Vc  1.0.0-dev
SIMD Vector Classes for C++
Public Member Functions | Static Public Member Functions | List of all members
Memory< V, Size1, Size2, InitPadding > Class Template Reference
Utilities

Detailed Description

template<typename V, size_t Size1, size_t Size2, bool InitPadding>
class Vc::Common::Memory< V, Size1, Size2, InitPadding >

A helper class for fixed-size two-dimensional arrays.

Parameters
VThe vector type you want to operate on. (e.g. float_v or uint_v)
Size1Number of rows
Size2Number of columns

Definition at line 132 of file memory.h.

#include <Vc/Memory>

Inherits AlignedBase< V::MemoryAlignment >, and MemoryBase< V, Parent, Dimension, RowMemory >.

Public Member Functions

template<typename Parent , typename RM >
Memory & operator= (const MemoryBase< V, Parent, 2, RM > &rhs)
 Copies the data from a different object. More...
 
Memory & operator= (const V &v)
 Initialize all data with the given vector. More...
 
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 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 = 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 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 P2 , typename RM >
Parent & operator+= (const MemoryBase< V, P2, Dimension, RM > &rhs)
 (Inefficient) shorthand to add up two arrays.
 
Parent & operator+= (EntryType rhs)
 (Inefficient) shorthand to add a value to an array.
 
template<typename P2 , typename RM >
Parent & operator-= (const MemoryBase< V, P2, Dimension, RM > &rhs)
 (Inefficient) shorthand to subtract two arrays.
 
Parent & operator-= (EntryType rhs)
 (Inefficient) shorthand to subtract a value from an array.
 
template<typename P2 , typename RM >
Parent & operator*= (const MemoryBase< V, P2, Dimension, RM > &rhs)
 (Inefficient) shorthand to multiply two arrays.
 
Parent & operator*= (EntryType rhs)
 (Inefficient) shorthand to multiply a value to an array.
 
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 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.
 

Static Public Member Functions

static constexpr size_t rowsCount ()
 
static constexpr size_t entriesCount ()
 
static constexpr size_t vectorsCount ()
 

Member Function Documentation

static constexpr size_t rowsCount ( )
inlinestatic
Returns
the number of rows in the array.
Note
This function can be eliminated by an optimizing compiler.

Definition at line 173 of file memory.h.

static constexpr size_t entriesCount ( )
inlinestatic
Returns
the number of scalar entries in the whole array.
Warning
Do not use this function for scalar iteration over the array since there will be padding between rows if Size2 is not divisible by V::Size.
Note
This function can be optimized into a compile-time constant.

Definition at line 182 of file memory.h.

static constexpr size_t vectorsCount ( )
inlinestatic
Returns
the number of vectors in the whole array.
Note
This function can be optimized into a compile-time constant.

Definition at line 188 of file memory.h.

Memory& operator= ( const MemoryBase< V, Parent, 2, RM > &  rhs)
inline

Copies the data from a different object.

Parameters
rhsThe object to copy the data from.
Returns
reference to the modified Memory object.
Note
Both objects must have the exact same vectorsCount().

Definition at line 200 of file memory.h.

Memory& operator= ( const V &  v)
inline

Initialize all data with the given vector.

Parameters
vThis vector will be used to initialize the memory.
Returns
reference to the modified Memory object.

Definition at line 218 of file memory.h.

size_t entriesCount ( ) const
inlineinherited
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
inlineinherited
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() 
)
inlineinherited
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
inlineinherited

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.

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() 
)
inlineinherited
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>& vectorAt ( size_t  i,
Flags  flags = Flags() 
)
inlineinherited
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
inlineinherited

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.

MemoryVector<V, Flags>& firstVector ( Flags  = Flags())
inlineinherited
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())
inlineinherited
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: