Vc  1.3.2-dev
SIMD Vector Classes for C++
Memory< V, Size1, Size2, InitPadding > Class Template Reference

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 135 of file memory.h.

#include <Vc/Memory>

Inherits AlignedBase< V::MemoryAlignment >, and MemoryBase< V, Memory< V, Size1, Size2, InitPadding >, 2, Memory< V, Size2, 0, false > >.

Public Member Functions

template<typename Parent , typename RM >
Memoryoperator= (const MemoryBase< V, Parent, 2, RM > &rhs)
 Copies the data from a different object. More...
 
Memoryoperator= (const V &v)
 Initialize all data with the given vector. More...
 
size_t entriesCount () const
 
size_t vectorsCount () const
 
MemoryVectorIterator< V, Flags > begin (Flags flags=Flags())
 Return a (vectorized) iterator to the start of this memory object.
 
MemoryVectorIterator< const V, Flags > begin (Flags flags=Flags()) const
 const overload of the above
 
MemoryVectorIterator< V, Flags > end (Flags flags=Flags())
 Return a (vectorized) iterator to the end of this memory object.
 
MemoryVectorIterator< const V, Flags > end (Flags flags=Flags()) const
 const overload of the above
 
std::enable_if<!std::is_convertible< Flags, int >::value, MemoryVector< V, Flags > >::type & vector (size_t i, Flags=Flags())
 
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...
 
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())
 
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.
 
MemoryVector< V, Flags > & vectorAt (size_t i, Flags flags=Flags())
 
MemoryVector< const V, Flags > & vectorAt (size_t i, Flags flags=Flags()) const
 Const overload of the above function. More...
 
MemoryVector< V, Flags > & firstVector (Flags=Flags())
 
MemoryVector< const V, Flags > & firstVector (Flags=Flags()) const
 Const overload of the above function.
 
MemoryVector< V, Flags > & lastVector (Flags=Flags())
 
MemoryVector< const V, Flags > & lastVector (Flags=Flags()) const
 Const overload of the above function.
 
void setZero ()
 Zero the whole memory area.
 
Memory< V, Size1, Size2, InitPadding > & operator+= (const MemoryBase< V, P2, Dimension, RM > &rhs)
 (Inefficient) shorthand to add up two arrays.
 
Memory< V, Size1, Size2, InitPadding > & operator+= (EntryType rhs)
 (Inefficient) shorthand to add a value to an array.
 
Memory< V, Size1, Size2, InitPadding > & operator-= (const MemoryBase< V, P2, Dimension, RM > &rhs)
 (Inefficient) shorthand to subtract two arrays.
 
Memory< V, Size1, Size2, InitPadding > & operator-= (EntryType rhs)
 (Inefficient) shorthand to subtract a value from an array.
 
Memory< V, Size1, Size2, InitPadding > & operator*= (const MemoryBase< V, P2, Dimension, RM > &rhs)
 (Inefficient) shorthand to multiply two arrays.
 
Memory< V, Size1, Size2, InitPadding > & operator*= (EntryType rhs)
 (Inefficient) shorthand to multiply a value to an array.
 
Memory< V, Size1, Size2, InitPadding > & operator/= (const MemoryBase< V, P2, Dimension, RM > &rhs)
 (Inefficient) shorthand to divide two arrays.
 
Memory< V, Size1, Size2, InitPadding > & operator/= (EntryType rhs)
 (Inefficient) shorthand to divide an array with a value.
 
bool operator== (const MemoryBase< V, P2, Dimension, RM > &rhs) const
 (Inefficient) shorthand compare equality of two arrays.
 
bool operator!= (const MemoryBase< V, P2, Dimension, RM > &rhs) const
 (Inefficient) shorthand compare two arrays.
 
bool operator< (const MemoryBase< V, P2, Dimension, RM > &rhs) const
 (Inefficient) shorthand compare two arrays.
 
bool operator<= (const MemoryBase< V, P2, Dimension, RM > &rhs) const
 (Inefficient) shorthand compare two arrays.
 
bool operator> (const MemoryBase< V, P2, Dimension, RM > &rhs) const
 (Inefficient) shorthand compare two arrays.
 
bool operator>= (const MemoryBase< V, P2, Dimension, RM > &rhs) const
 (Inefficient) shorthand compare two arrays.
 
new/delete overloads for correct alignment
void * operator new (size_t size)
 Allocates correctly aligned memory.
 
void * operator new (size_t, void *p)
 Returns p.
 
void * operator new[] (size_t size)
 Allocates correctly aligned memory.
 
void * operator new[] (size_t, void *p)
 Returns p.
 
void operator delete (void *ptr, size_t)
 Frees aligned memory.
 
void operator delete (void *, void *)
 Does nothing.
 
void operator delete[] (void *ptr, size_t)
 Frees aligned memory.
 
void operator delete[] (void *, void *)
 Does nothing.
 

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 192 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 201 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 207 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 219 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 237 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 380 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 385 of file memorybase.h.

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 429 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 439 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 513 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 463 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 478 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 535 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 550 of file memorybase.h.


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