[Bug tree-optimization/70267] New: ICE on valid code at -O1 and above on x86_64-linux-gnu in propagate_necessity, at tree-ssa-dce.c:924

[su at cs dot ucdavis.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70267

            Bug ID: 70267
           Summary: ICE on valid code at -O1 and above on x86_64-linux-gnu
                    in propagate_necessity, at tree-ssa-dce.c:924
           Product: gcc
           Version: 6.0
            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: ---

The following causes an ICE when compiled with the current GCC trunk at -O1 and
above on x86_64-linux-gnu in both 32-bit and 64-bit modes. 

It seems to also affect all GCC versions since at least 4.6.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 234278] (GCC) 
$ 
$ g++-trunk -w -c -O0 small.cpp
$ 
$ g++-trunk -w -c -O1 small.cpp
small.cpp: In function ‘void Bar4()’:
small.cpp:35:1: internal compiler error: in propagate_necessity, at
tree-ssa-dce.c:924
 }
 ^
0xe72be3 propagate_necessity
        ../../gcc-source-trunk/gcc/tree-ssa-dce.c:924
0xe730ba perform_tree_ssa_dce
        ../../gcc-source-trunk/gcc/tree-ssa-dce.c:1599
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.
$ 


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


extern "Java"
{
  typedef __java_int jint;
  namespace java
  {
    namespace lang
    {
      class Class;
      class Object;
      class Throwable {};
      class Foo;
    }
  }
} 

typedef struct java::lang::Object * jobject;
typedef struct java::lang::Throwable * jthrowable;
typedef class  java::lang::Class * jclass;

using java::lang::Foo;

class Foo: public java::lang::Throwable
{
  public:static::java::lang::Class class$;
};

extern "C" Foo _Jv_AllocObject (jclass) __attribute__ ((__malloc__));
extern "C" void _Jv_Throw (jthrowable) __attribute__ ((__noreturn__));

void 
Bar4 (void)
{
  Foo * f = new java::lang::Foo;
  throw (f);
}