Basic Types

Overview

The two main types offered by the AIE API are vectors (aie::vector) and accumulators (aie::accum).

A vector represents a collection of elements of the same type which is transparently mapped to the corresponding vector registers supported on each architecture. Vectors are parametrized by the element type and the number of elements, and any combination that defines a 128b/256b/512b/1024b vector is supported.

Supported vector types and sizes

int8	uint8	int16	int32	float	cint16	cint32	cfloat
16/32/64/128	16/32/64/128	8/16/32/64	4/8/16/32	4/8/16/32	4/8/16/32	2/4/8/16	2/4/8/16

An accumulator represents a collection of elements of the same class, typically obtained as a result of a multiplication operation, which is transparently mapped to the corresponding accumulator registers supported on each architecture. Accumulators commonly provide a large amount of bits, allowing users to perform long chains of operations whose intermediate results may exceed the range of regular vector types. Accumulators are parametrized by the element class, the required accumulation bits and the number of elements. Element class and accumulation bits are specified via type tags (seeAccumulator Element Tags). The accumulation bits define theminimumamount of bits and the AIE API maps them to the nearest native accumulator type that supports the requirement.

Supported accumulator types and sizes

	acc32	acc40	acc48	acc56	acc64	acc72	acc80	accfloat	cacc32	cacc40	cacc48	cacc56	cacc64	cacc72	cacc80	caccfloat
Sizes	8/16/32/64/128	8/16/32/64/128	8/16/32/64/128	8/16/32/64/128	4/8/16/32/64	4/8/16/32/64	4/8/16/32/64	4/8/16/32/64	4/8/16/32/64	4/8/16/32/64	4/8/16/32/64	4/8/16/32/64	2/4/8/16/32	2/4/8/16/32	2/4/8/16/32	2/4/8/16/32
Native accumulation	48b	48b	48b	80b	80b	80b	80b	32b	48b	48b	48b	80b	80b	80b	80b	32b
Portable	Yes	Yes	Yes	Yes	Yes	No	No	Yes	Yes	Yes	Yes	Yes	Yes	No	No	No

Some comparison operations return masks. A mask is a collection of values that can be 0 or 1.

Modules
	Vector and Accumulator Initialization
	Vector and Accumulator Conversions
	Concepts for Basic Types
	Accumulator Element Tags
	Lazy Operations

Typedefs
template<AccumElemBaseTypeMinAccumTag, unsigned Elems>
using	aie::accum=detail::accum< detail::accum_class_for_tag_v< MinAccumTag >, detail::accum_bits_for_tag_v< MinAccumTag >, Elems >
	More...
template
using	aie::mask=detail::mask< Elems >
	More...
template<ElemBaseTypeT, unsigned Elems = native_vector_length_v>
using	aie::vector=detail::vector< T, Elems >
	More...
template<ElemBaseTypeT, unsigned N>
using	aie::vector_elem_const_ref=detail::vector_elem_const_ref< T, N >
	More...
template<ElemBaseTypeT, unsigned N>
using	aie::vector_elem_ref=detail::vector_elem_ref< T, N >
	More...

Typedef Documentation

accum

template< AccumElemBaseTypeMinAccumTag, unsigned Elems>

usingaie::accum= typedefdetail::accum, detail::accum_bits_for_tag_v, Elems>

Type for vector accumulators. The documentation of this class and its members can be found atdetail::accum.

Template Parameters

MinAccumTag	Type tag that specifies the accumulator class and the required number of accumulation bits. Internally, this is rounded up to the smallest native accumulator size that meets the accuracy requirements. It must meetAccumElemBaseType.
Elems	Number of elements in the accumulator.

mask

template

usingaie::mask= typedefdetail::mask

Type for vector element masks. The documentation of this class and its members can be found atdetail::mask.

This type is returned by logical operations and used as input in selection operations.

Template Parameters

Elems

Number of elements represented in the mask.

vector

template< ElemBaseTypeT, unsigned Elems = native_vector_length_v>

usingaie::vector= typedefdetail::vector

Type for vector registers. The documentation of this class and its members can be found atdetail::vector.

Template Parameters

T	Type of the elements contained in the vector. It must meetElemBaseType.
Elems	Number of elements in the vector.

vector_elem_const_ref

template< ElemBaseTypeT, unsigned N>

usingaie::vector_elem_const_ref= typedefdetail::vector_elem_const_ref

Constant reference to vector element. This is similar toaie::vector_elem_ref, but the element cannot be modified.

Template Parameters

T	Type of the elements contained in the referenced vector. It must meetElemBaseType.
Elems	Number of elements in the referenced vector.

vector_elem_ref

template< ElemBaseTypeT, unsigned N>

usingaie::vector_elem_ref= typedefdetail::vector_elem_ref

Reference to vector element. This type is returned by element access functions and represents a proxy to the actual element, which allows for optimizations in the API such as accessing the element from its vector without extracting it. This is common in element / vector operations. Otherwise, the element value is extracted when assigned to a variable of type T.

Template Parameters

T	Type of the elements contained in the referenced vector. It must meetElemBaseType.
Elems	Number of elements in the referenced vector.