[Bug libstdc++/42273] New: atomic_2.h:111: = instead of == in if

[Bug libstdc++/42273] New: atomic_2.h:111: = instead of == in if

[to dot roma dot from dot bugcc at qwertty dot com]

Is it a silly bug or a contrived way of calling __sync_synchronize regardless
of the required memory_order?

--- atomic_2.h  2009-12-04 11:23:26.000000000 +0200
+++ atomic_2.h  2009-12-04 11:23:35.000000000 +0200
@@ -108,7 +108,7 @@
        {
          // write_mem_barrier();
          _M_i = __v;
-         if (__m = memory_order_seq_cst)
+         if (__m == memory_order_seq_cst)
            __sync_synchronize();
        }
     }


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           Summary: atomic_2.h:111: = instead of == in if
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: to dot roma dot from dot bugcc at qwertty dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42273

[Bug libstdc++/42273] atomic_2.h:111: = instead of == in if

[paolo dot carlini at oracle dot com]

------- Comment #1 from paolo dot carlini at oracle dot com  2009-12-04 09:31 -------
Benjamin, can you check this?


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paolo dot carlini at oracle dot com changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42273

[Bug libstdc++/42273] atomic_2.h:111: = instead of == in if

[redi at gcc dot gnu dot org]

------- Comment #2 from redi at gcc dot gnu dot org  2009-12-04 10:54 -------
the suggested change is correct


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42273

[Bug libstdc++/42273] atomic_2.h:111: = instead of == in if

[redi at gcc dot gnu dot org]

------- Comment #3 from redi at gcc dot gnu dot org  2009-12-04 11:00 -------
Although as I noted in Bug 40297 comment 2 I think that function should also
have a memory barrier when m == memory_order_release, which the current code
has "by accident" because of this bug ... so arguably it's better that way!


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42273

[Bug libstdc++/42273] atomic_2.h:111: = instead of == in if

[bkoz at gcc dot gnu dot org]

------- Comment #4 from bkoz at gcc dot gnu dot org  2009-12-04 18:43 -------

Agree with #2. This is a one-liner to fix.

Jonathan, can you put your comments in 40297 into the wiki page for atomics?
I'd forgotten about this whole commentary. We are just starting in again on
this.

See:
http://gcc.gnu.org/wiki/Atomic

best,
benjamin


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42273

[Bug libstdc++/42273] atomic_2.h:111: = instead of == in if

[redi at gcc dot gnu dot org]

------- Comment #5 from redi at gcc dot gnu dot org  2009-12-04 18:46 -------
will do


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redi at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |redi at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42273

[Bug libstdc++/42273] atomic_2.h:111: = instead of == in if

[bkoz at gcc dot gnu dot org]

------- Comment #6 from bkoz at gcc dot gnu dot org  2009-12-09 21:22 -------
Mine. Adjusting for 4.4. branch.


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bkoz at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |bkoz at gcc dot gnu dot org
                   |dot org                     |
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2009-12-09 21:22:20
               date|                            |
   Target Milestone|---                         |4.4.3
            Version|4.5.0                       |4.4.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42273

[Bug libstdc++/42273] atomic_2.h:111: = instead of == in if

[bkoz at gcc dot gnu dot org]

------- Comment #7 from bkoz at gcc dot gnu dot org  2009-12-09 22:07 -------
Subject: Bug 42273

Author: bkoz
Date: Wed Dec  9 22:06:59 2009
New Revision: 155117

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=155117
Log:
2009-12-09  Roman Odaisky  <to.roma.from.bugcc@qwertty.com>

        PR libstdc++/42273
        * include/bits/atomic_2.h: Fix typo.


Modified:
    trunk/libstdc++-v3/ChangeLog
    trunk/libstdc++-v3/include/bits/atomic_2.h


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42273

[Bug libstdc++/42273] atomic_2.h:111: = instead of == in if

[bkoz at gcc dot gnu dot org]

------- Comment #8 from bkoz at gcc dot gnu dot org  2009-12-09 22:39 -------
Subject: Bug 42273

Author: bkoz
Date: Wed Dec  9 22:38:57 2009
New Revision: 155118

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=155118
Log:
2009-12-09  Roman Odaisky  <to.roma.from.bugcc@qwertty.com>

        PR libstdc++/42273
        * include/bits/atomic_2.h: Fix typo.


Modified:
    branches/gcc-4_4-branch/libstdc++-v3/ChangeLog
    branches/gcc-4_4-branch/libstdc++-v3/include/bits/atomic_2.h


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42273

[Bug libstdc++/42273] atomic_2.h:111: = instead of == in if

[bkoz at gcc dot gnu dot org]

------- Comment #9 from bkoz at gcc dot gnu dot org  2009-12-15 21:46 -------
Fixed.


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bkoz at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42273