From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Hubicka To: law@redhat.com Cc: Richard Henderson , Toon Moene , gcc@gcc.gnu.org Subject: Re: Alias analysis - does base_alias_check still work ? Date: Mon, 12 Aug 2002 07:53:00 -0000 Message-id: <20020812145257.GB788@atrey.karlin.mff.cuni.cz> References: <20020719095446.A15598@redhat.com> <200208121452.g7CEqk904215@porcupine.slc.redhat.com> X-SW-Source: 2002-08/msg00653.html > In message <20020719095446.A15598@redhat.com>, Richard Henderson writes: > >On Fri, Jul 19, 2002 at 04:40:26PM +0200, Toon Moene wrote: > >> Which begs the question: Is there a reason -fschedule-insns isn't on by > >> default when using -O2 ? > > > >Yes. The fact that the scheduler doesn't understand register > >pressure means that pre-register-allocation scheduling generally > >sucks eggs on x86. > True. But the real reason -fschedule-insns isn't on by default for ia32 > is the return register problem -- which I believe you actually fixed > a while back, but we haven't gone back to see if it's safe/profitable to > enable the first scheduling pass for ia32. Did you really fixed all the problems regarding SMALL_REGISTER_CLASSes? When using register passing conventions I've seen ia32 compilation dying all the time. It may be interesting to set the flag on at least for x86_64 where register pressure is lower if it worked. Honza > > Jeff >