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Added rewriting distinct with bitvectors to false if bit-size is too low (#5956)

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* Fixed problem with registering bitvector functions

* Added rewriting distinct with bitvectors to false if bit-size is too low

* Removed debug output

* Incorporated Nikolaj's comments

* Simplifications
This commit is contained in:
Clemens Eisenhofer 2022-04-09 21:46:21 +02:00 committed by GitHub
parent f55b233228
commit 0b20a4ebf4
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GPG key ID: 4AEE18F83AFDEB23
3 changed files with 28 additions and 10 deletions
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15
src/ast/rewriter/bv_rewriter.cpp
View file

@ -2803,6 +2803,21 @@ br_status bv_rewriter::mk_ite_core(expr * c, expr * t, expr * e, expr_ref & resu
return BR_FAILED;
}
br_status bv_rewriter::mk_distinct(unsigned num_args, expr * const * args, expr_ref & result) {
if (num_args <= 1) {
result = m().mk_true();
return BR_DONE;
}
unsigned sz = get_bv_size(args[0]);
// check if num_args > 2^sz
if (sz >= 32)
return BR_FAILED;
if (num_args <= 1u << sz)
return BR_FAILED;
result = m().mk_false();
return BR_DONE;
}
br_status bv_rewriter::mk_bvsmul_no_overflow(unsigned num, expr * const * args, bool is_overflow, expr_ref & result) {
SASSERT(num == 2);
unsigned bv_sz;

3
src/ast/rewriter/bv_rewriter.h
View file

@ -180,7 +180,8 @@ public:
bool is_urem_any(expr * e, expr * & dividend, expr * & divisor);
br_status mk_eq_core(expr * lhs, expr * rhs, expr_ref & result);
br_status mk_ite_core(expr * c, expr * t, expr * e, expr_ref & resul);
br_status mk_ite_core(expr * c, expr * t, expr * e, expr_ref & result);
br_status mk_distinct(unsigned num_args, expr * const * args, expr_ref & result);
bool hi_div0() const { return m_hi_div0; }

20
src/ast/rewriter/th_rewriter.cpp
View file

@ -60,7 +60,7 @@ struct th_rewriter_cfg : public default_rewriter_cfg {
expr_substitution * m_subst = nullptr;
unsigned long long m_max_memory; // in bytes
bool m_new_subst = false;
unsigned m_max_steps = UINT_MAX;
unsigned m_max_steps = UINT_MAX;
bool m_pull_cheap_ite = true;
bool m_flat = true;
bool m_cache_all = false;
@ -180,7 +180,7 @@ struct th_rewriter_cfg : public default_rewriter_cfg {
// theory dispatch for =
SASSERT(num == 2);
family_id s_fid = args[0]->get_sort()->get_family_id();
if (s_fid == m_a_rw.get_fid())
if (s_fid == m_a_rw.get_fid())
st = m_a_rw.mk_eq_core(args[0], args[1], result);
else if (s_fid == m_bv_rw.get_fid())
st = m_bv_rw.mk_eq_core(args[0], args[1], result);
@ -193,10 +193,7 @@ struct th_rewriter_cfg : public default_rewriter_cfg {
else if (s_fid == m_seq_rw.get_fid())
st = m_seq_rw.mk_eq_core(args[0], args[1], result);
if (st != BR_FAILED)
return st;
}
if (k == OP_EQ) {
SASSERT(num == 2);
return st;
st = apply_tamagotchi(args[0], args[1], result);
if (st != BR_FAILED)
return st;
@ -210,16 +207,21 @@ struct th_rewriter_cfg : public default_rewriter_cfg {
return st;
}
if ((k == OP_AND || k == OP_OR) && m_seq_rw.u().has_re()) {
st = m_seq_rw.mk_bool_app(f, num, args, result);
st = m_seq_rw.mk_bool_app(f, num, args, result);
if (st != BR_FAILED)
return st;
}
if (k == OP_EQ && m_seq_rw.u().has_seq() && is_app(args[0]) &&
if (k == OP_EQ && m_seq_rw.u().has_seq() && is_app(args[0]) &&
to_app(args[0])->get_family_id() == m_seq_rw.get_fid()) {
st = m_seq_rw.mk_eq_core(args[0], args[1], result);
if (st != BR_FAILED)
return st;
}
if (k == OP_DISTINCT && num > 0 && m_bv_rw.is_bv(args[0])) {
st = m_bv_rw.mk_distinct(num, args, result);
if (st != BR_FAILED)
return st;
}
return m_b_rw.mk_app_core(f, num, args, result);
}
@ -250,7 +252,7 @@ struct th_rewriter_cfg : public default_rewriter_cfg {
if (fid == m_seq_rw.get_fid())
return m_seq_rw.mk_app_core(f, num, args, result);
if (fid == m_char_rw.get_fid())
return m_char_rw.mk_app_core(f, num, args, result);
return m_char_rw.mk_app_core(f, num, args, result);
if (fid == m_rec_rw.get_fid())
return m_rec_rw.mk_app_core(f, num, args, result);
return BR_FAILED;