[Bug tree-optimization/82549] New: ICE at -O1 and above: verify_gimple failed

[su at cs dot ucdavis.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82549

            Bug ID: 82549
           Summary: ICE at -O1 and above: verify_gimple failed
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: su at cs dot ucdavis.edu
  Target Milestone: ---

This seems to be a recent regression. 

$ gcctk -v
Using built-in specs.
COLLECT_GCC=gcctk
COLLECT_LTO_WRAPPER=/home/su/software/tmp/gcc/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/8.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-source-trunk/configure --enable-languages=c,c++,lto
--prefix=/home/su/software/tmp/gcc/gcc-trunk --disable-bootstrap
Thread model: posix
gcc version 8.0.0 20171013 (experimental) [trunk revision 253721] (GCC) 
$ 
$ gcctk -O0 small.c
$ gcc-7.2.0 -O1 small.c
$ 
$ gcctk -O1 small.c
small.c: In function ‘main’:
small.c:3:5: error: invalid position or size operand to BIT_FIELD_REF
 int main ()
     ^~~~
BIT_FIELD_REF <b, 32, 0xffffffffffffffffffffffffffffffc0>
small.c:5:22: note: in statement
   return !a || b[-2] || b[-2];
          ~~~~~~~~~~~~^~~~~~~~
_2 = BIT_FIELD_REF <b, 32, 0xffffffffffffffffffffffffffffffc0>;
during GIMPLE pass: cfg
small.c:3:5: internal compiler error: verify_gimple failed
 int main ()
     ^~~~
0xcbc4fb verify_gimple_in_cfg(function*, bool)
        ../../gcc-source-trunk/gcc/tree-cfg.c:5397
0xb80342 execute_function_todo
        ../../gcc-source-trunk/gcc/passes.c:1994
0xb80ce9 execute_todo
        ../../gcc-source-trunk/gcc/passes.c:2048
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
$ 


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


int a, b[1];

int main ()
{
  return !a || b[-2] || b[-2];
}