From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeffrey A Law To: mark@markmitchell.com Cc: amylaar@cygnus.co.uk, crux@pool.informatik.rwth-aachen.de, meissner@cygnus.com, toon@moene.indiv.nluug.nl, egcs@cygnus.com Subject: Re: Reload patch to improve 386 code Date: Sun, 06 Sep 1998 01:09:00 -0000 Message-id: <24271.905058439@hurl.cygnus.com> References: <199809060428.VAA02085@smtp.earthlink.net> X-SW-Source: 1998-09/msg00307.html In message < 199809060428.VAA02085@smtp.earthlink.net >you write: > I don't see why the base address tracking code should have to do > anything. My plan was just to use different alias sets for each spill > register (we have 2^32 of them, after all!). If you like, you could > reuse these from function to function, so the maximum number of alias > sets used up this was would be the number of spills in any one > function. My guess is that if that gets close to 4 billion, we have > worse problems. > > I'd be happy (delighted, even) to implement this, but I'd like a test > case that someone things will benefit. (I am in *no* way doubting the > existence of such a thing, but having one would allow me to verify my > work.) Just seemed easier to have a single alias set for spills. I'm not particularly partial to either solution. They should both work. As for a testcase. Who knows. I would think it would be reasonably straightforward to build one. ANy benefit right now would be in sched2 and possibly reload_cse since we don't have generalized spill code motion yet. Presumably we'd need a loop and something in the loop needs to be spilled to the stack and we need unrelated memory accesses throuh a pointer which we know nothing about. jeff