Compute assigned variables and dominance frontiers.

runtime/vm/bit_vector.cc

+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#include "vm/bit_vector.h"
+
+#include "vm/os.h"
+
+namespace dart {
+
+#ifdef DEBUG
+void BitVector::Print() {
+  bool first = true;
+  OS::Print("{");
+  for (int i = 0; i < length(); i++) {
+    if (Contains(i)) {
+      if (!first) OS::Print(",");
+      first = false;
+      OS::Print("%d", i);
+    }
+  }
+  OS::Print("}");
+}
+#endif
+
+
+void BitVector::Iterator::Advance() {
+  ++bit_index_;
+  // Skip zero words.
+  if (current_word_ == 0) {
+    do {
+      ++word_index_;
+      if (Done()) return;
+      current_word_ = target_->data_[word_index_];
+    } while (current_word_ == 0);
+    bit_index_ = current_word_ * sizeof(uword);
+  }
+  // Skip zero bytes.
+  while ((current_word_ & 0xff) == 0) {
+    current_word_ >>= 8;
+    bit_index_ += 8;
+  }
+  // Skip zero bits.
+  while ((current_word_ & 0x1) == 0) {
+    current_word_ >>= 1;
+    ++bit_index_;
+  }
+  current_word_ = current_word_ >> 1;
+}
+
+
+}  // namespace dart