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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2024-02-24 14:34:28 -08:00
parent 0e5b504c30
commit 58474df438
4 changed files with 170 additions and 55 deletions
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51
src/ast/sls/sls_valuation.cpp
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@ -199,6 +199,44 @@ namespace bv {
return true;
}
bool sls_valuation::set_random_at_most(bvect const& src, bvect& tmp, random_gen& r) {
if (!get_at_most(src, tmp))
return false;
if (is_zero(tmp) || (0 == r() % 2))
return try_set(tmp);
// random value below tmp
auto msb_bit = msb(tmp);
for (unsigned i = 0; i < nw; ++i)
tmp[i] = (random_bits(r) & ~fixed[i]) | (fixed[i] & tmp[i]);
for (unsigned i = msb_bit; i < bw; ++i)
tmp.set(i, false);
if (m_lo == m_hi || is_zero(m_lo) || m_lo <= tmp)
return try_set(tmp);
// for simplicity, bail out if we were not lucky
return get_at_most(src, tmp) && try_set(tmp);
}
bool sls_valuation::set_random_at_least(bvect const& src, bvect& tmp, random_gen& r) {
if (!get_at_least(src, tmp))
return false;
if (is_ones(tmp) || (0 == r() % 2))
return try_set(tmp);
// random value at least tmp
auto msb_bit = msb(tmp);
for (unsigned i = 0; i < nw; ++i)
tmp[i] = (random_bits(r) & ~fixed[i]) | (fixed[i] & tmp[i]);
tmp.set(msb_bit, true);
if (m_lo == m_hi || is_zero(m_hi) || m_hi > tmp)
return try_set(tmp);
// for simplicity, bail out if we were not lucky
return get_at_least(src, tmp) && try_set(tmp);
}
bool sls_valuation::set_repair(bool try_down, bvect& dst) {
for (unsigned i = 0; i < nw; ++i)
dst[i] = (~fixed[i] & dst[i]) | (fixed[i] & m_bits[i]);
@ -266,6 +304,19 @@ namespace bv {
dst[i] = m_bits[i];
}
digit_t sls_valuation::random_bits(random_gen& rand) {
digit_t r = 0;
for (digit_t i = 0; i < sizeof(digit_t); ++i)
r ^= rand() << (8 * i);
return r;
}
void sls_valuation::get_variant(bvect& dst, random_gen& r) const {
for (unsigned i = 0; i < nw; ++i)
dst[i] = (random_bits(r) & ~fixed[i]) | (fixed[i] & m_bits[i]);
clear_overflow_bits(dst);
}
//
// new_bits != bits => ~fixed
// 0 = (new_bits ^ bits) & fixed