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Diffstat (limited to 'contrib/epee/src/int-util.cpp')
-rw-r--r-- | contrib/epee/src/int-util.cpp | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/contrib/epee/src/int-util.cpp b/contrib/epee/src/int-util.cpp new file mode 100644 index 000000000..e9d0822e0 --- /dev/null +++ b/contrib/epee/src/int-util.cpp @@ -0,0 +1,48 @@ +// Copyright (c) 2019, The Monero Project +// +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without modification, are +// permitted provided that the following conditions are met: +// +// 1. Redistributions of source code must retain the above copyright notice, this list of +// conditions and the following disclaimer. +// +// 2. Redistributions in binary form must reproduce the above copyright notice, this list +// of conditions and the following disclaimer in the documentation and/or other +// materials provided with the distribution. +// +// 3. Neither the name of the copyright holder nor the names of its contributors may be +// used to endorse or promote products derived from this software without specific +// prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY +// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF +// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL +// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, +// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, +// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF +// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +#include <boost/multiprecision/cpp_int.hpp> + +void div128_64(uint64_t dividend_hi, uint64_t dividend_lo, uint64_t divisor, uint64_t* quotient_hi, uint64_t *quotient_lo, uint64_t *remainder_hi, uint64_t *remainder_lo) +{ + typedef boost::multiprecision::uint128_t uint128_t; + + uint128_t dividend = dividend_hi; + dividend <<= 64; + dividend |= dividend_lo; + + uint128_t q, r; + divide_qr(dividend, uint128_t(divisor), q, r); + + *quotient_hi = ((q >> 64) & 0xffffffffffffffffull).convert_to<uint64_t>(); + *quotient_lo = (q & 0xffffffffffffffffull).convert_to<uint64_t>(); + if (remainder_hi) + *remainder_hi = ((r >> 64) & 0xffffffffffffffffull).convert_to<uint64_t>(); + if (remainder_lo) + *remainder_lo = (r & 0xffffffffffffffffull).convert_to<uint64_t>(); +} |