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move to interval arithmetic

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2021-05-07 15:32:56 -07:00
parent 5f48cffbb6
commit e3e2860198
3 changed files with 142 additions and 54 deletions
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121
src/math/polysat/fixplex_def.h
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@ -23,6 +23,54 @@ Author:
namespace polysat {
template<typename Numeral>
interval<Numeral> interval<Numeral>::operator+(interval<Numeral> const& other) const {
if (is_free())
return *this;
if (other.is_free())
return interval::free();
Numeral sz = (hi - lo) + (other.hi - other.lo);
if (sz < (hi - lo))
return interval::free();
return interval(lo + other.lo, hi + other.hi);
}
template<typename Numeral>
interval<Numeral> interval<Numeral>::operator-(interval<Numeral> const& other) const {
return *this + (-other);
}
template<typename Numeral>
interval<Numeral> interval<Numeral>::operator-() const {
if (is_free())
return *this;
return interval(1 - hi, 1 - lo);
}
template<typename Numeral>
interval<Numeral> interval<Numeral>::operator*(Numeral const& n) const {
if (n == 0)
return interval(0, 1);
if (n == 1)
return *this;
if (is_free())
return *this;
Numeral sz = hi - lo;
if (0 - n < n) {
Numeral mn = 0 - n;
Numeral mz = mn * sz;
if (mz / mn != sz)
return interval::free();
return interval((hi - 1) * n, n * lo + 1);
}
else {
Numeral mz = n * sz;
if (mz / n != sz)
return interval::free();
return interval(n * lo, n * (hi - 1) + 1);
}
}
template<typename Ext>
fixplex<Ext>::~fixplex() {
reset();
@ -309,7 +357,7 @@ namespace polysat {
/**
* Compute delta to add to the value, such that value + delta is either lo(v), or hi(v) - 1
* A pre-condition is that value is not in the range [lo(v),hi(v)[,
* A pre-condition is that value is not in the interval [lo(v),hi(v)[,
* and therefore as a consequence lo(v) != hi(v).
*/
template<typename Ext>
@ -333,8 +381,8 @@ namespace polysat {
*/
template<typename Ext>
void fixplex<Ext>::set_bounds(var_t v, numeral const& lo, numeral const& hi) {
m_vars[v].m_lo = lo;
m_vars[v].m_hi = hi;
m_vars[v].lo = lo;
m_vars[v].hi = hi;
if (in_bounds(v))
return;
if (is_base(v))
@ -383,21 +431,15 @@ namespace polysat {
bool fixplex<Ext>::is_infeasible_row(var_t x) {
SASSERT(is_base(x));
auto r = base2row(x);
numeral lo_sum = 0, hi_sum = 0, diff = 0;
interval<numeral> range(0, 1);
for (auto const& e : M.row_entries(row(r))) {
var_t v = e.var();
numeral const& c = e.coeff();
if (lo(v) == hi(v))
return false;
lo_sum += lo(v) * c;
hi_sum += (hi(v) - 1) * c;
numeral range = hi(v) - lo(v);
if (!m.signed_mul(range, c, range))
return false;
if (!m.signed_add(diff, diff, range))
range += m_vars[v] * c;
if (range.is_free())
return false;
}
return 0 < lo_sum && lo_sum <= hi_sum;
return 0 < range.lo && range.lo < range.hi;
}
/**
@ -744,7 +786,8 @@ namespace polysat {
template<typename Ext>
void fixplex<Ext>::propagate_bounds(row const& r) {
numeral lo_sum = 0, hi_sum = 0, diff = 0, free_c = 0;
interval<numeral> range(0, 1);
numeral free_c = 0;
var_t free_v = null_var;
for (auto const& e : M.row_entries(r)) {
var_t v = e.var();
@ -752,34 +795,22 @@ namespace polysat {
if (is_free(v)) {
if (free_v != null_var)
return;
if (c != 1 && c + 1 != 0)
return;
free_v = v;
free_c = c;
continue;
}
lo_sum += lo(v) * c;
hi_sum += (hi(v) - 1) * c;
numeral range = hi(v) - lo(v);
if (!m.signed_mul(range, c, range))
return;
if (!m.signed_add(diff, diff, range))
range += m_vars[v] * c;
if (range.is_free())
return;
}
std::cout << "bounds " << free_v << " range " << range << "\n";
if (free_v != null_var) {
//
// c = 1:
// free_v in [0 - hi_sum, 1 - lo_sum[
// c = -1:
// free_v in [lo_sum, hi_sum + 1[
//
if (free_c == 1)
new_bound(r, free_v, 0 - hi_sum, 1 - lo_sum);
else
new_bound(r, free_v, lo_sum, hi_sum + 1);
range = (-range) * free_c;
if (range.is_free())
return;
new_bound(r, free_v, range.lo, range.hi);
SASSERT(in_bounds(free_v));
return;
}
@ -787,23 +818,19 @@ namespace polysat {
var_t v = e.var();
SASSERT(!is_free(v));
numeral const& c = e.coeff();
if (c != 1 && c + 1 != 0)
continue;
numeral lo_sum1 = lo_sum - lo(v) * c;
numeral hi_sum1 = hi_sum - (hi(v) - 1) * c;
if (c == 1)
new_bound(r, v, 0 - hi_sum1, 1 - lo_sum1);
else
new_bound(r, v, lo_sum1, hi_sum1 + 1);
SASSERT(in_bounds(v));
auto range1 = range - m_vars[v] * c;
new_bound(r, v, range1.lo, range1.hi);
// SASSERT(in_bounds(v));
}
}
template<typename Ext>
void fixplex<Ext>::new_bound(row const& r, var_t x, numeral const& l, numeral const& h) {
// TBD:
std::cout << is_free(x) << " " << l << " " << lo(x) << " " << hi(x) << " " << h << "\n";
if (!is_free(x) && l <= lo(x) && hi(x) <= h)
return;
IF_VERBOSE(0, verbose_stream() << "new-bound v" << x << " [" << l << "," << h << "[\n");
IF_VERBOSE(0, verbose_stream() << "new-bound v" << x << " [" << pp(l) << "," << pp(h) << "[\n");
}
template<typename Ext>
@ -811,7 +838,7 @@ namespace polysat {
M.display(out);
for (unsigned i = 0; i < m_vars.size(); ++i) {
var_info const& vi = m_vars[i];
out << "v" << i << " " << value(i) << " [" << lo(i) << ", " << hi(i) << "[ ";
out << "v" << i << " " << pp(value(i)) << " [" << pp(lo(i)) << ", " << pp(hi(i)) << "[ ";
if (vi.m_is_base) out << "b:" << vi.m_base2row << " ";
out << "\n";
}
@ -823,10 +850,10 @@ namespace polysat {
for (auto const& e : M.row_entries(r)) {
var_t v = e.var();
if (e.coeff() != 1)
out << e.coeff() << " * ";
out << pp(e.coeff()) << " * ";
out << "v" << v << " ";
if (values)
out << value(v) << " [" << lo(v) << ", " << hi(v) << "[ ";
out << pp(value(v)) << " [" << pp(lo(v)) << ", " << pp(hi(v)) << "[ ";
}
return out << "\n";
}