[Bug tree-optimization/51759] [4.5 Regression] miscompile writes past end of bitfield

2012-01-09 Thread jamborm at gcc dot gnu.org 
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51759

--- Comment #6 from Martin Jambor jamborm at gcc dot gnu.org 2012-01-09 
18:40:16 UTC ---
Author: jamborm
Date: Mon Jan  9 18:40:09 2012
New Revision: 183023

URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=183023
Log:
2012-01-09  Martin Jambor  mjam...@suse.cz

PR tree-optimization/51759

Backport from mainline
2010-09-15  Martin Jambor  mjam...@suse.cz

PR middle-end/45644
* tree-sra.c (create_access): Check for bit-fields directly.

* testsuite/gcc.dg/ipa/pr45644.c: New test.
* testsuite/g++.dg/ipa/pr51759.C: Likewise.


Added:
branches/gcc-4_5-branch/gcc/testsuite/g++.dg/ipa/pr51759.C
branches/gcc-4_5-branch/gcc/testsuite/gcc.dg/ipa/pr45644.c
Modified:
branches/gcc-4_5-branch/gcc/ChangeLog
branches/gcc-4_5-branch/gcc/testsuite/ChangeLog
branches/gcc-4_5-branch/gcc/tree-sra.c

[Bug tree-optimization/51759] [4.5 Regression] miscompile writes past end of bitfield

2012-01-09 Thread jamborm at gcc dot gnu.org 
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51759

--- Comment #7 from Martin Jambor jamborm at gcc dot gnu.org 2012-01-09 
19:52:13 UTC ---
Author: jamborm
Date: Mon Jan  9 19:52:06 2012
New Revision: 183029

URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=183029
Log:
2012-01-09  Martin Jambor  mjam...@suse.cz

PR tree-optimization/51759
* g++.dg/ipa/pr51759.C: New test.


Added:
trunk/gcc/testsuite/g++.dg/ipa/pr51759.C
Modified:
trunk/gcc/testsuite/ChangeLog

[Bug tree-optimization/51759] [4.5 Regression] miscompile writes past end of bitfield

2012-01-09 Thread jamborm at gcc dot gnu.org 
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51759

--- Comment #8 from Martin Jambor jamborm at gcc dot gnu.org 2012-01-09 
20:03:15 UTC ---
Author: jamborm
Date: Mon Jan  9 20:03:08 2012
New Revision: 183031

URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=183031
Log:
2012-01-09  Martin Jambor  mjam...@suse.cz

PR tree-optimization/51759
* g++.dg/ipa/pr51759.C: New test.


Added:
branches/gcc-4_6-branch/gcc/testsuite/g++.dg/ipa/pr51759.C
Modified:
branches/gcc-4_6-branch/gcc/testsuite/ChangeLog

[Bug tree-optimization/51759] [4.5 Regression] miscompile writes past end of bitfield

2012-01-09 Thread jamborm at gcc dot gnu.org 
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51759

Martin Jambor jamborm at gcc dot gnu.org changed:

   What|Removed |Added

 Status|ASSIGNED|RESOLVED
 Resolution||DUPLICATE

--- Comment #9 from Martin Jambor jamborm at gcc dot gnu.org 2012-01-09 
20:05:27 UTC ---
I have backported the fix to the 4.5 branch and also committed the testcase to
the the 4.6 branch and trunk.  Still it is a duplicate of PR 45644 and so I'm
closing this as such.

*** This bug has been marked as a duplicate of bug 45644 ***

[Bug tree-optimization/51759] [4.5 Regression] miscompile writes past end of bitfield

2012-01-06 Thread jamborm at gcc dot gnu.org 
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51759

Martin Jambor jamborm at gcc dot gnu.org changed:

   What|Removed |Added

URL||http://gcc.gnu.org/ml/gcc-p
   ||atches/2012-01/msg00300.htm
   ||l

--- Comment #5 from Martin Jambor jamborm at gcc dot gnu.org 2012-01-06 
13:33:14 UTC ---
Patch backporting the fix has been posted to the mailing list:
http://gcc.gnu.org/ml/gcc-patches/2012-01/msg00300.html

[Bug tree-optimization/51759] [4.5 Regression] miscompile writes past end of bitfield

2012-01-05 Thread rguenth at gcc dot gnu.org 
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51759

Richard Guenther rguenth at gcc dot gnu.org changed:

   What|Removed |Added

 Status|UNCONFIRMED |NEW
  Known to work||4.4.6, 4.6.0
   Keywords||wrong-code
   Last reconfirmed||2012-01-05
  Component|c++ |tree-optimization
 CC||jamborm at gcc dot gnu.org
 Ever Confirmed|0   |1
Summary|miscompile writes past end  |[4.5 Regression] miscompile
   |of bitfield |writes past end of bitfield
   Target Milestone|--- |4.5.4

--- Comment #3 from Richard Guenther rguenth at gcc dot gnu.org 2012-01-05 
10:00:37 UTC ---
It's a bug in IPA-SRA that creates non-mode-size stores:

void llvm::Type::_ZN4llvm4Type15setSubclassDataEj.clone.1(unsigned int:24*,
unsigned int) (unnamed-unsigned:24 * ISRA.6, unsigned int val)
{
...
bb 2:
  D.87358_2 = (unnamed-unsigned:24) val_1(D);
  *ISRA.6_8(D) = D.87358_2;

I think this has been fixed in 4.6 (not on the 4.5 branch though) which
no longer performs this substitution.  You can work around this using
-fno-ipa-sra.

The following is a simplified testcase:

extern C void abort (void);
struct S
{
  void __attribute__((noinline)) set(unsigned val)
{
  data = val;
  if (data != val)
abort ();
}
  int pad0;
  unsigned pad1 : 8;
  unsigned data : 24;
  int pad2;
};
int main()
{
  S s;
  s.pad2 = -1;
  s.set(0);
  if (s.pad2 != -1)
abort ();
}

Where 4.6 says:

Candidate (2069): this
! Disqualifying this - Encountered a bit-field access.

which hints at what needs backporting.

Martin?

[Bug tree-optimization/51759] [4.5 Regression] miscompile writes past end of bitfield

2012-01-05 Thread jamborm at gcc dot gnu.org 
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51759

Martin Jambor jamborm at gcc dot gnu.org changed:

   What|Removed |Added

 Status|NEW |ASSIGNED
 AssignedTo|unassigned at gcc dot   |jamborm at gcc dot gnu.org
   |gnu.org |

--- Comment #4 from Martin Jambor jamborm at gcc dot gnu.org 2012-01-05 
13:39:22 UTC ---
(In reply to comment #3)
 Where 4.6 says:
 
 Candidate (2069): this
 ! Disqualifying this - Encountered a bit-field access.
 
 which hints at what needs backporting.
 
 Martin?

Right, this seems to be PR 45644, for some reason I did not backport
the fix to 4.5.  It should be fixed by committing 
http://gcc.gnu.org/viewcvs?view=revisionrevision=164313
I'll do the backport and test it today.