2018 June 18

seashell

memory a: int[4] bank(2);
memory c: int[4] bank(2);
let b = 10;

for (let i = 0..1) {
  c[0][i] := a[0][i] + b;
  c[1][i] := a[1][i] + b;
}

current C out

int main()
{
    int a[2];
    int c[2];
    int  b = 10;
    for (int i = 0; i < 1; i += 1) {
        c[0+2*i] = a[0+2*i] + b;
        c[1+2*i] = a[1+2*i] + b;
    }
    return 0;
}

ideal C out

void madd(float A[N*N], float B, float C[N*N])
{
  int i;

  for (i = 0; i < N * N; i++)
      C[i] = A[i] + B;
}

input to HLS flow

void madd(float A[N*N], float B, float C[N*N])
{
  int i;

#pragma HLS ARRAY_PARTITION variable=A factor=ELE

  for (i = 0; i < N * N; i++)
#pragma HLS unroll factor=ELE
      C[i] = A[i] + B;
}

intermediate HLS input

void madd(float A[N*N], float B, float C[N*N])
{
  int i;

#pragma HLS ARRAY_PARTITION variable=A factor=ELE
#pragma HLS ARRAY_PARTITION variable=C factor=ELE

  for (int i = 0; i < N; i += 1) {
      C[0+N*i] = A[0+N*i] + B;
      C[1+N*i] = A[1+N*i] + B;
  }
}

for N=2 passes through HLS flow.