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z3/lib/smt_cg_table.h
Leonardo de Moura e9eab22e5c Z3 sources
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2012-10-02 11:35:25 -07:00

355 lines
11 KiB
C++

/*++
Copyright (c) 2006 Microsoft Corporation
Module Name:
smt_cg_table.h
Abstract:
<abstract>
Author:
Leonardo de Moura (leonardo) 2008-02-19.
Revision History:
--*/
#ifndef _SMT_CG_TABLE_H_
#define _SMT_CG_TABLE_H_
#include"smt_enode.h"
#include"hashtable.h"
#include"chashtable.h"
namespace smt {
typedef std::pair<enode *, bool> enode_bool_pair;
#if 0
/**
\brief Congruence table.
*/
class cg_table {
struct cg_khasher {
unsigned operator()(enode const * n) const { return n->get_decl_id(); }
};
struct cg_chasher {
unsigned operator()(enode const * n, unsigned idx) const {
return n->get_arg(idx)->get_root()->hash();
}
};
struct cg_hash {
cg_khasher m_khasher;
cg_chasher m_chasher;
public:
unsigned operator()(enode * n) const;
};
struct cg_eq {
bool & m_commutativity;
cg_eq(bool & comm):m_commutativity(comm) {}
bool operator()(enode * n1, enode * n2) const;
};
typedef ptr_hashtable<enode, cg_hash, cg_eq> table;
ast_manager & m_manager;
bool m_commutativity; //!< true if the last found congruence used commutativity
table m_table;
public:
cg_table(ast_manager & m);
/**
\brief Try to insert n into the table. If the table already
contains an element n' congruent to n, then do nothing and
return n' and a boolean indicating whether n and n' are congruence
modulo commutativity, otherwise insert n and return (n,false).
*/
enode_bool_pair insert(enode * n) {
// it doesn't make sense to insert a constant.
SASSERT(n->get_num_args() > 0);
m_commutativity = false;
enode * n_prime = m_table.insert_if_not_there(n);
SASSERT(contains(n));
return enode_bool_pair(n_prime, m_commutativity);
}
void erase(enode * n) {
SASSERT(n->get_num_args() > 0);
m_table.erase(n);
SASSERT(!contains(n));
}
bool contains(enode * n) const {
return m_table.contains(n);
}
enode * find(enode * n) const {
enode * r = 0;
return m_table.find(n, r) ? r : 0;
}
bool contains_ptr(enode * n) const {
enode * n_prime;
return m_table.find(n, n_prime) && n == n_prime;
}
void reset() {
m_table.reset();
}
void display(std::ostream & out) const;
void display_compact(std::ostream & out) const;
#ifdef Z3DEBUG
bool check_invariant() const;
#endif
};
#else
// one table per function symbol
/**
\brief Congruence table.
*/
class cg_table {
struct cg_unary_hash {
unsigned operator()(enode * n) const {
SASSERT(n->get_num_args() == 1);
return n->get_arg(0)->get_root()->hash();
}
};
struct cg_unary_eq {
bool operator()(enode * n1, enode * n2) const {
SASSERT(n1->get_num_args() == 1);
SASSERT(n2->get_num_args() == 1);
SASSERT(n1->get_decl() == n2->get_decl());
return n1->get_arg(0)->get_root() == n2->get_arg(0)->get_root();
}
};
typedef chashtable<enode *, cg_unary_hash, cg_unary_eq> unary_table;
struct cg_binary_hash {
unsigned operator()(enode * n) const {
SASSERT(n->get_num_args() == 2);
// too many collisions
// unsigned r = 17 + n->get_arg(0)->get_root()->hash();
// return r * 31 + n->get_arg(1)->get_root()->hash();
return combine_hash(n->get_arg(0)->get_root()->hash(), n->get_arg(1)->get_root()->hash());
}
};
struct cg_binary_eq {
bool operator()(enode * n1, enode * n2) const {
SASSERT(n1->get_num_args() == 2);
SASSERT(n2->get_num_args() == 2);
SASSERT(n1->get_decl() == n2->get_decl());
#if 1
return
n1->get_arg(0)->get_root() == n2->get_arg(0)->get_root() &&
n1->get_arg(1)->get_root() == n2->get_arg(1)->get_root();
#else
bool r =
n1->get_arg(0)->get_root() == n2->get_arg(0)->get_root() &&
n1->get_arg(1)->get_root() == n2->get_arg(1)->get_root();
static unsigned counter = 0;
static unsigned failed = 0;
if (!r)
failed++;
counter++;
if (counter % 100000 == 0)
std::cerr << "[cg_eq] " << counter << " " << failed << "\n";
return r;
#endif
}
};
typedef chashtable<enode*, cg_binary_hash, cg_binary_eq> binary_table;
struct cg_comm_hash {
unsigned operator()(enode * n) const {
SASSERT(n->get_num_args() == 2);
unsigned h1 = n->get_arg(0)->get_root()->hash();
unsigned h2 = n->get_arg(1)->get_root()->hash();
if (h1 > h2)
std::swap(h1, h2);
return hash_u((h1 << 16) | (h2 & 0xFFFF));
}
};
struct cg_comm_eq {
bool & m_commutativity;
cg_comm_eq(bool & c):m_commutativity(c) {}
bool operator()(enode * n1, enode * n2) const {
SASSERT(n1->get_num_args() == 2);
SASSERT(n2->get_num_args() == 2);
SASSERT(n1->get_decl() == n2->get_decl());
enode * c1_1 = n1->get_arg(0)->get_root();
enode * c1_2 = n1->get_arg(1)->get_root();
enode * c2_1 = n2->get_arg(0)->get_root();
enode * c2_2 = n2->get_arg(1)->get_root();
if (c1_1 == c2_1 && c1_2 == c2_2) {
return true;
}
if (c1_1 == c2_2 && c1_2 == c2_1) {
m_commutativity = true;
return true;
}
return false;
}
};
typedef chashtable<enode*, cg_comm_hash, cg_comm_eq> comm_table;
struct cg_hash {
unsigned operator()(enode * n) const;
};
struct cg_eq {
bool operator()(enode * n1, enode * n2) const;
};
typedef chashtable<enode*, cg_hash, cg_eq> table;
ast_manager & m_manager;
bool m_commutativity; //!< true if the last found congruence used commutativity
ptr_vector<void> m_tables;
obj_map<func_decl, unsigned> m_func_decl2id;
enum table_kind {
UNARY,
BINARY,
BINARY_COMM,
NARY
};
void * mk_table_for(func_decl * d);
unsigned set_func_decl_id(enode * n);
void * get_table(enode * n) {
unsigned tid = n->get_func_decl_id();
if (tid == UINT_MAX)
tid = set_func_decl_id(n);
SASSERT(tid < m_tables.size());
return m_tables[tid];
}
public:
cg_table(ast_manager & m);
~cg_table();
/**
\brief Try to insert n into the table. If the table already
contains an element n' congruent to n, then do nothing and
return n' and a boolean indicating whether n and n' are congruence
modulo commutativity, otherwise insert n and return (n,false).
*/
enode_bool_pair insert(enode * n) {
// it doesn't make sense to insert a constant.
SASSERT(n->get_num_args() > 0);
enode * n_prime;
void * t = get_table(n);
switch (static_cast<table_kind>(GET_TAG(t))) {
case UNARY:
n_prime = UNTAG(unary_table*, t)->insert_if_not_there(n);
return enode_bool_pair(n_prime, false);
case BINARY:
n_prime = UNTAG(binary_table*, t)->insert_if_not_there(n);
return enode_bool_pair(n_prime, false);
case BINARY_COMM:
m_commutativity = false;
n_prime = UNTAG(comm_table*, t)->insert_if_not_there(n);
return enode_bool_pair(n_prime, m_commutativity);
default:
n_prime = UNTAG(table*, t)->insert_if_not_there(n);
return enode_bool_pair(n_prime, false);
}
}
void erase(enode * n) {
SASSERT(n->get_num_args() > 0);
void * t = get_table(n);
switch (static_cast<table_kind>(GET_TAG(t))) {
case UNARY:
UNTAG(unary_table*, t)->erase(n);
break;
case BINARY:
UNTAG(binary_table*, t)->erase(n);
break;
case BINARY_COMM:
UNTAG(comm_table*, t)->erase(n);
break;
default:
UNTAG(table*, t)->erase(n);
break;
}
}
bool contains(enode * n) const {
SASSERT(n->get_num_args() > 0);
void * t = const_cast<cg_table*>(this)->get_table(n);
switch (static_cast<table_kind>(GET_TAG(t))) {
case UNARY:
return UNTAG(unary_table*, t)->contains(n);
case BINARY:
return UNTAG(binary_table*, t)->contains(n);
case BINARY_COMM:
return UNTAG(comm_table*, t)->contains(n);
default:
return UNTAG(table*, t)->contains(n);
}
}
enode * find(enode * n) const {
SASSERT(n->get_num_args() > 0);
enode * r = 0;
void * t = const_cast<cg_table*>(this)->get_table(n);
switch (static_cast<table_kind>(GET_TAG(t))) {
case UNARY:
return UNTAG(unary_table*, t)->find(n, r) ? r : 0;
case BINARY:
return UNTAG(binary_table*, t)->find(n, r) ? r : 0;
case BINARY_COMM:
return UNTAG(comm_table*, t)->find(n, r) ? r : 0;
default:
return UNTAG(table*, t)->find(n, r) ? r : 0;
}
}
bool contains_ptr(enode * n) const {
enode * r;
SASSERT(n->get_num_args() > 0);
void * t = const_cast<cg_table*>(this)->get_table(n);
switch (static_cast<table_kind>(GET_TAG(t))) {
case UNARY:
return UNTAG(unary_table*, t)->find(n, r) && n == r;
case BINARY:
return UNTAG(binary_table*, t)->find(n, r) && n == r;
case BINARY_COMM:
return UNTAG(comm_table*, t)->find(n, r) && n == r;
default:
return UNTAG(table*, t)->find(n, r) && n == r;
}
}
void reset();
void display(std::ostream & out) const;
void display_compact(std::ostream & out) const;
#ifdef Z3DEBUG
bool check_invariant() const;
#endif
};
#endif
};
#endif /* _SMT_CG_TABLE_H_ */