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guard pdd-AND against wrong semantics

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This commit is contained in:
Jakob Rath 2023-02-24 13:47:42 +01:00
parent ae8075e22d
commit 133661d81b
2 changed files with 26 additions and 8 deletions
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28
src/math/dd/dd_pdd.cpp
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@ -109,11 +109,29 @@ namespace dd {
pdd pdd_manager::add(rational const& r, pdd const& b) { pdd c(mk_val(r)); return pdd(apply(c.root, b.root, pdd_add_op), this); }
pdd pdd_manager::zero() { return pdd(zero_pdd, this); }
pdd pdd_manager::one() { return pdd(one_pdd, this); }
pdd pdd_manager::mk_or(pdd const& p, pdd const& q) { return p + q - (p*q); }
pdd pdd_manager::mk_xor(pdd const& p, pdd const& q) { if (m_semantics == mod2_e) return p + q; return (p*q*2) - p - q; }
pdd pdd_manager::mk_xor(pdd const& p, unsigned x) { pdd q(mk_val(x)); if (m_semantics == mod2_e) return p + q; return (p*q*2) - p - q; }
pdd pdd_manager::mk_not(pdd const& p) { return 1 - p; }
// NOTE: bit-wise AND cannot be expressed in mod2N_e semantics with the existing operations.
pdd pdd_manager::mk_and(pdd const& p, pdd const& q) {
VERIFY(m_semantics == mod2_e || m_semantics == zero_one_vars_e);
return p * q;
}
pdd pdd_manager::mk_or(pdd const& p, pdd const& q) {
return p + q - mk_and(p, q);
}
pdd pdd_manager::mk_xor(pdd const& p, pdd const& q) {
if (m_semantics == mod2_e)
return p + q;
return p + q - 2*mk_and(p, q);
}
pdd pdd_manager::mk_not(pdd const& p) {
if (m_semantics == mod2N_e)
return -p - 1;
VERIFY(m_semantics == mod2_e || m_semantics == zero_one_vars_e);
return 1 - p;
}
pdd pdd_manager::subst_val(pdd const& p, unsigned v, rational const& val) {
pdd r = mk_var(v) + val;