8319900: Recursive lightweight locking: riscv64 implementation

zifeihan · Jan 24, 2024 · 6f42bf9 · 6f42bf9
1 parent 5a74c2a
commit 6f42bf9
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Showing 9 changed files with 427 additions and 145 deletions.
diff --git a/src/hotspot/cpu/riscv/c1_MacroAssembler_riscv.cpp b/src/hotspot/cpu/riscv/c1_MacroAssembler_riscv.cpp
@@ -67,15 +67,17 @@ int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr
     lwu(hdr, Address(hdr, Klass::access_flags_offset()));
     test_bit(temp, hdr, exact_log2(JVM_ACC_IS_VALUE_BASED_CLASS));
     bnez(temp, slow_case, true /* is_far */);
+  } else if (LockingMode == LM_LIGHTWEIGHT) {
+    // null check obj. load_klass performs load if DiagnoseSyncOnValueBasedClasses != 0.
+    ld(hdr, Address(obj));
   }
 
-  // Load object header
-  ld(hdr, Address(obj, hdr_offset));
-
   if (LockingMode == LM_LIGHTWEIGHT) {
     lightweight_lock(obj, hdr, temp, t1, slow_case);
   } else if (LockingMode == LM_LEGACY) {
     Label done;
+    // Load object header
+    ld(hdr, Address(obj, hdr_offset));
     // and mark it as unlocked
     ori(hdr, hdr, markWord::unlocked_value);
     // save unlocked object header into the displaced header location on the stack
@@ -134,9 +136,6 @@ void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_
   verify_oop(obj);
 
   if (LockingMode == LM_LIGHTWEIGHT) {
-    ld(hdr, Address(obj, oopDesc::mark_offset_in_bytes()));
-    test_bit(temp, hdr, exact_log2(markWord::monitor_value));
-    bnez(temp, slow_case, /* is_far */ true);
     lightweight_unlock(obj, hdr, temp, t1, slow_case);
   } else if (LockingMode == LM_LEGACY) {
     // test if object header is pointing to the displaced header, and if so, restore