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r_interval, distance

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This commit is contained in:
Jakob Rath 2023-11-09 11:28:01 +01:00
parent 4efb06c60b
commit e393c2fe9b
1 changed files with 79 additions and 2 deletions
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81
src/math/polysat/interval.h
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@ -65,6 +65,83 @@ namespace polysat {
return os << "[" << i.lo() << " ; " << i.hi() << "[";
}
// distance from a to b, wrapping around at mod_value.
// basically mod(b - a, mod_value), but distance(0, mod_value, mod_value) = mod_value.
rational distance(rational const& a, rational const& b, rational const& mod_value) {
SASSERT(mod_value.is_power_of_two());
SASSERT(0 <= a && a < mod_value);
SASSERT(0 <= b && b <= mod_value);
rational x = b - a;
if (x.is_neg())
x += mod_value;
return x;
}
class r_interval {
rational m_lo;
rational m_hi;
r_interval(rational lo, rational hi)
: m_lo(std::move(lo)), m_hi(std::move(hi))
{}
public:
static r_interval empty() {
return {rational::zero(), rational::zero()};
}
static r_interval full() {
return {rational(-1), rational::zero()};
}
static r_interval proper(rational lo, rational hi) {
SASSERT(0 <= lo);
SASSERT(0 <= hi);
return {std::move(lo), std::move(hi)};
}
bool is_full() const { return m_lo.is_neg(); }
bool is_proper() const { return !is_full(); }
bool is_empty() const { return is_proper() && lo() == hi(); }
rational const& lo() const { SASSERT(is_proper()); return m_lo; }
rational const& hi() const { SASSERT(is_proper()); return m_hi; }
// this one also supports representing full intervals as [lo;mod_value[
static rational len(rational const& lo, rational const& hi, rational const& mod_value) {
SASSERT(mod_value.is_power_of_two());
SASSERT(0 <= lo && lo < mod_value);
SASSERT(0 <= hi && hi <= mod_value);
SASSERT(hi != mod_value || lo == 0); // hi == mod_value only allowed when lo == 0
rational len = hi - lo;
if (len.is_neg())
len += mod_value;
return len;
}
rational len(rational const& mod_value) const {
SASSERT(is_proper());
return len(lo(), hi(), mod_value);
}
// deals only with proper intervals
// but works with full intervals represented as [0;mod_value[ -- maybe we should just change representation of full intervals to this always
static bool contains(rational const& lo, rational const& hi, rational const& val) {
if (lo <= hi)
return lo <= val && val < hi;
else
return val < hi || val >= lo;
}
bool contains(rational const& val) const {
if (is_full())
return true;
else
return contains(lo(), hi(), val);
}
};
class eval_interval {
interval m_symbolic;
rational m_concrete_lo;
@ -73,7 +150,7 @@ namespace polysat {
eval_interval(interval&& i, rational const& lo_val, rational const& hi_val):
m_symbolic(std::move(i)), m_concrete_lo(lo_val), m_concrete_hi(hi_val) {}
public:
static eval_interval empty(dd::pdd_manager &m) {
static eval_interval empty(dd::pdd_manager& m) {
return {interval::empty(m), rational::zero(), rational::zero()};
}
@ -81,7 +158,7 @@ namespace polysat {
return {interval::full(), rational::zero(), rational::zero()};
}
static eval_interval proper(pdd const &lo, rational const &lo_val, pdd const &hi, rational const &hi_val) {
static eval_interval proper(pdd const& lo, rational const& lo_val, pdd const& hi, rational const& hi_val) {
SASSERT(0 <= lo_val && lo_val <= lo.manager().max_value());
SASSERT(0 <= hi_val && hi_val <= hi.manager().max_value());
return {interval::proper(lo, hi), lo_val, hi_val};