Hello folks,
This one looks pretty elementary, but to my big surprise
it doesn't work as I would expect.
I'd like to ask FreePascal compiler creators, how can I safely
evaluate double variables in case like this.
Sample program with comment is in attachement ...
Milano
//
// Hm. This is really weird. I assign 1 to x, which is of double type.
// Then I add 0.4 to the x, then I subtract 0.4 from x.
// So, now I should have 1 in x. But when I compare x with 1, I get
// wrong evaluation of "if x = 1 then" statement !
//
// I tried this on two different Windows Intel machines and it was wrong.
// I tried it also on Mac with PowerPC processor and it was also wrong.
// (Both Delphi & FPC compilers)
//
// [EMAIL PROTECTED]
//
program
floating_error_1_4 ;
{$APPTYPE CONSOLE }
var
x : double;
BEGIN
x:=1;
x:=x + 0.4;
x:=x - 0.4;
if x = 1.0 then
writeln('OK: x = 1 ' )
else
writeln('Error: "if x = 1" is evaluated wrong !!!! ' );
END._______________________________________________
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