From: Richard Henderson <rth@redhat.com>
To: Zack Weinberg <zack@codesourcery.com>
Cc: Mark Mitchell <mark@codesourcery.com>, Mike Stump <mrs@apple.com>,
Geoff Keating <geoffk@geoffk.org>,
"steby@enea.se" <steby@enea.se>,
"gcc@gcc.gnu.org" <gcc@gcc.gnu.org>
Subject: Re: GCC floating point usage
Date: Wed, 16 Oct 2002 22:50:00 -0000 [thread overview]
Message-ID: <20021016234620.GH30823@redhat.com> (raw)
In-Reply-To: <20021016223645.GE15067@codesourcery.com>
On Wed, Oct 16, 2002 at 03:36:45PM -0700, Zack Weinberg wrote:
> > You're going to need the front/middle-end to indicate whether
> > "floating point has been used", and if not, hide *all* existance
> > of the fp registers from the register allocators. Nothing less
> > gives you assurance they won't be used.
>
> Okay. Care to suggest how this should be accomplished?
For the second part?
Arrange for REG_CLASS_FROM_LETTER to return NO_REGS for 'f'
when appropriate would be one way. Mistakes here would result
in reload aborts, since reload would fail to find a way to
move data between, into, or out of the FP regs.
Marking the fp registers to be fixed for the duration of the
function would be another way, though it would seem that you'd
need a new hook run from rest_of_compilation, somewhere before
regclass/reload, in order to make this work.
r~
next prev parent reply other threads:[~2002-10-16 23:46 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-10-14 9:59 Stefan Bylund
2002-10-14 10:16 ` David Edelsohn
2002-10-14 10:25 ` Zack Weinberg
2002-10-14 10:55 ` Dale Johannesen
2002-10-14 22:22 ` Mark Mitchell
2002-10-15 15:35 ` Geoff Keating
2002-10-15 16:10 ` Mark Mitchell
2002-10-15 17:20 ` Geoff Keating
2002-10-15 18:09 ` Mark Mitchell
2002-10-16 7:40 ` Joel Sherrill
2002-10-15 19:04 ` Mike Stump
2002-10-16 12:06 ` Mark Mitchell
2002-10-16 13:35 ` Geoff Keating
2002-10-16 14:29 ` Mark Mitchell
2002-10-16 14:56 ` Michael Matz
2002-10-16 15:03 ` Mark Mitchell
2002-10-16 15:27 ` David Edelsohn
2002-10-16 15:36 ` Mark Mitchell
2002-10-16 16:35 ` Zack Weinberg
2002-10-16 16:36 ` Mark Mitchell
2002-10-16 16:46 ` David Edelsohn
2002-10-17 8:37 ` Paul Koning
2002-10-16 17:57 ` Mike Stump
2002-10-17 4:12 ` Mike Stump
2002-10-16 13:43 ` Richard Henderson
2002-10-16 14:35 ` Mark Mitchell
2002-10-16 14:56 ` Joel Sherrill
2002-10-16 16:38 ` Richard Henderson
2002-10-16 16:53 ` Zack Weinberg
2002-10-16 17:52 ` Michael Matz
2002-10-16 22:50 ` Richard Henderson [this message]
2002-10-21 12:21 ` Jeff Law
2002-10-16 17:29 ` Mike Stump
2002-10-17 2:19 ` Richard Henderson
2002-10-15 17:19 ` Mike Stump
2002-10-15 18:41 ` Zack Weinberg
2002-10-16 1:48 ` Fergus Henderson
2002-10-14 10:37 ` Stefan Bylund
2002-10-14 11:28 ` Mike Stump
2002-10-14 12:39 ` Joel Sherrill
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