Module: ppl/ppl Branch: floating_point Commit: 67bec8827d8c0ce1db133ae9f20dd36830ffffe8 URL: http://www.cs.unipr.it/git/gitweb.cgi?p=ppl/ppl.git;a=commit;h=67bec8827d8c0...

Author: Fabio Bossi bossi@cs.unipr.it Date: Wed Sep 2 14:41:51 2009 +0200

Added a first implementation of the relative_error and intervalize methods. Fixed a mistake with loops over linear forms. Several style improvements.

---

src/Constant_Floating_Point_Expression.inlines.hh | 3 +- src/Floating_Point_Expression.defs.hh | 5 +- src/Floating_Point_Expression.inlines.hh | 6 +- src/Floating_Point_Expression.templates.hh | 87 +++++++++++++++++++++ src/Makefile.am | 1 + 5 files changed, 95 insertions(+), 7 deletions(-)

diff --git a/src/Constant_Floating_Point_Expression.inlines.hh b/src/Constant_Floating_Point_Expression.inlines.hh index d1edd38..1fa15fb 100644 --- a/src/Constant_Floating_Point_Expression.inlines.hh +++ b/src/Constant_Floating_Point_Expression.inlines.hh @@ -34,6 +34,7 @@ Constant_Floating_Point_Expression(const boundary_type lb, const boundary_type ub) : value(lb) { assert(lb <= ub); + // FIXME: this may be incorrect for some policies. value.join_assign(ub); }

@@ -54,10 +55,8 @@ inline typename Constant_Floating_Point_Expression<FP_Interval_Type, FP_Format>::FP_Linear_Form Constant_Floating_Point_Expression<FP_Interval_Type, FP_Format> ::linearize(const FP_Interval_Abstract_Store& store) const { - FP_Linear_Form result = FP_Linear_Form(value); return result; - }

} // namespace Parma_Polyhedra_Library diff --git a/src/Floating_Point_Expression.defs.hh b/src/Floating_Point_Expression.defs.hh index 0d4e854..e712fd4 100644 --- a/src/Floating_Point_Expression.defs.hh +++ b/src/Floating_Point_Expression.defs.hh @@ -71,11 +71,11 @@ public:

static bool overflows(const FP_Linear_Form& lf);

+ static FP_Linear_Form relative_error(const FP_Linear_Form&); + static FP_Linear_Form intervalize(const FP_Linear_Form&, const FP_Interval_Abstract_Store& store);

- static FP_Linear_Form relative_error(const FP_Linear_Form&); - }; // class Floating_Point_Expression

// Initialize static members of the class. @@ -90,5 +90,6 @@ Floating_Point_Expression<FP_Interval_Type, FP_Format>::absolute_error = } // namespace Parma_Polyhedra_Library

#include "Floating_Point_Expression.inlines.hh" +#include "Floating_Point_Expression.templates.hh"

#endif // !defined(PPL_Floating_Point_Expression_defs_hh) diff --git a/src/Floating_Point_Expression.inlines.hh b/src/Floating_Point_Expression.inlines.hh index 20f37e9..3e38dd2 100644 --- a/src/Floating_Point_Expression.inlines.hh +++ b/src/Floating_Point_Expression.inlines.hh @@ -36,12 +36,12 @@ template <typename FP_Interval_Type, typename FP_Format> inline bool Floating_Point_Expression<FP_Interval_Type, FP_Format> ::overflows(const FP_Linear_Form& lf) { - if(!lf.inhomogeneous_term().is_bounded()) + if (!lf.inhomogeneous_term().is_bounded()) return true;

dimension_type dimension = lf.space_dimension(); - for(dimension_type i = 0; i <= dimension; ++i) { - if(!lf.coefficient(Variable(i)).is_bounded()) + for (dimension_type i = 0; i < dimension; ++i) { + if (!lf.coefficient(Variable(i)).is_bounded()) return true; }

diff --git a/src/Floating_Point_Expression.templates.hh b/src/Floating_Point_Expression.templates.hh new file mode 100644 index 0000000..3ea080a --- /dev/null +++ b/src/Floating_Point_Expression.templates.hh @@ -0,0 +1,87 @@ +/* Floating_Point_Expression class implementation: + non-inline template functions. + Copyright (C) 2001-2009 Roberto Bagnara bagnara@cs.unipr.it + +This file is part of the Parma Polyhedra Library (PPL). + +The PPL is free software; you can redistribute it and/or modify it +under the terms of the GNU General Public License as published by the +Free Software Foundation; either version 3 of the License, or (at your +option) any later version. + +The PPL is distributed in the hope that it will be useful, but WITHOUT +ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received a copy of the GNU General Public License +along with this program; if not, write to the Free Software Foundation, +Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111-1307, USA. + +For the most up-to-date information see the Parma Polyhedra Library +site: http://www.cs.unipr.it/ppl/ . */ + +#ifndef PPL_Floating_Point_Expression_templates_hh +#define PPL_Floating_Point_Expression_templates_hh 1 + +#include "Floating_Point_Expression.defs.hh" +#include <cmath> + +namespace Parma_Polyhedra_Library { + +template<typename FP_Interval_Type, typename FP_Format> +typename Floating_Point_Expression<FP_Interval_Type, FP_Format>::FP_Linear_Form +Floating_Point_Expression<FP_Interval_Type, FP_Format> +::relative_error(const FP_Linear_Form& lf) { + /* FIXME: here we assume that boundary_type can represent + (2)^(-FP_Format::fraction_bits) precisely. */ + FP_Interval_Type error_propagator(pow(-2, -FP_Format::fraction_bits)); + // FIXME: this may be incorrect for some policies. + error_propagator.join_assign(FP_Interval_Type( + pow(2, -FP_Format::fraction_bits))); + + // Handle the inhomogeneous term. + FP_Interval_Type current_term = lf.inhomogeneous_term(); + boundary_type current_multiplier = std::max(abs(current_term.lower()), + abs(current_term.upper())); + FP_Linear_Form current_result_term = FP_Linear_Form(current_multiplier * + error_propagator); + FP_Linear_Form result = FP_Linear_Form(current_result_term); + + // Handle the other terms. + dimension_type dimension = lf.space_dimension(); + for (dimension_type i = 0; i < dimension; ++i) { + current_term = lf.coefficient(Variable(i)); + current_multiplier = std::max(abs(current_term.lower()), + abs(current_term.upper())); + current_result_term = FP_Linear_Form(Variable(i)) * current_multiplier * + error_propagator; + result += current_result_term; + } + + return result; +} + +template<typename FP_Interval_Type, typename FP_Format> +typename Floating_Point_Expression<FP_Interval_Type, FP_Format>::FP_Linear_Form +Floating_Point_Expression<FP_Interval_Type, FP_Format> +::intervalize(const FP_Linear_Form& lf, + const FP_Interval_Abstract_Store& store) { + FP_Interval_Type resulting_interval = lf.inhomogeneous_term(); + dimension_type dimension = lf.space_dimension(); + for (dimension_type i = 0; i < dimension; ++i) { + typename FP_Interval_Abstract_Store::const_iterator + next_variable_value = store.find(i); + if (next_variable_value != store.end()) { + FP_Interval_Type current_coefficient = lf.coefficient(Variable(i)); + resulting_interval += current_coefficient * (*next_variable_value); + } + } + + FP_Linear_Form result = FP_Interval_Type(resulting_interval); + return result; +} + +} // namespace Parma_Polyhedra_Library + +#endif // !defined(PPL_Floating_Point_Expression_templates_hh) diff --git a/src/Makefile.am b/src/Makefile.am index 89c9d1e..9fd2582 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -344,6 +344,7 @@ wrap_string.hh \ Floating_Point_Expression.types.hh \ Floating_Point_Expression.defs.hh \ Floating_Point_Expression.inlines.hh \ +Floating_Point_Expression.templates.hh \ Constant_Floating_Point_Expression.types.hh \ Constant_Floating_Point_Expression.defs.hh \ Constant_Floating_Point_Expression.inlines.hh \