Hi All,

I have the following code:

var
  val: Currency;
  res: Double;
begin
  val := 2345.67;
  res := 1e300;
  if val >= res then WriteLn('val >=res')
  else WriteLn('val < res');
end;

The program compile and runs correctly on Linux x64, and Win7 32bit, but failed (SIGFPE) on Win7 64bit.

Can I safely compare a Currency against a Double?

Thanks!

Xiangrong

That's because currency has a bigger range than double. On Linux x64 and Windows 32 bit, the x87 fpu can be used, so the currency value can be converted to an 80 bits extended value. The x87 and hence also its 80 bits extended type have been deprecated on Win64, so FPC doesn't use it there anymore.

Can I safely compare a Currency against a Double?

No. It generally also doesn't make sense, because the whole point of using currency is to have an exact value without rounding errors, while a double value by nature very often contains rounding errors.

Jonas

Jonas Maebe wrote

That's because currency has a bigger range than double.

Or rather: a double cannot exactly represent every possible currency value.

Jonas

Thank you! I have changed all occurrences of Currency to Double in my program.

2014-12-08 21:25 GMT+08:00 Jonas Maebe :

Ehm....

The question is if that's the right approach.

And if you didn't top-post your message it was now immediately clear what I mean with this. Now you've created a little puzzle for yourself...

Regards,

Joost.