This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: Sharing hard registers
- From: Alan Lehotsky <apl at alum dot mit dot edu>
- To: law at redhat dot com
- Cc: "Eric Christopher" <echristo at redhat dot com>, gcc at gcc dot gnu dot org,gcc-patches at gcc dot gnu dot org
- Date: Thu, 13 Jun 2002 21:50:55 -0400
- Subject: Re: Sharing hard registers
- References: <2387.1024007246@porcupine.cygnus.com>
At 4:27 PM -0600 6/13/02, law@redhat.com wrote:
In message <200206132203.g5DM3lv24315@potter.sfbay.redhat.com>,
"Eric Christoph
er" writes:
> On Thu, 13 Jun 2002 13:27:39 -0700, law wrote:
>
>
> > It may be necessary to back out the last patch which makes gen_rtx_REG
> > share hard registers in some circumstances.
> >
The porting guide's "Structure Sharing Assumptions" needs to
be updated to
explicitly indicate that hard registers are "shared". Right
now, it just says
that pseudos are always shared.
Also, I'm curious about the issue of a hard-register with
more than one mode.
How does that work if R1 can be a SF or a SI mode value???
Doesn't the mode get in the way of sharing the hard register?
Or is this cached
by (mode,regno).?
--
Quality Software Management
http://home.earthlink.net/~qsmgmt
apl@alum.mit.edu
(978)287-0435 Voice
(978)808-6836 Cell
Software Process Improvement / Management Consulting
Language Design / Compiler Implementation