Module: ppl/ppl Branch: master Commit: e67bf301791f0ccf339effaec8acf17ece69b3a9 URL: http://www.cs.unipr.it/git/gitweb.cgi?p=ppl/ppl.git;a=commit;h=e67bf301791f0... Author: Enea Zaffanella <zaffanella@cs.unipr.it> Date: Thu Jun 28 11:10:36 2012 +0200 Added a section on README.configure describing dense/sparse row choices. --- README.configure | 62 ++++++++++++++++++++++++++++++++++++++++++----------- 1 files changed, 49 insertions(+), 13 deletions(-) diff --git a/README.configure b/README.configure index 24dfea5..7181c84 100644 --- a/README.configure +++ b/README.configure @@ -9,15 +9,16 @@ Configuration of the Parma Polyhedra Library Contents -------- -1. The Standard Thing (configure, make, make install) -2. Using the Right Version of GMP -3. Using the Right C and C++ Compilers -4. Enabling the Use of Alternative Coefficient Types -5. Configuring the Language Interfaces -6. Configuring for Optimized Performance -7. Configuring for Debugging -8. Programs that Come with the Library -9. Using the Git Sources + 1. The Standard Thing (configure, make, make install) + 2. Using the Right Version of GMP + 3. Using the Right C and C++ Compilers + 4. Enabling the Use of Alternative Coefficient Types + 5. Configuring the Language Interfaces + 6. Configuring for Optimized Performance + 7. Advanced Performance Tuning + 8. Configuring for Debugging + 9. Programs that Come with the Library +10. Using the Git Sources 1. The Standard Thing (configure, make, make install) @@ -373,7 +374,42 @@ in decreasing order of optimization, `--enable-optimization=mild' configure options that are useful for debugging purposes. -7. Configuring for Debugging +7. Advanced Performance Tuning +------------------------------ + +Starting from version 1.0, the library fully supports two different +representations for rows (i.e., sequences of coefficients): + + - the "dense" representation is an array-like representation tailored + to sequences having most of their coefficients different from zero; + + - the "sparse" representation saves memory space (as well as CPU + cycles) when most of the coefficients in the sequence are zero. + +A generic interface allows for a seamless interaction between the +dense and the sparse row representation. Most library entities (linear +expressions, constraints, generators, congruences, and their systems) +can be built using either representation, specified as a constructor's +argument. Reasonable default values for the row representation are +provided for each library entity, automatically leading to significant +memory space savings even in old client/library code, e.g., when +dealing with constraint systems describing weakly relational +abstractions such as boxes and octagonal shapes. + +If desired, these default values can be customized to user's needs by +changing just a few lines of library code. For instance, the +constraint systems stored inside C_Polyhedron and NNC_Polyhedron +objects can be made to use the sparse representation by just changing +the following line in Polyhedron.defs.hh: + + static const Representation default_con_sys_repr = DENSE; + +to become + + static const Representation default_con_sys_repr = SPARSE; + + +8. Configuring for Debugging ---------------------------- By default, the PPL is configured with debugging information enabled. @@ -411,7 +447,7 @@ In order to assess the coverage of the PPL test suite, the code to be used in conjunction with the `gcov' coverage testing tool. -8. Programs that Come with the Library +9. Programs that Come with the Library -------------------------------------- The PPL is shipped with two programs that are interesting per se, and @@ -439,8 +475,8 @@ In exchange, you will give up an important opportunity to discover whether the version of PPL you have built has been miscompiled. -9. Using the Git Sources ------------------------- +10. Using the Git Sources +------------------------- If you use the Git sources, then you need recent versions of Autoconf Automake and Libtool installed. After a `git clone' or `git pull'