Method Memory

ir/memory.cpp:1515–1558

}

Memory::Memory(State &state)
  : state(&state), escaped_local_blks(*this), observed_addrs(*this) {
  if (memory_unused())
    return;

  next_nonlocal_bid
    = has_null_block + num_globals_src + num_ptrinputs + has_fncall;

  if (skip_null())
    non_local_block_val.emplace_back();

  // TODO: should skip initialization of fully initialized constants
  for (unsigned bid = skip_null(), e = numNonlocals(); bid != e; ++bid) {
    non_local_block_val.emplace_back(mk_block_val_array(bid));
  }

  non_local_block_liveness = mk_liveness_array();

  // initialize all local blocks as non-pointer, poison value
  // This is okay because loading a pointer as non-pointer is also poison.
  if (numLocals() > 0) {
    auto poison_array
      = expr::mkConstArray(expr::mkUInt(0, Pointer::bitsShortOffset()),
                           Byte::mkPoisonByte(*this)());
    local_block_val.resize(numLocals(), {std::move(poison_array), DATA_NONE});

    // all local blocks are dead in the beginning
    local_block_liveness = expr::mkUInt(0, numLocals());
  }

  // no argument has been written to at entry
  if (has_initializes_attr) {
    unsigned bits = Pointer::bitsShortBid() + Pointer::bitsShortOffset();
    has_stored_arg = expr::mkConstArray(expr::mkUInt(0, bits), false);
  }

  stored_pointers.resize(numNonlocals());

  // Initialize a memory block for null pointer.
  if (skip_null()) {
    auto zero = expr::mkUInt(0, bits_size_t);
    alloc(&zero, bits_byte / 8, GLOBAL, false, false, 0);
  }
}

Memory Memory::dupNoRead() const {
  Memory ret(*state);