Messages in this thread | | | Date | Tue, 15 Mar 2005 11:43:10 -0600 | Subject | Re: [PATCH] PPC64 iSeries: cleanup viopath | From | Linas Vepstas <> |
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On Wed, Mar 16, 2005 at 02:53:39AM +1100, Stephen Rothwell was heard to remark: > On Tue, 15 Mar 2005 08:32:27 -0600 Hollis Blanchard <hollis@penguinppc.org> wrote: > > > > Why not use a byte instead of a full int (reordering the members for > > alignment)? > > Because "classical" boleans are ints. > > Because I don't know the relative speed of accessing single byte variables. > > Because it was easy. > > Because we only allocate 32 of these structures. Changing them really > only adds four bytes per structure. I guess using bytes and rearranging > the structure could actually save 4 bytes per structure.
FWIW, keep in mind that a cache miss due to large structures not fitting is a zillion times more expensive than byte-aligning in the cpu (even if byte operands had a cpu perf overhead, which I don't think they do on ppc).
> It really makes little difference,
Yep. So my apologies for making you read this email.
--linas
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