[Bug tree-optimization/36181] New: Simple for loop generates ICE with -ftree-parallelize-loops=2

["runeerle at stud dot ntnu dot no" <gcc-bugzilla at gcc dot gnu dot org>]

This simple test case fails:
--------------------------

#include <stdio.h>
int main(int argc, const char* argv[])
{
        int data[1024];
        int sum = 0;
        int i = 0;
        for(; i<1024; i++)
                sum += data[i];
        printf("%d", sum);
        return 0;
}

--------------------------

Options and output:

$ gcc-4.3 -O3 -ftree-parallelize-loops=2 main2.c -v
Using built-in specs.
Target: x86_64-linux-gnu
Configured with: ../src/configure linux gnu
Thread model: posix
gcc version 4.3.0 (Ubuntu 4.3.0-1ubuntu1) 
COLLECT_GCC_OPTIONS='-O3' '-ftree-parallelize-loops=2' '-v' '-mtune=generic'
'-pthread'
 /usr/lib/gcc/x86_64-linux-gnu/4.3.0/cc1 -quiet -v -D_REENTRANT main2.c -quiet
-dumpbase main2.c -mtune=generic -auxbase main2 -O3 -version
-ftree-parallelize-loops=2 -fstack-protector -fstack-protector -o
/tmp/cclHEQpb.s
ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
ignoring nonexistent directory
"/usr/lib/gcc/x86_64-linux-gnu/4.3.0/../../../../x86_64-linux-gnu/include"
ignoring nonexistent directory "/usr/include/x86_64-linux-gnu"
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/include
 /usr/lib/gcc/x86_64-linux-gnu/4.3.0/include
 /usr/lib/gcc/x86_64-linux-gnu/4.3.0/include-fixed
 /usr/include
End of search list.
GNU C (Ubuntu 4.3.0-1ubuntu1) version 4.3.0 (x86_64-linux-gnu)
        compiled by GNU C version 4.3.0, GMP version 4.2.2, MPFR version 2.3.1.
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 1cbb7f16ebc5c81a75d8a2ed8f02da6b
main2.c: In function ?main?:
main2.c:4: internal compiler error: in canonicalize_loop_ivs, at
tree-parloops.c:1329
Please submit a full bug report,
with preprocessed source if appropriate.


-- 
           Summary: Simple for loop generates ICE with -ftree-parallelize-
                    loops=2
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: runeerle at stud dot ntnu dot no
  GCC host triplet: x86_64-linux-gnu
GCC target triplet: x86_64-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36181