[Bug middle-end/81596] backwards threader misses simple copy within the same BB

[Bug middle-end/81596] backwards threader misses simple copy within the same BB

[law at redhat dot com]

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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81596

Jeffrey A. Law <law at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |law at redhat dot com

--- Comment #2 from Jeffrey A. Law <law at redhat dot com> ---
Jump threading is a fairly high overhead solution for this problem.  Simple
const/copy propagation is a better solution in cases like this IMHO.

The overhead could be reduced with some changes to the updating algorithm that
I want to implement, but haven't yet.  So perhaps keep it open as a low
priority issue.
>From gcc-bugs-return-572116-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org Tue Aug 15 03:20:21 2017
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From: "chrisj at rtems dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug demangler/81835] New: cxxabi.h has invalid link in comment.
Date: Tue, 15 Aug 2017 03:20:00 -0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81835

            Bug ID: 81835
           Summary: cxxabi.h has invalid link in comment.
           Product: gcc
           Version: 7.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: demangler
          Assignee: unassigned at gcc dot gnu.org
          Reporter: chrisj at rtems dot org
  Target Milestone: ---

Tiny issue.

Looking over cxxabi.h I noticed a link in a comment about __cxa_demangle is not
valid anymore:

   *  See http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt12ch39.html
   *  for other examples of use.

I am looking for the implementation of the demangler code we have on our
mebedded targets in RTEMS. A pointer to that location would be most welcomed.

Thanks
Chris
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Subject: Re: [Bug web/?????] New: Fwd: failure notice: Bugzilla down.
To: Eric Gallager <egall@gwmail.gwu.edu>
References: <CAMfHzOsXnceTY=YHFfC_qDPYYgkyer=dm5ESABuO_KjuQ60MXw@mail.gmail.com>
Cc: gcc-bugs@gcc.gnu.org, GCC Mailing List <gcc@gcc.gnu.org>
From: Martin Sebor <msebor@gmail.com>
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On 08/14/2017 04:22 PM, Eric Gallager wrote:
> I'm emailing this manually to the list because Bugzilla is down and I
> can't file a bug on Bugzilla about Bugzilla being down. The error
> message looks like this:

Bugzilla and the rest of gcc.gnu.org have been down much of
the afternoon/evening due to a hard drive upgrade (the old disk
apparently failed).  You're not the only one who found out about
it the hard way.  I (and I suspect most others) also discovered
it when things like Git and SVN (and Bugzilla) stopped working.

I've CC'd the gcc list to let others know (not sure what list
to subscribe to in order to get a heads up on these kinds of
maintenance issues).

Martin

>
> Software error:
>
> Can't connect to the database.
> Error: Can't connect to local MySQL server through socket
> '/var/lib/mysql/mysql.sock' (2)
>   Is your database installed and up and running?
>   Do you have the correct username and password selected in localconfig?
>
>
> For help, please send mail to the webmaster
> (sourcemaster@sourceware.org), giving this error message and the time
> and date of the error.
>
> Unfortunately, the email address listed for the webmaster,
> <sourcemaster@sourceware.org>, sends me its own error message when I
> try to email it, because the address apparently doesn't exist. I'm
> forwarding a copy of the failure email with this message. Is there a
> different address I should be emailing instead?
>
> Thanks,
> Eric Gallager
>
> ---------- Forwarded message ----------
> From: MAILER-DAEMON@sourceware.org
> Date: 14 Aug 2017 22:03:54 -0000
> Subject: failure notice
> To: egall@gwmail.gwu.edu
>
> Hi. This is the qmail-send program at sourceware.org.
> I'm afraid I wasn't able to deliver your message to the following addresses.
> This is a permanent error; I've given up. Sorry it didn't work out.
>
> <sourcemaster@sourceware.org>:
> Sorry, no mailbox here by that name. (#5.1.1)
>
> --- Below this line is a copy of the message.
>
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> From: Eric Gallager <egall@gwmail.gwu.edu>
> Date: Mon, 14 Aug 2017 18:03:48 -0400
> Message-ID: <CAMfHzOvVKr2AJ3d=j8iF64bWAsRgKO-u+2CwqNRwmuv=YY1qrQ@mail.gmail.com>
> Subject: GCC bugzilla down?
> To: sourcemaster@sourceware.org
> Content-Type: text/plain; charset="UTF-8"
>
> When I tried to access the GCC Bugzilla this evening of August 14,
> 2017, at 6PM Eastern Daylight Time, it displayed this error message:
>
> Software error:
>
> Can't connect to the database.
> Error: Can't connect to local MySQL server through socket
> '/var/lib/mysql/mysql.sock' (2)
>   Is your database installed and up and running?
>   Do you have the correct username and password selected in localconfig?
>
>
> For help, please send mail to the webmaster
> (sourcemaster@sourceware.org), giving this error message and the time
> and date of the error.
>
> So that's this email. Is the database okay?
>
> Thanks,
> Eric Gallager
>

[Bug middle-end/81596] backwards threader misses simple copy within the same BB

[aldyh at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81596

Aldy Hernandez <aldyh at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |WONTFIX
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #3 from Aldy Hernandez <aldyh at gcc dot gnu.org> ---
By design the backwards jump threader works on paths greater than one block, so
this is not even a candidate to eliminate with the threader.

  <bb 2> :
  x_2 = 25;
  xcopy_3 = x_2;
  if (xcopy_3 == 25)
    goto <bb 3>; [INV]
  else
    goto <bb 4>; [INV]

Closing.