Re: 64 bit arithmetic in the kernel

Michael Richardson (mcr@solidum.com)
Mon, 12 Jul 1999 21:14:59 -0400


>>>>> "Mike" == Mike Shaver <shaver@netscape.com> writes:

Mike> Michael Richardson wrote:
>> >>>>> "Richard" == Richard B Johnson <root@chaos.analogic.com> writes:
Richard> On Mon, 12 Jul 1999, Michael Richardson wrote:
>> >> This is with 2.2.10, on a Lintel box, and I'm using a module.
>>
Richard> Use inline asm. In Intel, you put the high long-word into edx,
Richard> the low long-word into eax, and "div" either by an immediate or
Richard> something in, say
>>
>> Uh, that's real portable.

Mike> To be fair, you did say that you were on a ``Lintel'' box, which could
Mike> reasonably be taken to mean that you only care about that situation.

I said that because it might be that other architectures have other issues.
I would not be surprised to learn that 64/32 to be either a single
instruction or thatno divide instructions exist at all, relying on a
subroutine as is the way with RISC machines.

:!mcr!: | Solidum Systems Corporation, http://www.solidum.com
Michael Richardson |For a better connected world,where data flows faster<tm>
Personal: <A HREF="http://www.sandelman.ottawa.on.ca/People/Michael_Richardson/Bio.html">mcr@sandelman.ottawa.on.ca</A>. PGP key available.
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