Module: ppl/ppl Branch: floating_point Commit: 1c4c91c248d74dc5abb8c5b45507dfe9665ff6b5 URL: http://www.cs.unipr.it/git/gitweb.cgi?p=ppl/ppl.git;a=commit;h=1c4c91c248d74...

Author: Fabio Bossi bossi@cs.unipr.it Date: Sat Jul 24 12:39:51 2010 +0200

Added a skeleton for the new linearization function.

Also added an idea for the linearization of the unary negation expression.

---

src/linearize.hh | 160 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 160 insertions(+), 0 deletions(-)

diff --git a/src/linearize.hh b/src/linearize.hh new file mode 100644 index 0000000..6a39f03 --- /dev/null +++ b/src/linearize.hh @@ -0,0 +1,160 @@ +1/* Linearization function implementation. + Copyright (C) 2001-2010 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_linearize_hh +#define PPL_linearize_hh 1 + +#include "Concrete_Expression.defs.hh" +#include "Float.defs.hh" +#include "Linear_Form.defs.hh" +#include "Box.defs.hh" +#include <map> + +namespace Parma_Polyhedra_Library { + +template <typename Target, typename FP_Interval_Type> +static bool +bnot_linearize(const Unary_Operator<Target>& uop_expr, + const Box<FP_Interval_Type>& int_store, + const std::map<dimension_type, Linear_Form<FP_Interval_Type>>& lf_store, + Linear_Form<FP_Interval_Type>& result) { + typedef typename FP_Interval_Type::boundary_type analyzer_format; + typedef Linear_Form<FP_Interval_Type> FP_Linear_Form; + typedef Box<FP_Interval_Type> FP_Interval_Abstract_Store; + typedef std::map<dimension_type, FP_Linear_Form> FP_Linear_Form_Abstract_Store; + + if (!linearize(uop_expr.get_arg(), int_store, lf_store, result)) + return false; + + FP_Interval_Type int_r; + result.intervalize(int_store, int_r); + bool lb_is_positive = (!int_r.is_lower_boundary_infinity() && + int_r.lower() > 0); + bool ub_is_negative = (!int_r.is_upper_boundary_infinity() && + int_r.upper() < 0); + if (lb_is_positive || ub_is_negative) { + result = FP_Linear_Form(FP_Interval(0)); + return true; + } + else if (int_r.is_singleton()) { + // Here int_r is the singleton of 0. + // FIXME: Check if the negation of 0 MUST be 1. + result = FP_Linear_Form(FP_Interval(1)); + return true; + } + else + // Here int_r strictly contains 0. + return false; +} + +template <typename Target, typename FP_Interval_Type> +bool +linearize(const Concrete_Expression<Target>& expr, + const Box<FP_Interval_Type>& int_store, + const std::map<dimension_type, Linear_Form<FP_Interval_Type>>& lf_store, + Linear_Form<FP_Interval_Type>& result) { + typedef typename FP_Interval_Type::boundary_type analyzer_format; + typedef Linear_Form<FP_Interval_Type> FP_Linear_Form; + typedef Box<FP_Interval_Type> FP_Interval_Abstract_Store; + typedef std::map<dimension_type, FP_Linear_Form> FP_Linear_Form_Abstract_Store; + + // Check that analyzer_format is a floating point type. + PPL_COMPILE_TIME_CHECK(!std::numeric_limits<analyzer_format>::is_exact, + "linearize<Target, FP_Interval_Type>:" + " FP_Interval_Type is not the type of an interval with floating point boundaries."); + + // Check that we are dealing with an expression of floating point type. + PPL_ASSERT(expr.is_floating_point()); + + /* + Floating_Point_Format analyzed_format = expr.floating_point_format(); + FP_Interval_Type absolute_error = + compute_absolute_error<FP_Interval_Type>(analyzed_format); + */ + switch(expr.kind()) { + case INT_CON: + // TODO. + break; + case FP_CON: + Floating_Point_Constant<Target> fpc_expr = + static_cast<Floating_Point_Constant<Target>>(expr); + result = FP_Linear_Form(FP_Interval(fpc_expr.get_value_as_string())); + return true; + break; + case UOP: + Unary_Operator<Target> uop_expr = + static_cast<Unary_Operator<Target>>(expr); + switch (uop_expr.get_uop()) { + case PLUS: + return linearize(uop_expr.get_arg(), int_store, lf_store, result); + break; + case MINUS: + if (!linearize(uop_expr.get_arg(), int_store, lf_store, result)) + return false; + + result.negate(); + return true; + break; + case BNOT: + return bnot_linearize(uop_expr, int_store, lf_store, result); + break; + default: + throw std::runtime_error("PPL internal error"); + } + break; + case BOP: + Binary_Operator<Target> bop_expr = + static_cast<Binary_Operator<Target>>(expr); + switch (bop_expr.get_bop()) { + case ADD: + return add_linearize(bop_expr, int_store, lf_store, result); + break; + case SUB: + return sub_linearize(bop_expr, int_store, lf_store, result); + break; + case MUL: + return mul_linearize(bop_expr, int_store, lf_store, result); + break; + case DIV: + return div_linearize(bop_expr, int_store, lf_store, result); + break; + case REM: + case BAND: + case BOR: + case BXOR: + case LSHIFT: + case RSHIFT: + default: + throw std::runtime_error("PPL internal error"); + } + break; + case CAST: + // TODO. + break; + default: + throw std::runtime_error("PPL internal error"); + } +} + +} // namespace Parma_Polyhedra_Library + +#endif // !defined(PPL_linearize_hh)