Re: [avr-gcc-list] clock skew detected

[David Brown]

> I'm using Windows XP, and I haven't seen this error on my old Windows 98
> computer.
> Should I just not worry about it, or could it be affecting my programs?
>

Are you using FAT32 instead of NTFS?  (And if so, why?)  I think the problem
was more related to the low accuracy of the timestamps (2 seconds) rather
than the OS.  I don't think it is a big problem - just "make" away happily,
but look at which files are rebuilt and check that the ones you want are
rebuilt.  To be absolutely sure, you can always delete all your object
files, and there is always the ineligant solution of using a batch file to
always recompile all your files - on a fast machine, it won't make much
difference.

> Also, for my application (RoboCup Junior soccer) I need to optimise my
code
> for speed, without having to worry much about space (32kB on the
ATMega32).
> Which optimisation setting should I specify in the makefile?

Off the top of my head,
try -O3 -fomit-frame-pointer -finline -funroll-all-loops.  Check the
generated assembly code for a few test cases to see if it makes much
difference.

>
> Thanks,
> Jack
>
> (sorry David if you get this twice)

The old "reply to" button on OE ?  Don't worry, I've done it a few times
myself...

David



>
> ----- Original Message -----
> From: "David Brown" <address@hidden>
> To: <address@hidden>
> Sent: Tuesday, September 30, 2003 4:53 PM
> Subject: Re: [avr-gcc-list] clock skew detected
>
>
> >
> >
> > > On Tue, Sep 30, 2003 at 11:01:40AM +1000, Jack Valmadre wrote:
> > > > I've just switched from using AVRStudio with AVRGCC 2.3 to using
> > > > Programmers Notepad with WinAVR. When I compile the project,
> > > > everything works fine except at the end I get a line saying: make:
***
> > > > Warning: Clock skew detected.  Your build may be incomplete. Is this
a
> > > > problem? How can I fix it?
> > >
> > >    Clock skew can be detected on networked development machines, if
> > > sharing build files between hosts, and the (time & date) clocks are
not
> > > synchronised. When the compiling host lags the fileserver, the
generated
> > > files are "older" than their inputs, which is a logical impossibility.
> > > This makes make's decision making problematical, hence the warning.
> > >
> > >    When this last happened here, a few years back, I synchronised date
&
> > > time, effecting an immediate cure.
> > >
> > >    It is not easy to imagine a way for this to happen on a single
host,
> > > without something being seriously broken. (Perhaps my lack of
experience
> > > with anything but various unices limits my imagination, though. :-)
> > >
> >
> > Clock skew can happen by itself on Win9x machines - it has to do with
the
> > low resolution of time stamps on FAT32 and the mechanisms used to fake a
> > real time stamp.
> >
> >
> >
> >
> > _______________________________________________
> > avr-gcc-list mailing list
> > address@hidden
> > http://www.avr1.org/mailman/listinfo/avr-gcc-list
>
>
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