llvm-project/libcxx/include/__random/generate_canonical.h
Louis Dionne 9783f28cbb
[libc++] Format the code base (#74334)
This patch runs clang-format on all of libcxx/include and libcxx/src, in
accordance with the RFC discussed at [1]. Follow-up patches will format
the benchmarks, the test suite and remaining parts of the code. I'm
splitting this one into its own patch so the diff is a bit easier to
review.

This patch was generated with:

   find libcxx/include libcxx/src -type f \
      | grep -v 'module.modulemap.in' \
      | grep -v 'CMakeLists.txt' \
      | grep -v 'README.txt' \
      | grep -v 'libcxx.imp' \
      | grep -v '__config_site.in' \
      | xargs clang-format -i

A Git merge driver is available in libcxx/utils/clang-format-merge-driver.sh
to help resolve merge and rebase issues across these formatting changes.

[1]: https://discourse.llvm.org/t/rfc-clang-formatting-all-of-libc-once-and-for-all
2023-12-18 14:01:33 -05:00

52 lines
1.6 KiB
C++

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP___RANDOM_GENERATE_CANONICAL_H
#define _LIBCPP___RANDOM_GENERATE_CANONICAL_H
#include <__config>
#include <__random/log2.h>
#include <cstdint>
#include <initializer_list>
#include <limits>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_PUSH_MACROS
#include <__undef_macros>
_LIBCPP_BEGIN_NAMESPACE_STD
// generate_canonical
template <class _RealType, size_t __bits, class _URNG>
_LIBCPP_HIDE_FROM_ABI _RealType generate_canonical(_URNG& __g) {
const size_t __dt = numeric_limits<_RealType>::digits;
const size_t __b = __dt < __bits ? __dt : __bits;
#ifdef _LIBCPP_CXX03_LANG
const size_t __log_r = __log2<uint64_t, _URNG::_Max - _URNG::_Min + uint64_t(1)>::value;
#else
const size_t __log_r = __log2<uint64_t, _URNG::max() - _URNG::min() + uint64_t(1)>::value;
#endif
const size_t __k = __b / __log_r + (__b % __log_r != 0) + (__b == 0);
const _RealType __rp = static_cast<_RealType>(_URNG::max() - _URNG::min()) + _RealType(1);
_RealType __base = __rp;
_RealType __sp = __g() - _URNG::min();
for (size_t __i = 1; __i < __k; ++__i, __base *= __rp)
__sp += (__g() - _URNG::min()) * __base;
return __sp / __base;
}
_LIBCPP_END_NAMESPACE_STD
_LIBCPP_POP_MACROS
#endif // _LIBCPP___RANDOM_GENERATE_CANONICAL_H