[Bug c++/44406] New: wrong code generation with -ftree-sra

[Bug c++/44406] New: wrong code generation with -ftree-sra

[torbenh at users dot sourceforge dot net]

attached code crashes, when compiled with -ftree-sra
works fine with 4.4.2

its probably an incarnation of PR44258


-- 
           Summary: wrong code generation with -ftree-sra
           Product: gcc
           Version: 4.5.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: torbenh at users dot sourceforge dot net
 GCC build triplet: x86_64-linux-gnu
  GCC host triplet: x86_64-linux-gnu
GCC target triplet: x86_64-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44406

[Bug c++/44406] wrong code generation with -ftree-sra

[torbenh at users dot sourceforge dot net]

------- Comment #1 from torbenh at users dot sourceforge dot net  2010-06-03 19:08 -------
Created an attachment (id=20819)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=20819&action=view)
code that crashes when compiled


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44406

[Bug c++/44406] wrong code generation with -ftree-sra

[torbenh at users dot sourceforge dot net]

------- Comment #2 from torbenh at users dot sourceforge dot net  2010-06-03 19:10 -------
Created an attachment (id=20820)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=20820&action=view)
preprocessed signals_test.cc


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44406

[Bug tree-optimization/44406] wrong code generation with -ftree-sra

[jamborm at gcc dot gnu dot org]

------- Comment #3 from jamborm at gcc dot gnu dot org  2010-06-04 16:42 -------
Thanks for a nice testcase. I've been looking at this briefly today
and so far I am inclined to say that this is not SRA's fault.  First,
I have identified the function that is miscompiled
(boost::detail::function::basic_vtable4<R, T0, T1, T2, T3>::assign_to)
and the transformation there is very simple and looks OK.

Furthermore, the testcase does not miscompile on the current trunk and
the output of SRA on the trunk and on the branch is exactly the
same.  I'll continue looking at this next week.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44406

[Bug tree-optimization/44406] wrong code generation with -ftree-sra

[jamborm at gcc dot gnu dot org]

------- Comment #4 from jamborm at gcc dot gnu dot org  2010-06-07 16:51 -------
Moreover, I cannot reproduce this bug on the 4.5 branch since:

r159866 | rguenth | 2010-05-26 13:46:01 +0200 (Wed, 26 May 2010) | 12 lines

2010-05-26  Richard Guenther  <rguenther@suse.de>

        PR rtl-optimization/44164
        * tree-ssa-alias.c (aliasing_component_refs_p): Fix the
        no-common access-path disambiguation.
        (indirect_ref_may_alias_decl_p): Adjust.
        (indirect_refs_may_alias_p): Likewise.
        (refs_may_alias_p_1): Likewise.

        * gcc.c-torture/execute/pr44164.c: New testcase.
        * g++.dg/tree-ssa/pr13146.C: Adjust.


So, I think it is the same bug and mark it accordingly.



*** This bug has been marked as a duplicate of 44164 ***


-- 

jamborm at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |DUPLICATE


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44406