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