From: "Ulrich Weigand" <uweigand@de.ibm.com>
To: hjl.tools@gmail.com (H.J. Lu)
Cc: gcc-patches@gcc.gnu.org, bernds@codesourcery.com
Subject: Re: PATCH [10/n]: Prepare x32: PR rtl-optimization/49114: Reload failed to handle (set reg:X (plus:X (subreg:X (reg:Y) 0) (const
Date: Mon, 27 Jun 2011 18:51:00 -0000 [thread overview]
Message-ID: <201106271828.p5RISq1L030434@d06av02.portsmouth.uk.ibm.com> (raw)
In-Reply-To: <BANLkTi=L9NyLjfbcB6ftE8FqVEq6_WF-sQ@mail.gmail.com> from "H.J. Lu" at Jun 27, 2011 11:03:14 AM
H.J. Lu wrote:
> On Mon, Jun 27, 2011 at 7:47 AM, Ulrich Weigand <uweigand@de.ibm.com> wrote:
> > The actual problem
> > here is that this part of gen_reload takes the approach to transform
> >
> > out <- op0 + op1
> >
> > into
> >
> > out <- op0
> > out <- out + op1
> >
> > which is invalid if writing to out clobbers op1.
> The problem is reload 0 puts OP1 in OUT. Adding
>
> gcc_assert (!reg_overlap_mentioned_p (out, op1));
>
> doesn't help in reload 2. How can I check if OP1 overlaps with
> OUT in previous reload?
Sorry, I don't understand how previous reloads come into play here.
gen_reload is supposed to load "in" (which happens to be of the
form op0 + op1) into "out", which means it is of course supposed
to clobber "out" (as long as that doesn't implictly clobber op0
or op1 before they're used). Any conflicts with other reloads ought
to have been resolved earlier.
Can you elaborate?
Bye,
Ulrich
--
Dr. Ulrich Weigand
GNU Toolchain for Linux on System z and Cell BE
Ulrich.Weigand@de.ibm.com
next prev parent reply other threads:[~2011-06-27 18:29 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-25 19:02 PATCH [10/n]: Prepare x32: PR rtl-optimization/49114: Reload failed to handle (set reg:X (plus:X (subreg:X (reg:Y) 0) (const_int))) H.J. Lu
2011-06-27 15:01 ` PATCH [10/n]: Prepare x32: PR rtl-optimization/49114: Reload failed to handle (set reg:X (plus:X (subreg:X (reg:Y) 0) (const_int Ulrich Weigand
2011-06-27 18:32 ` H.J. Lu
2011-06-27 18:51 ` Ulrich Weigand [this message]
2011-06-27 18:56 ` PATCH [10/n]: Prepare x32: PR rtl-optimization/49114: Reload failed to handle (set reg:X (plus:X (subreg:X (reg:Y) 0) (const H.J. Lu
2011-06-27 19:21 ` Ulrich Weigand
2011-06-27 21:20 ` H.J. Lu
2011-06-27 22:19 ` H.J. Lu
2011-06-27 22:26 ` Ulrich Weigand
2011-06-27 22:45 ` H.J. Lu
2011-06-27 22:53 ` H.J. Lu
2011-06-27 23:36 ` H.J. Lu
2011-06-28 15:05 ` Ulrich Weigand
2011-06-28 15:08 ` H.J. Lu
2011-06-28 15:19 ` H.J. Lu
2011-06-28 15:45 ` Ulrich Weigand
2011-06-28 16:18 ` H.J. Lu
2011-06-28 22:16 ` H.J. Lu
2011-06-29 13:00 ` Ulrich Weigand
2011-06-29 17:24 ` [commit] Fix -Werror build break (Re: PATCH [10/n]: Prepare x32: PR rtl-optimization/49114) Ulrich Weigand
2011-06-28 14:21 ` PATCH [10/n]: Prepare x32: PR rtl-optimization/49114: Reload failed to handle (set reg:X (plus:X (subreg:X (reg:Y) 0) (const H.J. Lu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=201106271828.p5RISq1L030434@d06av02.portsmouth.uk.ibm.com \
--to=uweigand@de.ibm.com \
--cc=bernds@codesourcery.com \
--cc=gcc-patches@gcc.gnu.org \
--cc=hjl.tools@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).