[Bug tree-optimization/59322] New: ICE with segfault on valid code at -O1, -O2, and -O3 on x86_64-linux-gnu

[su at cs dot ucdavis.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59322

            Bug ID: 59322
           Summary: ICE with segfault on valid code at -O1, -O2, and -O3
                    on x86_64-linux-gnu
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: su at cs dot ucdavis.edu

The following code causes an ICE when compiled with the current gcc trunk at
-O1, -O2 and -O3 on x86_64-linux-gnu in both 32-bit and 64-bit modes. 

It is a regression from 4.8.x. 

$ gcc-trunk -v
Using built-in specs.
COLLECT_GCC=gcc-trunk
COLLECT_LTO_WRAPPER=/usr/local/gcc-trunk/libexec/gcc/x86_64-unknown-linux-gnu/4.9.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ../gcc-trunk/configure --prefix=/usr/local/gcc-trunk
--enable-languages=c,c++ --disable-werror --enable-multilib
Thread model: posix
gcc version 4.9.0 20131127 (experimental) [trunk revision 205463] (GCC) 
$ 
$ gcc-trunk -O0 -c small.c
$ gcc-trunk -Os -c small.c
$ gcc-4.8.2 -O1 -c small.c
$ 
$ gcc-trunk -O1 -c small.c
small.c: In function ‘foo’:
small.c:5:1: internal compiler error: Segmentation fault
 foo ()
 ^
0x9ab60f crash_signal
    ../../gcc-trunk/gcc/toplev.c:336
0xb4c595 thread_through_all_blocks(bool)
    ../../gcc-trunk/gcc/tree-ssa-threadupdate.c:1651
0xa93a4a tree_ssa_dominator_optimize
    ../../gcc-trunk/gcc/tree-ssa-dom.c:886
0xa93a4a execute
    ../../gcc-trunk/gcc/tree-ssa-dom.c:984
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.
$ 


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


int a, b, d;
short c;

int
foo ()
{
  for (b = 0; b; b = a)
    for (c = 18; c < 10; c++)
      {
    d = c;
    if (d)
      return 0;
      }
  return 0;
}