[Bug tree-optimization/49610] New: Segfault with -ftree-vectorize (or -O3)

["arthur.j.odwyer at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49610

           Summary: Segfault with -ftree-vectorize (or -O3)
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: arthur.j.odwyer@gmail.com


Created attachment 24656
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24656
Output of "ajo-gcc -std=c99 -O -ftree-vectorize test.c -v"

This failure reproduces for me with svn revision 175547
(2011-06-27). I'm on Ubuntu 10.10, x86-64.

cat >test.c <<EOF
extern int g_7;
void func_13(int p_17) {
    for (int i=0; i < 16; i = (signed char)(i+1)) { 
        g_7 &= p_17;
        g_7 &= (p_17 > 1);
    }
}
EOF
gcc -std=c99 -O -ftree-vectorize test.c 

test.c: In function âfunc_13â:
test.c:2:6: internal compiler error: Segmentation fault

Program received signal SIGSEGV, Segmentation fault.
flow_bb_inside_loop_p (loop=0x7ffff7ec1f68, bb=0x0) at ../../gcc/cfgloop.c:776
776      source_loop = bb->loop_father;
(gdb) backtrace
#0  flow_bb_inside_loop_p (loop=0x7ffff7ec1f68, bb=0x0)
    at ../../gcc/cfgloop.c:776
#1  0x00000000009cb3bb in vect_is_slp_reduction (loop_info=0x14c56e0, phi=XXX)
    at ../../gcc/tree-vect-loop.c:1807
#2  vect_is_simple_reduction_1 (loop_info=0x14c56e0, phi=XXX)
    at ../../gcc/tree-vect-loop.c:2269
[...]


This test case is reduced from the output of Csmith 2.1.0 (git hash 01aa8b04,
https://github.com/Quuxplusone/csmith/), using the following command line:
csmith --no-paranoid --longlong --pointers --arrays --no-jumps --consts
--no-volatiles --checksum --no-divs --muls --bitfields --packed-struct -s
1439171589