OberonCore

MODULETestMath; (** AUTHOR ""; PURPOSE ""; *)
IMPORT Commands, Stopwatch;
 
VAR a, b, c: ARRAY [ *, * ] OF SIGNED32;
VAR buf: ARRAY 32 OF CHAR;
 
(** *)
PROCEDURE Do*( context: Commands.Context );
VAR N: SIZE;
BEGIN
   IF ~context.arg.GetSize(N, FALSE) THEN N := 1024 END;
   context.out.String( "N = " ); context.out.Size( N ); context.out.Ln;
 
   NEW( a, N, N ); NEW( b, N, N ); NEW( c, N, N );
   a := 5; b := 10;
   VAR sw: Stopwatch.T; sw.Start;
       c := a * b;
   VAR t := sw.Elapsed( ); sw.Stop;
   Stopwatch.ToString( t, buf );
   context.out.String( buf ); context.out.Ln;
END Do;
 
BEGIN
 
END TestMath.Do ~
 
TestMath.Do 1024~
TestMath.Do 2048~
 
 
System.Free TestMath~

for i in [1 2 4 8 16]
  print(i, ": ")
  N = 1024 * i
  A = fill(Int32(5), (N, N))
  B = fill(Int32(10), (N, N))
  @time begin
    C = A * B
  end
end

1:   0.520594 seconds (8 allocations: 4.000 MiB)
2:   4.198689 seconds (8 allocations: 16.000 MiB)
4:  33.793543 seconds (8 allocations: 64.000 MiB, 0.22% gc time)
8: 276.754758 seconds (8 allocations: 256.000 MiB, 0.04% gc time)
16: 2046.192749 seconds (8 allocations: 1.000 GiB, 0.00% gc time)