lean2/src/util/numerics/mpz.cpp

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/*
Copyright (c) 2013 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Leonardo de Moura
*/
#include <memory>
#include "util/numerics/mpz.h"
namespace lean {
unsigned mpz::log2() const {
if (is_nonpos())
return 0;
unsigned r = mpz_sizeinbase(m_val, 2);
lean_assert(r > 0);
return r - 1;
}
unsigned mpz::mlog2() const {
if (is_nonneg())
return 0;
mpz * _this = const_cast<mpz*>(this);
_this->neg();
lean_assert(is_pos());
unsigned r = mpz_sizeinbase(m_val, 2);
_this->neg();
lean_assert(is_neg());
return r - 1;
}
bool mpz::is_power_of_two(unsigned & shift) const {
if (is_nonpos())
return false;
if (mpz_popcount(m_val) == 1) {
shift = log2();
return true;
} else {
return false;
}
}
mpz operator%(mpz const & a, mpz const & b) {
mpz r(rem(a, b));
if (r.is_neg()) {
if (b.is_pos())
r += b;
else
r -= b;
}
return r;
}
bool root(mpz & root, mpz const & a, unsigned k) {
static thread_local mpz rem;
mpz_rootrem(root.m_val, rem.m_val, a.m_val, k);
return rem.is_zero();
}
void display(std::ostream & out, __mpz_struct const * v) {
size_t sz = mpz_sizeinbase(v, 10) + 2;
if (sz < 1024) {
char buffer[1024];
mpz_get_str(buffer, 10, v);
out << buffer;
} else {
std::unique_ptr<char> buffer(new char[sz]);
mpz_get_str(buffer.get(), 10, v);
out << buffer.get();
}
}
std::ostream & operator<<(std::ostream & out, mpz const & v) {
display(out, v.m_val);
return out;
}
static mpz g_zero;
mpz const & numeric_traits<mpz>::zero() {
lean_assert(is_zero(g_zero));
return g_zero;
}
}
void print(lean::mpz const & n) { std::cout << n << std::endl; }