changeset 56533:9691a169f1dd

8173196: [REDO] C2 does not optimize redundant memory operations with G1 Reviewed-by: thartmann, kvn
author roland
date Tue, 21 May 2019 15:46:09 +0200
parents ba171f871932
children 6c205bbdafd2
files src/hotspot/share/gc/g1/c2/g1BarrierSetC2.cpp src/hotspot/share/gc/shared/c2/cardTableBarrierSetC2.cpp src/hotspot/share/opto/graphKit.cpp src/hotspot/share/opto/graphKit.hpp
diffstat 4 files changed, 15 insertions(+), 2 deletions(-) [+]
line wrap: on
line diff
--- a/src/hotspot/share/gc/g1/c2/g1BarrierSetC2.cpp	Tue May 28 14:56:58 2019 +0200
+++ b/src/hotspot/share/gc/g1/c2/g1BarrierSetC2.cpp	Tue May 21 15:46:09 2019 +0200
@@ -472,7 +472,7 @@
 
         __ if_then(card_val, BoolTest::ne, young_card); {
           kit->sync_kit(ideal);
-          kit->insert_mem_bar(Op_MemBarVolatile, oop_store);
+          kit->insert_store_load_for_barrier();
           __ sync_kit(kit);
 
           Node* card_val_reload = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
--- a/src/hotspot/share/gc/shared/c2/cardTableBarrierSetC2.cpp	Tue May 28 14:56:58 2019 +0200
+++ b/src/hotspot/share/gc/shared/c2/cardTableBarrierSetC2.cpp	Tue May 21 15:46:09 2019 +0200
@@ -105,7 +105,7 @@
 
   if (UseCondCardMark) {
     if (ct->scanned_concurrently()) {
-      kit->insert_mem_bar(Op_MemBarVolatile, oop_store);
+      kit->insert_store_load_for_barrier();
       __ sync_kit(kit);
     }
     // The classic GC reference write barrier is typically implemented
--- a/src/hotspot/share/opto/graphKit.cpp	Tue May 28 14:56:58 2019 +0200
+++ b/src/hotspot/share/opto/graphKit.cpp	Tue May 21 15:46:09 2019 +0200
@@ -3306,6 +3306,18 @@
   return membar;
 }
 
+void GraphKit::insert_store_load_for_barrier() {
+  Node* mem = reset_memory();
+  MemBarNode* mb = MemBarNode::make(C, Op_MemBarVolatile, Compile::AliasIdxRaw);
+  mb->init_req(TypeFunc::Control, control());
+  mb->init_req(TypeFunc::Memory, mem);
+  Node* membar = _gvn.transform(mb);
+  set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
+  Node* newmem = _gvn.transform(new ProjNode(membar, TypeFunc::Memory));
+  set_all_memory(mem);
+  set_memory(newmem, Compile::AliasIdxRaw);
+}
+
 //------------------------------shared_lock------------------------------------
 // Emit locking code.
 FastLockNode* GraphKit::shared_lock(Node* obj) {
--- a/src/hotspot/share/opto/graphKit.hpp	Tue May 28 14:56:58 2019 +0200
+++ b/src/hotspot/share/opto/graphKit.hpp	Tue May 21 15:46:09 2019 +0200
@@ -811,6 +811,7 @@
   int next_monitor();
   Node* insert_mem_bar(int opcode, Node* precedent = NULL);
   Node* insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent = NULL);
+  void insert_store_load_for_barrier();
   // Optional 'precedent' is appended as an extra edge, to force ordering.
   FastLockNode* shared_lock(Node* obj);
   void shared_unlock(Node* box, Node* obj);