src/hotspot/share/utilities/bitMap.cpp

rev 50076 : Fold Partial GC into Traversal GC

@@ -670,10 +670,32 @@
 void BitMap::print_on_error(outputStream* st, const char* prefix) const {
   st->print_cr("%s[" PTR_FORMAT ", " PTR_FORMAT ")",
       prefix, p2i(map()), p2i((char*)map() + (size() >> LogBitsPerByte)));
 }
 
+void BitMap::copy_from(BitMap& other, idx_t start_bit, idx_t end_bit) {
+  // Copy prefix.
+  while (bit_in_word(start_bit) != 0 && start_bit < end_bit) {
+    tty->print_cr("prefix: "SIZE_FORMAT, start_bit);
+    at_put(start_bit, other.at(start_bit));
+    start_bit++;
+  }
+  // Copy suffix.
+  while (bit_in_word(end_bit) != 0 && end_bit > start_bit) {
+    end_bit--;
+    at_put(end_bit, other.at(end_bit));
+    tty->print_cr("suffix: "SIZE_FORMAT, end_bit);
+  }
+
+  assert(bit_in_word(start_bit) == 0, "can only handle aligned copy for now, bit: "SIZE_FORMAT, bit_in_word(start_bit));
+  assert(bit_in_word(end_bit) == 0,   "can only handle aligned copy for now, bit: "SIZE_FORMAT, bit_in_word(end_bit));
+
+  idx_t start_word = word_index(start_bit);
+  idx_t end_word = word_index(end_bit);
+  Copy::conjoint_jbytes(other._map + start_word, _map + start_word, (end_word - start_word) * sizeof(bm_word_t));
+}
+
 #ifndef PRODUCT
 
 void BitMap::print_on(outputStream* st) const {
   tty->print("Bitmap(" SIZE_FORMAT "):", size());
   for (idx_t index = 0; index < size(); index++) {