[Bug tree-optimization/20458] New: [4.1 regression] structure aliasing causes wrong code

[Bug tree-optimization/20458] New: [4.1 regression] structure aliasing causes wrong code

[belyshev at depni dot sinp dot msu dot ru]

$ g++ bug.cc -O2
$ ./a.out 
Segmentation fault
$ g++ bug.cc -O2 -fno-tree-salias
$ ./a.out 
$ 

testcase:
------------------------------------------------------------------------------
#include <sstream>

void foo ()
{
  std::stringbuf b;
}

int main()
{
  foo ();
  return 0;
}
------------------------------------------------------------------------------

-- 
           Summary: [4.1 regression] structure aliasing causes wrong code
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: critical
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: belyshev at depni dot sinp dot msu dot ru
                CC: gcc-bugs at gcc dot gnu dot org
  GCC host triplet: x86_64-unknown-linux-gnu
GCC target triplet: x86_64-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20458

[Bug tree-optimization/20458] [4.1 regression] structure aliasing causes wrong code

[belyshev at depni dot sinp dot msu dot ru]

------- Additional Comments From belyshev at depni dot sinp dot msu dot ru  2005-03-13 17:02 -------
working on smaller preprocessed testcase (640Kbytes left).

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20458

[Bug tree-optimization/20458] [4.1 regression] structure aliasing causes wrong code

[belyshev at depni dot sinp dot msu dot ru]

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20458

[Bug tree-optimization/20458] [4.1 regression] structure aliasing causes wrong code

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu dot
                   |                            |org
   Target Milestone|---                         |4.1.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20458

[Bug tree-optimization/20458] [4.1 regression] structure aliasing causes wrong code

[belyshev at depni dot sinp dot msu dot ru]

------- Additional Comments From belyshev at depni dot sinp dot msu dot ru  2005-03-13 18:18 -------
Created an attachment (id=8383)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=8383&action=view)
smaller testcase (2293 bytes)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20458

[Bug tree-optimization/20458] [4.1 regression] structure aliasing causes wrong code

[belyshev at depni dot sinp dot msu dot ru]

------- Additional Comments From belyshev at depni dot sinp dot msu dot ru  2005-03-13 19:10 -------
even smaller testcase:
------------------------------------------------------------------------------
namespace std
{
  class locale
  {
  public:
    locale();
    ~locale();
  };
}

struct B
{
  std::locale _M_buf_locale;
  virtual ~B() {}
};

struct C : public B
{
  char *s;
};

void foo ()
{
  C c;
}

int main()
{
  foo ();
  return 0;
}
------------------------------------------------------------------------------

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20458

[Bug tree-optimization/20458] [4.1 regression] structure aliasing causes wrong code

[dberlin at gcc dot gnu dot org]

------- Additional Comments From dberlin at gcc dot gnu dot org  2005-03-13 19:20 -------
I can't reproduce on i686-pc-linux-gnu with either testcase

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.1.0                       |---


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20458

[Bug tree-optimization/20458] [4.1 regression] structure aliasing causes wrong code

[dberlin at gcc dot gnu dot org]

------- Additional Comments From dberlin at gcc dot gnu dot org  2005-03-13 21:01 -------
Confirmed on x86-64.
I'm bootstrapping a fix for this.


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |dberlin at gcc dot gnu dot
                   |dot org                     |org
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2005-03-13 21:01:42
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20458

[Bug tree-optimization/20458] [4.1 regression] structure aliasing causes wrong code

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.1.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20458

[Bug tree-optimization/20458] [4.1 regression] structure aliasing causes wrong code

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-03-15 01:26 -------
Subject: Bug 20458

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	dberlin@gcc.gnu.org	2005-03-15 01:26:35

Modified files:
	gcc            : ChangeLog tree-flow-inline.h 
	                 tree-ssa-operands.c tree-tailcall.c 
Added files:
	gcc/testsuite/g++.dg/tree-ssa: pr20458.C 

Log message:
	2005-03-14  Daniel Berlin <dberlin@dberlin.org>
	
	Fix PR tree-optimization/20458
	
	* tree-flow-inline.h (mark_call_clobbered): Don't fiddle
	DECL_EXTERNAL on STRUCT_FIELD tags.
	(clear_call_clobbered): Ditto.
	* tree-ssa-operands.c (note_addressable): Make sure the original
	variable doesn't slip into the addressable list if we have
	subvars.
	* tree-tailcall.c (suitable_for_tail_opt_p): Look at STRUCT_FIELD
	tags too.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.7854&r2=2.7855
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree-flow-inline.h.diff?cvsroot=gcc&r1=2.32&r2=2.33
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree-ssa-operands.c.diff?cvsroot=gcc&r1=2.67&r2=2.68
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree-tailcall.c.diff?cvsroot=gcc&r1=2.37&r2=2.38
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/tree-ssa/pr20458.C.diff?cvsroot=gcc&r1=NONE&r2=1.1



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20458

[Bug tree-optimization/20458] [4.1 regression] structure aliasing causes wrong code

[dberlin at gcc dot gnu dot org]

------- Additional Comments From dberlin at gcc dot gnu dot org  2005-03-15 01:27 -------
Fixed

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20458