yosys/libs/ezsat/ezsat.h

333 lines
13 KiB
C++

/*
* ezSAT -- A simple and easy to use CNF generator for SAT solvers
*
* Copyright (C) 2013 Clifford Wolf <clifford@clifford.at>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*/
#ifndef EZSAT_H
#define EZSAT_H
#include <set>
#include <map>
#include <vector>
#include <string>
#include <stdio.h>
class ezSAT
{
// each token (terminal or non-terminal) is represented by an interger number
//
// the zero token:
// the number zero is not used as valid token number and is used to encode
// unused parameters for the functions.
//
// positive numbers are literals, with 1 = TRUE and 2 = FALSE;
//
// negative numbers are non-literal expressions. each expression is represented
// by an operator id and a list of expressions (literals or non-literals).
public:
enum OpId {
OpNot, OpAnd, OpOr, OpXor, OpIFF, OpITE
};
static const int TRUE;
static const int FALSE;
private:
std::map<std::string, int> literalsCache;
std::vector<std::string> literals;
std::map<std::pair<OpId, std::vector<int>>, int> expressionsCache;
std::vector<std::pair<OpId, std::vector<int>>> expressions;
bool cnfConsumed;
int cnfVariableCount, cnfClausesCount;
std::vector<int> cnfLiteralVariables, cnfExpressionVariables;
std::vector<std::vector<int>> cnfClauses;
std::set<int> cnfAssumptions;
void add_clause(const std::vector<int> &args);
void add_clause(const std::vector<int> &args, bool argsPolarity, int a = 0, int b = 0, int c = 0);
void add_clause(int a, int b = 0, int c = 0);
int bind_cnf_not(const std::vector<int> &args);
int bind_cnf_and(const std::vector<int> &args);
int bind_cnf_or(const std::vector<int> &args);
public:
int solverTimeout;
bool solverTimoutStatus;
ezSAT();
virtual ~ezSAT();
// manage expressions
int value(bool val);
int literal();
int literal(const std::string &name);
int expression(OpId op, int a = 0, int b = 0, int c = 0, int d = 0, int e = 0, int f = 0);
int expression(OpId op, const std::vector<int> &args);
void lookup_literal(int id, std::string &name) const;
const std::string &lookup_literal(int id) const;
void lookup_expression(int id, OpId &op, std::vector<int> &args) const;
const std::vector<int> &lookup_expression(int id, OpId &op) const;
int parse_string(const std::string &text);
std::string to_string(int id) const;
int numLiterals() const { return literals.size(); }
int numExpressions() const { return expressions.size(); }
int eval(int id, const std::vector<int> &values) const;
// SAT solver interface
// If you are planning on using the solver API (and not simply create a CNF) you must use a child class
// of ezSAT that actually implements a solver backend, such as ezMiniSAT (see ezminisat.h).
// Note: Solvers that can output don't-care values for model variables return a twice as big modelValues
// vector. The first half contains the values and the second half the don't-care flags.
virtual bool solver(const std::vector<int> &modelExpressions, std::vector<bool> &modelValues, const std::vector<int> &assumptions);
bool solve(const std::vector<int> &modelExpressions, std::vector<bool> &modelValues, const std::vector<int> &assumptions) {
return solver(modelExpressions, modelValues, assumptions);
}
bool solve(const std::vector<int> &modelExpressions, std::vector<bool> &modelValues, int a = 0, int b = 0, int c = 0, int d = 0, int e = 0, int f = 0) {
std::vector<int> assumptions;
if (a != 0) assumptions.push_back(a);
if (b != 0) assumptions.push_back(b);
if (c != 0) assumptions.push_back(c);
if (d != 0) assumptions.push_back(d);
if (e != 0) assumptions.push_back(e);
if (f != 0) assumptions.push_back(f);
return solver(modelExpressions, modelValues, assumptions);
}
bool solve(int a = 0, int b = 0, int c = 0, int d = 0, int e = 0, int f = 0) {
std::vector<int> assumptions, modelExpressions;
std::vector<bool> modelValues;
if (a != 0) assumptions.push_back(a);
if (b != 0) assumptions.push_back(b);
if (c != 0) assumptions.push_back(c);
if (d != 0) assumptions.push_back(d);
if (e != 0) assumptions.push_back(e);
if (f != 0) assumptions.push_back(f);
return solver(modelExpressions, modelValues, assumptions);
}
void setSolverTimeout(int newTimeoutSeconds) {
solverTimeout = newTimeoutSeconds;
}
bool getSolverTimoutStatus() {
return solverTimoutStatus;
}
// manage CNF (usually only accessed by SAT solvers)
virtual void clear();
void assume(int id);
int bind(int id);
const std::set<int> &assumed() const { return cnfAssumptions; }
int bound(int id) const;
int numCnfVariables() const { return cnfVariableCount; }
int numCnfClauses() const { return cnfClausesCount; }
const std::vector<std::vector<int>> &cnf() const { return cnfClauses; }
void consumeCnf();
void consumeCnf(std::vector<std::vector<int>> &cnf);
// simple helpers for build expressions easily
struct _V {
int id;
std::string name;
_V(int id) : id(id) { }
_V(const char *name) : id(0), name(name) { }
_V(const std::string &name) : id(0), name(name) { }
int get(ezSAT *that) {
if (name.empty())
return id;
return that->literal(name);
}
};
int VAR(_V a) {
return a.get(this);
}
int NOT(_V a) {
return expression(OpNot, a.get(this));
}
int AND(_V a = 0, _V b = 0, _V c = 0, _V d = 0, _V e = 0, _V f = 0) {
return expression(OpAnd, a.get(this), b.get(this), c.get(this), d.get(this), e.get(this), f.get(this));
}
int OR(_V a = 0, _V b = 0, _V c = 0, _V d = 0, _V e = 0, _V f = 0) {
return expression(OpOr, a.get(this), b.get(this), c.get(this), d.get(this), e.get(this), f.get(this));
}
int XOR(_V a = 0, _V b = 0, _V c = 0, _V d = 0, _V e = 0, _V f = 0) {
return expression(OpXor, a.get(this), b.get(this), c.get(this), d.get(this), e.get(this), f.get(this));
}
int IFF(_V a, _V b = 0, _V c = 0, _V d = 0, _V e = 0, _V f = 0) {
return expression(OpIFF, a.get(this), b.get(this), c.get(this), d.get(this), e.get(this), f.get(this));
}
int ITE(_V a, _V b, _V c) {
return expression(OpITE, a.get(this), b.get(this), c.get(this));
}
void SET(_V a, _V b) {
assume(IFF(a.get(this), b.get(this)));
}
// simple helpers for building expressions with bit vectors
std::vector<int> vec_const_signed(int64_t value, int bits);
std::vector<int> vec_const_unsigned(uint64_t value, int bits);
std::vector<int> vec_var(int bits);
std::vector<int> vec_var(std::string name, int bits);
std::vector<int> vec_cast(const std::vector<int> &vec1, int toBits, bool signExtend = false);
std::vector<int> vec_not(const std::vector<int> &vec1);
std::vector<int> vec_and(const std::vector<int> &vec1, const std::vector<int> &vec2);
std::vector<int> vec_or(const std::vector<int> &vec1, const std::vector<int> &vec2);
std::vector<int> vec_xor(const std::vector<int> &vec1, const std::vector<int> &vec2);
std::vector<int> vec_iff(const std::vector<int> &vec1, const std::vector<int> &vec2);
std::vector<int> vec_ite(const std::vector<int> &vec1, const std::vector<int> &vec2, const std::vector<int> &vec3);
std::vector<int> vec_ite(int sel, const std::vector<int> &vec2, const std::vector<int> &vec3);
std::vector<int> vec_count(const std::vector<int> &vec, int bits, bool clip = true);
std::vector<int> vec_add(const std::vector<int> &vec1, const std::vector<int> &vec2);
std::vector<int> vec_sub(const std::vector<int> &vec1, const std::vector<int> &vec2);
std::vector<int> vec_neg(const std::vector<int> &vec);
void vec_cmp(const std::vector<int> &vec1, const std::vector<int> &vec2, int &carry, int &overflow, int &sign, int &zero);
int vec_lt_signed(const std::vector<int> &vec1, const std::vector<int> &vec2);
int vec_le_signed(const std::vector<int> &vec1, const std::vector<int> &vec2);
int vec_ge_signed(const std::vector<int> &vec1, const std::vector<int> &vec2);
int vec_gt_signed(const std::vector<int> &vec1, const std::vector<int> &vec2);
int vec_lt_unsigned(const std::vector<int> &vec1, const std::vector<int> &vec2);
int vec_le_unsigned(const std::vector<int> &vec1, const std::vector<int> &vec2);
int vec_ge_unsigned(const std::vector<int> &vec1, const std::vector<int> &vec2);
int vec_gt_unsigned(const std::vector<int> &vec1, const std::vector<int> &vec2);
int vec_eq(const std::vector<int> &vec1, const std::vector<int> &vec2);
int vec_ne(const std::vector<int> &vec1, const std::vector<int> &vec2);
std::vector<int> vec_shl(const std::vector<int> &vec1, int shift, bool signExtend = false);
std::vector<int> vec_srl(const std::vector<int> &vec1, int shift);
std::vector<int> vec_shr(const std::vector<int> &vec1, int shift, bool signExtend = false) { return vec_shl(vec1, -shift, signExtend); }
std::vector<int> vec_srr(const std::vector<int> &vec1, int shift) { return vec_srl(vec1, -shift); }
void vec_append(std::vector<int> &vec, const std::vector<int> &vec1) const;
void vec_append_signed(std::vector<int> &vec, const std::vector<int> &vec1, int64_t value);
void vec_append_unsigned(std::vector<int> &vec, const std::vector<int> &vec1, uint64_t value);
int64_t vec_model_get_signed(const std::vector<int> &modelExpressions, const std::vector<bool> &modelValues, const std::vector<int> &vec1) const;
uint64_t vec_model_get_unsigned(const std::vector<int> &modelExpressions, const std::vector<bool> &modelValues, const std::vector<int> &vec1) const;
int vec_reduce_and(const std::vector<int> &vec1);
int vec_reduce_or(const std::vector<int> &vec1);
void vec_set(const std::vector<int> &vec1, const std::vector<int> &vec2);
void vec_set_signed(const std::vector<int> &vec1, int64_t value);
void vec_set_unsigned(const std::vector<int> &vec1, uint64_t value);
// helpers for generating ezSATbit and ezSATvec objects
struct ezSATbit bit(_V a);
struct ezSATvec vec(const std::vector<int> &vec);
// printing CNF and internal state
void printDIMACS(FILE *f, bool verbose = false) const;
void printInternalState(FILE *f) const;
// more sophisticated constraints (designed to be used directly with assume(..))
int onehot(const std::vector<int> &vec, bool max_only = false);
int manyhot(const std::vector<int> &vec, int min_hot, int max_hot = -1);
int ordered(const std::vector<int> &vec1, const std::vector<int> &vec2, bool allow_equal = true);
};
// helper classes for using operator overloading when generating complex expressions
struct ezSATbit
{
ezSAT &sat;
int id;
ezSATbit(ezSAT &sat, ezSAT::_V a) : sat(sat), id(sat.VAR(a)) { }
ezSATbit operator ~() { return ezSATbit(sat, sat.NOT(id)); }
ezSATbit operator &(const ezSATbit &other) { return ezSATbit(sat, sat.AND(id, other.id)); }
ezSATbit operator |(const ezSATbit &other) { return ezSATbit(sat, sat.OR(id, other.id)); }
ezSATbit operator ^(const ezSATbit &other) { return ezSATbit(sat, sat.XOR(id, other.id)); }
ezSATbit operator ==(const ezSATbit &other) { return ezSATbit(sat, sat.IFF(id, other.id)); }
ezSATbit operator !=(const ezSATbit &other) { return ezSATbit(sat, sat.NOT(sat.IFF(id, other.id))); }
operator int() const { return id; }
operator ezSAT::_V() const { return ezSAT::_V(id); }
operator std::vector<int>() const { return std::vector<int>(1, id); }
};
struct ezSATvec
{
ezSAT &sat;
std::vector<int> vec;
ezSATvec(ezSAT &sat, const std::vector<int> &vec) : sat(sat), vec(vec) { }
ezSATvec operator ~() { return ezSATvec(sat, sat.vec_not(vec)); }
ezSATvec operator -() { return ezSATvec(sat, sat.vec_neg(vec)); }
ezSATvec operator &(const ezSATvec &other) { return ezSATvec(sat, sat.vec_and(vec, other.vec)); }
ezSATvec operator |(const ezSATvec &other) { return ezSATvec(sat, sat.vec_or(vec, other.vec)); }
ezSATvec operator ^(const ezSATvec &other) { return ezSATvec(sat, sat.vec_xor(vec, other.vec)); }
ezSATvec operator +(const ezSATvec &other) { return ezSATvec(sat, sat.vec_add(vec, other.vec)); }
ezSATvec operator -(const ezSATvec &other) { return ezSATvec(sat, sat.vec_sub(vec, other.vec)); }
ezSATbit operator < (const ezSATvec &other) { return ezSATbit(sat, sat.vec_lt_unsigned(vec, other.vec)); }
ezSATbit operator <=(const ezSATvec &other) { return ezSATbit(sat, sat.vec_le_unsigned(vec, other.vec)); }
ezSATbit operator ==(const ezSATvec &other) { return ezSATbit(sat, sat.vec_eq(vec, other.vec)); }
ezSATbit operator !=(const ezSATvec &other) { return ezSATbit(sat, sat.vec_ne(vec, other.vec)); }
ezSATbit operator >=(const ezSATvec &other) { return ezSATbit(sat, sat.vec_ge_unsigned(vec, other.vec)); }
ezSATbit operator > (const ezSATvec &other) { return ezSATbit(sat, sat.vec_gt_unsigned(vec, other.vec)); }
ezSATvec operator <<(int shift) { return ezSATvec(sat, sat.vec_shl(vec, shift)); }
ezSATvec operator >>(int shift) { return ezSATvec(sat, sat.vec_shr(vec, shift)); }
operator std::vector<int>() const { return vec; }
};
#endif