[Bug tree-optimization/58946] New: [4.9 Regression] internal compiler error: in operator[], at vec.h:722

[octoploid at yandex dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58946

            Bug ID: 58946
           Summary: [4.9 Regression] internal compiler error: in
                    operator[], at vec.h:722
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: octoploid at yandex dot com

Building dev-util/kdevplatform-1.5.2 ICEs.

markus@x4 tmp % cat test.ii
class A {
public:
  A(int p1) : m_index(p1) {
    if (!p1)
      m_index = DummyMask;
  }
  enum {
    DummyMask = 1 << 31
  };
  unsigned m_fn1() const {
    int a;
    a = m_index & DummyMask;
    if (a)
      return 0;
    return m_index;
  }
  unsigned m_index;
};

class B {
public:
  int contains___trans_tmp_4;
  void m_fn1(int &p1) {
    const A &b = p1;
    contains___trans_tmp_4 = b.m_fn1();
  }
};
void fn1(A p1, B &p2) {
  int c;
  c = p1.m_fn1();
  p2.m_fn1(c);
}

markus@x4 tmp % g++ -c -O2 test.ii
test.ii: In function ‘void fn1(A, B&)’:
test.ii:28:6: internal compiler error: in operator[], at vec.h:722
 void fn1(A p1, B &p2) {
      ^
0xc819a7 vec<operand_entry*, va_heap, vl_embed>::operator[](unsigned int)
        ../../gcc/gcc/vec.h:722
0xc84207 vec<operand_entry*, va_heap, vl_embed>::operator[](unsigned int)
        ../../gcc/gcc/tree.h:2806
0xc84207 vec<operand_entry*, va_heap, vl_ptr>::operator[](unsigned int)
        ../../gcc/gcc/vec.h:1152
0xc84207 update_ops
        ../../gcc/gcc/tree-ssa-reassoc.c:2619
0xc8c1fa maybe_optimize_range_tests
        ../../gcc/gcc/tree-ssa-reassoc.c:2907
0xc8c1fa reassociate_bb
        ../../gcc/gcc/tree-ssa-reassoc.c:4325
0xc8b927 reassociate_bb
        ../../gcc/gcc/tree-ssa-reassoc.c:4482
0xc8b927 reassociate_bb
        ../../gcc/gcc/tree-ssa-reassoc.c:4482
0xc8e2db do_reassoc
        ../../gcc/gcc/tree-ssa-reassoc.c:4515
0xc8e2db execute_reassoc
        ../../gcc/gcc/tree-ssa-reassoc.c:4597
0xc8e2db execute
        ../../gcc/gcc/tree-ssa-reassoc.c:4639
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.

Looks related to PR58911.