[Bug c/14065] New: tree-ssa generates duplicate definision of invisible sybmbol forward defined

[Bug c/14065] New: tree-ssa generates duplicate definision of invisible sybmbol forward defined

[fjahanian at apple dot com]

This bug was also uncovered building gap of the spec benchmark with tree-ssa. In the
following trivial test case, tree-ssa gcc produces two definition of the locally declaraed extern
which is later defined. Compile with -O2.

/* Bug in tree-ssa, tested on Apple, darwin, ppc. Compile with O2:

mygcct5o -O2 prxxx.c
/var/tmp//ccZZXOy5.s:8:FATAL:Symbol _CPN already defined.

*/


void collect()
{
    extern long         CPN;
}
long         CPN=1;

-- 
           Summary: tree-ssa generates duplicate definision of invisible
                    sybmbol forward defined
           Product: gcc
           Version: tree-ssa
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: fjahanian at apple dot com
                CC: gcc-bugs at gcc dot gnu dot org
  GCC host triplet: powerpc-apple-darwin7.0.0
GCC target triplet: powerpc-apple-darwin7.0.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14065

[Bug optimization/14065] [tree-ssa] [unit-at-a-time] generates duplicate definision of invisible sybmbol forward defined

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-02-07 19:17 -------
Confirmed.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu dot
                   |                            |org, hubicka at gcc dot gnu
                   |                            |dot org
           Severity|normal                      |critical
             Status|UNCONFIRMED                 |NEW
          Component|c                           |optimization
     Ever Confirmed|                            |1
           Keywords|                            |wrong-code
      Known to fail|                            |tree-ssa
      Known to work|                            |3.5.0
           Priority|P2                          |P1
   Last reconfirmed|0000-00-00 00:00:00         |2004-02-07 19:17:34
               date|                            |
            Summary|tree-ssa generates duplicate|[tree-ssa] [unit-at-a-time]
                   |definision of invisible     |generates duplicate
                   |sybmbol forward defined     |definision of invisible
                   |                            |sybmbol forward defined
   Target Milestone|---                         |tree-ssa


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14065

[Bug optimization/14065] [tree-ssa] [unit-at-a-time] generates duplicate definision of invisible sybmbol forward defined

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-02-07 19:23 -------
Okay some analysis of the bug.  When in not unit-at-a-time mode, the symbol CPN is not put in the 
function scope while with it is.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14065

[Bug optimization/14065] [tree-ssa] [unit-at-a-time] generates duplicate definition of invisible sybmbol forward defined

[fjahanian at apple dot com]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |zack at codesourcery dot com
                   |dot org                     |
             Status|NEW                         |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14065

[Bug optimization/14065] [tree-ssa] [unit-at-a-time] generates duplicate definition of invisible sybmbol forward defined

[dnovillo at gcc dot gnu dot org]

------- Additional Comments From dnovillo at gcc dot gnu dot org  2004-03-02 18:31 -------

I've looked at it briefly.  Found that merge_decls was doing something odd, but
Zack mentioned on IRC that the fix implies changing a few data structures around.


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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14065

[Bug optimization/14065] [tree-ssa] [unit-at-a-time] generates duplicate definition of invisible symbol forward declared

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-03-10 16:54 -------
*** Bug 14036 has been marked as a duplicate of this bug. ***

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14065

[Bug optimization/14065] [tree-ssa] [unit-at-a-time] generates duplicate definition of invisible symbol forward declared

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-03-10 16:55 -------
The problem is that when converting from generic to gimple, the variable goes from 
extern to static for some reason.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14065

[Bug optimization/14065] [tree-ssa] [unit-at-a-time] generates duplicate definition of invisible symbol forward declared

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|critical                    |normal


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14065

[Bug optimization/14065] [tree-ssa] [unit-at-a-time] generates duplicate definition of invisible symbol forward declared

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-03-27 20:34 -------
This was fixed by Zack's rewrite of c-decl.c so closing.

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14065