Bagnara <bagnara@cs.unipr.it>
This is free software; see the file COPYING in the source distribution
or use the command ppl-config --copying to obtain the copying
conditions. There is NO warranty; not even for MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.