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Classes
struct	BitTraits

struct	BitTraits< std::int64_t >

struct	BitTraits< std::int32_t >

struct	BitTraits< std::int16_t >

struct	BitTraits< std::int8_t >

struct	BitTraits< std::uint64_t >

struct	BitTraits< std::uint32_t >

struct	BitTraits< std::uint16_t >

struct	BitTraits< std::uint8_t >

struct	Sorting
	This is a template suitable for sorting small arrays on device. More...

struct	Sorting< T, 3 >
	Template specialization for sorting arrays with 3 elements. More...

struct	Sorting< T, 4 >
	Template specialization for sorting arrays with 4 elements. More...

class	Timer
	A simple Timer class to measure execution time. More...

class	LexiComparator
	Compares std::vector< T > in lexicographic order. More...

Functions
AXOM_HOST_DEVICE int	countr_zero (std::uint64_t word) noexcept
	Counts the number of trailing zeros in word. More...

AXOM_HOST_DEVICE int	popcount (std::uint64_t word) noexcept
	Counts the number of set bits in word. More...

AXOM_HOST_DEVICE std::int32_t	countl_zero (std::int32_t word) noexcept
	Counts the number of leading zeros in word. More...

template<typename FlagType , typename BitType >
constexpr AXOM_HOST_DEVICE bool	bitIsSet (FlagType flags, BitType bit)
	Determine whether the bit is set in flags. More...

template<typename FlagType , typename BitType >
constexpr AXOM_HOST_DEVICE void	setBit (FlagType &flags, BitType bit, bool value=true)
	Set the bit in flags. More...

template<typename FlagType , typename BitType >
constexpr AXOM_HOST_DEVICE void	setBitOn (FlagType &flags, BitType bit)
	Set the bit in flags. More...

template<typename T , typename... Args>
static AXOM_HOST_DEVICE void	sort_multiple (T first, Args... args)
	Sort multiple arrays, using the first array as the key for sorting. All other arrays are sorted the same. More...

template<typename T , typename... Args>
static AXOM_HOST_DEVICE void	reverse_sort_multiple (T first, Args... args)
	Sort multiple arrays in reverse order, using the first array as the key for sorting. All other arrays are sorted the same. More...

std::string	getHostName ()
	Returns the name of the machine. More...

std::string	getUserName ()
	Returns the name of the current user. More...

std::locale	locale (const std::string &name="en_US.UTF-8")
	Returns a valid locale for the current system. More...

void	processAbort ()
	Gracefully aborts the application. More...

template<typename T >
AXOM_HOST_DEVICE T	abs (const T &x)
	Returns the absolute value of x. More...

template<typename T >
AXOM_HOST_DEVICE T	floor (const T &x)
	Returns the largest integer less than or equal to x. More...

template<typename T >
AXOM_HOST_DEVICE T	ceil (const T &x)
	Returns the smallest integer greater than or equal to x. More...

template<typename T >
AXOM_HOST_DEVICE const T &	max (const T &x, const T &y)
	Returns the max value of x and y. More...

template<typename T >
AXOM_HOST_DEVICE const T &	min (const T &x, const T &y)
	Returns the min value of x and y. More...

template<typename T >
AXOM_HOST_DEVICE void	swap (T &a, T &b)
	Swaps the values of a, b. More...

template<typename T >
AXOM_HOST_DEVICE T	fma (const T &a, const T &b, const T &c)
	Returns the fused-multiply-add of a, b, and c. More...

template<typename T >
T	log2 (T val)
	Returns the base 2 logarithm of the input. More...

template<typename T >
AXOM_HOST_DEVICE T	lerp (T v0, T v1, T t)
	Linearly interpolates between two values. More...

template<typename T >
AXOM_HOST_DEVICE T	clampVal (T val, T lower, T upper)
	Clamps an input value to a given range. More...

template<typename T >
AXOM_HOST_DEVICE T	clampUpper (T val, T upper)
	Clamps the upper range on an input value. More...

template<typename T >
AXOM_HOST_DEVICE T	clampLower (T val, T lower)
	Clamps the lower range on an input value. More...

template<typename T >
constexpr AXOM_HOST_DEVICE bool	inBounds_0_N (T value, T upper)
	Determine whether a value is in [0,upper). More...

int	binomialCoefficient (int n, int k)
	Computes the binomial coefficient `n choose k` More...

template<typename T >
T	random_real (const T &a, const T &b)
	Returns a random real number within the specified interval. More...

template<typename T >
T	random_real (const T &a, const T &b, unsigned int seed)
	Returns a random real number within the specified interval given the bounds of the interval and a seed value for the underlying random number generator. More...

bool	isLittleEndian ()
	Tests the endianness of the system. More...

template<typename T >
constexpr T	byteswap (T val) noexcept
	Reverses the bytes of the input value. More...

template<typename RealType >
AXOM_HOST_DEVICE bool	isNearlyEqual (RealType a, RealType b, RealType thresh=1.0e-8)
	Fuzzy comparison of two real valued quantities. More...

template<typename RealType >
AXOM_HOST_DEVICE bool	isNearlyEqualRelative (RealType a, RealType b, RealType relThresh=1.0e-6, RealType absThresh=1.0e-8)
	Fuzzy comparison of two real valued quantities. More...

template<typename T >
int	sign_of (const T &v, const T &eps={0})
	Sign of a value of any type that supports comparison and negation operators. More...

template<typename DataType , typename Predicate = std::less<DataType>>
AXOM_SUPPRESS_HD_WARN AXOM_HOST_DEVICE void	insertionSort (DataType *array, IndexType n, Predicate cmp={})
	Insertion sort of an array. More...

template<typename ContainerT , typename T >
AXOM_HOST_DEVICE std::int32_t	binary_search (const ContainerT &cont, T value)
	Use binary search to find the index of the value in the supplied sorted container. More...

AXOM_HOST_DEVICE std::uint64_t	hash_bytes (const std::uint8_t *data, std::uint32_t length)
	Hash a stream of bytes into a uint64_t hash value. More...

Function Documentation

◆ countr_zero()

AXOM_HOST_DEVICE int axom::utilities::countr_zero ( std::uint64_t word )

inlinenoexcept

Counts the number of trailing zeros in word.

Returns: The number of zeros to the right of the first set bit in \word, starting with the least significant bit, or 64 if word == 0.

◆ popcount()

AXOM_HOST_DEVICE int axom::utilities::popcount ( std::uint64_t word )

inlinenoexcept

Counts the number of set bits in word.

Returns: number of bits in word that are set to 1

References axom::slic::inherit::masks.

◆ countl_zero()

AXOM_HOST_DEVICE std::int32_t axom::utilities::countl_zero ( std::int32_t word )

inlinenoexcept

Counts the number of leading zeros in word.

Returns: The number of zeros to the left of the first set bit in \word, starting with the least significant bit.

◆ bitIsSet()

template<typename FlagType , typename BitType >

constexpr AXOM_HOST_DEVICE bool axom::utilities::bitIsSet	(	FlagType	flags,
		BitType	bit
	)

constexpr

Determine whether the bit is set in flags.

Template Parameters

FlagType	The integer type that contains the flags.
BitType	The index type that stores the bit index.

Parameters

[in]	flags	The flags whose bit we're testing.
[in]	bit	The bit we're testing.

Returns: True if the bit is set; false otherwise.

◆ setBit()

template<typename FlagType , typename BitType >

constexpr AXOM_HOST_DEVICE void axom::utilities::setBit	(	FlagType &	flags,
		BitType	bit,
		bool	value = `true`
	)

constexpr

Set the bit in flags.

Template Parameters

FlagType	The integer type that contains the flags.
BitType	The index type that stores the bit index.

Parameters

[in,out]	flags	The flags whose bit we're setting.
[in]	bit	The bit we're setting.
[in]	value	The value we're setting into the bit.

◆ setBitOn()

template<typename FlagType , typename BitType >

constexpr AXOM_HOST_DEVICE void axom::utilities::setBitOn	(	FlagType &	flags,
		BitType	bit
	)

constexpr

Set the bit in flags.

Template Parameters

FlagType	The integer type that contains the flags.
BitType	The index type that stores the bit index.

Parameters

[in,out]	flags	The flags whose bit we're setting.
[in]	bit	The bit we're setting.

◆ sort_multiple()

template<typename T , typename... Args>

static AXOM_HOST_DEVICE void axom::utilities::sort_multiple	(	T	first,
		Args...	args
	)

inlinestatic

Sort multiple arrays, using the first array as the key for sorting. All other arrays are sorted the same.

Template Parameters

T	The type of the first array.
Args	Parameter pack containing multiple array types and an int.

Parameters

first	The first data array.
args	A parameter pack of all other args.

Note: This function is not part of the Sorting struct because CUDA did not like variadic templates on member functions.

References axom::utilities::detail::sort_multiple_internal().

◆ reverse_sort_multiple()

template<typename T , typename... Args>

static AXOM_HOST_DEVICE void axom::utilities::reverse_sort_multiple	(	T	first,
		Args...	args
	)

inlinestatic

Sort multiple arrays in reverse order, using the first array as the key for sorting. All other arrays are sorted the same.

Template Parameters

T	The type of the first array.
Args	Parameter pack containing multiple array types and an int.

Parameters

first	The first data array.
args	A parameter pack of all other args.

Note: This function is not part of the Sorting struct because CUDA did not like variadic templates on member functions.

References axom::utilities::detail::sort_multiple_internal().

◆ getHostName()

std::string axom::utilities::getHostName ( )

Returns the name of the machine.

Returns: The name of the current machine, empty string on failure

◆ getUserName()

std::string axom::utilities::getUserName ( )

Returns the name of the current user.

Returns: The name of the current user, empty string on failure

◆ locale()

std::locale axom::utilities::locale ( const std::string & name = "en_US.UTF-8" )

Returns a valid locale for the current system.

Parameters

name	The name of the desired locale

◆ processAbort()

void axom::utilities::processAbort ( )

Gracefully aborts the application.

◆ abs()

template<typename T >

AXOM_HOST_DEVICE T axom::utilities::abs ( const T & x )

inline

Returns the absolute value of x.

Parameters

[in] x value whose absolute value is computed.

Returns: abs(x) the absolute value of x.

◆ floor()

template<typename T >

AXOM_HOST_DEVICE T axom::utilities::floor ( const T & x )

inline

Returns the largest integer less than or equal to x.

Parameters

[in] x value whose floor value is computed.

Returns: floor(x) the largest integer less than or equal to x.

◆ ceil()

template<typename T >

AXOM_HOST_DEVICE T axom::utilities::ceil ( const T & x )

inline

Returns the smallest integer greater than or equal to x.

Parameters

[in] x value whose ceil value is computed.

Returns: ceil(x) the smallest integer greater than or equal to x.

◆ max()

template<typename T >

AXOM_HOST_DEVICE const T& axom::utilities::max	(	const T &	x,
		const T &	y
	)

inline

Returns the max value of x and y.

Parameters

[in]	x	the first value to check.
[in]	y	the second value to check.

Returns: max(x, y) the max value of x and y.

◆ min()

template<typename T >

AXOM_HOST_DEVICE const T& axom::utilities::min	(	const T &	x,
		const T &	y
	)

inline

Returns the min value of x and y.

Parameters

[in]	x	the first value to check.
[in]	y	the second value to check.

Returns: min(x, y) the min value of x and y.

◆ swap()

template<typename T >

AXOM_HOST_DEVICE void axom::utilities::swap	(	T &	a,
		T &	b
	)

inline

Swaps the values of a, b.

Parameters

[in,out]	a	1st object to swap.
[in,out]	b	2nd object to swap.

◆ fma()

template<typename T >

AXOM_HOST_DEVICE T axom::utilities::fma	(	const T &	a,
		const T &	b,
		const T &	c
	)

inline

Returns the fused-multiply-add of a, b, and c.

Parameters

[in] a,b,c the values

Returns: a*b+c computed using an fma operation

◆ log2()

template<typename T >

T axom::utilities::log2 ( T val )

inline

Returns the base 2 logarithm of the input.

Parameters

[in] val The input value

◆ lerp()

template<typename T >

AXOM_HOST_DEVICE T axom::utilities::lerp	(	T	v0,
		T	v1,
		T	t
	)

inline

Linearly interpolates between two values.

Parameters

[in]	val0	The first value
[in]	val2	The second value
[in]	t	The interpolation parameter.

Returns: The interpolated value

◆ clampVal()

template<typename T >

AXOM_HOST_DEVICE T axom::utilities::clampVal	(	T	val,
		T	lower,
		T	upper
	)

inline

Clamps an input value to a given range.

Parameters

[in]	val	The value to clamp.
[in]	lower	The lower range.
[in]	upper	The upper range.

Returns: The clamped value.

Precondition: lower <= upper

Postcondition: lower <= returned value <= upper.

◆ clampUpper()

template<typename T >

AXOM_HOST_DEVICE T axom::utilities::clampUpper	(	T	val,
		T	upper
	)

inline

Clamps the upper range on an input value.

Parameters

[in]	val	The value to clamp
[in]	upper	The upper range

Returns: upper if val > upper, else val

Postcondition: returned value is less than or equal to upper

◆ clampLower()

template<typename T >

AXOM_HOST_DEVICE T axom::utilities::clampLower	(	T	val,
		T	lower
	)

inline

Clamps the lower range on an input value.

Parameters

[in]	val	The value to clamp
[in]	lower	The lower range

Returns: lower if val < lower, else val

Postcondition: returned value is greater than or equal to lower

◆ inBounds_0_N()

template<typename T >

constexpr AXOM_HOST_DEVICE bool axom::utilities::inBounds_0_N	(	T	value,
		T	upper
	)

inlineconstexpr

Determine whether a value is in [0,upper).

Parameters

value	The value to check in the range.
upper	The upper value for the range (non-inclusive).

Returns: True if value is in [0,upper); False otherwise.

Note: For unsigned types value must be >= 0 so we do not compare against 0.

◆ binomialCoefficient()

int axom::utilities::binomialCoefficient	(	int	n,
		int	k
	)

Computes the binomial coefficient n choose k

Returns: \( {n\choose k} = n! / (k! * (n-k)!)\) when \( n \ge k \ge 0 \), 0 otherwise.

◆ random_real() [1/2]

template<typename T >

T axom::utilities::random_real	(	const T &	a,
		const T &	b
	)

inline

Returns a random real number within the specified interval.

Parameters

[in]	a	the interval's lower bound
[in]	b	the interval's upper bound

Returns: r the random real number within the specified interval.

Template Parameters

T	a built-in floating point type, e.g., double, float, long double.

Note: Consecutive calls to this method will generate a non-deterministic sequence of numbers.

Precondition: a < b

Postcondition: a <= r < b

References AXOM_STATIC_ASSERT.

◆ random_real() [2/2]

template<typename T >

T axom::utilities::random_real	(	const T &	a,
		const T &	b,
		unsigned int	seed
	)

inline

Returns a random real number within the specified interval given the bounds of the interval and a seed value for the underlying random number generator.

Parameters

[in]	a	the interval's lower bound
[in]	b	the interval's upper bound
[in]	seed	user-supplied seed for the random number generator

Returns: r the random real number within the specified interval.

Template Parameters

T	a built-in floating type, e.g., double, float, long double.

Note: Consecutive calls to this method will generate a deterministic sequence of numbers.

Precondition: a < b

Postcondition: a <= r < b

References AXOM_STATIC_ASSERT.

◆ isLittleEndian()

bool axom::utilities::isLittleEndian ( )

inline

Tests the endianness of the system.

Returns: True, if the system is little endian, false otherwise.

◆ byteswap()

template<typename T >

constexpr T axom::utilities::byteswap ( T val )

constexprnoexcept

Reverses the bytes of the input value.

Parameters

[in] val The input value

Returns: The value with swapped bytes

Note: Assumes endianness is either little or big (not PDP).

Precondition: T is a native arithmetic type (i.e. integral or floating point).; sizeof(T) must be 1, 2, 4, or 8 bytes.

References AXOM_STATIC_ASSERT_MSG.

◆ isNearlyEqual()

template<typename RealType >

AXOM_HOST_DEVICE bool axom::utilities::isNearlyEqual	(	RealType	a,
		RealType	b,
		RealType	thresh = `1.0e-8`
	)

inline

Fuzzy comparison of two real valued quantities.

Parameters

[in]	a	The first real valued quantities we are comparing.
[in]	b	The second real valued quantities we are comparing.
[in]	thresh	The threshold of the fuzzy comparison. Default is 1.0e-8.

Returns: True if the absolute value of the difference is less than thresh and false otherwise.

References abs().

◆ isNearlyEqualRelative()

template<typename RealType >

AXOM_HOST_DEVICE bool axom::utilities::isNearlyEqualRelative	(	RealType	a,
		RealType	b,
		RealType	relThresh = `1.0e-6`,
		RealType	absThresh = `1.0e-8`
	)

inline

Fuzzy comparison of two real valued quantities.

Parameters

[in]	a	The first real valued quantities we are comparing.
[in]	b	The second real valued quantities we are comparing.
[in]	relThresh	The relative threshold of the fuzzy comparison. Default is 1.0e-6.
[in]	absThresh	The absolute threshold of the fuzzy comparison. Default is 1.0e-8.

Returns: True if the absolute value of the difference is less than the sum of absThresh and the relative difference (relThresh times the absolute max of a and b).

References abs(), and max().

◆ sign_of()

template<typename T >

int axom::utilities::sign_of	(	const T &	v,
		const T &	eps = `{0}`
	)

inline

Sign of a value of any type that supports comparison and negation operators.

Returns: 0 for v in [-eps, eps], -1 for v < eps and +1 for v > eps

◆ insertionSort()

template<typename DataType , typename Predicate = std::less<DataType>>

AXOM_SUPPRESS_HD_WARN AXOM_HOST_DEVICE void axom::utilities::insertionSort	(	DataType *	array,
		IndexType	n,
		Predicate	cmp = `{}`
	)

inline

Insertion sort of an array.

Parameters

[in]	array	The array to sort.
[in]	n	The number of entries in the array.
[in]	cmp	The comparator to use for comparing elements; "less than" by default.

◆ binary_search()

template<typename ContainerT , typename T >

AXOM_HOST_DEVICE std::int32_t axom::utilities::binary_search	(	const ContainerT &	cont,
		T	value
	)

Use binary search to find the index of the value in the supplied sorted container.

Template Parameters

ContainerT	A container or view of T. It must support size(), operator[].
T	The type of elements we're handling.

Parameters

[in]	cont	A view or container that contains the sorted search data values.
[in]	value	The search value.

Returns: The index where value was located in view or -1 if not found. If the container contained repeats of value, the first index is returned.

◆ hash_bytes()

AXOM_HOST_DEVICE std::uint64_t axom::utilities::hash_bytes	(	const std::uint8_t *	data,
		std::uint32_t	length
	)

inline

Hash a stream of bytes into a uint64_t hash value.

Parameters

[in]	data	The bytes to be hashed.
[in]	length	The number of bytes to be hashed.

Returns: A uint64_t hash for the byte stream.

Note: The byte stream is hashed using a Jenkins-hash algorithm forwards and backwards and the two results are merged into a uint64_t. The length is also part of the hash to guard against a lot of repeated values in the byte stream hashing to the same thing.; We make this function inline since it is not a template and we want to use it in both host and device code.

Namespaces

Classes

Functions

Function Documentation

◆ countr_zero()

◆ popcount()

◆ countl_zero()

◆ bitIsSet()

◆ setBit()

◆ setBitOn()

◆ sort_multiple()

◆ reverse_sort_multiple()

◆ getHostName()

◆ getUserName()

◆ locale()

◆ processAbort()

◆ abs()

◆ floor()

◆ ceil()

◆ max()

◆ min()

◆ swap()

◆ fma()

◆ log2()

◆ lerp()

◆ clampVal()

◆ clampUpper()

◆ clampLower()

◆ inBounds_0_N()

◆ binomialCoefficient()

◆ random_real() [1/2]

◆ random_real() [2/2]

◆ isLittleEndian()

◆ byteswap()

◆ isNearlyEqual()

◆ isNearlyEqualRelative()

◆ sign_of()

◆ insertionSort()

◆ binary_search()

◆ hash_bytes()