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use offset/length for fixed slices to allow super-slices

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2024-01-11 10:05:08 -08:00
parent 80184c6ee2
commit 6b12bd6dcd
5 changed files with 33 additions and 24 deletions
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29
src/sat/smt/polysat/fixed_bits.cpp
View file

@ -32,28 +32,35 @@ namespace polysat {
// if x[hi:lo] = value, then
// 2^(w-hi+1)* x >=
bool fixed_bits::check(rational const& val, fi_record& fi) {
unsigned sz = c.size(m_var);
for (auto const& s : m_fixed_slices) {
rational bw = rational::power_of_two(s.hi - s.lo + 1);
if (s.value != mod(machine_div2k(val, s.lo + 1), bw)) {
rational bw = rational::power_of_two(s.length);
// slice is properly contained in bit-vector variable
if (s.length <= sz && s.value != mod(machine_div2k(val, s.offset + 1), bw)) {
SASSERT(s.offset + s.length <= sz);
rational hi_val = s.value;
rational lo_val = mod(s.value + 1, bw);
unsigned sz = c.size(m_var);
pdd lo = c.value(rational::power_of_two(sz - s.hi - 1) * lo_val, c.size(m_var));
pdd hi = c.value(rational::power_of_two(sz - s.hi - 1) * hi_val, c.size(m_var));
rational lo_val = mod(s.value + 1, bw);
pdd lo = c.value(rational::power_of_two(sz - s.offset - s.length) * lo_val, c.size(m_var));
pdd hi = c.value(rational::power_of_two(sz - s.offset - s.length) * hi_val, c.size(m_var));
fi.reset();
fi.interval = eval_interval::proper(lo, lo_val, hi, hi_val);
fi.deps.push_back(dependency({ m_var, s }));
fi.bit_width = s.hi - s.lo + 1;
fi.bit_width = s.length;
fi.coeff = 1;
return false;
}
// slice, properly contains variable.
// s.offset refers to offset in containing value.
if (s.length > sz) {
NOT_IMPLEMENTED_YET();
}
}
return true;
}
std::ostream& fixed_bits::display(std::ostream& out) const {
for (auto const& s : m_fixed_slices)
out << s.hi << " " << s.lo << " " << s.value << "\n";
out << s.value << "[" << s.length << "]@" << s.offset << "\n";
return out;
}
@ -80,7 +87,7 @@ namespace polysat {
if (d.parity(N) < k)
return false;
rational const b = machine_div2k(d, k);
out = fixed_slice(N - k - 1, 0, b);
out = fixed_slice(b, 0, N - k);
SASSERT_EQ(d, b * rational::power_of_two(k));
SASSERT_EQ(p, (p.manager().mk_var(p.var()) - out.value) * rational::power_of_two(k));
return true;
@ -148,8 +155,8 @@ namespace polysat {
rational const c = is_strict ? rhs.val() : (rhs.val() + 1);
unsigned const k = c.next_power_of_two();
if (k < N) {
out.hi = N - 1;
out.lo = k;
out.length = N - k;
out.offset = k;
out.value = 0;
return true;
}

10
src/sat/smt/polysat/types.h
View file

@ -36,17 +36,17 @@ namespace polysat {
class signed_constraint;
struct fixed_slice {
unsigned hi = 0;
unsigned lo = 0;
unsigned offset = 0;
unsigned length = 0;
rational value;
fixed_slice() = default;
fixed_slice(unsigned hi, unsigned lo, rational value) : hi(hi), lo(lo), value(value) {}
fixed_slice(rational value, unsigned offset, unsigned length) : offset(offset), length(length), value(value) {}
};
struct fixed_claim : public fixed_slice {
pvar v;
fixed_claim() = default;
fixed_claim(pvar v, unsigned hi, unsigned lo, rational value) : fixed_slice(hi, lo, value), v(v) {}
fixed_claim(pvar v, rational value, unsigned offset, unsigned length) : fixed_slice(value, offset, length), v(v) {}
fixed_claim(pvar, fixed_slice const& s) : fixed_slice(s), v(v) {}
};
@ -100,7 +100,7 @@ namespace polysat {
}
else if (d.is_fixed_claim()) {
auto fixed = d.fixed();
return out << fixed.value << " == v" << fixed.v << " [" << fixed.hi << ":" << fixed.lo << "]";
return out << fixed.value << " == v" << fixed.v << " [" << fixed.length << "]@" << fixed.offset;
}
else {
UNREACHABLE();

14
src/sat/smt/polysat_egraph.cpp
View file

@ -94,8 +94,9 @@ namespace polysat {
// walk the e-graph to retrieve fixed overlaps
void solver::get_fixed_bits(pvar pv, fixed_bits_vector& out) {
std::function<bool(euf::enode*, unsigned)> consume_slice = [&](euf::enode* n, unsigned offset) {
// verbose_stream() << "sub-slice " << ctx.bpp(n) << " " << offset << "\n";
if (!n->interpreted())
return true;
auto w = n->get_root()->get_th_var(get_id());
@ -104,13 +105,14 @@ namespace polysat {
auto const& p = m_var2pdd[w];
if (!p.is_var())
return true;
unsigned lo = offset, hi = bv.get_bv_size(n->get_expr());
unsigned length = bv.get_bv_size(n->get_expr());
rational value;
VERIFY(bv.is_numeral(n->get_expr(), value));
out.push_back({ fixed_slice(lo, hi, value) });
out.push_back({ fixed_slice(value, offset, length) });
return false;
};
theory_var v = m_pddvar2var[pv];
// verbose_stream() << "Get fixed_bits " << ctx.bpp(var2enode(v)) << "\n";
m_bv_plugin->sub_slices(var2enode(v), consume_slice);
}
@ -120,12 +122,12 @@ namespace polysat {
m_bv_plugin->explain_slice(var2enode(v), offset, var2enode(w), consume_eq);
}
void solver::explain_fixed(pvar pv, unsigned lo, unsigned hi, rational const& value, std::function<void(euf::enode*, euf::enode*)>& consume_eq) {
void solver::explain_fixed(pvar pv, fixed_slice const& slice, std::function<void(euf::enode*, euf::enode*)>& consume_eq) {
euf::theory_var v = m_pddvar2var[pv];
expr_ref val(bv.mk_numeral(value, hi - lo + 1), m);
expr_ref val(bv.mk_numeral(slice.value, slice.length), m);
euf::enode* b = ctx.get_egraph().find(val);
SASSERT(b);
m_bv_plugin->explain_slice(var2enode(v), lo, b, consume_eq);
m_bv_plugin->explain_slice(var2enode(v), slice.offset, b, consume_eq);
}
}

2
src/sat/smt/polysat_solver.cpp
View file

@ -147,7 +147,7 @@ namespace polysat {
std::function<void(euf::enode*, euf::enode*)> consume = [&](auto* a, auto* b) {
eqs.push_back({ a, b });
};
explain_fixed(o.v, o.lo, o.hi, o.value, consume);
explain_fixed(o.v, o, consume);
}
else if (d.is_offset_claim()) {
auto const& offs = d.offset();

2
src/sat/smt/polysat_solver.h
View file

@ -112,7 +112,7 @@ namespace polysat {
sat::check_result intblast();
void explain_slice(pvar v, pvar w, unsigned offset, std::function<void(euf::enode*, euf::enode*)>& consume);
void explain_fixed(pvar v, unsigned lo, unsigned hi, rational const& value, std::function<void(euf::enode*, euf::enode*)>& consume_eq);
void explain_fixed(pvar v, fixed_slice const& s, std::function<void(euf::enode*, euf::enode*)>& consume_eq);
// internalize
bool visit(expr* e) override;