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z3/src/sat/smt/polysat/op_constraint.h
Nikolaj Bjorner a315c7c47a work on ashr
Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
2023-12-16 16:50:01 -08:00

86 lines
2.7 KiB
C++

/*++
Copyright (c) 2021 Microsoft Corporation
Module Name:
Op constraint.
lshr: r == p >> q
ashr: r == p >>a q
lshl: r == p << q
and: r == p & q
not: r == ~p
Author:
Jakob Rath, Nikolaj Bjorner (nbjorner) 2021-12-09
--*/
#pragma once
#include "sat/smt/polysat/constraints.h"
#include <optional>
namespace polysat {
class core;
class op_constraint final : public constraint {
public:
enum class code {
/// r is the logical right shift of p by q.
lshr_op,
/// r is the arithmetic right shift of p by q.
ashr_op,
/// r is the left shift of p by q.
shl_op,
/// r is the bit-wise 'and' of p and q.
and_op,
/// r is the smallest multiplicative pseudo-inverse of p;
/// by definition we set r == 0 when p == 0.
/// Note that in general, there are 2^parity(p) many pseudo-inverses of p.
inv_op,
};
protected:
friend class constraints;
code m_op;
pdd p; // operand1
pdd q; // operand2
pdd r; // result
op_constraint(code c, pdd const& r, pdd const& p, pdd const& q);
lbool eval(pdd const& r, pdd const& p, pdd const& q) const;
static lbool eval_lshr(pdd const& p, pdd const& q, pdd const& r);
static lbool eval_ashr(pdd const& p, pdd const& q, pdd const& r);
static lbool eval_shl(pdd const& p, pdd const& q, pdd const& r);
static lbool eval_and(pdd const& p, pdd const& q, pdd const& r);
static lbool eval_inv(pdd const& p, pdd const& r);
void propagate_lshr(core& s, dependency const& dep);
void propagate_ashr(core& s, dependency const& dep);
void propagate_shl(core& s, dependency const& dep);
void propagate_and(core& s, dependency const& dep);
void propagate_inv(core& s, dependency const& dep);
std::ostream& display(std::ostream& out, char const* eq) const;
void activate_and(core& s, dependency const& d);
void activate_ashr(core& s, dependency const& d);
public:
~op_constraint() override {}
code get_op() const { return m_op; }
std::ostream& display(std::ostream& out, lbool status) const override;
std::ostream& display(std::ostream& out) const override;
lbool eval() const override;
lbool eval(assignment const& a) const override;
bool is_always_true() const { return false; }
bool is_always_false() const { return false; }
void activate(core& c, bool sign, dependency const& dep) override;
void propagate(core& c, lbool value, dependency const& dep) override;
};
}