Re: Pentium 1.8Ghz / Windows 2000 / Delphi 6 problem

From: Martin Harvey (Demon account) (martin_at_nospam_pergolesi.demon.co.uk)
Date: 10/29/04 

Date: Fri, 29 Oct 2004 18:38:44 GMT

On Thu, 28 Oct 2004 20:56:17 GMT, pgx@pgrahams.com wrote:

>What harm does setting the control word for extended calculations do
>to other programs, other than making FP results slightly more accurate
>and slightly slower?

This is what makes no sense - altering the FPU control word in your
process has no effect on anything in any other process.

There are only two ways the Novell stuff can change the FPU control
word.

1. Reside in your process as a DLL in user mode ... either registered
to do something, or as a result of having set a systemwide windows
hook.
2. Run some sort of driver in kernel mode.

In either case, changing the FPU control word and not restoring it is
a fairly major blunder ... (actually, Novell Netware seems to wreak
havoc on modern machines, but that's another matter).

Any setting of the FPU control word that you do as a user process does
not affect any other processes.

MH.