Kernel functions can use private, read-only data structures that are accessed as file-scoped variables. The compiler allocates a limited amount of static heap space for such data. As an example, consider the following header file (user_parameter.h).
#ifndef USER_PARAMETER_H
#define USER_PARAMETER_H
#include <adf.h>
static int16 lutarray[8] = {1,2,3,4,5,6,0,0} ;
#endif
This header file can be included in the kernel source file
and the lookup table can be accessed inside a kernel function directly. The static
modifier ensures that the array definition is
local to this file. The AI Engine compiler allocates this array in static heap space
for the processor where this kernel is used.
#include <aie_api/aie.hpp>
#include <aie_api/aie_adf.hpp>
#include "user_parameter.h"
using namespace adf;
void simple_lut(input_buffer<int16> &in, output_buffer<int16> &out){
aie::vector<int16,32> sbuff;
aie::vector<int16,8> coeffs=aie::load_v<8>((int16*)lutarray);
auto inIter=aie::begin_vector<32>(in);
sbuff=*inIter++;
auto acc = aie::sliding_mul<8,16>(coeffs, 0, sbuff, 0);
auto outIter=aie::begin_vector<8>(out);
*outIter++=acc.to_vector<int16>(0);
}