[Bug middle-end/65680] New: ICE at -O1 and above on x86_64-linux-gnu in expand_assignment, at expr.c:4830

[su at cs dot ucdavis.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65680

            Bug ID: 65680
           Summary: ICE at -O1 and above on x86_64-linux-gnu in
                    expand_assignment, at expr.c:4830
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          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 and above on x86_64-linux-gnu in the 64-bit mode (but not in the 32-bit
mode). 

It also affects 4.9.2 and 4.8.4. 


$ 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/5.0.0/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 5.0.0 20150406 (experimental) [trunk revision 221876] (GCC) 
$ 
$ gcc-trunk -O0 -c small.c
$           
$ gcc-trunk -O1 -c small.c
small.c: In function ‘fn1’:
small.c:9:28: internal compiler error: in expand_assignment, at expr.c:4830
   a[100000000000000000][0] = b;
                            ^
0x81f0c5 expand_assignment(tree_node*, tree_node*, bool)
    ../../gcc-trunk/gcc/expr.c:4830
0x71fbb7 expand_gimple_stmt_1
    ../../gcc-trunk/gcc/cfgexpand.c:3401
0x71fbb7 expand_gimple_stmt
    ../../gcc-trunk/gcc/cfgexpand.c:3497
0x7248e6 expand_gimple_basic_block
    ../../gcc-trunk/gcc/cfgexpand.c:5509
0x727607 execute
    ../../gcc-trunk/gcc/cfgexpand.c:6127
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.
$ 


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


struct S0 
{
  int f0:1;
} a[100000000000000001][3];

void fn1() 
{
  struct S0 b = { 0 };
  a[100000000000000000][0] = b;
}