I mean this:

let
A=(a_1,a_2,..., a_n)
B=(b_1,b_2,..., b_n)

do the calculation: sum =dot(A, B) = a_1 * b_2 + a_1 * b_2 + ... + a_n * b_n.

I would like to see how ESIMD uses shared local memory in the calculation.

In other words, how to rewrite the following program with SYCL ESIMD:

#include <stdlib.h>
#include <math.h>
#include <stdio.h>
#include <iostream>
#define N 1<<10
int main(int argc, char *argv[] )
{
 double *A = new double[N];
 double *B = new double[N];
 for(int i = 0; i < N; i++){
 A[i] = 0.1;
 B[i] = 0.2;
 }
 double sum = 0.0;
 for(int i = 0; i < N; i++){
 sum += A[i]*B[i];
 }
 std::cout << " sum =" << sum << std::endl;
 delete []A;
 delete []B;
 return 0;
}

Tagging @kbobrovs and @DenisBakhvalov here to help answering the question

@jinz2014, it is not portable to other devices (even Intel CPUs).

It is documented as intel extension: https://github.com/intel/llvm/tree/sycl/sycl/doc/extensions/supported/sycl_ext_intel_esimd which generally means that it won't/can't be supported on HW from other vendors.

And it also explicitly states that this is an interface to Intel GPU HW capabilities:

The main motivation for introducing the "Explicit SIMD" SYCL extension (or simply "ESIMD") is enabling efficient low-level programming for Intel graphics architectures.

Essentially, it is not portable because it almost directly maps to Intel GPU ISA.