64 bit Intels?

John Nelson john at computation.com
Mon Apr 22 10:12:48 PDT 2002

Have the number of bits per machine instruction also increased to 64 bits?  
This would imply that all of your compiled executables have now doubled in
size (although I don't know why you would need 2**32 additional
instructions).  Are all pointers consistantly using 64 bits?  If so, there
will be a proportional growth in the size of your executable.

The larger architecture also impacts your data formats. If your data sets
are in binary format, and depending on the language you are using, there
may be incompatibilities as well as new demands on storage.

Stating the obvious I guess, but there are considerations when going to
larger architectures.

-- John

On Mon, 22 Apr 2002, Joe Griffin wrote:

> The Itanium is NOT 64 bit like a CRAY is 64 bit.
> It is an LP64 (longs and pointers).
> In FORTRAN: INTEGERs and REALs are still 32 bits.
> In C, int are still 32 bits.
> You are allowed larger addressing because
> longs and pointers are 64 bits.


John T. Nelson
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