[Bug c++/70285] New: ICE on valid code on x86_64-linux-gnu: verify_gimple failed

[su at cs dot ucdavis.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70285

            Bug ID: 70285
           Summary: ICE on valid code on x86_64-linux-gnu: verify_gimple
                    failed
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: su at cs dot ucdavis.edu
  Target Milestone: ---

The following code causes an ICE when compiled with the current GCC trunk on
x86_64-linux-gnu in both 32-bit and 64-bit modes. 

This is a regression from 5.3.x. 


$ g++-trunk -v
Using built-in specs.
COLLECT_GCC=g++-trunk
COLLECT_LTO_WRAPPER=/usr/local/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/6.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-source-trunk/configure --enable-languages=c,c++,lto
--prefix=/usr/local/gcc-trunk --disable-bootstrap
Thread model: posix
gcc version 6.0.0 20160317 (experimental) [trunk revision 234279] (GCC) 
$ 
$ g++-5.3 small.cpp -c
$ 
$ g++-trunk small.cpp -c
small.cpp: In function ‘int fn1()’:
small.cpp:9:1: error: non-trivial conversion at assignment
 fn1 ()
 ^~~
int
signed char
D.2294 = b.i;
small.cpp:9:1: internal compiler error: verify_gimple failed
0xd8b5fd verify_gimple_in_seq(gimple*)
        ../../gcc-source-trunk/gcc/tree-cfg.c:4792
0xae1a0b gimplify_body(tree_node*, bool)
        ../../gcc-source-trunk/gcc/gimplify.c:11404
0xae1dc6 gimplify_function_tree(tree_node*)
        ../../gcc-source-trunk/gcc/gimplify.c:11492
0x960027 cgraph_node::analyze()
        ../../gcc-source-trunk/gcc/cgraphunit.c:625
0x962b90 analyze_functions
        ../../gcc-source-trunk/gcc/cgraphunit.c:1086
0x963df8 symbol_table::finalize_compilation_unit()
        ../../gcc-source-trunk/gcc/cgraphunit.c:2542
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; 

struct S 
{
  int i:8;
} b;

int
fn1 ()
{
  return &fn1 ? b.i : a;
}