Subj : Re: Any help on why?
To   : borland.public.cpp.borlandcpp
From : Stan DeGroff
Date : Wed Jul 07 2004 02:56 pm

BC++ V5.02 Copyright 1997

You've come up with exactly what I think was going on.  I've seen other
cases do the same.
printf doesn't seem to invoke code that produces values that stick around
beyond their non-printf use.

When I look at the CPU screen I see that code is optimized.  (Even though I
have "no optimization" checked in the project->options screen.  Some
statements can't be used as break points as they have been optimized away as
well.)

Is there a way to insure optimization is not invoked?



"Bob Gonder" <notbg@notmindspring.invalid> wrote in message
news:3d8ne01afvj3q4ph7s71lklv2ej45c90gl@4ax.com...
> Stan DeGroff wrote:
>
> >   for (i=0; i<x; i++){
> >      xresult = double va_arg(arglist, double);
> >    result += xresult;
> >      printf("%d  %X, %X\n", i, xresult, result);
> >   }
> > That prints the
> >variable "xresult" resulted in printing 0x0000. However the variable
> >"result" printed ok.  Any ideas why the compiler forgets xresult?
>
> I know this sounds weird, but try this.
>
>    for (i=0; i<x; i++){
>       xresult = double va_arg(arglist, double);
>       printf("%d  %X, %X\n", i, xresult, result);
>     result += xresult;
>    }
>
> I think that because xresult isn't needed later, it is optimised away.
> If xresult were global, or used later, it would be made "real".
> (Apparantly, being inside a printf is being invisible.)
> There's a bug in the optimizer.
>
> BTW, which compiler are you using?
>
>

.