mirrors/z3
3
0
Fork 0
mirror of https://github.com/Z3Prover/z3 synced 2025-06-02 20:31:21 +00:00
Code Activity

update viable

Browse source 
Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2021-12-03 17:57:08 -08:00
parent a81a00a93c
commit 4d0f55febd
2 changed files with 18 additions and 120 deletions
Download patch file Download diff file Expand all files Collapse all files

114
src/math/polysat/forbidden_intervals.cpp
View file

@ -63,7 +63,7 @@ namespace polysat {
SASSERT(b1.is_val());
SASSERT(b2.is_val());
coeff = a1;
coeff = a1.is_zero() ? a2 : a1;
_backtrack.released = true;
@ -77,12 +77,6 @@ namespace polysat {
return true;
#if 0
if (match_linear4(c, a1, b1, e1, a2, b2, e2, out_interval, out_side_cond))
return true;
if (match_linear5(c, a1, b1, e1, a2, b2, e2, out_interval, out_side_cond))
return true;
#endif
_backtrack.released = false;
return false;
}
@ -230,110 +224,4 @@ namespace polysat {
}
return false;
}
#if 0
/**
* a1*y + e1 = 0, with a1 odd
*/
bool forbidden_intervals::match_linear4(signed_constraint const& c,
rational & a1, pdd const& b1, pdd const& e1,
rational & a2, pdd const& b2, pdd const& e2,
eval_interval& interval, vector<signed_constraint>& side_cond) {
if (a1.is_odd() && a2.is_zero() && b2.val().is_zero()) {
push_eq(true, e2, side_cond);
rational a_inv, pow2 = e1.manager().max_value() + 1;
VERIFY(a1.mult_inverse(e1.manager().power_of_2(), a_inv));
auto lo = -e1 * a_inv;
auto lo_val = mod(-b1.val() * a_inv, pow2);
auto hi = lo + 1;
auto hi_val = mod(lo_val + 1, pow2);
interval = to_interval(c, false, rational::one(), lo_val, lo, hi_val, hi);
return true;
}
return false;
}
/**
* Ad-hoc linear forbidden intervals
* ax <= b, b != -1, a < b: x not in [ceil((b+1)/a) .. floor((2^K-1)/a)]
* b <= ax, 0 < a < b: x not in [0 .. floor((b-1)/a)]
* ax < b, a < b: x not in [ceil(b/a) .. floor((2^K-1)/a)]
* b < ax, 0 < a <= b: x not in [0 .. floor(b/a)]
*
* TODO: generalize to ax + b <= c scenarios where ax does not overflow
* and ax+b does not overflow, but is larger than c
* Scenarios:
* - ax + b <= c
* - ax + b < c
* - c <= ax + b
* - c < ax + b
*/
bool forbidden_intervals::match_linear5(signed_constraint const& c,
rational & a1, pdd const& b1, pdd const& e1,
rational & a2, pdd const& b2, pdd const& e2,
eval_interval& interval, vector<signed_constraint>& side_cond) {
auto& m = e1.manager();
// ax <= b, b != -1, a < b: x not in [ceil((b+1)/a) .. floor((2^K-1)/a)]
if (c.is_positive() &&
!a1.is_zero() && !a1.is_one() &&
a2.is_zero() && b1.is_zero() && e2.is_val() &&
a1 < b2.val() && b2.val() != m.max_value()) {
if (!e1.is_val())
side_cond.push_back(s.eq(e1));
auto lo_val = ceil((b2.val() + 1) / a1);
auto hi_val = floor(m.max_value() / a1) + 1;
SASSERT(lo_val < hi_val);
auto lo = m.mk_val(lo_val);
auto hi = m.mk_val(hi_val);
interval = eval_interval::proper(lo, lo_val, hi, hi_val);
return true;
}
// b <= ax, 0 < a < b: x not in [0 .. floor((b-1)/a)]
if (c.is_positive() &&
!a2.is_zero() && !a2.is_one() &&
a1.is_zero() && b2.is_zero() &&
a2 < b1.val() && e1.is_val()) {
if (!e2.is_val())
side_cond.push_back(s.eq(e2));
rational lo_val = rational::zero();
rational hi_val = floor((b1.val() - 1) / a2) + 1;
SASSERT(lo_val < hi_val);
auto lo = m.mk_val(lo_val);
auto hi = m.mk_val(hi_val);
interval = eval_interval::proper(lo, lo_val, hi, hi_val);
return true;
}
// ax < b, a < b: x not in [ceil(b/a) .. floor((2^K-1)/a)]
if (c.is_negative() &&
!a2.is_zero() && !a2.is_one() && b2.is_zero() &&
a1.is_zero() && e1.is_val() && a2 < b1.val()) {
if (!e2.is_val())
side_cond.push_back(s.eq(e2));
rational lo_val = ceil(b1.val() / a2);
rational hi_val = floor(m.max_value() / a2) + 1;
auto lo = m.mk_val(lo_val);
auto hi = m.mk_val(hi_val);
interval = eval_interval::proper(lo, lo_val, hi, hi_val);
return true;
}
// b < ax, 0 < a <= b: x not in [0 .. floor(b/a)]
if (c.is_negative() &&
!a1.is_zero() && !a1.is_one() && b1.is_zero() &&
a2.is_zero() && e2.is_val() && a1 <= b2.val()) {
if (!e1.is_val())
side_cond.push_back(s.eq(e2));
rational lo_val = rational::zero();
rational hi_val = floor(b2.val() / a1) + 1;
auto lo = m.mk_val(lo_val);
auto hi = m.mk_val(hi_val);
interval = eval_interval::proper(lo, lo_val, hi, hi_val);
return true;
}
return false;
}
#endif
}