The AI Engine API is a portable programming interface for AI Engine accelerators. The AI Engine API User Guide (UG1529) indicates if the API is supported only on a specific architecture. The API are implemented as a C++ header-only library that provides types and operations that get translated into efficient low-level intrinsics. The API also provides higher-level abstractions such as iterators.
Usually, two header files are needed in kernel source code:
-
aie_api/aie.hpp
- AI Engine main entry point.
-
aie_api/aie_adf.hpp
- Graph buffer and stream interfaces.
AI Engine
API provides a helper file to print aie::vector
and
aie::mask
values in simulation when profiling
is enabled:
-
aie_api/utils.hpp
:aie::print
andaie::print_matrix
functions are provided.
To support operator overloading on some operations, include header
file aie_api/operators.hpp
and use namespace
aie::operators
. For additional information, see
Operator Overloading.
A typical example of using the API for an AI Engine kernel is as follows.
#include <aie_api/aie.hpp>
#include <aie_api/aie_adf.hpp>
#include <aie_api/utils.hpp>
using namespace adf;
void vec_incr(input_buffer<int32>& data, output_buffer<int32>& out) {
//set all elements to 1
aie::vector<int32,16> vec1=aie::broadcast(1);
auto inIter=aie::begin_vector<16>(data);
auto outIter=aie::begin_vector<16>(out);
for(int i=0;i<16;i++) chess_prepare_for_pipelining {
aie::vector<int32,16> vdata=*inIter++;
//print vector in a line
aie::print(vdata,true,"vdata=");
//print vdata as a 2x8 matrix
aie::print_matrix(vdata,8,"vdata matrix=");
//increment each element in vdata by 1
aie::vector<int32,16> vresult=aie::add(vdata,vec1);
*outIter++=vresult;
}
}
vdata=0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
vdata matrix=0 1 2 3 4 5 6 7
8 9 10 11 12 13 14 15
vdata=16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
vdata matrix=16 17 18 19 20 21 22 23
24 25 26 27 28 29 30 31
vdata=32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
vdata matrix=32 33 34 35 36 37 38 39
40 41 42 43 44 45 46 47
vdata=48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63
vdata matrix=48 49 50 51 52 53 54 55
56 57 58 59 60 61 62 63
vdata=64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79
vdata matrix=64 65 66 67 68 69 70 71
72 73 74 75 76 77 78 79
...
vdata=208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223
vdata matrix=208 209 210 211 212 213 214 215
216 217 218 219 220 221 222 223
vdata=224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239
vdata matrix=224 225 226 227 228 229 230 231
232 233 234 235 236 237 238 239
vdata=240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255
vdata matrix=240 241 242 243 244 245 246 247
248 249 250 251 252 253 254 255
Vector data type and operations are covered in following sections.