src/share/vm/opto/graphKit.cpp

rev 8802 : G1 performance improvements: card batching, joining, sorting, prefetching and write barrier fence elision and simplification based on a global syncrhonization using handshakes piggybacking on thread-local safepoints.
rev 8803 : Implementation improvements to pass JPRT

*** 4183,4192 ****
--- 4183,4193 ----
    Node* tls = __ thread(); // ThreadLocalStorage
  
    Node* no_base = __ top();
    float likely  = PROB_LIKELY(0.999);
    float unlikely  = PROB_UNLIKELY(0.999);
+   Node* clean_card = __ ConI((jint)CardTableModRefBS::clean_card_val());
    Node* young_card = __ ConI((jint)G1SATBCardTableModRefBS::g1_young_card_val());
    Node* dirty_card = __ ConI((jint)CardTableModRefBS::dirty_card_val());
    Node* zeroX = __ ConX(0);
  
    // Get the alias_index for raw card-mark memory
*** 4240,4249 ****
--- 4241,4255 ----
          // Ok must mark the card if not already dirty
  
          // load the original value of the card
          Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
  
+         if (G1ElideMembar) {
+           __ if_then(card_val, BoolTest::eq, clean_card); {
+             g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
+           } __ end_if();
+         } else {
            __ if_then(card_val, BoolTest::ne, young_card); {
              sync_kit(ideal);
              // Use Op_MemBarVolatile to achieve the effect of a StoreLoad barrier.
              insert_mem_bar(Op_MemBarVolatile, oop_store);
              __ sync_kit(this);
*** 4251,4260 ****
--- 4257,4267 ----
              Node* card_val_reload = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
              __ if_then(card_val_reload, BoolTest::ne, dirty_card); {
                g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
              } __ end_if();
            } __ end_if();
+         }
        } __ end_if();
      } __ end_if();
    } else {
      // Object.clone() instrinsic uses this path.
      g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);