[Bug c/57923] New: ICE in handle_braces (gcc.c) at -O3 (both 32-bit and 64-bit modes)

[su at cs dot ucdavis.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57923

            Bug ID: 57923
           Summary: ICE in handle_braces (gcc.c) at -O3 (both 32-bit and
                    64-bit modes)
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          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
-O3 on x86_64-linux (both 32-bit and 64-bit modes). This is a regression from
4.8.x.

$ gcc-trunk -v
gcc version 4.9.0 20130718 (experimental) [trunk revision 201019] (GCC) 
$ gcc-trunk -O2 -c small.c
$ gcc-4.8 -O3 -c small.c
$ gcc-trunk -O3 small.c
gcc-trunk: internal compiler error: Segmentation fault (program cc1)
0x40c95d execute
    ../../gcc-trunk/gcc/gcc.c:2824
0x40ccb4 do_spec_1
    ../../gcc-trunk/gcc/gcc.c:4616
0x40f841 process_brace_body
    ../../gcc-trunk/gcc/gcc.c:5873
0x40f841 handle_braces
    ../../gcc-trunk/gcc/gcc.c:5787
0x40d3ea do_spec_1
    ../../gcc-trunk/gcc/gcc.c:5270
0x40f841 process_brace_body
    ../../gcc-trunk/gcc/gcc.c:5873
0x40f841 handle_braces
    ../../gcc-trunk/gcc/gcc.c:5787
0x40d3ea do_spec_1
    ../../gcc-trunk/gcc/gcc.c:5270
0x40cf3b do_spec_1
    ../../gcc-trunk/gcc/gcc.c:5375
0x40f841 process_brace_body
    ../../gcc-trunk/gcc/gcc.c:5873
0x40f841 handle_braces
    ../../gcc-trunk/gcc/gcc.c:5787
0x40d3ea do_spec_1
    ../../gcc-trunk/gcc/gcc.c:5270
0x40f841 process_brace_body
    ../../gcc-trunk/gcc/gcc.c:5873
0x40f841 handle_braces
    ../../gcc-trunk/gcc/gcc.c:5787
0x40d3ea do_spec_1
    ../../gcc-trunk/gcc/gcc.c:5270
0x40f841 process_brace_body
    ../../gcc-trunk/gcc/gcc.c:5873
0x40f841 handle_braces
    ../../gcc-trunk/gcc/gcc.c:5787
0x40d3ea do_spec_1
    ../../gcc-trunk/gcc/gcc.c:5270
0x40f841 process_brace_body
    ../../gcc-trunk/gcc/gcc.c:5873
0x40f841 handle_braces
    ../../gcc-trunk/gcc/gcc.c:5787
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.
$ 


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

char a;

foo (int **p)
{
  int b;
  for (;;) {
    int c[1] = {};
    unsigned *d = &c[0];
    for (b=7; b; b--)
      **p &= --*d >= a;
  }
}
$