[Bug c/43771] New: ICE on valid when compiling ParMetis with gcc 4.5.0 and -O3

[martin dot audet at imi dot cnrc-nrc dot gc dot ca]

The following inocent looking C function:

void KWayNodeRefine__(int nparts, int *gpwgts, int *badminpwgt, int
*badmaxpwgt)
{
   int i;

   for (i=0; i<nparts; i+=2) {
       badminpwgt[i] = badminpwgt[i+1] = gpwgts[i]+gpwgts[i+1];
       badmaxpwgt[i] = badmaxpwgt[i+1] = gpwgts[i]+gpwgts[i+1];
   }
}

when compiled with gcc 4.5.0 generate an internal compiler error:

[au...@mc1 experiences]$ g++ -O3 -c nr.c
nr.c: In function 'void KWayNodeRefine__(int, int*, int*, int*)':
nr.c:2:6: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.
[au...@mc1 experiences]$

Note that there is no such error with -O2 or without options or when gcc 4.4.2
is used. Note also that the code above originate from ParMetis (parallel graph
partitionner). I simplified it the most I could (and I think we cannot simplify
it further to still triger the gcc ICE).

Now here are some information about my system:
[au...@mc1 experiences]$ gcc --version
gcc (GCC) 4.5.0
Copyright (C) 2010 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

[au...@mc1 experiences]$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/home/publique/gcc45/bin/../libexec/gcc/x86_64-unknown-linux-gnu/4.5.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ../gcc-4.5.0/configure --prefix=/usr/local/gcc45
--enable-shared --enable-threads=posix --with-system-zlib
--with-gmp=/usr/local/gmp-4.3.2 --with-mpfr=/usr/local/mpfr-2.4.2
--with-mpc=/usr/local/mpc-0.8.1 --with-ppl=/usr/local/ppl-0.10.2
--with-cloog=/usr/local/cloog-ppl-0.15.9 --with-libelf=/usr/local/libelf-0.8.12
--enable-__cxa_atexit --enable-languages=c,c++,fortran
Thread model: posix
gcc version 4.5.0 (GCC)
[au...@mc1 experiences]$ uname -a
Linux mc1 2.6.22.9-91.fc7 #1 SMP Thu Jun 18 16:01:22 EDT 2009 x86_64 x86_64
x86_64 GNU/Linux
[au...@mc1 experiences]$

As you can see my system uses Fedora Linux 7 distribution. gcc was compiled and
tested (make -k check) this morning on this machine. Only a small fraction of
the tests failled.

Regards,


-- 
           Summary: ICE on valid when compiling ParMetis with gcc 4.5.0 and
                    -O3
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: critical
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: martin dot audet at imi dot cnrc-nrc dot gc dot ca


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43771