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get comments out of the way

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Jakob Rath 2023-11-07 16:20:45 +01:00
parent be0e6c3267
commit 4efb06c60b
2 changed files with 122 additions and 101 deletions
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54
src/math/polysat/viable.cpp
View file

@ -1089,7 +1089,7 @@ namespace polysat {
find_t viable::find_viable(pvar v, rational& lo) { find_t viable::find_viable(pvar v, rational& lo) {
rational hi; rational hi;
switch (find_viable2(v, lo, hi)) { switch (find_viable2_new(v, lo, hi)) {
case l_true: case l_true:
if (hi < 0) { if (hi < 0) {
// fallback solver, treat propagations as decisions for now // fallback solver, treat propagations as decisions for now
@ -1276,16 +1276,6 @@ namespace polysat {
} }
lbool viable::find_viable2(pvar v, rational& lo, rational& hi) {
fixed_bits_info fbi;
if (!collect_bit_information(v, true, fbi))
return l_false; // conflict already added
pvar_vector overlaps;
s.m_slicing.collect_simple_overlaps(v, overlaps);
std::sort(overlaps.begin(), overlaps.end(), [&](pvar x, pvar y) { return s.size(x) > s.size(y); });
// TODO: (combining intervals across equivalence classes from slicing) // TODO: (combining intervals across equivalence classes from slicing)
// //
@ -1320,7 +1310,7 @@ namespace polysat {
// //
// one could also try starting at the smallest bit-width to detect conflicts faster. // one could also try starting at the smallest bit-width to detect conflicts faster.
// question: how to do recursion "upwards" without exponentially many holes to fill? // question: how to do recursion "upwards" without exponentially many holes to fill?
//
// Mapping intervals (by example): // Mapping intervals (by example):
// //
// A) Removing/appending LSB: // A) Removing/appending LSB:
@ -1351,20 +1341,19 @@ namespace polysat {
// //
// x[6:0] \not\in [15;30[ // x[6:0] \not\in [15;30[
// ==> x[5:0] \not\in \emptyset // ==> x[5:0] \not\in \emptyset
//
//
//
//
//
// start covering on the highest level. // start covering on the highest level.
// - at first, use a low refinement budget: we do not want to get stuck in a refinement loop if lower-bits intervals may already cover everything. // - at first, use a low refinement budget: we do not want to get stuck in a refinement loop if lower-bits intervals may already cover everything.
// //
//
// - if we can cover everything except a hole of size < 2^{bits of next layer} // - if we can cover everything except a hole of size < 2^{bits of next layer}
// - recursively try to cover that hole on lower level // - recursively try to cover that hole on lower level
// - otherwise // - otherwise
// - recursively try to cover the whole domain on lower level // - recursively try to cover the whole domain on lower level
// //
//
// - if the lower level succeeds, we are done. // - if the lower level succeeds, we are done.
// - if the lower level does not succeed, we can try refinement with a higher budget. // - if the lower level does not succeed, we can try refinement with a higher budget.
// //
@ -1376,12 +1365,39 @@ namespace polysat {
// i.e., we have a fixed-bit interval that covers half of the area. then extend that interval based on lower bits. // i.e., we have a fixed-bit interval that covers half of the area. then extend that interval based on lower bits.
// whether this is useful I'm not sure but it could skip some "virtual layers" where we only have a bit but no intervals. // whether this is useful I'm not sure but it could skip some "virtual layers" where we only have a bit but no intervals.
// //
//
// - how to integrate fallback solver? // - how to integrate fallback solver?
// when lowest level fails, we can try more refinement there. // when lowest level fails, we can try more refinement there.
// in case of refinement loop, try fallback solver with constraints only from lower level. // in case of refinement loop, try fallback solver with constraints only from lower level.
lbool viable::find_viable2_new(pvar v, rational& lo, rational& hi) {
fixed_bits_info fbi;
if (!collect_bit_information(v, true, fbi))
return l_false; // conflict already added
pvar_vector overlaps;
s.m_slicing.collect_simple_overlaps(v, overlaps);
std::sort(overlaps.begin(), overlaps.end(), [&](pvar x, pvar y) { return s.size(x) > s.size(y); });
LOG("Overlaps with v" << v << ":");
for (pvar x : overlaps) {
unsigned hi, lo;
if (s.m_slicing.is_extract(x, v, hi, lo))
LOG(" v" << x << " = v" << v << "[" << hi << ":" << lo << "]");
else
LOG(" v" << x << " not extracted from v" << v << "; size " << s.size(x));
}
NOT_IMPLEMENTED_YET();
return l_undef;
}
lbool viable::find_viable2(pvar v, rational& lo, rational& hi) {
fixed_bits_info fbi;
if (!collect_bit_information(v, true, fbi))
return l_false; // conflict already added
// max number of interval refinements before falling back to the univariate solver // max number of interval refinements before falling back to the univariate solver
unsigned const refinement_budget = 1000; unsigned const refinement_budget = 1000;

5
src/math/polysat/viable.h
View file

@ -67,6 +67,7 @@ namespace polysat {
struct layer final { struct layer final {
entry* entries = nullptr; entry* entries = nullptr;
// TODO: cache longest?
unsigned bit_width = 0; unsigned bit_width = 0;
layer(unsigned bw): bit_width(bw) {} layer(unsigned bw): bit_width(bw) {}
}; };
@ -197,6 +198,10 @@ namespace polysat {
*/ */
lbool find_viable_fallback(pvar v, rational& out_lo, rational& out_hi); lbool find_viable_fallback(pvar v, rational& out_lo, rational& out_hi);
lbool find_viable2_new(pvar v, rational& out_lo, rational& out_hi);
public: public:
viable(solver& s); viable(solver& s);