[Bug c++/49223] New: Internal compiler error when using OpenMP

["ttsiodras at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49223

           Summary: Internal compiler error when using OpenMP
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: ttsiodras@gmail.com


Created attachment 24391
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24391
Preprocessed output from input C++ file that triggers the bug.

When using -fopenmp, compiling my open source renderer (
http://users.softlab.ece.ntua.gr/~ttsiod/renderer.html ) triggers an internal
compiler error. This did not happen with previous versions of GCC (I've added
OpenMP support and seen it work fine since GCC 4.3.2). 

bash$ make
...
g++ -DHAVE_CONFIG_H -I.  -I/usr/include/SDL -D_GNU_SOURCE=1 -D_REENTRANT
-I./../lib3ds-1.3.0/ -fopenmp  -O3 -g -Wall -Wextra -fomit-frame-pointer
-ffast-math -funsafe-math-optimizations -mtune=native -msse -mrecip
-mfpmath=sse -msse2 -mssse3 -DNDEBUG -MT renderer-Rasterizers.o -MD -MP -MF
.deps/renderer-Rasterizers.Tpo -c -o renderer-Rasterizers.o `test -f
'Rasterizers.cc' || echo './'`Rasterizers.cc
Rasterizers.cc: In member function 'void
RasterizeScene<TriangleCarrier>::DrawTriangles(int, int) const':
Rasterizers.cc:250:100: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.

I attach the preprocessed output that easily reproduces the bug. With -fopenmp,
the compiler crashes:

    bash$ g++ -c -fopenmp  -O3 -g -Wall -Wextra -fomit-frame-pointer
-ffast-math -funsafe-math-optimizations -mtune=native -msse -mrecip
-mfpmath=sse -msse2 -mssse3 renderer-Rasterizers.i

...without it, it works:

    bash$ g++ -c -O3 -g -Wall -Wextra -fomit-frame-pointer -ffast-math
-funsafe-math-optimizations -mtune=native -msse -mrecip -mfpmath=sse -msse2
-mssse3 renderer-Rasterizers.i

Version of GCC (g++ -v):

Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc/i686-pc-linux-gnu/4.6.0/lto-wrapper
Target: i686-pc-linux-gnu
Configured with: /build/src/gcc-4.6-20110513/configure --prefix=/usr
--libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man
--infodir=/usr/share/info --with-bugurl=https://bugs.archlinux.org/
--enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++ --enable-shared
--enable-threads=posix --with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-clocale=gnu --enable-gnu-unique-object
--enable-linker-build-id --with-ppl --enable-cloog-backend=isl --enable-lto
--enable-gold --enable-ld=default --enable-plugin --with-plugin-ld=ld.gold
--disable-multilib --disable-libstdcxx-pch --enable-checking=release
Thread model: posix
gcc version 4.6.0 20110513 (prerelease) (GCC) 

System Type (uname -a):

Linux home 2.6.38-ARCH #1 SMP PREEMPT Fri May 13 07:54:18 UTC 2011 i686
Intel(R) Celeron(R) CPU E3400 @ 2.60GHz GenuineIntel GNU/Linux

Kind regards,
Thanassis Tsiodras, Dr.-Ing.