----- Original Message -----
From: "Richard Maine" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, December 15, 2003 7:02 PM
Subject: Re: Fortran 95 on Opteron
[...]
>
> You seem to be assuming that 64-bit mode means 64-bit default
> integers. I don't know about the particular mode of the particular
> compiler in question, but that is not true in general.
>
> In general, 64-bit mode means 64-bit addresses. That is *ALL*.
Since
> addresses are not explicitly manipulated in Fortran source code,
this
> doesn't tend to affect the validity standard-conforming code. (If
you
> play nonstandard tricks to manipulate addresses, that's a different
> matter). You might end up wanting to use 64-bit integers in some
> contexts if the reason you need 64-bit addresses is that you have
huge
> arrays, but it does not necessarily follow that default integers are
> 64 bits.
>
Yes, you can have 64-bit integers in 32-bit mode. '64' is being used
in two senses as Richard points out. 32-bit mode means you have a much
smaller addressable space and the OS might curtail the size of your
exe, no matter how much RAM your processor possesses.
--
Ciao,
Gerry T.
|