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move out sign

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2020-01-19 09:34:22 -06:00
parent 89c91765f6
commit d3b105f9f8
15 changed files with 176 additions and 168 deletions
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70
src/math/polynomial/upolynomial.cpp
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@ -1327,25 +1327,25 @@ namespace upolynomial {
div(sz, p, 2, two_x_1, buffer);
}
polynomial::sign manager::sign_of(numeral const & c) {
sign manager::sign_of(numeral const & c) {
if (m().is_zero(c))
return polynomial::sign_zero;
return sign_zero;
if (m().is_pos(c))
return polynomial::sign_pos;
return sign_pos;
else
return polynomial::sign_neg;
return sign_neg;
}
// Return the number of sign changes in the coefficients of p
unsigned manager::sign_changes(unsigned sz, numeral const * p) {
unsigned r = 0;
auto prev_sign = polynomial::sign_zero;
auto prev_sign = sign_zero;
unsigned i = 0;
for (; i < sz; i++) {
auto sign = sign_of(p[i]);
if (sign == polynomial::sign_zero)
if (sign == sign_zero)
continue;
if (sign != prev_sign && prev_sign != polynomial::sign_zero)
if (sign != prev_sign && prev_sign != sign_zero)
r++;
prev_sign = sign;
}
@ -1375,7 +1375,7 @@ namespace upolynomial {
}
return sign_changes(Q.size(), Q.c_ptr());
#endif
polynomial::sign prev_sign = polynomial::sign_zero;
sign prev_sign = sign_zero;
unsigned num_vars = 0;
// a0 a1 a2 a3
// a0 a0+a1 a0+a1+a2 a0+a1+a2+a3
@ -1389,9 +1389,9 @@ namespace upolynomial {
m().add(Q[k], Q[k-1], Q[k]);
}
auto sign = sign_of(Q[k-1]);
if (polynomial::is_zero(sign))
if (::is_zero(sign))
continue;
if (sign != prev_sign && !polynomial::is_zero(prev_sign)) {
if (sign != prev_sign && !::is_zero(prev_sign)) {
num_vars++;
if (num_vars > 1)
return num_vars;
@ -1729,14 +1729,14 @@ namespace upolynomial {
}
// Evaluate the sign of p(b)
polynomial::sign manager::eval_sign_at(unsigned sz, numeral const * p, mpbq const & b) {
sign manager::eval_sign_at(unsigned sz, numeral const * p, mpbq const & b) {
// Actually, given b = c/2^k, we compute the sign of (2^k)^n*p(b)
// Original Horner Sequence
// ((a_n * b + a_{n-1})*b + a_{n-2})*b + a_{n-3} ...
// Variation of the Horner Sequence for (2^k)^n*p(b)
// ((a_n * c + a_{n-1}*2_k)*c + a_{n-2}*(2_k)^2)*c + a_{n-3}*(2_k)^3 ... + a_0*(2_k)^n
if (sz == 0)
return polynomial::sign_zero;
return sign_zero;
if (sz == 1)
return sign_of(p[0]);
numeral const & c = b.numerator();
@ -1762,14 +1762,14 @@ namespace upolynomial {
}
// Evaluate the sign of p(b)
polynomial::sign manager::eval_sign_at(unsigned sz, numeral const * p, mpq const & b) {
sign manager::eval_sign_at(unsigned sz, numeral const * p, mpq const & b) {
// Actually, given b = c/d, we compute the sign of (d^n)*p(b)
// Original Horner Sequence
// ((a_n * b + a_{n-1})*b + a_{n-2})*b + a_{n-3} ...
// Variation of the Horner Sequence for (d^n)*p(b)
// ((a_n * c + a_{n-1}*d)*c + a_{n-2}*d^2)*c + a_{n-3}*d^3 ... + a_0*d^n
if (sz == 0)
return polynomial::sign_zero;
return sign_zero;
if (sz == 1)
return sign_of(p[0]);
numeral const & c = b.numerator();
@ -1796,11 +1796,11 @@ namespace upolynomial {
}
// Evaluate the sign of p(b)
polynomial::sign manager::eval_sign_at(unsigned sz, numeral const * p, mpz const & b) {
sign manager::eval_sign_at(unsigned sz, numeral const * p, mpz const & b) {
// Using Horner Sequence
// ((a_n * b + a_{n-1})*b + a_{n-2})*b + a_{n-3} ...
if (sz == 0)
return polynomial::sign_zero;
return sign_zero;
if (sz == 1)
return sign_of(p[0]);
scoped_numeral r(m());
@ -1817,21 +1817,21 @@ namespace upolynomial {
return sign_of(r);
}
polynomial::sign manager::eval_sign_at_zero(unsigned sz, numeral const * p) {
sign manager::eval_sign_at_zero(unsigned sz, numeral const * p) {
if (sz == 0)
return polynomial::sign_zero;
return sign_zero;
return sign_of(p[0]);
}
polynomial::sign manager::eval_sign_at_plus_inf(unsigned sz, numeral const * p) {
sign manager::eval_sign_at_plus_inf(unsigned sz, numeral const * p) {
if (sz == 0)
return polynomial::sign_zero;
return sign_zero;
return sign_of(p[sz-1]);
}
polynomial::sign manager::eval_sign_at_minus_inf(unsigned sz, numeral const * p) {
sign manager::eval_sign_at_minus_inf(unsigned sz, numeral const * p) {
if (sz == 0)
return polynomial::sign_zero;
return sign_zero;
unsigned degree = sz - 1;
if (degree % 2 == 0)
return sign_of(p[sz-1]);
@ -2751,7 +2751,7 @@ namespace upolynomial {
The arguments sign_a and sign_b must contain the values returned by
eval_sign_at(sz, p, a) and eval_sign_at(sz, p, b).
*/
bool manager::refine_core(unsigned sz, numeral const * p, polynomial::sign sign_a, mpbq_manager & bqm, mpbq & a, mpbq & b) {
bool manager::refine_core(unsigned sz, numeral const * p, sign sign_a, mpbq_manager & bqm, mpbq & a, mpbq & b) {
SASSERT(sign_a == eval_sign_at(sz, p, a));
SASSERT(-sign_a == eval_sign_at(sz, p, b));
SASSERT(sign_a != 0);
@ -2759,7 +2759,7 @@ namespace upolynomial {
bqm.add(a, b, mid);
bqm.div2(mid);
auto sign_mid = eval_sign_at(sz, p, mid);
if (polynomial::is_zero(sign_mid)) {
if (::is_zero(sign_mid)) {
swap(mid, a);
return false;
}
@ -2774,8 +2774,8 @@ namespace upolynomial {
// See refine_core
bool manager::refine(unsigned sz, numeral const * p, mpbq_manager & bqm, mpbq & a, mpbq & b) {
polynomial::sign sign_a = eval_sign_at(sz, p, a);
SASSERT(!polynomial::is_zero(sign_a));
sign sign_a = eval_sign_at(sz, p, a);
SASSERT(!::is_zero(sign_a));
return refine_core(sz, p, sign_a, bqm, a, b);
}
@ -2784,8 +2784,8 @@ namespace upolynomial {
//
// Return TRUE, if interval was squeezed, and new interval is stored in (a,b).
// Return FALSE, if the actual root was found, it is stored in a.
bool manager::refine_core(unsigned sz, numeral const * p, polynomial::sign sign_a, mpbq_manager & bqm, mpbq & a, mpbq & b, unsigned prec_k) {
SASSERT(sign_a != polynomial::sign_zero);
bool manager::refine_core(unsigned sz, numeral const * p, sign sign_a, mpbq_manager & bqm, mpbq & a, mpbq & b, unsigned prec_k) {
SASSERT(sign_a != sign_zero);
SASSERT(sign_a == eval_sign_at(sz, p, a));
SASSERT(-sign_a == eval_sign_at(sz, p, b));
scoped_mpbq w(bqm);
@ -2802,16 +2802,16 @@ namespace upolynomial {
}
bool manager::refine(unsigned sz, numeral const * p, mpbq_manager & bqm, mpbq & a, mpbq & b, unsigned prec_k) {
polynomial::sign sign_a = eval_sign_at(sz, p, a);
sign sign_a = eval_sign_at(sz, p, a);
SASSERT(eval_sign_at(sz, p, b) == -sign_a);
SASSERT(sign_a != 0);
return refine_core(sz, p, sign_a, bqm, a, b, prec_k);
}
bool manager::convert_q2bq_interval(unsigned sz, numeral const * p, mpq const & a, mpq const & b, mpbq_manager & bqm, mpbq & c, mpbq & d) {
polynomial::sign sign_a = eval_sign_at(sz, p, a);
polynomial::sign sign_b = eval_sign_at(sz, p, b);
SASSERT(!polynomial::is_zero(sign_a) && !polynomial::is_zero(sign_b));
sign sign_a = eval_sign_at(sz, p, a);
sign sign_b = eval_sign_at(sz, p, b);
SASSERT(!::is_zero(sign_a) && !::is_zero(sign_b));
SASSERT(sign_a == -sign_b);
bool found_d = false;
TRACE("convert_bug",
@ -2843,7 +2843,7 @@ namespace upolynomial {
SASSERT(bqm.lt(upper, b));
while (true) {
auto sign_upper = eval_sign_at(sz, p, upper);
if (polynomial::is_zero(sign_upper)) {
if (::is_zero(sign_upper)) {
// found root
bqm.swap(c, upper);
bqm.del(lower); bqm.del(upper);
@ -2887,8 +2887,8 @@ namespace upolynomial {
SASSERT(bqm.lt(lower, upper));
SASSERT(bqm.lt(lower, b));
while (true) {
polynomial::sign sign_lower = eval_sign_at(sz, p, lower);
if (polynomial::is_zero(sign_lower)) {
sign sign_lower = eval_sign_at(sz, p, lower);
if (::is_zero(sign_lower)) {
// found root
bqm.swap(c, lower);
bqm.del(lower); bqm.del(upper);