mirrors/z3
3
0
Fork 0
mirror of https://github.com/Z3Prover/z3 synced 2025-05-04 14:25:46 +00:00
Code Activity

add unsat core, activity, quick pass for viable

Browse source
This commit is contained in:
Nikolaj Bjorner 2021-11-24 13:23:28 +01:00
parent b82c3cfd33
commit caef8d026f
6 changed files with 91 additions and 43 deletions
Download patch file Download diff file Expand all files Collapse all files

32
src/math/polysat/viable.cpp
View file

@ -10,6 +10,14 @@ Author:
Nikolaj Bjorner (nbjorner) 2021-03-19
Jakob Rath 2021-04-6
Notes:
TODO: Investigate in depth a notion of phase caching for variables.
The Linear solver can be used to supply a phase in some cases.
In other cases, the phase of a variable assignment across branches
might be used in a call to is_viable. With phase caching on, it may
just check if the cached phase is viable without detecting that it is a propagation.
--*/
@ -17,7 +25,6 @@ Author:
#include "math/polysat/viable.h"
#include "math/polysat/solver.h"
namespace polysat {
viable::viable(solver& s) : s(s) {}
@ -139,6 +146,13 @@ namespace polysat {
if (!e)
return true;
entry* first = e;
entry* last = e->prev();
// quick check: last interval doesn't wrap around, so hi_val
// has not been covered
if (last->interval.lo_val() < last->interval.hi_val())
return true;
auto const& max_value = s.var2pdd(v).max_value();
do {
if (e->interval.is_full())
@ -221,6 +235,17 @@ namespace polysat {
entry* first = e;
entry* last = first->prev();
// quick check: last interval does not wrap around
// and has space for 2 unassigned values.
auto& max_value = s.var2pdd(v).max_value();
if (last->interval.lo_val() < last->interval.hi_val() &&
last->interval.hi_val() < max_value) {
lo = last->interval.hi_val();
return dd::find_t::multiple;
}
// find lower bound
if (last->interval.currently_contains(lo))
lo = last->interval.hi_val();
do {
@ -234,7 +259,8 @@ namespace polysat {
if (e->interval.currently_contains(lo))
return dd::find_t::empty;
rational hi = s.var2pdd(v).max_value();
// find upper bound
rational hi = max_value;
e = last;
do {
if (!e->interval.currently_contains(hi))
@ -271,7 +297,7 @@ namespace polysat {
}
for (auto sc : e->side_cond)
core.insert(sc);
e->src->set_var_dependent(); // ?
e->src->set_var_dependent();
core.insert(e->src);
e = n;
}