[Bug lto/47936] New: [4.6 Regression] Missed optimization with LTO due to strict aliasing issues

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* [Bug lto/47936] New: [4.6 Regression] Missed optimization with LTO due to strict aliasing issues
@ 2011-03-01  7:11 d.g.gorbachev at gmail dot com
  2011-03-01 10:28 ` [Bug lto/47936] " rguenth at gcc dot gnu.org
                   ` (9 more replies)
  0 siblings, 10 replies; 11+ messages in thread
From: d.g.gorbachev at gmail dot com @ 2011-03-01  7:11 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47936

           Summary: [4.6 Regression] Missed optimization with LTO due to
                    strict aliasing issues
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: lto
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: d.g.gorbachev@gmail.com


Created attachment 23497
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23497
Testcase

This seems to be different from bug 47924.


^ permalink raw reply	[flat|nested] 11+ messages in thread

* [Bug lto/47936] [4.6 Regression] Missed optimization with LTO due to strict aliasing issues
  2011-03-01  7:11 [Bug lto/47936] New: [4.6 Regression] Missed optimization with LTO due to strict aliasing issues d.g.gorbachev at gmail dot com
@ 2011-03-01 10:28 ` rguenth at gcc dot gnu.org
  2011-03-01 10:30 ` rguenth at gcc dot gnu.org
                   ` (8 subsequent siblings)
  9 siblings, 0 replies; 11+ messages in thread
From: rguenth at gcc dot gnu.org @ 2011-03-01 10:28 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47936

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |missed-optimization
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2011.03.01 10:28:51
   Target Milestone|---                         |4.6.0
     Ever Confirmed|0                           |1

--- Comment #1 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-03-01 10:28:51 UTC ---
Confirmed.  This one happens because we merge struct S and struct T for
TBAA purposes (they get the same TYPE_CANONICAL).

This is by design to allow cross-language (and slightly invalid) code to
not fall over TBAA issues too easily.


^ permalink raw reply	[flat|nested] 11+ messages in thread

* [Bug lto/47936] [4.6 Regression] Missed optimization with LTO due to strict aliasing issues
  2011-03-01  7:11 [Bug lto/47936] New: [4.6 Regression] Missed optimization with LTO due to strict aliasing issues d.g.gorbachev at gmail dot com
  2011-03-01 10:28 ` [Bug lto/47936] " rguenth at gcc dot gnu.org
@ 2011-03-01 10:30 ` rguenth at gcc dot gnu.org
  2011-03-03 11:25 ` rguenth at gcc dot gnu.org
                   ` (7 subsequent siblings)
  9 siblings, 0 replies; 11+ messages in thread
From: rguenth at gcc dot gnu.org @ 2011-03-01 10:30 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47936

--- Comment #2 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-03-01 10:30:12 UTC ---
IMHO WONTFIX.  Eventually we could add a -fvery-strict-aliasing, but it's
probably not worth it.

Leaving open to eventually document this fact somewhere.


^ permalink raw reply	[flat|nested] 11+ messages in thread

* [Bug lto/47936] [4.6 Regression] Missed optimization with LTO due to strict aliasing issues
  2011-03-01  7:11 [Bug lto/47936] New: [4.6 Regression] Missed optimization with LTO due to strict aliasing issues d.g.gorbachev at gmail dot com
  2011-03-01 10:28 ` [Bug lto/47936] " rguenth at gcc dot gnu.org
  2011-03-01 10:30 ` rguenth at gcc dot gnu.org
@ 2011-03-03 11:25 ` rguenth at gcc dot gnu.org
  2011-03-25 20:03 ` [Bug lto/47936] [4.6/4.7 " jakub at gcc dot gnu.org
                   ` (6 subsequent siblings)
  9 siblings, 0 replies; 11+ messages in thread
From: rguenth at gcc dot gnu.org @ 2011-03-03 11:25 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47936

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P5

--- Comment #3 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-03-03 11:25:22 UTC ---
But downgrading priority.


^ permalink raw reply	[flat|nested] 11+ messages in thread

* [Bug lto/47936] [4.6/4.7 Regression] Missed optimization with LTO due to strict aliasing issues
  2011-03-01  7:11 [Bug lto/47936] New: [4.6 Regression] Missed optimization with LTO due to strict aliasing issues d.g.gorbachev at gmail dot com
                   ` (2 preceding siblings ...)
  2011-03-03 11:25 ` rguenth at gcc dot gnu.org
@ 2011-03-25 20:03 ` jakub at gcc dot gnu.org
  2011-06-27 16:09 ` jakub at gcc dot gnu.org
                   ` (5 subsequent siblings)
  9 siblings, 0 replies; 11+ messages in thread
From: jakub at gcc dot gnu.org @ 2011-03-25 20:03 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47936

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.6.0                       |4.6.1

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-03-25 19:52:53 UTC ---
GCC 4.6.0 is being released, adjusting target milestone.


^ permalink raw reply	[flat|nested] 11+ messages in thread

* [Bug lto/47936] [4.6/4.7 Regression] Missed optimization with LTO due to strict aliasing issues
  2011-03-01  7:11 [Bug lto/47936] New: [4.6 Regression] Missed optimization with LTO due to strict aliasing issues d.g.gorbachev at gmail dot com
                   ` (3 preceding siblings ...)
  2011-03-25 20:03 ` [Bug lto/47936] [4.6/4.7 " jakub at gcc dot gnu.org
@ 2011-06-27 16:09 ` jakub at gcc dot gnu.org
  2011-07-14 23:19 ` d.g.gorbachev at gmail dot com
                   ` (4 subsequent siblings)
  9 siblings, 0 replies; 11+ messages in thread
From: jakub at gcc dot gnu.org @ 2011-06-27 16:09 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47936

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.6.1                       |4.6.2

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-06-27 12:33:06 UTC ---
GCC 4.6.1 is being released.


^ permalink raw reply	[flat|nested] 11+ messages in thread

* [Bug lto/47936] [4.6/4.7 Regression] Missed optimization with LTO due to strict aliasing issues
  2011-03-01  7:11 [Bug lto/47936] New: [4.6 Regression] Missed optimization with LTO due to strict aliasing issues d.g.gorbachev at gmail dot com
                   ` (4 preceding siblings ...)
  2011-06-27 16:09 ` jakub at gcc dot gnu.org
@ 2011-07-14 23:19 ` d.g.gorbachev at gmail dot com
  2011-10-26 17:46 ` jakub at gcc dot gnu.org
                   ` (3 subsequent siblings)
  9 siblings, 0 replies; 11+ messages in thread
From: d.g.gorbachev at gmail dot com @ 2011-07-14 23:19 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47936

Dmitry Gorbachev <d.g.gorbachev at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |4.7.0

--- Comment #6 from Dmitry Gorbachev <d.g.gorbachev at gmail dot com> 2011-07-14 23:19:23 UTC ---
It seems to work in 4.7.


^ permalink raw reply	[flat|nested] 11+ messages in thread

* [Bug lto/47936] [4.6/4.7 Regression] Missed optimization with LTO due to strict aliasing issues
  2011-03-01  7:11 [Bug lto/47936] New: [4.6 Regression] Missed optimization with LTO due to strict aliasing issues d.g.gorbachev at gmail dot com
                   ` (5 preceding siblings ...)
  2011-07-14 23:19 ` d.g.gorbachev at gmail dot com
@ 2011-10-26 17:46 ` jakub at gcc dot gnu.org
  2012-03-01 15:09 ` jakub at gcc dot gnu.org
                   ` (2 subsequent siblings)
  9 siblings, 0 replies; 11+ messages in thread
From: jakub at gcc dot gnu.org @ 2011-10-26 17:46 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47936

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.6.2                       |4.6.3

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-10-26 17:13:50 UTC ---
GCC 4.6.2 is being released.


^ permalink raw reply	[flat|nested] 11+ messages in thread

* [Bug lto/47936] [4.6/4.7 Regression] Missed optimization with LTO due to strict aliasing issues
  2011-03-01  7:11 [Bug lto/47936] New: [4.6 Regression] Missed optimization with LTO due to strict aliasing issues d.g.gorbachev at gmail dot com
                   ` (6 preceding siblings ...)
  2011-10-26 17:46 ` jakub at gcc dot gnu.org
@ 2012-03-01 15:09 ` jakub at gcc dot gnu.org
  2013-02-07  0:40 ` [Bug lto/47936] [4.6 " d.g.gorbachev at gmail dot com
  2013-04-12 16:18 ` jakub at gcc dot gnu.org
  9 siblings, 0 replies; 11+ messages in thread
From: jakub at gcc dot gnu.org @ 2012-03-01 15:09 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47936

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.6.3                       |4.6.4

--- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-03-01 14:39:04 UTC ---
GCC 4.6.3 is being released.


^ permalink raw reply	[flat|nested] 11+ messages in thread

* [Bug lto/47936] [4.6 Regression] Missed optimization with LTO due to strict aliasing issues
  2011-03-01  7:11 [Bug lto/47936] New: [4.6 Regression] Missed optimization with LTO due to strict aliasing issues d.g.gorbachev at gmail dot com
                   ` (7 preceding siblings ...)
  2012-03-01 15:09 ` jakub at gcc dot gnu.org
@ 2013-02-07  0:40 ` d.g.gorbachev at gmail dot com
  2013-04-12 16:18 ` jakub at gcc dot gnu.org
  9 siblings, 0 replies; 11+ messages in thread
From: d.g.gorbachev at gmail dot com @ 2013-02-07  0:40 UTC (permalink / raw)
  To: gcc-bugs


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47936

Dmitry Gorbachev <d.g.gorbachev at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|4.7.0                       |4.7.3, 4.8.0
            Summary|[4.6/4.7/4.8 Regression]    |[4.6 Regression] Missed
                   |Missed optimization with    |optimization with LTO due
                   |LTO due to strict aliasing  |to strict aliasing issues
                   |issues                      |
      Known to fail|4.6.0                       |4.6.4

--- Comment #9 from Dmitry Gorbachev <d.g.gorbachev at gmail dot com> 2013-02-07 00:40:06 UTC ---
I can't reproduce it with GCC 4.7.3 and 4.8.0.


^ permalink raw reply	[flat|nested] 11+ messages in thread

* [Bug lto/47936] [4.6 Regression] Missed optimization with LTO due to strict aliasing issues
  2011-03-01  7:11 [Bug lto/47936] New: [4.6 Regression] Missed optimization with LTO due to strict aliasing issues d.g.gorbachev at gmail dot com
                   ` (8 preceding siblings ...)
  2013-02-07  0:40 ` [Bug lto/47936] [4.6 " d.g.gorbachev at gmail dot com
@ 2013-04-12 16:18 ` jakub at gcc dot gnu.org
  9 siblings, 0 replies; 11+ messages in thread
From: jakub at gcc dot gnu.org @ 2013-04-12 16:18 UTC (permalink / raw)
  To: gcc-bugs


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47936

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|4.6.4                       |4.7.0

--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-04-12 16:17:53 UTC ---
The 4.6 branch has been closed, fixed in GCC 4.7.0.


^ permalink raw reply	[flat|nested] 11+ messages in thread

end of thread, other threads:[~2013-04-12 16:18 UTC | newest]

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2011-03-01  7:11 [Bug lto/47936] New: [4.6 Regression] Missed optimization with LTO due to strict aliasing issues d.g.gorbachev at gmail dot com
2011-03-01 10:28 ` [Bug lto/47936] " rguenth at gcc dot gnu.org
2011-03-01 10:30 ` rguenth at gcc dot gnu.org
2011-03-03 11:25 ` rguenth at gcc dot gnu.org
2011-03-25 20:03 ` [Bug lto/47936] [4.6/4.7 " jakub at gcc dot gnu.org
2011-06-27 16:09 ` jakub at gcc dot gnu.org
2011-07-14 23:19 ` d.g.gorbachev at gmail dot com
2011-10-26 17:46 ` jakub at gcc dot gnu.org
2012-03-01 15:09 ` jakub at gcc dot gnu.org
2013-02-07  0:40 ` [Bug lto/47936] [4.6 " d.g.gorbachev at gmail dot com
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