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Simplify RCF C API. Add Z3_rcf_mk_roots (C API) and MkRoots (Python API). Implement basic root isolation support.

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
This commit is contained in:
Leonardo de Moura 2013-01-07 12:25:28 -08:00
parent 3c1f1a3b65
commit 09b5724d82
6 changed files with 216 additions and 118 deletions

View file

@ -23,29 +23,10 @@ Notes:
#include"z3.h"
#include"api_log_macros.h"
#include"api_context.h"
#include"api_rcf.h"
#include"realclosure.h"
extern "C" {
void Z3_API Z3_rcf_inc_ref(Z3_context c, Z3_rcf_num a) {
Z3_TRY;
LOG_Z3_rcf_inc_ref(c, a);
RESET_ERROR_CODE();
to_rcf_num(a)->inc_ref();
Z3_CATCH;
}
void Z3_API Z3_rcf_dec_ref(Z3_context c, Z3_rcf_num a) {
Z3_TRY;
LOG_Z3_rcf_dec_ref(c, a);
RESET_ERROR_CODE();
if (to_rcf_num(a)->ref_count() == 1) {
mk_c(c)->rcfm().del(to_rcnumeral(a));
}
to_rcf_num(a)->dec_ref();
Z3_CATCH;
}
static rcmanager & rcfm(Z3_context c) {
return mk_c(c)->rcfm();
}
@ -53,14 +34,24 @@ extern "C" {
static void reset_rcf_cancel(Z3_context c) {
rcfm(c).reset_cancel();
}
static Z3_rcf_num mk_rcf_num(Z3_context c, rcnumeral & a) {
Z3_rcf_num_ref * r = alloc(Z3_rcf_num_ref);
rcfm(c).swap(r->m_num, a);
mk_c(c)->save_object(r);
return of_rcf_num(r);
static rcnumeral to_rcnumeral(Z3_rcf_num a) {
return rcnumeral::mk(a);
}
static Z3_rcf_num from_rcnumeral(rcnumeral a) {
return reinterpret_cast<Z3_rcf_num>(a.c_ptr());
}
void Z3_API Z3_rcf_del(Z3_context c, Z3_rcf_num a) {
Z3_TRY;
LOG_Z3_rcf_del(c, a);
RESET_ERROR_CODE();
rcnumeral _a = to_rcnumeral(a);
rcfm(c).del(_a);
Z3_CATCH;
}
Z3_rcf_num Z3_API Z3_rcf_mk_rational(Z3_context c, Z3_string val) {
Z3_TRY;
LOG_Z3_rcf_mk_rational(c, val);
@ -68,9 +59,9 @@ extern "C" {
reset_rcf_cancel(c);
scoped_mpq q(rcfm(c).qm());
rcfm(c).qm().set(q, val);
scoped_rcnumeral r(rcfm(c));
rcnumeral r;
rcfm(c).set(r, q);
RETURN_Z3(mk_rcf_num(c, r));
RETURN_Z3(from_rcnumeral(r));
Z3_CATCH_RETURN(0);
}
@ -79,9 +70,9 @@ extern "C" {
LOG_Z3_rcf_mk_small_int(c, val);
RESET_ERROR_CODE();
reset_rcf_cancel(c);
scoped_rcnumeral r(rcfm(c));
rcnumeral r;
rcfm(c).set(r, val);
RETURN_Z3(mk_rcf_num(c, r));
RETURN_Z3(from_rcnumeral(r));
Z3_CATCH_RETURN(0);
}
@ -90,9 +81,9 @@ extern "C" {
LOG_Z3_rcf_mk_pi(c);
RESET_ERROR_CODE();
reset_rcf_cancel(c);
scoped_rcnumeral r(rcfm(c));
rcnumeral r;
rcfm(c).mk_pi(r);
RETURN_Z3(mk_rcf_num(c, r));
RETURN_Z3(from_rcnumeral(r));
Z3_CATCH_RETURN(0);
}
@ -101,9 +92,9 @@ extern "C" {
LOG_Z3_rcf_mk_e(c);
RESET_ERROR_CODE();
reset_rcf_cancel(c);
scoped_rcnumeral r(rcfm(c));
rcnumeral r;
rcfm(c).mk_e(r);
RETURN_Z3(mk_rcf_num(c, r));
RETURN_Z3(from_rcnumeral(r));
Z3_CATCH_RETURN(0);
}
@ -112,9 +103,37 @@ extern "C" {
LOG_Z3_rcf_mk_infinitesimal(c, name);
RESET_ERROR_CODE();
reset_rcf_cancel(c);
scoped_rcnumeral r(rcfm(c));
rcnumeral r;
rcfm(c).mk_infinitesimal(name, r);
RETURN_Z3(mk_rcf_num(c, r));
RETURN_Z3(from_rcnumeral(r));
Z3_CATCH_RETURN(0);
}
unsigned Z3_API Z3_rcf_mk_roots(Z3_context c, unsigned n, Z3_rcf_num const a[], Z3_rcf_num roots[]) {
Z3_TRY;
LOG_Z3_rcf_mk_roots(c, n, a, roots);
RESET_ERROR_CODE();
reset_rcf_cancel(c);
rcnumeral_vector av;
unsigned rz = 0;
for (unsigned i = 0; i < n; i++) {
if (!rcfm(c).is_zero(to_rcnumeral(a[i])))
rz = i + 1;
av.push_back(to_rcnumeral(a[i]));
}
if (rz == 0) {
// it is the zero polynomial
SET_ERROR_CODE(Z3_INVALID_ARG);
return 0;
}
av.shrink(rz);
rcnumeral_vector rs;
rcfm(c).isolate_roots(av.size(), av.c_ptr(), rs);
unsigned num_roots = rs.size();
for (unsigned i = 0; i < num_roots; i++) {
roots[i] = from_rcnumeral(rs[i]);
}
return num_roots;
Z3_CATCH_RETURN(0);
}
@ -123,9 +142,9 @@ extern "C" {
LOG_Z3_rcf_add(c, a, b);
RESET_ERROR_CODE();
reset_rcf_cancel(c);
scoped_rcnumeral r(rcfm(c));
rcnumeral r;
rcfm(c).add(to_rcnumeral(a), to_rcnumeral(b), r);
RETURN_Z3(mk_rcf_num(c, r));
RETURN_Z3(from_rcnumeral(r));
Z3_CATCH_RETURN(0);
}
@ -134,9 +153,9 @@ extern "C" {
LOG_Z3_rcf_sub(c, a, b);
RESET_ERROR_CODE();
reset_rcf_cancel(c);
scoped_rcnumeral r(rcfm(c));
rcnumeral r;
rcfm(c).sub(to_rcnumeral(a), to_rcnumeral(b), r);
RETURN_Z3(mk_rcf_num(c, r));
RETURN_Z3(from_rcnumeral(r));
Z3_CATCH_RETURN(0);
}
@ -145,9 +164,9 @@ extern "C" {
LOG_Z3_rcf_mul(c, a, b);
RESET_ERROR_CODE();
reset_rcf_cancel(c);
scoped_rcnumeral r(rcfm(c));
rcnumeral r;
rcfm(c).mul(to_rcnumeral(a), to_rcnumeral(b), r);
RETURN_Z3(mk_rcf_num(c, r));
RETURN_Z3(from_rcnumeral(r));
Z3_CATCH_RETURN(0);
}
@ -156,9 +175,9 @@ extern "C" {
LOG_Z3_rcf_div(c, a, b);
RESET_ERROR_CODE();
reset_rcf_cancel(c);
scoped_rcnumeral r(rcfm(c));
rcnumeral r;
rcfm(c).div(to_rcnumeral(a), to_rcnumeral(b), r);
RETURN_Z3(mk_rcf_num(c, r));
RETURN_Z3(from_rcnumeral(r));
Z3_CATCH_RETURN(0);
}
@ -167,9 +186,9 @@ extern "C" {
LOG_Z3_rcf_neg(c, a);
RESET_ERROR_CODE();
reset_rcf_cancel(c);
scoped_rcnumeral r(rcfm(c));
rcnumeral r;
rcfm(c).neg(to_rcnumeral(a), r);
RETURN_Z3(mk_rcf_num(c, r));
RETURN_Z3(from_rcnumeral(r));
Z3_CATCH_RETURN(0);
}
@ -178,9 +197,9 @@ extern "C" {
LOG_Z3_rcf_inv(c, a);
RESET_ERROR_CODE();
reset_rcf_cancel(c);
scoped_rcnumeral r(rcfm(c));
rcnumeral r;
rcfm(c).inv(to_rcnumeral(a), r);
RETURN_Z3(mk_rcf_num(c, r));
RETURN_Z3(from_rcnumeral(r));
Z3_CATCH_RETURN(0);
}

View file

@ -1,38 +0,0 @@
/*++
Copyright (c) 2013 Microsoft Corporation
Module Name:
api_rcf.h
Abstract:
Additional APIs for handling elements of the Z3 real closed field that contains:
- transcendental extensions
- infinitesimal extensions
- algebraic extensions
Author:
Leonardo de Moura (leonardo) 2012-01-05
Notes:
--*/
#ifndef _API_RCF_H_
#define _API_RCF_H_
#include"api_util.h"
#include"realclosure.h"
struct Z3_rcf_num_ref : public api::object {
rcnumeral m_num;
virtual ~Z3_rcf_num_ref() {}
};
inline Z3_rcf_num_ref * to_rcf_num(Z3_rcf_num n) { return reinterpret_cast<Z3_rcf_num_ref *>(n); }
inline Z3_rcf_num of_rcf_num(Z3_rcf_num_ref * n) { return reinterpret_cast<Z3_rcf_num>(n); }
inline rcnumeral & to_rcnumeral(Z3_rcf_num n) { SASSERT(n != 0); return to_rcf_num(n)->m_num; }
#endif

View file

@ -32,6 +32,22 @@ def MkInfinitesimal(name="eps", ctx=None):
ctx = z3._get_ctx(ctx)
return RCFNum(Z3_rcf_mk_infinitesimal(ctx.ref(), name), ctx)
def MkRoots(p, ctx=None):
ctx = z3._get_ctx(ctx)
num = len(p)
_tmp = []
_as = (RCFNumObj * num)()
_rs = (RCFNumObj * num)()
for i in range(num):
_a = _to_rcfnum(p[i], ctx)
_tmp.append(_a) # prevent GC
_as[i] = _a.num
nr = Z3_rcf_mk_roots(ctx.ref(), num, _as, _rs)
r = []
for i in range(nr):
r.append(RCFNum(_rs[i], ctx))
return r
class RCFNum:
def __init__(self, num, ctx=None):
# TODO: add support for converting AST numeral values into RCFNum
@ -41,10 +57,9 @@ class RCFNum:
else:
self.ctx = z3._get_ctx(ctx)
self.num = Z3_rcf_mk_rational(self.ctx_ref(), str(num))
Z3_rcf_inc_ref(self.ctx_ref(), self.num)
def __del__(self):
Z3_rcf_dec_ref(self.ctx_ref(), self.num)
Z3_rcf_del(self.ctx_ref(), self.num)
def ctx_ref(self):
return self.ctx.ref()
@ -53,28 +68,36 @@ class RCFNum:
return Z3_rcf_num_to_string(self.ctx_ref(), self.num)
def __add__(self, other):
return RCFNum(Z3_rcf_add(self.ctx_ref(), self.num, _to_rcfnum(other, self.ctx).num), self.ctx)
v = _to_rcfnum(other, self.ctx)
return RCFNum(Z3_rcf_add(self.ctx_ref(), self.num, v.num), self.ctx)
def __radd__(self, other):
return RCFNum(Z3_rcf_add(self.ctx_ref(), _to_rcfnum(other, self.ctx).num, self.num), self.ctx)
v = _to_rcfnum(other, self.ctx)
return RCFNum(Z3_rcf_add(self.ctx_ref(), v.num, self.num), self.ctx)
def __mul__(self, other):
return RCFNum(Z3_rcf_mul(self.ctx_ref(), self.num, _to_rcfnum(other, self.ctx).num), self.ctx)
v = _to_rcfnum(other, self.ctx)
return RCFNum(Z3_rcf_mul(self.ctx_ref(), self.num, v.num), self.ctx)
def __rmul__(self, other):
return RCFNum(Z3_rcf_mul(self.ctx_ref(), _to_rcfnum(other, self.ctx).num, self.num), self.ctx)
v = _to_rcfnum(other, self.ctx)
return RCFNum(Z3_rcf_mul(self.ctx_ref(), v.num, self.num), self.ctx)
def __sub__(self, other):
return RCFNum(Z3_rcf_sub(self.ctx_ref(), self.num, _to_rcfnum(other, self.ctx).num), self.ctx)
v = _to_rcfnum(other, self.ctx)
return RCFNum(Z3_rcf_sub(self.ctx_ref(), self.num, v.num), self.ctx)
def __rsub__(self, other):
return RCFNum(Z3_rcf_sub(self.ctx_ref(), _to_rcfnum(other, self.ctx).num, self.num), self.ctx)
v = _to_rcfnum(other, self.ctx)
return RCFNum(Z3_rcf_sub(self.ctx_ref(), v.num, self.num), self.ctx)
def __div__(self, other):
return RCFNum(Z3_rcf_div(self.ctx_ref(), self.num, _to_rcfnum(other, self.ctx).num), self.ctx)
v = _to_rcfnum(other, self.ctx)
return RCFNum(Z3_rcf_div(self.ctx_ref(), self.num, v.num), self.ctx)
def __rdiv__(self, other):
return RCFNum(Z3_rcf_div(self.ctx_ref(), _to_rcfnum(other, self.ctx).num, self.num), self.ctx)
v = _to_rcfnum(other, self.ctx)
return RCFNum(Z3_rcf_div(self.ctx_ref(), v.num, self.num), self.ctx)
def __neg__(self):
return self.__rsub__(0)
@ -83,32 +106,42 @@ class RCFNum:
return Z3_rcf_num_to_decimal_string(self.ctx_ref(), self.num, prec)
def __lt__(self, other):
return Z3_rcf_lt(self.ctx_ref(), self.num, _to_rcfnum(other, self.ctx).num)
v = _to_rcfnum(other, self.ctx)
return Z3_rcf_lt(self.ctx_ref(), self.num, v.num)
def __rlt__(self, other):
return Z3_rcf_lt(self.ctx_ref(), _to_rcfnum(other, self.ctx).num, self.num)
v = _to_rcfnum(other, self.ctx)
return Z3_rcf_lt(self.ctx_ref(), v.num, self.num)
def __gt__(self, other):
return Z3_rcf_gt(self.ctx_ref(), self.num, _to_rcfnum(other, self.ctx).num)
v = _to_rcfnum(other, self.ctx)
return Z3_rcf_gt(self.ctx_ref(), self.num, v.num)
def __rgt__(self, other):
return Z3_rcf_gt(self.ctx_ref(), _to_rcfnum(other, self.ctx).num, self.num)
v = _to_rcfnum(other, self.ctx)
return Z3_rcf_gt(self.ctx_ref(), v.num, self.num)
def __le__(self, other):
return Z3_rcf_le(self.ctx_ref(), self.num, _to_rcfnum(other, self.ctx).num)
v = _to_rcfnum(other, self.ctx)
return Z3_rcf_le(self.ctx_ref(), self.num, v.num)
def __rle__(self, other):
return Z3_rcf_le(self.ctx_ref(), _to_rcfnum(other, self.ctx).num, self.num)
v = _to_rcfnum(other, self.ctx)
return Z3_rcf_le(self.ctx_ref(), v.num, self.num)
def __ge__(self, other):
return Z3_rcf_ge(self.ctx_ref(), self.num, _to_rcfnum(other, self.ctx).num)
v = _to_rcfnum(other, self.ctx)
return Z3_rcf_ge(self.ctx_ref(), self.num, v.num)
def __rge__(self, other):
return Z3_rcf_ge(self.ctx_ref(), _to_rcfnum(other, self.ctx).num, self.num)
v = _to_rcfnum(other, self.ctx)
return Z3_rcf_ge(self.ctx_ref(), v.num, self.num)
def __eq__(self, other):
return Z3_rcf_eq(self.ctx_ref(), self.num, _to_rcfnum(other, self.ctx).num)
v = _to_rcfnum(other, self.ctx)
return Z3_rcf_eq(self.ctx_ref(), self.num, v.num)
def __ne__(self, other):
return Z3_rcf_neq(self.ctx_ref(), self.num, _to_rcfnum(other, self.ctx).num)
v = _to_rcfnum(other, self.ctx)
return Z3_rcf_neq(self.ctx_ref(), self.num, v.num)

View file

@ -27,18 +27,11 @@ extern "C" {
#endif // __cplusplus
/**
\brief Increment the reference counter of a RCF numeral.
def_API('Z3_rcf_inc_ref', VOID, (_in(CONTEXT), _in(RCF_NUM)))
*/
void Z3_API Z3_rcf_inc_ref(__in Z3_context c, __in Z3_rcf_num a);
\brief Delete a RCF numeral created using the RCF API.
/**
\brief Decrement the reference counter of a RCF numeral.
def_API('Z3_rcf_dec_ref', VOID, (_in(CONTEXT), _in(RCF_NUM)))
def_API('Z3_rcf_del', VOID, (_in(CONTEXT), _in(RCF_NUM)))
*/
void Z3_API Z3_rcf_dec_ref(__in Z3_context c, __in Z3_rcf_num a);
void Z3_API Z3_rcf_del(__in Z3_context c, __in Z3_rcf_num a);
/**
\brief Return a RCF rational using the given string.
@ -75,6 +68,17 @@ extern "C" {
*/
Z3_rcf_num Z3_API Z3_rcf_mk_infinitesimal(__in Z3_context c, __in Z3_string name);
/**
\brief Store in roots the roots of the polynomial <tt>a[n-1]*x^{n-1} + ... + a[0]</tt>.
The output vector \c roots must have size \c n.
It returns the number of roots of the polynomial.
\pre The input polynomial is not the zero polynomial.
def_API('Z3_rcf_mk_roots', UINT, (_in(CONTEXT), _in(UINT), _in_array(1, RCF_NUM), _out_array(1, RCF_NUM)))
*/
unsigned Z3_API Z3_rcf_mk_roots(__in Z3_context c, __in unsigned n, __in_ecount(n) Z3_rcf_num const a[], __out_ecount(n) Z3_rcf_num roots[]);
/**
\brief Return the value a + b.

View file

@ -1082,10 +1082,86 @@ namespace realclosure {
}
}
void isolate_roots(unsigned n, numeral const * as, numeral_vector & roots) {
/**
\brief Root isolation for polynomials that are
- nonlinear (degree > 2)
- zero is not a root
- square free
- nonconstant
*/
void nl_nz_sqf_isolate_roots(unsigned n, value * const * as, numeral_vector & roots) {
SASSERT(n > 2);
SASSERT(!is_zero(as[0]));
SASSERT(!is_zero(as[n-1]));
// TODO
}
/**
\brief Root isolation for polynomials that are
- zero is not a root
- square free
- nonconstant
*/
void nz_sqf_isolate_roots(unsigned n, value * const * as, numeral_vector & roots) {
SASSERT(n > 1);
SASSERT(!is_zero(as[0]));
SASSERT(!is_zero(as[n-1]));
if (n == 2) {
// we don't need a field extension for linear polynomials.
numeral r;
value_ref neg_as_0(*this);
neg_as_0 = neg(as[0]);
set(r, div(neg_as_0, as[1]));
roots.push_back(r);
}
else {
nl_nz_sqf_isolate_roots(n, as, roots);
}
}
/**
\brief Root isolation for polynomials where 0 is not a root.
*/
void nz_isolate_roots(unsigned n, value * const * as, numeral_vector & roots) {
SASSERT(n > 0);
SASSERT(!is_zero(as[0]));
SASSERT(!is_zero(as[n-1]));
if (n == 1) {
// constant polynomial
return;
}
value_ref_buffer sqf(*this);
square_free(n, as, sqf);
nz_sqf_isolate_roots(sqf.size(), sqf.c_ptr(), roots);
}
/**
\brief Root isolation entry point.
*/
void isolate_roots(unsigned n, numeral const * as, numeral_vector & roots) {
SASSERT(n > 0);
SASSERT(!is_zero(as[n-1]));
if (n == 1) {
// constant polynomial
return;
}
unsigned i = 0;
for (; i < n; i++) {
if (!is_zero(as[i]))
break;
}
SASSERT(i < n);
SASSERT(!is_zero(as[i]));
ptr_buffer<value> as_values;
for (; i < n; i++)
as_values.push_back(as[i].m_value);
nz_isolate_roots(as_values.size(), as_values.c_ptr(), roots);
if (as_values.size() < n) {
// zero is a root
roots.push_back(numeral());
}
}
void reset(numeral & a) {
del(a);
SASSERT(is_zero(a));

View file

@ -278,6 +278,10 @@ namespace realclosure {
value * m_value;
public:
num():m_value(0) {}
// Low level functions for implementing the C API
void * c_ptr() { return m_value; }
static num mk(void * ptr) { num r; r.m_value = reinterpret_cast<value*>(ptr); return r; }
};
};