SystemVerilog foreach syntax for looping through lower dimension of multidimensional array

Question

What is the standard way of looping through the lower dimension of a multidimensional array? With the higher dimension fixed.

In the following example:

  automatic int i = 2;
  foreach (my_req[i][j]) begin // <-- WARNING
    $display("i:%0d,j:%0d", i, j);
  end

I see the warning:

** Warning: testbench.sv(16): (vlog-LRM-2897) Using non-standard foreach loop variable list syntax.

Full code example on EDA Playground: http://www.edaplayground.com/x/nh

Answer 1

You can do this:

$display("Loop through i=2");
begin
  automatic int i = 2;
  foreach (my_req[,j]) begin // notice the "," before j
    $display("i:%0d,j:%0d", i, j);
  end
end

Working code on EDA Playground: http://www.edaplayground.com/x/2Qn

Answer 2

The warning is to let you know that the code you are writing may not be compatible with other simulators. I do know that at one time, another simulator accepted foreach (array[i][j]) where i was not previously defined to mean the same thing as foreach(array[i,j]), and that syntax would not be compatible with what you are trying to do.

The correct syntax is foreach (my_req[,j])