cub::CacheModifiedInputIterator< MODIFIER, ValueType, OffsetT > Class Template Reference

A random-access input wrapper for dereferencing array values using a PTX cache load modifier. More...

Detailed Description

template<CacheLoadModifier MODIFIER, typename ValueType, typename OffsetT = ptrdiff_t>
class cub::CacheModifiedInputIterator< MODIFIER, ValueType, OffsetT >

A random-access input wrapper for dereferencing array values using a PTX cache load modifier.

Overview

• CacheModifiedInputIteratorTis a random-access input iterator that wraps a native device pointer of type ValueType*. ValueType references are made by reading ValueType values through loads modified by MODIFIER.
• Can be used to load any data type from memory using PTX cache load modifiers (e.g., "LOAD_LDG", "LOAD_CG", "LOAD_CA", "LOAD_CS", "LOAD_CV", etc.).
• Can be constructed, manipulated, and exchanged within and between host and device functions, but can only be dereferenced within device functions.
• Compatible with Thrust API v1.7 or newer.

Snippet

The code snippet below illustrates the use of CacheModifiedInputIteratorTto dereference a device array of double using the "ldg" PTX load modifier (i.e., load values through texture cache).

#include <cub/cub.cuh>   // or equivalently <cub/iterator/cache_modified_input_iterator.cuh>

// Declare, allocate, and initialize a device array
double *d_in;            // e.g., [8.0, 6.0, 7.0, 5.0, 3.0, 0.0, 9.0]

// Create an iterator wrapper
cub::CacheModifiedInputIterator<cub::LOAD_LDG, double> itr(d_in);

// Within device code:
printf("%f\n", itr[0]);  // 8.0
printf("%f\n", itr[1]);  // 6.0
printf("%f\n", itr[6]);  // 9.0

Template Parameters

CacheLoadModifier	The cub::CacheLoadModifier to use when accessing data
ValueType	The value type of this iterator
OffsetT	The difference type of this iterator (Default: ptrdiff_t)

Definition at line 107 of file cache_modified_input_iterator.cuh.

Public Types
typedef CacheModifiedInputIterator	self_type
	My own type.
typedef OffsetT	difference_type
	Type to express the result of subtracting one iterator from another.
typedef ValueType	value_type
	The type of the element the iterator can point to.
typedef ValueType *	pointer
	The type of a pointer to an element the iterator can point to.
typedef ValueType	reference
	The type of a reference to an element the iterator can point to.
typedef std::random_access_iterator_tag	iterator_category
	The iterator category.

Public Member Functions
template<typename QualifiedValueType >
__host__ __device__ __forceinline__	CacheModifiedInputIterator (QualifiedValueType *ptr)
	Constructor. More...
__host__ __device__ __forceinline__ self_type	operator++ (int)
	Postfix increment.
__host__ __device__ __forceinline__ self_type	operator++ ()
	Prefix increment.
__device__ __forceinline__ reference	operator * () const
	Indirection.
template<typename Distance >
__host__ __device__ __forceinline__ self_type	operator+ (Distance n) const
	Addition.
template<typename Distance >
__host__ __device__ __forceinline__ self_type &	operator+= (Distance n)
	Addition assignment.
template<typename Distance >
__host__ __device__ __forceinline__ self_type	operator- (Distance n) const
	Subtraction.
template<typename Distance >
__host__ __device__ __forceinline__ self_type &	operator-= (Distance n)
	Subtraction assignment.
__host__ __device__ __forceinline__ difference_type	operator- (self_type other) const
	Distance.
template<typename Distance >
__device__ __forceinline__ reference	operator[] (Distance n) const
	Array subscript.
__device__ __forceinline__ pointer	operator-> ()
	Structure dereference.
__host__ __device__ __forceinline__ bool	operator== (const self_type &rhs)
	Equal to.
__host__ __device__ __forceinline__ bool	operator!= (const self_type &rhs)
	Not equal to.

Data Fields
ValueType *	ptr
	Wrapped native pointer.

Friends
std::ostream &	operator<< (std::ostream &os, const self_type &)
	ostream operator

Constructor & Destructor Documentation

CacheModifiedInputIterator()

template<CacheLoadModifier MODIFIER, typename ValueType, typename OffsetT = ptrdiff_t>

template<typename QualifiedValueType >

__host__ __device__ __forceinline__ cub::CacheModifiedInputIterator< MODIFIER, ValueType, OffsetT >::CacheModifiedInputIterator ( QualifiedValueType *  ptr )

inline

Constructor.

Parameters

ptr	Native pointer to wrap

Definition at line 138 of file cache_modified_input_iterator.cuh.

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The documentation for this class was generated from the following file:

• openfpm_data/src/util/cuda/cub_old/iterator/cache_modified_input_iterator.cuh