aie::parallel_lookup< T, MyLUT, oor_policy > Struct Template Reference

Detailed Description

template<typename T, ParallelLUT MyLUT, lut_oor_policy oor_policy = lut_oor_policy::saturate>
struct aie::parallel_lookup< T, MyLUT, oor_policy >

Type with functionality to directly index a LUT based on input vector of values.

Supported types

Input	LUT values
int8	int8 int16
int16	bfloat16/>int32

Template Parameters

T	Type of the input vector, containing values used to index the lookup table.
MyLUT	Definition of the LUT type, using the lut type
oor_policy	Defines the "out of range policy" for when index values on the input go beyond the size of the LUT. It can either saturate taking on the max/min value or truncate retaining the lower bits. Saturating is the default behaviour, but for certain non-linear functions which repeat after an interval you may want to truncate.

#include <aie.hpp>

Public Member Functions
	parallel_lookup (const MyLUT &l, unsigned step_bits=0, int bias=0)
	More...
template<Vector Vec>
vector< typename MyLUT::offset_type, Vec::size()>	fetch (const Vec &input)
	More...

Constructor & Destructor Documentation

parallel_lookup()

template<typename T , ParallelLUT MyLUT, lut_oor_policy oor_policy = lut_oor_policy::saturate>

aie::parallel_lookup< T, MyLUT, oor_policy >::parallel_lookup ( const MyLUT &  l, unsigned  step_bits = 0, int  bias = 0  )

inline

Constructor, configures aspects of how the lookup is performed.

Parameters

l	LUT containing the stored values used for the linear approximation.
step_bits	Optional lower bits that will be ignored for indexing the LUT.
bias	Optional offset added to the input values used to index, for example to center on 0 by adding half the number of LUT elements.

Member Function Documentation

fetch()

template<typename T , ParallelLUT MyLUT, lut_oor_policy oor_policy = lut_oor_policy::saturate>

template<Vector Vec>

vector<typename MyLUT::offset_type, Vec::size()> aie::parallel_lookup< T, MyLUT, oor_policy >::fetch ( const Vec &  input )

inline

Accesses the lookup table based on the provided input values, will return a vector of the same number of elements as the input vector.
Input values are interpreted from MSB to LSB: headroom | LUT elements | step_bits

Parameters

input

Vector of input values that are used to index the look-up table.

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

• aie.hpp