Vc  1.0.0-dev
SIMD Vector Classes for C++
Public Types | Public Member Functions | List of all members
MemoryBase< V, Parent, Dimension, RowMemory > Class Template Reference

Detailed Description

template<typename V, typename Parent, int Dimension, typename RowMemory>
class Vc::Common::MemoryBase< V, Parent, Dimension, RowMemory >

Common interface to all Memory classes, independent of allocation on the stack or heap.

Parameters
VThe vector type you want to operate on. (e.g. float_v or uint_v)
ParentThis type is the complete type of the class that derives from MemoryBase.
DimensionThe number of dimensions the implementation provides.
RowMemoryClass to be used to work on a single row.

Definition at line 349 of file memorybase.h.

#include <Vc/Memory>

Inherits MemoryDimensionBase< V, Parent, Dimension, RowMemory >.

Inherited by Memory< V, Size1, Size2, InitPadding >, and Memory< V, Size, 0u, InitPadding >.

Public Types

typedef V::EntryType EntryType
 The type of the scalar entries in the array.
 

Public Member Functions

size_t entriesCount () const
 
size_t vectorsCount () const
 
template<typename Flags = AlignedTag>
MemoryVectorIterator< V, Flags > begin (Flags flags=Flags())
 Return a (vectorized) iterator to the start of this memory object.
 
template<typename Flags = AlignedTag>
MemoryVectorIterator< const V, Flags > begin (Flags flags=Flags()) const
 const overload of the above
 
template<typename Flags = AlignedTag>
MemoryVectorIterator< V, Flags > end (Flags flags=Flags())
 Return a (vectorized) iterator to the end of this memory object.
 
template<typename Flags = AlignedTag>
MemoryVectorIterator< const V, Flags > end (Flags flags=Flags()) const
 const overload of the above
 
template<typename Flags = AlignedTag>
std::enable_if<!std::is_convertible< Flags, int >::value, MemoryVector< V, Flags > >::type & vector (size_t i, Flags=Flags())
 
template<typename Flags = AlignedTag>
std::enable_if<!std::is_convertible< Flags, int >::value, MemoryVector< const V, Flags > >::type & vector (size_t i, Flags=Flags()) const
 Const overload of the above function. More...
 
template<typename Flags = UnalignedTag>
MemoryVector< V, Flags > & vectorAt (size_t i, Flags flags=Flags())
 
template<typename Flags = UnalignedTag>
MemoryVector< const V, Flags > & vectorAt (size_t i, Flags flags=Flags()) const
 Const overload of the above function. More...
 
template<typename ShiftT , typename Flags = decltype(Unaligned)>
std::enable_if< std::is_convertible< ShiftT, int >::value, MemoryVector< V, decltype(std::declval< Flags >)|Unaligned)> >::type & vector (size_t i, ShiftT shift, Flags=Flags())
 
template<typename ShiftT , typename Flags = decltype(Unaligned)>
std::enable_if< std::is_convertible< ShiftT, int >::value, MemoryVector< const V, decltype(std::declval< Flags >)|Unaligned)> >::type & vector (size_t i, ShiftT shift, Flags=Flags()) const
 Const overload of the above function.
 
template<typename Flags = AlignedTag>
MemoryVector< V, Flags > & firstVector (Flags=Flags())
 
template<typename Flags = AlignedTag>
MemoryVector< const V, Flags > & firstVector (Flags=Flags()) const
 Const overload of the above function.
 
template<typename Flags = AlignedTag>
MemoryVector< V, Flags > & lastVector (Flags=Flags())
 
template<typename Flags = AlignedTag>
MemoryVector< const V, Flags > & lastVector (Flags=Flags()) const
 Const overload of the above function.
 
void setZero ()
 Zero the whole memory area.
 
template<typename U >
Parent & operator= (U &&x)
 Assign a value to all vectors in the array.
 
template<typename P2 , typename RM >
Parent & operator+= (const MemoryBase< V, P2, Dimension, RM > &rhs)
 (Inefficient) shorthand to add up two arrays.
 
template<typename P2 , typename RM >
Parent & operator-= (const MemoryBase< V, P2, Dimension, RM > &rhs)
 (Inefficient) shorthand to subtract two arrays.
 
template<typename P2 , typename RM >
Parent & operator*= (const MemoryBase< V, P2, Dimension, RM > &rhs)
 (Inefficient) shorthand to multiply two arrays.
 
template<typename P2 , typename RM >
Parent & operator/= (const MemoryBase< V, P2, Dimension, RM > &rhs)
 (Inefficient) shorthand to divide two arrays.
 
Parent & operator+= (EntryType rhs)
 (Inefficient) shorthand to add a value to an array.
 
Parent & operator-= (EntryType rhs)
 (Inefficient) shorthand to subtract a value from an array.
 
Parent & operator*= (EntryType rhs)
 (Inefficient) shorthand to multiply a value to an array.
 
Parent & operator/= (EntryType rhs)
 (Inefficient) shorthand to divide an array with a value.
 
template<typename P2 , typename RM >
bool operator== (const MemoryBase< V, P2, Dimension, RM > &rhs) const
 (Inefficient) shorthand compare equality of two arrays.
 
template<typename P2 , typename RM >
bool operator!= (const MemoryBase< V, P2, Dimension, RM > &rhs) const
 (Inefficient) shorthand compare two arrays.
 
template<typename P2 , typename RM >
bool operator< (const MemoryBase< V, P2, Dimension, RM > &rhs) const
 (Inefficient) shorthand compare two arrays.
 
template<typename P2 , typename RM >
bool operator<= (const MemoryBase< V, P2, Dimension, RM > &rhs) const
 (Inefficient) shorthand compare two arrays.
 
template<typename P2 , typename RM >
bool operator> (const MemoryBase< V, P2, Dimension, RM > &rhs) const
 (Inefficient) shorthand compare two arrays.
 
template<typename P2 , typename RM >
bool operator>= (const MemoryBase< V, P2, Dimension, RM > &rhs) const
 (Inefficient) shorthand compare two arrays.
 

Member Function Documentation

size_t entriesCount ( ) const
inline
Returns
the number of scalar entries in the array. This function is optimized away if a constant size array is used.

Definition at line 368 of file memorybase.h.

size_t vectorsCount ( ) const
inline
Returns
the number of vector entries that span the array. This function is optimized away if a constant size array is used.

Definition at line 373 of file memorybase.h.

Referenced by Memory< V, Size1, Size2, InitPadding >::operator=(), and Memory< V, 0u, 0u, true >::operator=().

std::enable_if<!std::is_convertible<Flags, int>::value, MemoryVector<V, Flags> >::type& vector ( size_t  i,
Flags  = Flags() 
)
inline
Parameters
iSelects the offset, where the vector should be read.
Returns
a smart object to wrap the i-th vector in the memory.

The return value can be used as any other vector object. I.e. you can substitute something like

float_v a = ..., b = ...;
a += b;

with

mem.vector(i) += b;

This function ensures that only aligned loads and stores are used. Thus it only allows to access memory at fixed strides. If access to known offsets from the aligned vectors is needed the vector(size_t, int) function can be used.

Definition at line 417 of file memorybase.h.

std::enable_if<!std::is_convertible<Flags, int>::value, MemoryVector<const V, Flags> >::type& vector ( size_t  i,
Flags  = Flags() 
) const
inline

Const overload of the above function.

Parameters
iSelects the offset, where the vector should be read.
Returns
a smart object to wrap the i-th vector in the memory.

Definition at line 427 of file memorybase.h.

MemoryVector<V, Flags>& vectorAt ( size_t  i,
Flags  flags = Flags() 
)
inline
Returns
a smart object to wrap the vector starting from the i-th scalar entry in the memory.

Example:

Memory<float_v, N> mem;
mem.setZero();
for (int i = 0; i < mem.entriesCount(); i += float_v::Size) {
mem.vectorAt(i) += b;
}
Parameters
iSpecifies the scalar entry from where the vector will be loaded/stored. I.e. the values scalar(i), scalar(i + 1), ..., scalar(i + V::Size - 1) will be read/overwritten.
flagsYou must take care to determine whether an unaligned load/store is required. Per default an unaligned load/store is used. If i is a multiple of V::Size you may want to pass Vc::Aligned here.

Definition at line 451 of file memorybase.h.

MemoryVector<const V, Flags>& vectorAt ( size_t  i,
Flags  flags = Flags() 
) const
inline

Const overload of the above function.

Returns
a smart object to wrap the vector starting from the i-th scalar entry in the memory.
Parameters
iSpecifies the scalar entry from where the vector will be loaded/stored. I.e. the values scalar(i), scalar(i + 1), ..., scalar(i + V::Size - 1) will be read/overwritten.
flagsYou must take care to determine whether an unaligned load/store is required. Per default an unaligned load/store is used. If i is a multiple of V::Size you may want to pass Vc::Aligned here.

Definition at line 466 of file memorybase.h.

std::enable_if< std::is_convertible<ShiftT, int>::value, MemoryVector<V, decltype(std::declval<Flags>) | Unaligned)> >::type& vector ( size_t  i,
ShiftT  shift,
Flags  = Flags() 
)
inline
Returns
a smart object to wrap the i-th vector + shift in the memory.

This function ensures that only unaligned loads and stores are used. It allows to access memory at any location aligned to the entry type.

Parameters
iSelects the memory location of the i-th vector. Thus if V::Size == 4 and i is set to 3 the base address for the load/store will be the 12th entry (same as &mem[12]).
shiftShifts the base address determined by parameter i by shift many entries. Thus vector(3, 1) for V::Size == 4 will load/store the 13th - 16th entries (same as &mem[13]).
Note
Any shift value is allowed as long as you make sure it stays within bounds of the allocated memory. Shift values that are a multiple of V::Size will not result in aligned loads. You have to use the above vector(size_t) function for aligned loads instead.
Thus a simple way to access vectors randomly is to set i to 0 and use shift as the parameter to select the memory address:
// don't use:
mem.vector(i / V::Size, i % V::Size) += 1;
// instead use:
mem.vector(0, i) += 1;

Definition at line 501 of file memorybase.h.

MemoryVector<V, Flags>& firstVector ( Flags  = Flags())
inline
Returns
the first vector in the allocated memory.

This function is simply a shorthand for vector(0).

Definition at line 523 of file memorybase.h.

MemoryVector<V, Flags>& lastVector ( Flags  = Flags())
inline
Returns
the last vector in the allocated memory.

This function is simply a shorthand for vector(vectorsCount() - 1).

Definition at line 538 of file memorybase.h.

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