Hi,
I managed to get boost multi-precision to work with 128 bit integers on Windows
using clang.
I had to change this in clang.hpp:
#if defined(__SIZEOF_INT128__) && !defined(BOOST_NVCC_CXX03) &&
!defined(_MSC_VER) <--- remove this last thing
# define BOOST_HAS_INT128
#endif
Clang-cl defines _
Hi,
In my program I am seeing my code use the slower (I assume)
subtract_unsigned_constexpr rather than subtract_unsigned with he borrow chain
handled intrinsics.
This seems to be happening because of these lines in intel_intrinsics.hpp:
#if defined(__clang__) && (__clang__ < 9)
// We appear to
Hi,
In my program I see a lot of time taken up by add/subtract_unsigned. I have a
couple of thoughts on the code:
Carry propagation outside the range of the smallest number can be improved:
for (; i < x && carry; ++i)
carry = ::boost::multiprecision::detail::addcarry_limb(carry, pa
Hi,
The architecture of cpp_int being build on 64 bit arithmetic using 128 bit
double_limb_type is interesting.
I have a question on the large divide (divide_unsigned_helper). It uses the
upper portions of the large integers to get an estimation of the quotient.
Subtracts out a multiple of that
given what you tell me I think my way forward is to try and get a better
version of the divide routines working.
Neill.
-Original Message-
From: Boost-users On Behalf Of John
Maddock via Boost-users
Sent: Friday, August 20, 2021 9:43 AM
To: Neill Clift via Boost-users
Cc: John Maddock
Hi,
I was trying to understand the algorithm inside the main divide routine. I
struggled with this bit of code:
if ((prem[r_order] <= py[y_order]) && (r_order > 0))
{
double_limb_type a = (static_cast(prem[r_order]) <<
CppInt1::limb_bits) | prem[r_order - 1];
double
