Module: ppl/ppl Branch: floating_point Commit: c85b888fd3f403f17df903db4016411d2c199196 URL: http://www.cs.unipr.it/git/gitweb.cgi?p=ppl/ppl.git;a=commit;h=c85b888fd3f40...
Author: Fabio Bossi bossi@cs.unipr.it Date: Wed Jul 21 13:35:29 2010 +0200
Implemented Linear_Form::overflows and Linear_Form::relative_error.
---
src/Linear_Form.defs.hh | 7 ++++ src/Linear_Form.inlines.hh | 16 +++++++++ src/Linear_Form.templates.hh | 70 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 93 insertions(+), 0 deletions(-)
diff --git a/src/Linear_Form.defs.hh b/src/Linear_Form.defs.hh index c58fbbc..c80b605 100644 --- a/src/Linear_Form.defs.hh +++ b/src/Linear_Form.defs.hh @@ -322,6 +322,13 @@ public: //! Swaps \p *this with \p y. void swap(Linear_Form& y);
+ // Floating point analysis related methods. + + bool overflows() const; + + void relative_error(Floating_Point_Format analyzed_format, + Linear_Form& result) const; + private: //! The generic coefficient equal to the singleton zero. static C zero; diff --git a/src/Linear_Form.inlines.hh b/src/Linear_Form.inlines.hh index 60f03de..43ca4e6 100644 --- a/src/Linear_Form.inlines.hh +++ b/src/Linear_Form.inlines.hh @@ -204,6 +204,22 @@ Linear_Form<C>::ascii_load(std::istream& s) { return false; }
+// Floating point analysis related methods. +template <typename C> +inline bool +Linear_Form<C>::overflows() const { + if (!inhomogeneous_term().is_bounded()) + return true; + + dimension_type dimension = space_dimension(); + for (dimension_type i = 0; i < dimension; ++i) { + if (!coefficient(Variable(i)).is_bounded()) + return true; + } + + return false; +} + } // namespace Parma_Polyhedra_Library
diff --git a/src/Linear_Form.templates.hh b/src/Linear_Form.templates.hh index 9c39fc3..83e7c1f 100644 --- a/src/Linear_Form.templates.hh +++ b/src/Linear_Form.templates.hh @@ -375,6 +375,76 @@ Linear_Form<C>::OK() const { return true; }
+// Floating point analysis related methods. +template <typename C> +void +Linear_Form<C>::relative_error( + const Floating_Point_Format analyzed_format, + Linear_Form& result) const { + typedef typename C::boundary_type analyzer_format; + + // Get the necessary information on the analyzed's format. + unsigned int f_base; + unsigned int f_mantissa_bits; + switch (analyzed_format) { + case IEEE754_HALF: + f_base = float_ieee754_half::BASE; + f_mantissa_bits = float_ieee754_half::MANTISSA_BITS; + break; + case IEEE754_SINGLE: + f_base = float_ieee754_single::BASE; + f_mantissa_bits = float_ieee754_single::MANTISSA_BITS; + break; + case IEEE754_DOUBLE: + f_base = float_ieee754_double::BASE; + f_mantissa_bits = float_ieee754_double::MANTISSA_BITS; + break; + case IBM_SINGLE: + f_base = float_ibm_single::BASE; + f_mantissa_bits = float_ibm_single::MANTISSA_BITS; + break; + case IEEE754_QUAD: + f_base = float_ieee754_quad::BASE; + f_mantissa_bits = float_ieee754_quad::MANTISSA_BITS; + break; + case INTEL_DOUBLE_EXTENDED: + f_base = float_intel_double_extended::BASE; + f_mantissa_bits = float_intel_double_extended::MANTISSA_BITS; + break; + } + + C error_propagator; + analyzer_format lb = -pow(f_base, + -static_cast<analyzer_format>(f_mantissa_bits)); + error_propagator.build(i_constraint(GREATER_OR_EQUAL, lb), + i_constraint(LESS_OR_EQUAL, -lb)); + + // Handle the inhomogeneous term. + const C* current_term = &inhomogeneous_term(); + assert(current_term->is_bounded()); + + C current_multiplier(std::max(std::abs(current_term->lower()), + std::abs(current_term->upper()))); + Linear_Form current_result_term(current_multiplier); + current_result_term *= error_propagator; + result = Linear_Form(current_result_term); + + // Handle the other terms. + dimension_type dimension = space_dimension(); + for (dimension_type i = 0; i < dimension; ++i) { + current_term = &coefficient(Variable(i)); + assert(current_term->is_bounded()); + current_multiplier = C(std::max(std::abs(current_term->lower()), + std::abs(current_term->upper()))); + current_result_term = Linear_Form(Variable(i)); + current_result_term *= current_multiplier; + current_result_term *= error_propagator; + result += current_result_term; + } + + return; +} + /*! \relates Parma_Polyhedra_Library::Linear_Form */ template <typename C> std::ostream&