From 1a1e403d9fb17ccc21adfc9780d7a2cdd978b846 Mon Sep 17 00:00:00 2001
From: Kunshan Wang <wks1986@gmail.com>
Date: Fri, 10 Jul 2026 15:56:46 +0800
Subject: [PATCH 1/3] Upstream API change w.r.t. field log bits

---
 mmtk/Cargo.lock                   | 2 --
 mmtk/Cargo.toml                   | 4 ++--
 mmtk/src/object_model.rs          | 3 ++-
 mmtk/src/vm_metadata/constants.rs | 6 +++++-
 4 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/mmtk/Cargo.lock b/mmtk/Cargo.lock
index 106e4bee..6507379b 100644
--- a/mmtk/Cargo.lock
+++ b/mmtk/Cargo.lock
@@ -582,7 +582,6 @@ dependencies = [
 [[package]]
 name = "mmtk"
 version = "0.32.0"
-source = "git+https://github.com/mmtk/mmtk-core.git?rev=37d81218028d788f7a24158aac0588c3f6925d08#37d81218028d788f7a24158aac0588c3f6925d08"
 dependencies = [
  "atomic",
  "atomic-traits",
@@ -618,7 +617,6 @@ dependencies = [
 [[package]]
 name = "mmtk-macros"
 version = "0.32.0"
-source = "git+https://github.com/mmtk/mmtk-core.git?rev=37d81218028d788f7a24158aac0588c3f6925d08#37d81218028d788f7a24158aac0588c3f6925d08"
 dependencies = [
  "proc-macro-error",
  "proc-macro2",
diff --git a/mmtk/Cargo.toml b/mmtk/Cargo.toml
index 9c7287b0..6bb8d3ce 100644
--- a/mmtk/Cargo.toml
+++ b/mmtk/Cargo.toml
@@ -36,9 +36,9 @@ probe = "0.5"
 # - change branch
 # - change repo name
 # But other changes including adding/removing whitespaces in commented lines may break the CI.
-mmtk = { git = "https://github.com/mmtk/mmtk-core.git", rev = "37d81218028d788f7a24158aac0588c3f6925d08" }
+# mmtk = { git = "https://github.com/mmtk/mmtk-core.git", rev = "37d81218028d788f7a24158aac0588c3f6925d08" }
 # Uncomment the following to build locally
-# mmtk = { path = "../repos/mmtk-core" }
+mmtk = { path = "../../mmtk-core" }
 
 [build-dependencies]
 built = { version = "0.7.7", features = ["git2"] }
diff --git a/mmtk/src/object_model.rs b/mmtk/src/object_model.rs
index 945b20b2..fbd9aad1 100644
--- a/mmtk/src/object_model.rs
+++ b/mmtk/src/object_model.rs
@@ -9,7 +9,8 @@ use mmtk::vm::*;
 pub struct VMObjectModel<const COMPRESSED: bool> {}
 
 impl<const COMPRESSED: bool> ObjectModel<OpenJDK<COMPRESSED>> for VMObjectModel<COMPRESSED> {
-    const GLOBAL_LOG_BIT_SPEC: VMGlobalLogBitSpec = vm_metadata::LOGGING_SIDE_METADATA_SPEC;
+    const GLOBAL_OBJECT_UNLOG_BIT_SPEC: VMGlobalObjectUnlogBitSpec = vm_metadata::OBJECT_LOGGING_SIDE_METADATA_SPEC;
+    const GLOBAL_FIELD_UNLOG_BIT_SPEC: VMGlobalFieldUnlogBitSpec = vm_metadata::FIELD_LOGGING_SIDE_METADATA_SPEC;
 
     const LOCAL_FORWARDING_POINTER_SPEC: VMLocalForwardingPointerSpec =
         vm_metadata::FORWARDING_POINTER_METADATA_SPEC;
diff --git a/mmtk/src/vm_metadata/constants.rs b/mmtk/src/vm_metadata/constants.rs
index e9e5a6ac..ef1aac1a 100644
--- a/mmtk/src/vm_metadata/constants.rs
+++ b/mmtk/src/vm_metadata/constants.rs
@@ -13,7 +13,11 @@ pub(crate) const FORWARDING_POINTER_OFFSET: isize = 0;
 
 /// Global logging bit metadata spec
 /// 1 bit per object
-pub(crate) const LOGGING_SIDE_METADATA_SPEC: VMGlobalLogBitSpec = VMGlobalLogBitSpec::side_first();
+pub(crate) const OBJECT_LOGGING_SIDE_METADATA_SPEC: VMGlobalObjectUnlogBitSpec =
+    VMGlobalObjectUnlogBitSpec::side_first();
+
+pub(crate) const FIELD_LOGGING_SIDE_METADATA_SPEC: VMGlobalFieldUnlogBitSpec =
+    VMGlobalFieldUnlogBitSpec::in_header(0);
 
 // Global MetadataSpecs - End
 

From 4e75de2b17369196ac77843fa4dc6cc66f5ffe4a Mon Sep 17 00:00:00 2001
From: Kunshan Wang <wks1986@gmail.com>
Date: Fri, 17 Jul 2026 16:13:07 +0800
Subject: [PATCH 2/3] WIP: Make interpreter work with field-logging barrier.

---
 mmtk/src/slots.rs                                       | 5 +++++
 mmtk/src/vm_metadata/constants.rs                       | 2 +-
 openjdk/cpu/x86/mmtkUnlogBitBarrierSetAssembler_x86.cpp | 4 ++--
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/mmtk/src/slots.rs b/mmtk/src/slots.rs
index 02896836..58d40000 100644
--- a/mmtk/src/slots.rs
+++ b/mmtk/src/slots.rs
@@ -205,6 +205,11 @@ impl<const COMPRESSED: bool> Slot for OpenJDKSlot<COMPRESSED> {
             unsafe { self.addr.store(object) }
         }
     }
+
+    fn to_address(&self) -> Address {
+        assert!(!COMPRESSED);
+        self.addr
+    }
 }
 
 /// A range of OpenJDKSlot, usually used for arrays.
diff --git a/mmtk/src/vm_metadata/constants.rs b/mmtk/src/vm_metadata/constants.rs
index ef1aac1a..99d17538 100644
--- a/mmtk/src/vm_metadata/constants.rs
+++ b/mmtk/src/vm_metadata/constants.rs
@@ -17,7 +17,7 @@ pub(crate) const OBJECT_LOGGING_SIDE_METADATA_SPEC: VMGlobalObjectUnlogBitSpec =
     VMGlobalObjectUnlogBitSpec::side_first();
 
 pub(crate) const FIELD_LOGGING_SIDE_METADATA_SPEC: VMGlobalFieldUnlogBitSpec =
-    VMGlobalFieldUnlogBitSpec::in_header(0);
+    VMGlobalFieldUnlogBitSpec::side_after(OBJECT_LOGGING_SIDE_METADATA_SPEC.as_spec());
 
 // Global MetadataSpecs - End
 
diff --git a/openjdk/cpu/x86/mmtkUnlogBitBarrierSetAssembler_x86.cpp b/openjdk/cpu/x86/mmtkUnlogBitBarrierSetAssembler_x86.cpp
index 4c3a28f0..8f472d9a 100644
--- a/openjdk/cpu/x86/mmtkUnlogBitBarrierSetAssembler_x86.cpp
+++ b/openjdk/cpu/x86/mmtkUnlogBitBarrierSetAssembler_x86.cpp
@@ -62,8 +62,8 @@ void MMTkUnlogBitBarrierSetAssembler::object_reference_write_pre_or_post(MacroAs
   // compressed oops, the `val` register will be holding a compressed pointer to the target object
   // due to the way `BarrierSetAssembler::store_at` works. If the write barrier needs to know the
   // target, we will need to decompress it before passing it to the barrier slow path.
-  __ xorptr(c_rarg1, c_rarg1);
-  __ xorptr(c_rarg2, c_rarg2);
+  __ lea(c_rarg1, dst);
+  __ movptr(c_rarg2, val);
 
   address entry_point = mmtk_enable_barrier_fastpath ? FN_ADDR(MMTkBarrierSetRuntime::object_reference_write_slow_call)
                       : pre                          ? FN_ADDR(MMTkBarrierSetRuntime::object_reference_write_pre_call)

From d1980053cc50a3c84b7928a4ea9bfeb3d8b524ad Mon Sep 17 00:00:00 2001
From: Kunshan Wang <wks1986@gmail.com>
Date: Mon, 27 Jul 2026 18:06:46 +0800
Subject: [PATCH 3/3] Rename barrier-related classes.

`ObjectBarrier` -> `GenBarrier`.  It is related to generational GC, and
can be object or field-grained.

`UnlogBit` -> `ObjectUnlogBit`.  Added `Object` prefix to prepare for
adding field unlog bit barriers.
---
 mmtk/Cargo.lock                                        |  1 -
 ...ch64.cpp => mmtkGenBarrierSetAssembler_aarch64.cpp} |  4 ++--
 ...ch64.hpp => mmtkGenBarrierSetAssembler_aarch64.hpp} |  4 ++--
 ... mmtkObjectUnlogBitBarrierSetAssembler_aarch64.cpp} | 10 +++++-----
 ... mmtkObjectUnlogBitBarrierSetAssembler_aarch64.hpp} |  2 +-
 .../aarch64/mmtkSATBBarrierSetAssembler_aarch64.hpp    |  4 ++--
 ..._riscv.cpp => mmtkGenBarrierSetAssembler_riscv.cpp} |  4 ++--
 ..._riscv.hpp => mmtkGenBarrierSetAssembler_riscv.hpp} |  2 +-
 ...bler_x86.cpp => mmtkGenBarrierSetAssembler_x86.cpp} |  6 +++---
 ...bler_x86.hpp => mmtkGenBarrierSetAssembler_x86.hpp} |  4 ++--
 ...p => mmtkObjectUnlogBitBarrierSetAssembler_x86.cpp} | 10 +++++-----
 ...p => mmtkObjectUnlogBitBarrierSetAssembler_x86.hpp} |  2 +-
 openjdk/cpu/x86/mmtkSATBBarrierSetAssembler_x86.hpp    |  4 ++--
 ...er_zero.hpp => mmtkGenBarrierSetAssembler_zero.hpp} |  2 +-
 openjdk/share/barriers/mmtkObjectBarrier.hpp           |  4 ++--
 15 files changed, 31 insertions(+), 32 deletions(-)
 rename openjdk/cpu/aarch64/{mmtkObjectBarrierSetAssembler_aarch64.cpp => mmtkGenBarrierSetAssembler_aarch64.cpp} (75%)
 rename openjdk/cpu/aarch64/{mmtkObjectBarrierSetAssembler_aarch64.hpp => mmtkGenBarrierSetAssembler_aarch64.hpp} (83%)
 rename openjdk/cpu/aarch64/{mmtkUnlogBitBarrierSetAssembler_aarch64.cpp => mmtkObjectUnlogBitBarrierSetAssembler_aarch64.cpp} (81%)
 rename openjdk/cpu/aarch64/{mmtkUnlogBitBarrierSetAssembler_aarch64.hpp => mmtkObjectUnlogBitBarrierSetAssembler_aarch64.hpp} (92%)
 rename openjdk/cpu/riscv/{mmtkObjectBarrierSetAssembler_riscv.cpp => mmtkGenBarrierSetAssembler_riscv.cpp} (92%)
 rename openjdk/cpu/riscv/{mmtkObjectBarrierSetAssembler_riscv.hpp => mmtkGenBarrierSetAssembler_riscv.hpp} (89%)
 rename openjdk/cpu/x86/{mmtkObjectBarrierSetAssembler_x86.cpp => mmtkGenBarrierSetAssembler_x86.cpp} (78%)
 rename openjdk/cpu/x86/{mmtkObjectBarrierSetAssembler_x86.hpp => mmtkGenBarrierSetAssembler_x86.hpp} (85%)
 rename openjdk/cpu/x86/{mmtkUnlogBitBarrierSetAssembler_x86.cpp => mmtkObjectUnlogBitBarrierSetAssembler_x86.cpp} (81%)
 rename openjdk/cpu/x86/{mmtkUnlogBitBarrierSetAssembler_x86.hpp => mmtkObjectUnlogBitBarrierSetAssembler_x86.hpp} (92%)
 rename openjdk/cpu/zero/{mmtkObjectBarrierSetAssembler_zero.hpp => mmtkGenBarrierSetAssembler_zero.hpp} (84%)

diff --git a/mmtk/Cargo.lock b/mmtk/Cargo.lock
index 6507379b..69152755 100644
--- a/mmtk/Cargo.lock
+++ b/mmtk/Cargo.lock
@@ -599,7 +599,6 @@ dependencies = [
  "lazy_static",
  "libc",
  "log",
- "memoffset",
  "mmtk-macros",
  "num-traits",
  "num_cpus",
diff --git a/openjdk/cpu/aarch64/mmtkObjectBarrierSetAssembler_aarch64.cpp b/openjdk/cpu/aarch64/mmtkGenBarrierSetAssembler_aarch64.cpp
similarity index 75%
rename from openjdk/cpu/aarch64/mmtkObjectBarrierSetAssembler_aarch64.cpp
rename to openjdk/cpu/aarch64/mmtkGenBarrierSetAssembler_aarch64.cpp
index 518441b7..e69759fc 100644
--- a/openjdk/cpu/aarch64/mmtkObjectBarrierSetAssembler_aarch64.cpp
+++ b/openjdk/cpu/aarch64/mmtkGenBarrierSetAssembler_aarch64.cpp
@@ -6,12 +6,12 @@
 
 #define __ masm->
 
-void MMTkObjectBarrierSetAssembler::object_reference_write_post(MacroAssembler* masm, DecoratorSet decorators, Address dst, Register val, Register tmp1, Register tmp2, Register tmp3) const {
+void MMTkGenBarrierSetAssembler::object_reference_write_post(MacroAssembler* masm, DecoratorSet decorators, Address dst, Register val, Register tmp1, Register tmp2, Register tmp3) const {
   if (can_remove_barrier(decorators, val, /* skip_const_null */ true)) return;
   object_reference_write_pre_or_post(masm, decorators, dst, val, tmp1, tmp2, tmp3, /* pre = */ false);
 }
 
-void MMTkObjectBarrierSetAssembler::arraycopy_epilogue(MacroAssembler* masm, DecoratorSet decorators, bool is_oop,
+void MMTkGenBarrierSetAssembler::arraycopy_epilogue(MacroAssembler* masm, DecoratorSet decorators, bool is_oop,
                                   Register src, Register dst, Register count, Register tmp, RegSet saved_regs) {
   // see also void G1BarrierSetAssembler::gen_write_ref_array_post_barrier
   assert_different_registers(src, dst, count);
diff --git a/openjdk/cpu/aarch64/mmtkObjectBarrierSetAssembler_aarch64.hpp b/openjdk/cpu/aarch64/mmtkGenBarrierSetAssembler_aarch64.hpp
similarity index 83%
rename from openjdk/cpu/aarch64/mmtkObjectBarrierSetAssembler_aarch64.hpp
rename to openjdk/cpu/aarch64/mmtkGenBarrierSetAssembler_aarch64.hpp
index 60801b55..4253e91d 100644
--- a/openjdk/cpu/aarch64/mmtkObjectBarrierSetAssembler_aarch64.hpp
+++ b/openjdk/cpu/aarch64/mmtkGenBarrierSetAssembler_aarch64.hpp
@@ -2,11 +2,11 @@
 #define MMTK_OPENJDK_MMTK_OBJECT_BARRIER_SET_ASSEMBLER_AARCH64_HPP
 
 #include "utilities/macros.hpp"
-#include CPU_HEADER(mmtkUnlogBitBarrierSetAssembler)
+#include CPU_HEADER(mmtkObjectUnlogBitBarrierSetAssembler)
 
 //////////////////// Assembler ////////////////////
 
-class MMTkObjectBarrierSetAssembler: public MMTkUnlogBitBarrierSetAssembler {
+class MMTkGenBarrierSetAssembler: public MMTkObjectUnlogBitBarrierSetAssembler {
 protected:
   virtual void object_reference_write_post(MacroAssembler* masm, DecoratorSet decorators, Address dst, Register val, Register tmp1, Register tmp2, Register tmp3) const override;
 public:
diff --git a/openjdk/cpu/aarch64/mmtkUnlogBitBarrierSetAssembler_aarch64.cpp b/openjdk/cpu/aarch64/mmtkObjectUnlogBitBarrierSetAssembler_aarch64.cpp
similarity index 81%
rename from openjdk/cpu/aarch64/mmtkUnlogBitBarrierSetAssembler_aarch64.cpp
rename to openjdk/cpu/aarch64/mmtkObjectUnlogBitBarrierSetAssembler_aarch64.cpp
index 32b5e6b5..bb7afbbc 100644
--- a/openjdk/cpu/aarch64/mmtkUnlogBitBarrierSetAssembler_aarch64.cpp
+++ b/openjdk/cpu/aarch64/mmtkObjectUnlogBitBarrierSetAssembler_aarch64.cpp
@@ -4,7 +4,7 @@
 #include "c1/c1_MacroAssembler.hpp"
 
 #include "utilities/macros.hpp"
-#include CPU_HEADER(mmtkUnlogBitBarrierSetAssembler)
+#include CPU_HEADER(mmtkObjectUnlogBitBarrierSetAssembler)
 
 #include <cstdint>
 
@@ -12,7 +12,7 @@
 
 #define __ masm->
 
-void MMTkUnlogBitBarrierSetAssembler::emit_check_unlog_bit_fast_path(MacroAssembler* masm, Label &done, Register obj, Register tmp1, Register tmp2, Register tmp3) {
+void MMTkObjectUnlogBitBarrierSetAssembler::emit_check_unlog_bit_fast_path(MacroAssembler* masm, Label &done, Register obj, Register tmp1, Register tmp2, Register tmp3) {
   // Note that `tmp1` and `tmp2` are actual temporary registers available for use,
   // not the `tmp1` and `tmp2` from `store_at`.
   assert_different_registers(obj, tmp1, tmp2, tmp3);
@@ -33,7 +33,7 @@ void MMTkUnlogBitBarrierSetAssembler::emit_check_unlog_bit_fast_path(MacroAssemb
 
 #define __ masm->
 
-void MMTkUnlogBitBarrierSetAssembler::object_reference_write_pre_or_post(MacroAssembler* masm, DecoratorSet decorators, Address dst, Register val, Register tmp1, Register tmp2, Register tmp3, bool pre) {
+void MMTkObjectUnlogBitBarrierSetAssembler::object_reference_write_pre_or_post(MacroAssembler* masm, DecoratorSet decorators, Address dst, Register val, Register tmp1, Register tmp2, Register tmp3, bool pre) {
   Label done;
   Register obj = dst.base();
   if (mmtk_enable_barrier_fastpath) {
@@ -80,7 +80,7 @@ void MMTkUnlogBitBarrierSetAssembler::object_reference_write_pre_or_post(MacroAs
 
 #define __ ce->masm()->
 
-void MMTkUnlogBitBarrierSetAssembler::generate_c1_unlog_bit_barrier_slow_path_stub(LIR_Assembler* ce, MMTkC1UnlogBitBarrierSlowPathStub* stub) const {
+void MMTkObjectUnlogBitBarrierSetAssembler::generate_c1_unlog_bit_barrier_slow_path_stub(LIR_Assembler* ce, MMTkC1UnlogBitBarrierSlowPathStub* stub) const {
   MMTkBarrierSetC1* bs = (MMTkBarrierSetC1*) BarrierSet::barrier_set()->barrier_set_c1();
   __ bind(*stub->entry());
   ce->store_parameter(stub->src->as_pointer_register(), 0);
@@ -94,7 +94,7 @@ void MMTkUnlogBitBarrierSetAssembler::generate_c1_unlog_bit_barrier_slow_path_st
 }
 
 void MMTkC1UnlogBitBarrierSlowPathStub::emit_code(LIR_Assembler* ce) {
-  MMTkUnlogBitBarrierSetAssembler* bs = (MMTkUnlogBitBarrierSetAssembler*) BarrierSet::barrier_set()->barrier_set_assembler();
+  MMTkObjectUnlogBitBarrierSetAssembler* bs = (MMTkObjectUnlogBitBarrierSetAssembler*) BarrierSet::barrier_set()->barrier_set_assembler();
   bs->generate_c1_unlog_bit_barrier_slow_path_stub(ce, this);
 }
 
diff --git a/openjdk/cpu/aarch64/mmtkUnlogBitBarrierSetAssembler_aarch64.hpp b/openjdk/cpu/aarch64/mmtkObjectUnlogBitBarrierSetAssembler_aarch64.hpp
similarity index 92%
rename from openjdk/cpu/aarch64/mmtkUnlogBitBarrierSetAssembler_aarch64.hpp
rename to openjdk/cpu/aarch64/mmtkObjectUnlogBitBarrierSetAssembler_aarch64.hpp
index e6a558c7..2a8557ad 100644
--- a/openjdk/cpu/aarch64/mmtkUnlogBitBarrierSetAssembler_aarch64.hpp
+++ b/openjdk/cpu/aarch64/mmtkObjectUnlogBitBarrierSetAssembler_aarch64.hpp
@@ -9,7 +9,7 @@
 
 //////////////////// Assembler ////////////////////
 
-class MMTkUnlogBitBarrierSetAssembler: public MMTkBarrierSetAssembler {
+class MMTkObjectUnlogBitBarrierSetAssembler: public MMTkBarrierSetAssembler {
 protected:
   static void emit_check_unlog_bit_fast_path(MacroAssembler* masm, Label &done, Register obj, Register tmp1, Register tmp2, Register tmp3);
   static void object_reference_write_pre_or_post(MacroAssembler* masm, DecoratorSet decorators, Address dst, Register val, Register tmp1, Register tmp2, Register tmp3, bool pre);
diff --git a/openjdk/cpu/aarch64/mmtkSATBBarrierSetAssembler_aarch64.hpp b/openjdk/cpu/aarch64/mmtkSATBBarrierSetAssembler_aarch64.hpp
index 4deb12d0..02173f1f 100644
--- a/openjdk/cpu/aarch64/mmtkSATBBarrierSetAssembler_aarch64.hpp
+++ b/openjdk/cpu/aarch64/mmtkSATBBarrierSetAssembler_aarch64.hpp
@@ -2,11 +2,11 @@
 #define MMTK_OPENJDK_MMTK_SATB_BARRIER_SET_ASSEMBLER_AARCH64_HPP
 
 #include "utilities/macros.hpp"
-#include CPU_HEADER(mmtkUnlogBitBarrierSetAssembler)
+#include CPU_HEADER(mmtkObjectUnlogBitBarrierSetAssembler)
 
 //////////////////// Assembler ////////////////////
 
-class MMTkSATBBarrierSetAssembler: public MMTkUnlogBitBarrierSetAssembler {
+class MMTkSATBBarrierSetAssembler: public MMTkObjectUnlogBitBarrierSetAssembler {
 protected:
   virtual void object_reference_write_pre(MacroAssembler* masm, DecoratorSet decorators, Address dst, Register val, Register tmp1, Register tmp2, Register tmp3) const override;
 public:
diff --git a/openjdk/cpu/riscv/mmtkObjectBarrierSetAssembler_riscv.cpp b/openjdk/cpu/riscv/mmtkGenBarrierSetAssembler_riscv.cpp
similarity index 92%
rename from openjdk/cpu/riscv/mmtkObjectBarrierSetAssembler_riscv.cpp
rename to openjdk/cpu/riscv/mmtkGenBarrierSetAssembler_riscv.cpp
index 9c2c761f..132ba8db 100644
--- a/openjdk/cpu/riscv/mmtkObjectBarrierSetAssembler_riscv.cpp
+++ b/openjdk/cpu/riscv/mmtkGenBarrierSetAssembler_riscv.cpp
@@ -30,7 +30,7 @@
 //         li      a1,0
 //         mv      a0,a4
 //         tail    _Z32object_reference_write_slow_callPvS_m
-void MMTkObjectBarrierSetAssembler::object_reference_write_post(MacroAssembler* masm, DecoratorSet decorators, Address dst, Register val, Register tmp1, Register tmp2) const {
+void MMTkGenBarrierSetAssembler::object_reference_write_post(MacroAssembler* masm, DecoratorSet decorators, Address dst, Register val, Register tmp1, Register tmp2) const {
   // tmp1 and tmp2 is from MacroAssembler::access_store_at
   // For do_oop_store, we have three tmps, x28/t3, x29/t4, x13/a3
   // printf("object_reference_write_post\n");
@@ -83,7 +83,7 @@ void MMTkObjectBarrierSetAssembler::object_reference_write_post(MacroAssembler*
   }
 }
 
-void MMTkObjectBarrierSetAssembler::arraycopy_epilogue(MacroAssembler* masm, DecoratorSet decorators, bool is_oop,
+void MMTkGenBarrierSetAssembler::arraycopy_epilogue(MacroAssembler* masm, DecoratorSet decorators, bool is_oop,
                                   Register src, Register dst, Register count, Register tmp, RegSet saved_regs) {
   // see also void G1BarrierSetAssembler::gen_write_ref_array_post_barrier
   assert_different_registers(src, dst, count);
diff --git a/openjdk/cpu/riscv/mmtkObjectBarrierSetAssembler_riscv.hpp b/openjdk/cpu/riscv/mmtkGenBarrierSetAssembler_riscv.hpp
similarity index 89%
rename from openjdk/cpu/riscv/mmtkObjectBarrierSetAssembler_riscv.hpp
rename to openjdk/cpu/riscv/mmtkGenBarrierSetAssembler_riscv.hpp
index ca7a9ca2..ff444876 100644
--- a/openjdk/cpu/riscv/mmtkObjectBarrierSetAssembler_riscv.hpp
+++ b/openjdk/cpu/riscv/mmtkGenBarrierSetAssembler_riscv.hpp
@@ -1,7 +1,7 @@
 #ifndef MMTK_OPENJDK_MMTK_OBJECT_BARRIER_SET_ASSEMBLER_RISCV_HPP
 #define MMTK_OPENJDK_MMTK_OBJECT_BARRIER_SET_ASSEMBLER_RISCV_HPP
 
-class MMTkObjectBarrierSetAssembler: public MMTkBarrierSetAssembler {
+class MMTkGenBarrierSetAssembler: public MMTkBarrierSetAssembler {
 protected:
   virtual void object_reference_write_post(MacroAssembler* masm, DecoratorSet decorators, Address dst, Register val, Register tmp1, Register tmp2) const override;
 public:
diff --git a/openjdk/cpu/x86/mmtkObjectBarrierSetAssembler_x86.cpp b/openjdk/cpu/x86/mmtkGenBarrierSetAssembler_x86.cpp
similarity index 78%
rename from openjdk/cpu/x86/mmtkObjectBarrierSetAssembler_x86.cpp
rename to openjdk/cpu/x86/mmtkGenBarrierSetAssembler_x86.cpp
index 474d958a..ddd32cac 100644
--- a/openjdk/cpu/x86/mmtkObjectBarrierSetAssembler_x86.cpp
+++ b/openjdk/cpu/x86/mmtkGenBarrierSetAssembler_x86.cpp
@@ -6,12 +6,12 @@
 
 #define __ masm->
 
-void MMTkObjectBarrierSetAssembler::object_reference_write_post(MacroAssembler* masm, DecoratorSet decorators, Address dst, Register val, Register tmp1, Register tmp2, Register tmp3, bool compensate_val_reg) const {
+void MMTkGenBarrierSetAssembler::object_reference_write_post(MacroAssembler* masm, DecoratorSet decorators, Address dst, Register val, Register tmp1, Register tmp2, Register tmp3, bool compensate_val_reg) const {
   if (can_remove_barrier(decorators, val, /* skip_const_null */ true)) return;
   object_reference_write_pre_or_post(masm, decorators, dst, val, tmp1, tmp2, tmp3, /* pre = */ false);
 }
 
-void MMTkObjectBarrierSetAssembler::arraycopy_prologue(MacroAssembler* masm, DecoratorSet decorators, BasicType type, Register src, Register dst, Register count) {
+void MMTkGenBarrierSetAssembler::arraycopy_prologue(MacroAssembler* masm, DecoratorSet decorators, BasicType type, Register src, Register dst, Register count) {
   // `count` or `dst` register values may get overwritten after the array copy, and `arraycopy_epilogue` can receive invalid addresses.
   // Save the register values here and restore them in `arraycopy_epilogue`.
   // See https://github.com/openjdk/jdk/blob/jdk-11%2B19/src/hotspot/cpu/x86/gc/shared/modRefBarrierSetAssembler_x86.cpp#L37-L50
@@ -31,7 +31,7 @@ void MMTkObjectBarrierSetAssembler::arraycopy_prologue(MacroAssembler* masm, Dec
   }
 }
 
-void MMTkObjectBarrierSetAssembler::arraycopy_epilogue(MacroAssembler* masm, DecoratorSet decorators, BasicType type, Register src, Register dst, Register count) {
+void MMTkGenBarrierSetAssembler::arraycopy_epilogue(MacroAssembler* masm, DecoratorSet decorators, BasicType type, Register src, Register dst, Register count) {
   bool checkcast = (decorators & ARRAYCOPY_CHECKCAST) != 0;
   bool disjoint = (decorators & ARRAYCOPY_DISJOINT) != 0;
   bool obj_int = type == T_OBJECT LP64_ONLY(&& UseCompressedOops);
diff --git a/openjdk/cpu/x86/mmtkObjectBarrierSetAssembler_x86.hpp b/openjdk/cpu/x86/mmtkGenBarrierSetAssembler_x86.hpp
similarity index 85%
rename from openjdk/cpu/x86/mmtkObjectBarrierSetAssembler_x86.hpp
rename to openjdk/cpu/x86/mmtkGenBarrierSetAssembler_x86.hpp
index 2f294cfc..0f897c97 100644
--- a/openjdk/cpu/x86/mmtkObjectBarrierSetAssembler_x86.hpp
+++ b/openjdk/cpu/x86/mmtkGenBarrierSetAssembler_x86.hpp
@@ -2,11 +2,11 @@
 #define MMTK_OPENJDK_MMTK_OBJECT_BARRIER_SET_ASSEMBLER_X86_HPP
 
 #include "utilities/macros.hpp"
-#include CPU_HEADER(mmtkUnlogBitBarrierSetAssembler)
+#include CPU_HEADER(mmtkObjectUnlogBitBarrierSetAssembler)
 
 //////////////////// Assembler ////////////////////
 
-class MMTkObjectBarrierSetAssembler: public MMTkUnlogBitBarrierSetAssembler {
+class MMTkGenBarrierSetAssembler: public MMTkObjectUnlogBitBarrierSetAssembler {
 protected:
   virtual void object_reference_write_post(MacroAssembler* masm, DecoratorSet decorators, Address dst, Register val, Register tmp1, Register tmp2, Register tmp3, bool compensate_val_reg) const override;
 public:
diff --git a/openjdk/cpu/x86/mmtkUnlogBitBarrierSetAssembler_x86.cpp b/openjdk/cpu/x86/mmtkObjectUnlogBitBarrierSetAssembler_x86.cpp
similarity index 81%
rename from openjdk/cpu/x86/mmtkUnlogBitBarrierSetAssembler_x86.cpp
rename to openjdk/cpu/x86/mmtkObjectUnlogBitBarrierSetAssembler_x86.cpp
index 8f472d9a..1c349469 100644
--- a/openjdk/cpu/x86/mmtkUnlogBitBarrierSetAssembler_x86.cpp
+++ b/openjdk/cpu/x86/mmtkObjectUnlogBitBarrierSetAssembler_x86.cpp
@@ -4,7 +4,7 @@
 #include "c1/c1_MacroAssembler.hpp"
 
 #include "utilities/macros.hpp"
-#include CPU_HEADER(mmtkUnlogBitBarrierSetAssembler)
+#include CPU_HEADER(mmtkObjectUnlogBitBarrierSetAssembler)
 
 #include <cstdint>
 
@@ -12,7 +12,7 @@
 
 #define __ masm->
 
-void MMTkUnlogBitBarrierSetAssembler::emit_check_unlog_bit_fast_path(MacroAssembler* masm, Label &done, Register obj, Register tmp1, Register tmp2, Register tmp3) {
+void MMTkObjectUnlogBitBarrierSetAssembler::emit_check_unlog_bit_fast_path(MacroAssembler* masm, Label &done, Register obj, Register tmp1, Register tmp2, Register tmp3) {
   // Note that `tmp1` and `tmp2` are actual temporary registers available for use,
   // not the `tmp1` and `tmp2` from `store_at`.
   assert_different_registers(obj, tmp1, tmp2, tmp3);
@@ -39,7 +39,7 @@ void MMTkUnlogBitBarrierSetAssembler::emit_check_unlog_bit_fast_path(MacroAssemb
 
 #define __ masm->
 
-void MMTkUnlogBitBarrierSetAssembler::object_reference_write_pre_or_post(MacroAssembler* masm, DecoratorSet decorators, Address dst, Register val, Register tmp1, Register tmp2, Register tmp3, bool pre) {
+void MMTkObjectUnlogBitBarrierSetAssembler::object_reference_write_pre_or_post(MacroAssembler* masm, DecoratorSet decorators, Address dst, Register val, Register tmp1, Register tmp2, Register tmp3, bool pre) {
   Label done;
   Register obj = dst.base();
   if (mmtk_enable_barrier_fastpath) {
@@ -86,7 +86,7 @@ void MMTkUnlogBitBarrierSetAssembler::object_reference_write_pre_or_post(MacroAs
 
 #define __ ce->masm()->
 
-void MMTkUnlogBitBarrierSetAssembler::generate_c1_unlog_bit_barrier_slow_path_stub(LIR_Assembler* ce, MMTkC1UnlogBitBarrierSlowPathStub* stub) const {
+void MMTkObjectUnlogBitBarrierSetAssembler::generate_c1_unlog_bit_barrier_slow_path_stub(LIR_Assembler* ce, MMTkC1UnlogBitBarrierSlowPathStub* stub) const {
   MMTkBarrierSetC1* bs = (MMTkBarrierSetC1*) BarrierSet::barrier_set()->barrier_set_c1();
   __ bind(*stub->entry());
   ce->store_parameter(stub->src->as_pointer_register(), 0);
@@ -100,7 +100,7 @@ void MMTkUnlogBitBarrierSetAssembler::generate_c1_unlog_bit_barrier_slow_path_st
 }
 
 void MMTkC1UnlogBitBarrierSlowPathStub::emit_code(LIR_Assembler* ce) {
-  MMTkUnlogBitBarrierSetAssembler* bs = (MMTkUnlogBitBarrierSetAssembler*) BarrierSet::barrier_set()->barrier_set_assembler();
+  MMTkObjectUnlogBitBarrierSetAssembler* bs = (MMTkObjectUnlogBitBarrierSetAssembler*) BarrierSet::barrier_set()->barrier_set_assembler();
   bs->generate_c1_unlog_bit_barrier_slow_path_stub(ce, this);
 }
 
diff --git a/openjdk/cpu/x86/mmtkUnlogBitBarrierSetAssembler_x86.hpp b/openjdk/cpu/x86/mmtkObjectUnlogBitBarrierSetAssembler_x86.hpp
similarity index 92%
rename from openjdk/cpu/x86/mmtkUnlogBitBarrierSetAssembler_x86.hpp
rename to openjdk/cpu/x86/mmtkObjectUnlogBitBarrierSetAssembler_x86.hpp
index 1d9f87bf..b774e174 100644
--- a/openjdk/cpu/x86/mmtkUnlogBitBarrierSetAssembler_x86.hpp
+++ b/openjdk/cpu/x86/mmtkObjectUnlogBitBarrierSetAssembler_x86.hpp
@@ -9,7 +9,7 @@
 
 //////////////////// Assembler ////////////////////
 
-class MMTkUnlogBitBarrierSetAssembler: public MMTkBarrierSetAssembler {
+class MMTkObjectUnlogBitBarrierSetAssembler: public MMTkBarrierSetAssembler {
 protected:
   static void emit_check_unlog_bit_fast_path(MacroAssembler* masm, Label &done, Register obj, Register tmp1, Register tmp2, Register tmp3);
   static void object_reference_write_pre_or_post(MacroAssembler* masm, DecoratorSet decorators, Address dst, Register val, Register tmp1, Register tmp2, Register tmp3, bool pre);
diff --git a/openjdk/cpu/x86/mmtkSATBBarrierSetAssembler_x86.hpp b/openjdk/cpu/x86/mmtkSATBBarrierSetAssembler_x86.hpp
index 5e977b8b..49e2875d 100644
--- a/openjdk/cpu/x86/mmtkSATBBarrierSetAssembler_x86.hpp
+++ b/openjdk/cpu/x86/mmtkSATBBarrierSetAssembler_x86.hpp
@@ -2,11 +2,11 @@
 #define MMTK_OPENJDK_MMTK_SATB_BARRIER_SET_ASSEMBLER_X86_HPP
 
 #include "utilities/macros.hpp"
-#include CPU_HEADER(mmtkUnlogBitBarrierSetAssembler)
+#include CPU_HEADER(mmtkObjectUnlogBitBarrierSetAssembler)
 
 //////////////////// Assembler ////////////////////
 
-class MMTkSATBBarrierSetAssembler: public MMTkUnlogBitBarrierSetAssembler {
+class MMTkSATBBarrierSetAssembler: public MMTkObjectUnlogBitBarrierSetAssembler {
 protected:
   virtual void object_reference_write_pre(MacroAssembler* masm, DecoratorSet decorators, Address dst, Register val, Register tmp1, Register tmp2, Register tmp3) const override;
 public:
diff --git a/openjdk/cpu/zero/mmtkObjectBarrierSetAssembler_zero.hpp b/openjdk/cpu/zero/mmtkGenBarrierSetAssembler_zero.hpp
similarity index 84%
rename from openjdk/cpu/zero/mmtkObjectBarrierSetAssembler_zero.hpp
rename to openjdk/cpu/zero/mmtkGenBarrierSetAssembler_zero.hpp
index 7fbfd37b..06fe2a00 100644
--- a/openjdk/cpu/zero/mmtkObjectBarrierSetAssembler_zero.hpp
+++ b/openjdk/cpu/zero/mmtkGenBarrierSetAssembler_zero.hpp
@@ -1,5 +1,5 @@
 #ifndef MMTK_OPENJDK_MMTK_OBJECT_BARRIER_SET_ASSEMBLER_ZERO_HPP
 #define MMTK_OPENJDK_MMTK_OBJECT_BARRIER_SET_ASSEMBLER_ZERO_HPP
 
-class MMTkObjectBarrierSetAssembler;
+class MMTkGenBarrierSetAssembler;
 #endif // MMTK_OPENJDK_MMTK_OBJECT_BARRIER_SET_ASSEMBLER_ZERO_HPP
diff --git a/openjdk/share/barriers/mmtkObjectBarrier.hpp b/openjdk/share/barriers/mmtkObjectBarrier.hpp
index 14af6d8b..c2e7d138 100644
--- a/openjdk/share/barriers/mmtkObjectBarrier.hpp
+++ b/openjdk/share/barriers/mmtkObjectBarrier.hpp
@@ -5,7 +5,7 @@
 #include "../mmtkBarrierSet.hpp"
 #include "utilities/macros.hpp"
 #include CPU_HEADER(mmtkBarrierSetAssembler)
-#include CPU_HEADER(mmtkObjectBarrierSetAssembler)
+#include CPU_HEADER(mmtkGenBarrierSetAssembler)
 #include "mmtkUnlogBitBarrier.hpp"
 #ifdef COMPILER1
 #include "../mmtkBarrierSetC1.hpp"
@@ -67,7 +67,7 @@ class MMTkObjectBarrierSetC2;
 
 struct MMTkObjectBarrier: MMTkBarrierImpl<
   MMTkObjectBarrierSetRuntime,
-  MMTkObjectBarrierSetAssembler,
+  MMTkGenBarrierSetAssembler,
   MMTkObjectBarrierSetC1,
   MMTkObjectBarrierSetC2
 > {};