[PPL-devel] [GIT] ppl/ppl(floating_point): Added a first implementation of the relative_error and intervalize
Fabio Bossi
bossi at cs.unipr.it
Wed Sep 2 14:45:41 CEST 2009
Module: ppl/ppl
Branch: floating_point
Commit: 67bec8827d8c0ce1db133ae9f20dd36830ffffe8
URL: http://www.cs.unipr.it/git/gitweb.cgi?p=ppl/ppl.git;a=commit;h=67bec8827d8c0ce1db133ae9f20dd36830ffffe8
Author: Fabio Bossi <bossi at 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 at 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 \
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