Date: Tue, 22 Jun 2010 00:40:48 -0600 (MDT) From: "M. Warner Losh" <imp@bsdimp.com> To: c.jayachandran@gmail.com Cc: freebsd-mips@freebsd.org Subject: Re: Merging 64 bit changes to -HEAD - part 3 Message-ID: <20100622.004048.624519315654756672.imp@bsdimp.com> In-Reply-To: <AANLkTikv__dQnu3iEMl-Of2xzJc6xoPSCrEpLz5GVg6R@mail.gmail.com> References: <AANLkTimQbw57AUGXd2A9Ql98VvtkInsdHX7jDor1rLwe@mail.gmail.com> <20100621.164056.10150326092187581.imp@bsdimp.com> <AANLkTikv__dQnu3iEMl-Of2xzJc6xoPSCrEpLz5GVg6R@mail.gmail.com>
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In message: <AANLkTikv__dQnu3iEMl-Of2xzJc6xoPSCrEpLz5GVg6R@mail.gmail.c=
om>
"Jayachandran C." <c.jayachandran@gmail.com> writes:
: On Tue, Jun 22, 2010 at 4:10 AM, M. Warner Losh <imp@bsdimp.com> wrot=
e:
: > The changes to asm.h change the ABI for all ABIs, no? =A0Does that
: > matter? =A0The jumpbuf is a user-visible thing... =A0I'm guessing t=
hat we
: > can say it is OK, but it sure would be nice if we could MFC this
: > change before 8.1-RELEASE (but given the locked-down nature of the
: > tree, I'm not hopeful).
: =
: Currently, it should not disturb the o32 ABI, since it is inside an i=
fdef.
: In n32/n64 the jmpbuf entries are 64bit and we will use one more
: register for GP.
Good point. I missed that when I was looking at it. My bad.a
: Slightly off-topic, _JBLEN is 95 for mips, I cannot see a reason for=
: this value, any hints?
Hmmm. 31 normal registers (we don't save $0 :). 32 floating point
registers that are double size. 31 + 2 * 32 =3D=3D 95. Maybe that's
why...
There's at least one Mips that has CP1 registers for its specialized
hardware. If we ever are going to support saving/restoring that state
along with the core and FP registers, we will need to expand this...
Warner
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