constexpr_math.cuh File Reference

mathematical functions (mostly very-simple ones) implemented using compile-time-executable code. More...

#include "common.cuh"
#include <cassert>
#include <type_traits>

Namespaces
	kat::unsafe
	Faster implementations of mathematical functions which can be incorrect for extremal or near-extremal values.
	kat::constexpr_
	This namespace has functions whose constexpr (compile-time) implementation should not be used at run-time.

Macros
#define	CUDA_KAT_ON_DEVICE_CONSTEXPR_MATH_CUH_
#define	sqrt_HELPER_MID   ((low + high + 1) / 2)

Functions
template<typename T , typename Lower = T, typename Upper = T>
constexpr KAT_FHD bool	kat::between_or_equal (T x, Lower l, Upper u) noexcept
template<typename T , typename Lower = T, typename Upper = T>
constexpr KAT_FHD bool	kat::strictly_between (T x, Lower l, Upper u) noexcept
template<typename T >
constexpr KAT_FHD bool	kat::is_power_of_2 (T val) noexcept
template<typename T >
constexpr KAT_FHD T	kat::detail::ipow (T base, unsigned exponent, T coefficient) noexcept
template<typename I >
constexpr KAT_FHD I	kat::ipow (I base, unsigned exponent) noexcept
template<typename I , typename I2 >
constexpr KAT_FHD I	kat::div_rounding_up (I dividend, const I2 divisor) noexcept
template<typename I , typename I2 >
constexpr KAT_FHD I	kat::round_down (const I dividend, const I2 divisor) noexcept
template<typename I , typename I2 = I>
constexpr KAT_FHD I	kat::round_down_to_power_of_2 (I x, I2 power_of_2) noexcept
template<typename I >
constexpr KAT_FHD I	kat::round_down_to_full_warps (I x) noexcept
template<typename I , typename I2 = I>
constexpr KAT_FHD I	kat::round_up (I x, I2 y) noexcept
template<typename I , typename I2 = I>
constexpr KAT_FHD I	kat::round_up_to_power_of_2 (I x, I2 power_of_2) noexcept
template<typename I >
constexpr KAT_FHD I	kat::round_up_to_full_warps (I x) noexcept
template<typename S , typename T = S>
constexpr KAT_FHD std::common_type< S, T >::type	kat::gcd (S u, T v) noexcept
template<typename S , typename T = S>
constexpr KAT_FHD std::common_type< S, T >::type	kat::lcm (S u, T v) noexcept
template<typename I >
constexpr KAT_FHD bool	kat::divides (I non_zero_divisor, I dividend) noexcept
template<typename I >
constexpr KAT_FHD bool	kat::is_divisible_by (I dividend, I non_zero_divisor) noexcept
template<typename I >
constexpr KAT_FHD I	kat::modulo_power_of_2 (I x, I power_of_2_modulus) noexcept
template<typename I >
constexpr KAT_FHD bool	kat::power_of_2_divides (I power_of_2_divisor, I dividend) noexcept
template<typename I >
constexpr KAT_FHD bool	kat::is_divisible_by_power_of_2 (I dividend, I power_of_2_divisor) noexcept
template<typename I >
constexpr KAT_FHD bool	kat::is_even (I x) noexcept
template<typename I >
constexpr KAT_FHD bool	kat::is_odd (I x) noexcept
template<typename I >
constexpr KAT_FHD I	kat::detail::increment_modular_remainder (I modular_remainder, I modulus) noexcept
template<typename I >
constexpr KAT_FHD I	kat::detail::decrement_modular_remainder (I modular_remainder, I modulus) noexcept
template<typename I >
constexpr KAT_FHD I	kat::modular_increment (I x, I modulus)
template<typename I >
constexpr KAT_FHD I	kat::modular_decrement (I x, I modulus)
template<typename I , typename I2 = I>
constexpr KAT_FHD I	kat::unsafe::round_up_to_power_of_2 (I x, I2 power_of_2) noexcept
template<typename I >
constexpr KAT_FHD I	kat::unsafe::round_up_to_full_warps (I x) noexcept
template<typename I1 , typename I2 >
constexpr KAT_FHD I1	kat::unsafe::div_rounding_up (I1 x, const I2 modulus) noexcept
template<typename I1 , typename I2 = I1>
constexpr KAT_FHD I1	kat::unsafe::round_up (I1 x, I2 y) noexcept
template<typename I >
constexpr I	kat::unsafe::modular_increment (I x, I modulus)
template<typename I >
constexpr I	kat::unsafe::modular_decrement (I x, I modulus)
template<typename I >
constexpr KAT_FHD int	kat::constexpr_::log2 (I val) noexcept
template<typename T >
constexpr KAT_FHD T	kat::constexpr_::detail::sqrt_helper (T x, T low, T high) noexcept
template<typename T >
constexpr KAT_FHD T	kat::constexpr_::sqrt (T x) noexcept

Detailed Description

mathematical functions (mostly very-simple ones) implemented using compile-time-executable code.

Note

Some of these mathematical functions are also the reasonable runtime- executable version, some are less efficient, to avoid non-constexpr constructs. The former appear outside of any namespace, the latter have their own namespace (constexpr_) to make them their use be more explicit. This will only be able to change when CUDA supports C++20, which will have a std::is_constant_evaluated type trait.

Function Documentation

round_down_to_full_warps()

template<typename I >

constexpr KAT_FHD I kat::round_down_to_full_warps ( I  x )

noexcept

Note

Don't use this with negative values.

round_up_to_power_of_2()

template<typename I , typename I2 = I>

constexpr KAT_FHD I kat::round_up_to_power_of_2 ( I  x, I2  power_of_2  )

noexcept

Note

careful, this may overflow!