[Bug c++/55405] New: ICE with optimization

[Bug c++/55405] New: ICE with optimization

[cas43 at cs dot stanford.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55405

             Bug #: 55405
           Summary: ICE with optimization
    Classification: Unclassified
           Product: gcc
           Version: 4.6.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: cas43@cs.stanford.edu


How to compile: g++ prog.cpp -O3 -c

Result:
prog.cpp: In function ‘void foo()’:
prog.cpp:22:1: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-4.6/README.Bugs> for instructions.
Preprocessed source stored into /tmp/ccLwjBSn.out file, please attach this to
your bugreport.

Code:

template<class T>
struct A
{
    A(){}
    ~A(){}
    T a[1];
    void f(int i);
};
struct B
{
    virtual ~B();
};
void bar();
void foo()
{
    B b;
    A<A<int> > x;
    for(int i=0;i<4;i++) x.f(0);
    A<A<A<int> > > y,z;
    bar();
    bar();
}

Version:

Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.6/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro
4.6.3-1ubuntu5' --with-bugurl=file:///usr/share/doc/gcc-4.6/README.Bugs
--enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-4.6 --enable-shared --enable-linker-build-id
--with-system-zlib --libexecdir=/usr/lib --without-included-gettext
--enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.6
--libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object
--enable-plugin --enable-objc-gc --disable-werror --with-arch-32=i686
--with-tune=generic --enable-checking=release --build=x86_64-linux-gnu
--host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5)

[Bug c++/55405] ICE with optimization

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55405

--- Comment #1 from Paolo Carlini <paolo.carlini at oracle dot com> 2012-11-20 00:22:54 UTC ---
Mainline and 4_7-branch are fine.

[Bug c++/55405] ICE with optimization

[mikpe at it dot uu.se]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55405

Mikael Pettersson <mikpe at it dot uu.se> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |mikpe at it dot uu.se

--- Comment #2 from Mikael Pettersson <mikpe at it dot uu.se> 2012-11-25 11:11:35 UTC ---
The ICE at -O3 was first silenced for 4.7 by r171450:
http://gcc.gnu.org/ml/gcc-cvs/2011-03/msg00874.html,
when Richard Biener added an FRE pass after early SRA.

At that point the ICE still occurs with -O3 -fno-tree-fre.

The ICE at -O3 -fno-tree-fre was then silenced for 4.7 by r181014:
http://gcc.gnu.org/ml/gcc-cvs/2011-11/msg00300.html,
a missed-optimization patch.

The ICE before r181014 occurs because except.c:emit_to_new_bb_before is called
on an insn whose BLOCK_FOR_INSN is NULL, but that NULL pointer is
unconditionally dereferenced causing a SEGV.  I don't see a sane way of
handling that locally.

[Bug tree-optimization/55405] ICE with optimization

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55405

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|c++                         |tree-optimization

--- Comment #3 from Paolo Carlini <paolo.carlini at oracle dot com> 2012-11-25 11:31:50 UTC ---
Ok, let's change the Component to something more sensible, anyway.

[Bug tree-optimization/55405] ICE with optimization

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55405

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
                 CC|                            |mpolacek at gcc dot gnu.org
         Resolution|---                         |FIXED

--- Comment #4 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
All active branches seem to be fine now.