Date: Wed, 1 May 2002 09:40:33 +0100 From: Doug Rabson <dfr@nlsystems.com> To: Marcel Moolenaar <marcel@cup.hp.com> Cc: cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/ia64/ia64 exception.s src/sys/ia64/include frame.h Message-ID: <200205010940.33776.dfr@nlsystems.com> In-Reply-To: <20020430195757.GA70203@gauss.cup.hp.com> References: <200204300637.g3U6bQc25956@freefall.freebsd.org> <20020430165257.M25863-100000@herring.nlsystems.com> <20020430195757.GA70203@gauss.cup.hp.com>
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On Tuesday 30 April 2002 8:57 pm, Marcel Moolenaar wrote: > On Tue, Apr 30, 2002 at 04:53:59PM +0100, Doug Rabson wrote: > > On Mon, 29 Apr 2002, Marcel Moolenaar wrote: > > > marcel 2002/04/29 23:37:25 PDT > > > > > > Modified files: > > > sys/ia64/ia64 exception.s > > > sys/ia64/include frame.h > > > Log: > > > Add ar.lc and ar.ec to the trapframe. These are not saved for > > > syscalls, only for exceptions. > > > > I was kind-of relying on the C calling conventions saving/restoring t= hese > > as needed. > > ar.lc is callee saved. We have to do it even for the syscall case. > ar.ec is automatic as part of the call/return mechanism. We need to > explicitly save it only if it's possible to have syscalls inlined. What I actually meant by that statement was that since the exception entr= y=20 path didn't disturb the value of ar.lc (or ar.ec for that matter) and tha= t it=20 can rely on the value being preserved by the higher level handlers (e.g.=20 trap, interrupt, syscall etc), it can also rely on the value in=20 exception_restore being the user's value. > > I think we should save them both for syscalls as well. Thoughts? I don't think so (for the above reason). --=20 Doug Rabson=09=09=09=09Mail: dfr@nlsystems.com =09=09=09=09=09Phone: +44 20 8348 6160 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message
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