Unnecessary array instantiations

[Rüdiger Franke]

Examples that use constant data often result in huge code because OpenModelica instantiates these arrays over and over again. Have for instance a look the Modelica.Media.Examples.R134a.* examples.

Here is a simpler version:

package ArrayData
  constant Integer[:] data = {1, 2, 3, 4, 5, 6, 7, 8, 9};

  function f
    input Integer[:] idata;
    input Integer idx;
    output Integer y;
  algorithm
    y := idata[idx] + data[idx] + data[idx + 1];
  end f;
  
  model Test
    input Integer idx = 0;
    parameter Integer[:] tdata = {1, 2, 3, 4, 5, 6, 7, 8, 9};
    Integer y = f(tdata, idx+1);
  end Test;
end ArrayData;

ArrayData.Test is instantiated to:

function ArrayData.f
  input Integer[:] idata;
  input Integer idx;
  output Integer y;
algorithm
  y := idata[idx] + {1, 2, 3, 4, 5, 6, 7, 8, 9}[idx] + {1, 2, 3, 4, 5, 6, 7, 8, 9}[1 + idx];
end ArrayData.f;

class ArrayData.Test
  input Integer idx = 0;
  parameter Integer tdata[1] = 1;
  parameter Integer tdata[2] = 2;
  parameter Integer tdata[3] = 3;
  parameter Integer tdata[4] = 4;
  parameter Integer tdata[5] = 5;
  parameter Integer tdata[6] = 6;
  parameter Integer tdata[7] = 7;
  parameter Integer tdata[8] = 8;
  parameter Integer tdata[9] = 9;
  Integer y = ArrayData.f({tdata[1], tdata[2], tdata[3], tdata[4], tdata[5], tdata[6], tdata[7], tdata[8], tdata[9]}, 1 + idx);
end ArrayData.Test;

It is bad if a temporary array is created when calling the function f, instead of just passing tdata. It is worse if the whole data array is created temporarily again and again whenever the function f wants to access one element of it.