[Bug lto/46879] New: [4.6 Regression] ICE: in separate_decls_in_region_debug_bind, at tree-parloops.c:778 with -flto -ftree-parallelize-loops -gdwarf-3

[Bug lto/46879] New: [4.6 Regression] ICE: in separate_decls_in_region_debug_bind, at tree-parloops.c:778 with -flto -ftree-parallelize-loops -gdwarf-3

[zsojka at seznam dot cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46879

           Summary: [4.6 Regression] ICE: in
                    separate_decls_in_region_debug_bind, at
                    tree-parloops.c:778 with -flto
                    -ftree-parallelize-loops -gdwarf-3
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: lto
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: zsojka@seznam.cz
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu


Created attachment 22700
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=22700
reduced testcase

Compiler output:
$ gcc -O -flto -ftree-parallelize-loops=4 -gdwarf-3 pr46879.c  
In file included from :0:0:
pr46879.c: In function 'main':
pr46879.c:18:5: internal compiler error: in
separate_decls_in_region_debug_bind, at tree-parloops.c:778
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.
lto-wrapper:
/mnt/svn/gcc-trunk/binary-167643-lto-fortran-checking-yes-rtl-df/bin/gcc
returned 1 exit status
collect2: lto-wrapper returned 1 exit status

Tested revisions:
r167643 - crash
r165699 - crash
r161659 - OK
4.5 r166509 - OK

[Bug tree-optimization/46879] [4.6 Regression] ICE: in separate_decls_in_region_debug_bind, at tree-parloops.c:778 with -flto -ftree-parallelize-loops -gdwarf-3

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46879

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|lto                         |tree-optimization
   Target Milestone|---                         |4.6.0

[Bug tree-optimization/46879] [4.6 Regression] ICE: in separate_decls_in_region_debug_bind, at tree-parloops.c:778 with -flto -ftree-parallelize-loops -gdwarf-3

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46879

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> 2010-12-10 14:59:22 UTC ---
This looks like a lto bug to me.
1765              tree *basep = &op;
1766              while (handled_component_p (*basep))
1767            basep = &TREE_OPERAND (*basep, 0);
1768              if (TREE_CODE (*basep) == VAR_DECL
1769              && !auto_var_in_fn_p (*basep, current_function_decl))
1770            {
1771              bool volatilep = TREE_THIS_VOLATILE (*basep);
1772              *basep = build2 (MEM_REF, TREE_TYPE (*basep),
1773                       build_fold_addr_expr (*basep),
1774                       build_int_cst (build_pointer_type
1775                              (TREE_TYPE (*basep)), 0));
1776              TREE_THIS_VOLATILE (*basep) = volatilep;
1777            }

in output_gimple_stmt is not suitable for the first argument of a GIMPLE_DEBUG
stmt - where the argument must be a DECL.

[Bug tree-optimization/46879] [4.6 Regression] ICE: in separate_decls_in_region_debug_bind, at tree-parloops.c:778 with -flto -ftree-parallelize-loops -gdwarf-3

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46879

--- Comment #2 from Richard Guenther <rguenth at gcc dot gnu.org> 2010-12-10 15:21:28 UTC ---
(In reply to comment #1)
> This looks like a lto bug to me.
> 1765              tree *basep = &op;
> 1766              while (handled_component_p (*basep))
> 1767            basep = &TREE_OPERAND (*basep, 0);
> 1768              if (TREE_CODE (*basep) == VAR_DECL
> 1769              && !auto_var_in_fn_p (*basep, current_function_decl))
> 1770            {
> 1771              bool volatilep = TREE_THIS_VOLATILE (*basep);
> 1772              *basep = build2 (MEM_REF, TREE_TYPE (*basep),
> 1773                       build_fold_addr_expr (*basep),
> 1774                       build_int_cst (build_pointer_type
> 1775                              (TREE_TYPE (*basep)), 0));
> 1776              TREE_THIS_VOLATILE (*basep) = volatilep;
> 1777            }
> 
> in output_gimple_stmt is not suitable for the first argument of a GIMPLE_DEBUG
> stmt - where the argument must be a DECL.

Hm, well.  Then the debug machinery has to deal with type mismatches I guess.

But I wonder why we have debug-stmts for global variables anyway?  I thought
they are only used for registers.

[Bug tree-optimization/46879] [4.6 Regression] ICE: in separate_decls_in_region_debug_bind, at tree-parloops.c:778 with -flto -ftree-parallelize-loops -gdwarf-3

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46879

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> 2010-12-10 15:32:40 UTC ---
(In reply to comment #2)
> Hm, well.  Then the debug machinery has to deal with type mismatches I guess.

Well, all the debug machinery cares is that the var has the original, declared
type.

> But I wonder why we have debug-stmts for global variables anyway?  I thought
> they are only used for registers.

It is not a global variable, it is a VAR_DECL with DECL_ABSTRACT_ORIGIN
PARM_DECL in bar, i.e. optimized away parameter/automatic variable.  It is a
non-localized var in main, because it is never referenced there, except for
GIMPLE_DEBUG.

[Bug tree-optimization/46879] [4.6 Regression] ICE: in separate_decls_in_region_debug_bind, at tree-parloops.c:778 with -flto -ftree-parallelize-loops -gdwarf-3

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46879

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2010.12.10 15:58:39
     Ever Confirmed|0                           |1

--- Comment #4 from Richard Guenther <rguenth at gcc dot gnu.org> 2010-12-10 15:58:39 UTC ---
(In reply to comment #3)
> (In reply to comment #2)
> > Hm, well.  Then the debug machinery has to deal with type mismatches I guess.
> 
> Well, all the debug machinery cares is that the var has the original, declared
> type.
> 
> > But I wonder why we have debug-stmts for global variables anyway?  I thought
> > they are only used for registers.
> 
> It is not a global variable, it is a VAR_DECL with DECL_ABSTRACT_ORIGIN
> PARM_DECL in bar, i.e. optimized away parameter/automatic variable.  It is a
> non-localized var in main, because it is never referenced there, except for
> GIMPLE_DEBUG.

Ah, ok.  The fix is then to amend the

1768              if (TREE_CODE (*basep) == VAR_DECL
1769              && !auto_var_in_fn_p (*basep, current_function_decl))

check properly.  The easiest check would be && !is_gimple_debug, or
a auto_var_in_fn_p variant without a specific function, thus auto_var_p.

[Bug lto/46879] [4.6 Regression] ICE: in separate_decls_in_region_debug_bind, at tree-parloops.c:778 with -flto -ftree-parallelize-loops -gdwarf-3

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46879

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
         AssignedTo|unassigned at gcc dot       |jakub at gcc dot gnu.org
                   |gnu.org                     |

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> 2010-12-13 11:04:58 UTC ---
Patch posted: http://gcc.gnu.org/ml/gcc-patches/2010-12/msg00911.html

[Bug lto/46879] [4.6 Regression] ICE: in separate_decls_in_region_debug_bind, at tree-parloops.c:778 with -flto -ftree-parallelize-loops -gdwarf-3

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46879

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> 2010-12-13 17:37:27 UTC ---
Author: jakub
Date: Mon Dec 13 17:37:20 2010
New Revision: 167755

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=167755
Log:
    PR lto/46879
    * lto-streamer-out.c (output_gimple_stmt): Never replace first
    GIMPLE_DEBUG argument with MEM_REF.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/lto-streamer-out.c

[Bug lto/46879] [4.6 Regression] ICE: in separate_decls_in_region_debug_bind, at tree-parloops.c:778 with -flto -ftree-parallelize-loops -gdwarf-3

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46879

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

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

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> 2010-12-13 17:41:24 UTC ---
Fixed.