[fpc-pascal] Why the difference in the rounded results?

[Gabor Boros via fpc-pascal]

Hi All,

I got different results with 32bit vs. 64bit, 3.2.2 vs. 3.3.1, FPC vs. 
Delphi. Why?

var
  d1,d2:Double;

begin
  d1:=20.5;
  d2:=1.05;
  Writeln(RoundTo(d1*d2,-2));
  Writeln(SimpleRoundTo(d1*d2));
  d1:=28.9;
  Writeln;
  Writeln(RoundTo(d1*d2,-2));
  Writeln(SimpleRoundTo(d1*d2));
  d1:=21.5;
  Writeln;
  Writeln(RoundTo(d1*d2,-2));
  Writeln(SimpleRoundTo(d1*d2));
  Readln;
end.

- FPC 3.2.2 Win32

 2.1530000000000001E+001
 2.1530000000000001E+001

 3.0340000000000000E+001
 3.0340000000000000E+001

 2.2570000000000000E+001
 2.2570000000000000E+001

- FPC 3.2.2 Win64

 2.1520000000000003E+001
 2.1530000000000001E+001

 3.0340000000000007E+001
 3.0350000000000001E+001

 2.2570000000000004E+001
 2.2579999999999998E+001

- FPC 3.3.1 Win32

 2.1530000000000001E+001
 2.1530000000000001E+001

 3.0340000000000000E+001
 3.0340000000000000E+001

 2.2570000000000000E+001
 2.2570000000000000E+001

- FPC 3.3.1 Win64

 2.1520000000000003E+001
 2.1530000000000001E+001

 3.0340000000000007E+001
 3.0350000000000001E+001

 2.2570000000000004E+001
 2.2579999999999998E+001

- Delphi 10.4.2 Win32

 2.15300000000000E+0001
 2.15300000000000E+0001

 3.03400000000000E+0001
 3.03400000000000E+0001

 2.25800000000000E+0001
 2.25800000000000E+0001

- Delphi 10.4.2 Win64

 2.15200000000000E+0001
 2.15300000000000E+0001

 3.03400000000000E+0001
 3.03500000000000E+0001

 2.25800000000000E+0001
 2.25800000000000E+0001

Gabor
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