I've found an inconsistancy in a floating point operation
that depends on the version of OlePro32.dll on the user's
system at run-time. I've tested this compiled program on
about 12 machines. A good mix of both Win95 and WinNT4
machines with various service packs.

Here are the vital stats:

The 2 versions of OlePro32.dll I'm working with are:
OlePro32.dll -> File Version: 5.0.4118
OlePro32.dll -> File Version: 5.0.4055

Here's the project that demonstrates the inconsistancy:

program Project1;

uses
  Forms,
  OleCtrls, //Inclusion of this file causes the inconsistancy!!!!
  Unit1 in 'Unit1.pas' {Form1};

{$R *.RES}

begin
  Application.Initialize;
  Application.CreateForm(TForm1, Form1);
  Application.Run;
end.

procedure TForm1.Button1Click(Sender: TObject);
var
  f3 : Extended;

begin
  f3 := Exp(83);
  Edit1.Text := FloatToStrF(f3, ffExponent, 18, 18);
end;

If you examine the value of f3 when version 5.0.4118 of OlePro32.dll is
active on the system you get:
1.11286375479176464E+36
               ^^^^
                     <Differs here>

If version 5.0.4055 is active then you get:
1.11286375479175942E+36
               ^^^^
                   <Differs here>

I've got a workaround for the problem right now, but if anyone can figure
this out, I'd really like to know the cause.

Thanks in advance,

--
Christopher D. Coppola
Advanced Creative Technologies III, Inc.
copp...@act-3.com
http://www.act-3.com

On Wed, 4 Jun 1997 06:43:50 -0700, copp...@act-3.com (Christopher D.

Are you sure this is a cause, or is it just a symtom?  Could it be
that there is some other file (probably one that gets pulled in by
OldPro32.dll) that is also different?

What happens if you copy the 5.0.4118 version onto a system that had
the 5.0.4055 version?  Does it's calculation change?

Have you tried forcing the compiler to generate "Flawed Pentium" safe
code?  Before the calculation, try {$U+} and after, {$U-}

With or without OleCtrls in my USES statement, I got the 6464 answer.

Chuck Gadd
Director of Software Development, {*word*104} FX Communications.
e-mail:cgadd-NOS...@{*word*104}-fx.com  http://www.{*word*104}-fx.com
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