AMD64 Linux documentation

[Jakub Jelinek]

On Fri, Dec 12, 2003 at 12:04:00PM -0500, Jeremy Katz wrote:
> Libraries should be built so that they don't have a problem (since the
> canonical location for native system libraries on e.g. x86_64 is lib64
> instead of lib).  For binaries, it really is something you want to
> choose and not have two separate sets in two separate paths that may or
> may not be in your PATH and ... :-)

Yeah, wonder why user should always think if he wants to run 32-bit or
64-bit ls.  They both give the same output, so the one that is faster
is usually the ultimate choice.
On AMD64, usually 64-bit programs are faster than 32-bit (bigger memory
footprint is overweighted by additional registers, %rip addressing etc.).
On e.g. SPARC or PPC it is the opposite (bigger memory footprint makes
64-bit programs slower).  So, on AMD64 you want most things 64-bit,
plus 32-bit libraries and some programs so that you can run things
which are only 32-bit.  I'm very curious if 64-bit OOo would be a win
on AMD64 though, given its insane memory footprint.
On SPARC/PPC, you want most of the programs 32-bit, with the exception
of programs which need bigger address space, do lots of computation
in 64-bit arithmetics or are too much connected with the kernel (so that
data doesn't have to be converted back and forth, for specialized utilities
the conversion code may not even be written).

	Jakub