Bug with extended type?

Hi,
  I have a function in a shared utility that I use to convert the 
major version and minor version to an extended type.
 
class function TmxcUtil.ConvertVersionAsExtended(AMajorVersion, 
AMinorVersion: Integer) : Extended;
begin
  Result := AMajorVersion + AMinorVersion/100
end;

If I call with ConvertVersionAsExtended(1, 20), it should return me 
with 1.2.

The version controls what the program can read from a file. The file 
can change between versions, so I need to check its version to know 
what I can read.

The problem is that the comparison doesn't always work...

if ConvertVersionAsExtended(1, 20) >= 1.20 then
  Read;  // <-- I don't go here!!!

I am suprised that ConvertVersionAsExtended(1, 20) returns 
1.19999999999999996 instead of 1.2, since it can (assign 1.2 in an 
extended variable and check with the debugger, you will see that the 
value of the variable is still 1.2).

I made a sample test project that called my function with the same 
parameter and that time, ConvertVersionAsExtended(1, 20) returns 1.2 
as I expected it.

How can that happened?

I check the generated code with the debugger and the code generated 
for the same function in my two projects is different.

So, my guess is that with my real project, the compiler doesn't use 
and extended type as supposed, but it uses a double instead, but in 
my test project, the compiler make the computation with extended 
variables.

To prove that, I put the result returned by ConvertVersionAsExtended
(1, 20) in a variable of type double and the variable is equal to 
1.19999999999999996. So the extended variable that is returned by my 
function, in fact has the precision of a double?!?

I placed all my variables in my function in new variables of 
extended type before doing the computation and the result is still 
the same...

Anyone has ever seen something like this?

I'm using Delphi 5 Pro.

Thanks,
Michael



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