Re: [RFC] div64_64 support

From: H. Peter Anvin
Date: Mon Feb 26 2007 - 20:21:40 EST


Stephen Hemminger wrote:

Hmm. Those are the GCC internal versions, that are picked up but
doing divide in place. Do we want to allow general 64 bit in kernel to
be easily used? It could cause sloppy slow code, but it would look
cleaner.


... and it would handle datatypes which may be architecture-dependent a lot cleaner.

I thought the motivation for div64() was that a 64:32->32 divide could be done a lot faster on a number of platforms (including the important x86) than a generic 64:64->64 divide, but gcc doesn't handle the devolution automatically -- there is no such libgcc function.

-hpa
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