8373266: Strengthen constant CardTable base accesses

Reviewed-by: tschatzl, xpeng

src/hotspot/cpu/aarch64/macroAssembler_aarch64.cpp

@@ -5606,12 +5606,11 @@ void MacroAssembler::adrp(Register reg1, const Address &dest, uint64_t &byte_off
 }
 
 void MacroAssembler::load_byte_map_base(Register reg) {
-  CardTable::CardValue* byte_map_base =
-    ((CardTableBarrierSet*)(BarrierSet::barrier_set()))->card_table()->byte_map_base();
+  CardTableBarrierSet* ctbs = CardTableBarrierSet::barrier_set();
 
-  // Strictly speaking the byte_map_base isn't an address at all, and it might
+  // Strictly speaking the card table base isn't an address at all, and it might
   // even be negative. It is thus materialised as a constant.
-  mov(reg, (uint64_t)byte_map_base);
+  mov(reg, (uint64_t)ctbs->card_table_base_const());
 }
 
 void MacroAssembler::build_frame(int framesize) {

src/hotspot/cpu/arm/gc/shared/cardTableBarrierSetAssembler_arm.cpp

@@ -67,9 +67,7 @@ void CardTableBarrierSetAssembler::store_at(MacroAssembler* masm, DecoratorSet d
 void CardTableBarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators,
                                                                     Register addr, Register count, Register tmp) {
   BLOCK_COMMENT("CardTablePostBarrier");
-  BarrierSet* bs = BarrierSet::barrier_set();
-  CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs);
-  CardTable* ct = ctbs->card_table();
+  CardTableBarrierSet* ctbs = CardTableBarrierSet::barrier_set();
 
   Label L_cardtable_loop, L_done;
 
@@ -83,7 +81,7 @@ void CardTableBarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembl
   __ sub(count, count, addr); // nb of cards
 
   // warning: Rthread has not been preserved
-  __ mov_address(tmp, (address) ct->byte_map_base());
+  __ mov_address(tmp, (address)ctbs->card_table_base_const());
   __ add(addr,tmp, addr);
 
   Register zero = __ zero_register(tmp);
@@ -122,8 +120,7 @@ void CardTableBarrierSetAssembler::store_check_part1(MacroAssembler* masm, Regis
   assert(bs->kind() == BarrierSet::CardTableBarrierSet,
          "Wrong barrier set kind");
 
-  CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs);
-  CardTable* ct = ctbs->card_table();
+  CardTableBarrierSet* ctbs = CardTableBarrierSet::barrier_set();
 
   // Load card table base address.
 
@@ -140,7 +137,7 @@ void CardTableBarrierSetAssembler::store_check_part1(MacroAssembler* masm, Regis
      Possible cause is a cache miss (card table base address resides in a
      rarely accessed area of thread descriptor).
   */
-  __ mov_address(card_table_base, (address)ct->byte_map_base());
+  __ mov_address(card_table_base, (address)ctbs->card_table_base_const());
 }
 
 // The 2nd part of the store check.
@@ -170,8 +167,8 @@ void CardTableBarrierSetAssembler::store_check_part2(MacroAssembler* masm, Regis
 
 void CardTableBarrierSetAssembler::set_card(MacroAssembler* masm, Register card_table_base, Address card_table_addr, Register tmp) {
   CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
-  CardTable* ct = ctbs->card_table();
-  if ((((uintptr_t)ct->byte_map_base() & 0xff) == 0)) {
+
+  if ((((uintptr_t)ctbs->card_table_base_const() & 0xff) == 0)) {
     // Card table is aligned so the lowest byte of the table address base is zero.
     // This works only if the code is not saved for later use, possibly
     // in a context where the base would no longer be aligned.

src/hotspot/cpu/ppc/gc/shared/cardTableBarrierSetAssembler_ppc.cpp

@@ -103,8 +103,7 @@ void CardTableBarrierSetAssembler::resolve_jobject(MacroAssembler* masm, Registe
 
 void CardTableBarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators, Register addr,
                                                                     Register count, Register preserve) {
-  CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
-  CardTable* ct = ctbs->card_table();
+  CardTableBarrierSet* ctbs = CardTableBarrierSet::barrier_set();
   assert_different_registers(addr, count, R0);
 
   Label Lskip_loop, Lstore_loop;
@@ -117,7 +116,7 @@ void CardTableBarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembl
   __ srdi(addr, addr, CardTable::card_shift());
   __ srdi(count, count, CardTable::card_shift());
   __ subf(count, addr, count);
-  __ add_const_optimized(addr, addr, (address)ct->byte_map_base(), R0);
+  __ add_const_optimized(addr, addr, (address)ctbs->card_table_base_const(), R0);
   __ addi(count, count, 1);
   __ li(R0, 0);
   __ mtctr(count);
@@ -140,8 +139,8 @@ void CardTableBarrierSetAssembler::card_table_write(MacroAssembler* masm,
 }
 
 void CardTableBarrierSetAssembler::card_write_barrier_post(MacroAssembler* masm, Register store_addr, Register tmp) {
-  CardTableBarrierSet* bs = barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
-  card_table_write(masm, bs->card_table()->byte_map_base(), tmp, store_addr);
+  CardTableBarrierSet* bs = CardTableBarrierSet::barrier_set();
+  card_table_write(masm, bs->card_table_base_const(), tmp, store_addr);
 }
 
 void CardTableBarrierSetAssembler::oop_store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,

src/hotspot/cpu/ppc/gc/shenandoah/shenandoahBarrierSetAssembler_ppc.cpp

@@ -771,9 +771,6 @@ void ShenandoahBarrierSetAssembler::cmpxchg_oop(MacroAssembler *masm, Register b
 void ShenandoahBarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators,
                                                                      Register addr, Register count, Register preserve) {
   assert(ShenandoahCardBarrier, "Should have been checked by caller");
-
-  ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
-  CardTable* ct = bs->card_table();
   assert_different_registers(addr, count, R0);
 
   Label L_skip_loop, L_store_loop;

src/hotspot/cpu/riscv/macroAssembler_riscv.cpp

@@ -5110,9 +5110,8 @@ void MacroAssembler::get_thread(Register thread) {
 }
 
 void MacroAssembler::load_byte_map_base(Register reg) {
-  CardTable::CardValue* byte_map_base =
-    ((CardTableBarrierSet*)(BarrierSet::barrier_set()))->card_table()->byte_map_base();
-  mv(reg, (uint64_t)byte_map_base);
+  CardTableBarrierSet* ctbs = CardTableBarrierSet::barrier_set();
+  mv(reg, (uint64_t)ctbs->card_table_base_const());
 }
 
 void MacroAssembler::build_frame(int framesize) {

src/hotspot/cpu/s390/gc/shared/cardTableBarrierSetAssembler_s390.cpp

@@ -83,8 +83,7 @@ void CardTableBarrierSetAssembler::resolve_jobject(MacroAssembler* masm, Registe
 
 void CardTableBarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators, Register addr, Register count,
                                                                     bool do_return) {
-  CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
-  CardTable* ct = ctbs->card_table();
+  CardTableBarrierSet* ctbs = CardTableBarrierSet::barrier_set();
 
   NearLabel doXC, done;
   assert_different_registers(Z_R0, Z_R1, addr, count);
@@ -105,7 +104,7 @@ void CardTableBarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembl
   __ add2reg_with_index(count, -BytesPerHeapOop, count, addr);
 
   // Get base address of card table.
-  __ load_const_optimized(Z_R1, (address)ct->byte_map_base());
+  __ load_const_optimized(Z_R1, (address)ctbs->card_table_base_const());
 
   // count = (count>>shift) - (addr>>shift)
   __ z_srlg(addr,  addr,  CardTable::card_shift());
@@ -179,13 +178,12 @@ void CardTableBarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembl
 void CardTableBarrierSetAssembler::store_check(MacroAssembler* masm, Register store_addr, Register tmp) {
   // Does a store check for the oop in register obj. The content of
   // register obj is destroyed afterwards.
-  CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
-  CardTable* ct = ctbs->card_table();
+  CardTableBarrierSet* ctbs = CardTableBarrierSet::barrier_set();
 
   assert_different_registers(store_addr, tmp);
 
   __ z_srlg(store_addr, store_addr, CardTable::card_shift());
-  __ load_absolute_address(tmp, (address)ct->byte_map_base());
+  __ load_absolute_address(tmp, (address)ctbs->card_table_base_const());
   __ z_agr(store_addr, tmp);
   __ z_mvi(0, store_addr, CardTable::dirty_card_val());
 }

src/hotspot/cpu/x86/gc/shared/cardTableBarrierSetAssembler_x86.cpp

@@ -95,11 +95,7 @@ void CardTableBarrierSetAssembler::store_at(MacroAssembler* masm, DecoratorSet d
 
 void CardTableBarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators,
                                                                     Register addr, Register count, Register tmp) {
-  BarrierSet *bs = BarrierSet::barrier_set();
-  CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs);
-  CardTable* ct = ctbs->card_table();
-  intptr_t disp = (intptr_t) ct->byte_map_base();
-  SHENANDOAHGC_ONLY(assert(!UseShenandoahGC, "Shenandoah byte_map_base is not constant.");)
+  CardTableBarrierSet* ctbs = CardTableBarrierSet::barrier_set();
 
   Label L_loop, L_done;
   const Register end = count;
@@ -115,7 +111,7 @@ void CardTableBarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembl
   __ shrptr(end, CardTable::card_shift());
   __ subptr(end, addr); // end --> cards count
 
-  __ mov64(tmp, disp);
+  __ mov64(tmp, (intptr_t)ctbs->card_table_base_const());
   __ addptr(addr, tmp);
 __ BIND(L_loop);
   __ movb(Address(addr, count, Address::times_1), 0);
@@ -128,10 +124,7 @@ __ BIND(L_done);
 void CardTableBarrierSetAssembler::store_check(MacroAssembler* masm, Register obj, Address dst) {
   // Does a store check for the oop in register obj. The content of
   // register obj is destroyed afterwards.
-  BarrierSet* bs = BarrierSet::barrier_set();
-
-  CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs);
-  CardTable* ct = ctbs->card_table();
+  CardTableBarrierSet* ctbs = CardTableBarrierSet::barrier_set();
 
   __ shrptr(obj, CardTable::card_shift());
 
@@ -142,7 +135,7 @@ void CardTableBarrierSetAssembler::store_check(MacroAssembler* masm, Register ob
   // So this essentially converts an address to a displacement and it will
   // never need to be relocated. On 64bit however the value may be too
   // large for a 32bit displacement.
-  intptr_t byte_map_base = (intptr_t)ct->byte_map_base();
+  intptr_t byte_map_base = (intptr_t)ctbs->card_table_base_const();
   if (__ is_simm32(byte_map_base)) {
     card_addr = Address(noreg, obj, Address::times_1, byte_map_base);
   } else {

src/hotspot/os_cpu/linux_arm/javaThread_linux_arm.cpp

@@ -43,7 +43,8 @@ void JavaThread::cache_global_variables() {
   BarrierSet* bs = BarrierSet::barrier_set();
 
   if (bs->is_a(BarrierSet::CardTableBarrierSet)) {
-    _card_table_base = (address) (barrier_set_cast<CardTableBarrierSet>(bs)->card_table()->byte_map_base());
+    CardTableBarrierSet* ctbs = CardTableBarrierSet::barrier_set();
+    _card_table_base = (address)ctbs->card_table_base_const();
   } else {
     _card_table_base = nullptr;
   }

src/hotspot/share/ci/ciUtilities.cpp

@@ -42,10 +42,7 @@ const char* basictype_to_str(BasicType t) {
 
 // ------------------------------------------------------------------
 // card_table_base
-CardTable::CardValue* ci_card_table_address() {
-  BarrierSet* bs = BarrierSet::barrier_set();
-  CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs);
-  CardTable* ct = ctbs->card_table();
-  assert(!UseShenandoahGC, "Shenandoah byte_map_base is not constant.");
-  return ct->byte_map_base();
+CardTable::CardValue* ci_card_table_address_const() {
+  CardTableBarrierSet* ctbs = CardTableBarrierSet::barrier_set();
+  return ctbs->card_table_base_const();
 }

src/hotspot/share/ci/ciUtilities.hpp

@@ -51,9 +51,9 @@ inline const char* bool_to_str(bool b) {
 
 const char* basictype_to_str(BasicType t);
 
-CardTable::CardValue* ci_card_table_address();
+CardTable::CardValue* ci_card_table_address_const();
 template <typename T> T ci_card_table_address_as() {
-  return reinterpret_cast<T>(ci_card_table_address());
+  return reinterpret_cast<T>(ci_card_table_address_const());
 }
 
 #endif // SHARE_CI_CIUTILITIES_HPP

src/hotspot/share/compiler/disassembler.cpp

@@ -607,10 +607,27 @@ void decode_env::print_address(address adr) {
       return;
     }
 
+    address card_table_base = nullptr;
     BarrierSet* bs = BarrierSet::barrier_set();
-    if (bs->is_a(BarrierSet::CardTableBarrierSet) &&
-        adr == ci_card_table_address_as<address>()) {
-      st->print("word_map_base");
+#if INCLUDE_G1GC
+    if (bs->is_a(BarrierSet::G1BarrierSet)) {
+      G1BarrierSet* g1bs = barrier_set_cast<G1BarrierSet>(bs);
+      card_table_base = g1bs->card_table()->byte_map_base();
+    } else
+#endif
+#if INCLUDE_SHENANDOAHGC
+    if (bs->is_a(BarrierSet::ShenandoahBarrierSet)) {
+      ShenandoahBarrierSet* sbs = barrier_set_cast<ShenandoahBarrierSet>(bs);
+      if (sbs->card_table() != nullptr) {
+        card_table_base = sbs->card_table()->byte_map_base();
+      }
+    } else
+#endif
+    if (bs->is_a(BarrierSet::CardTableBarrierSet)) {
+      card_table_base = ci_card_table_address_as<address>();
+    }
+    if (card_table_base != nullptr && adr == card_table_base) {
+      st->print("card_table_base");
       if (WizardMode) st->print(" " INTPTR_FORMAT, p2i(adr));
       return;
     }

src/hotspot/share/gc/shared/c1/cardTableBarrierSetC1.cpp

@@ -104,11 +104,8 @@ void CardTableBarrierSetC1::post_barrier(LIRAccess& access, LIR_Opr addr, LIR_Op
     return;
   }
 
-  BarrierSet* bs = BarrierSet::barrier_set();
-  CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs);
-  CardTable* ct = ctbs->card_table();
-  LIR_Const* card_table_base = new LIR_Const(ct->byte_map_base());
-  SHENANDOAHGC_ONLY(assert(!UseShenandoahGC, "Shenandoah byte_map_base is not constant.");)
+  CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
+  LIR_Const* card_table_base = new LIR_Const(ctbs->card_table_base_const());
 
   if (addr->is_address()) {
     LIR_Address* address = addr->as_address_ptr();

src/hotspot/share/gc/shared/c2/cardTableBarrierSetC2.cpp

@@ -116,7 +116,7 @@ Node* CardTableBarrierSetC2::atomic_xchg_at_resolved(C2AtomicParseAccess& access
 
 Node* CardTableBarrierSetC2::byte_map_base_node(GraphKit* kit) const {
   // Get base of card map
-  CardTable::CardValue* card_table_base = ci_card_table_address();
+  CardTable::CardValue* card_table_base = ci_card_table_address_const();
    if (card_table_base != nullptr) {
      return kit->makecon(TypeRawPtr::make((address)card_table_base));
    } else {

src/hotspot/share/gc/shared/cardTableBarrierSet.hpp

@@ -27,6 +27,7 @@
 
 #include "gc/shared/barrierSet.hpp"
 #include "gc/shared/cardTable.hpp"
+#include "gc/shared/gc_globals.hpp"
 #include "memory/memRegion.hpp"
 #include "utilities/align.hpp"
 
@@ -60,6 +61,10 @@ public:
   CardTableBarrierSet(CardTable* card_table);
   virtual ~CardTableBarrierSet();
 
+  inline static CardTableBarrierSet* barrier_set() {
+    return barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
+  }
+
   template <DecoratorSet decorators, typename T>
   inline void write_ref_field_pre(T* addr) {}
 
@@ -86,6 +91,10 @@ public:
   inline void write_ref_array(HeapWord* start, size_t count);
 
   CardTable* card_table() const { return _card_table; }
+  CardValue* card_table_base_const() const {
+    assert(UseSerialGC || UseParallelGC, "Only these GCs have constant card table base");
+    return _card_table->byte_map_base();
+  }
 
   virtual void on_slowpath_allocation_exit(JavaThread* thread, oop new_obj);
 

src/hotspot/share/jvmci/jvmciCompilerToVMInit.cpp

@@ -236,16 +236,23 @@ void CompilerToVM::Data::initialize(JVMCI_TRAPS) {
   JVMTI_ONLY( _should_notify_object_alloc = &JvmtiExport::_should_notify_object_alloc; )
 
   BarrierSet* bs = BarrierSet::barrier_set();
+#if INCLUDE_G1GC
+  if (bs->is_a(BarrierSet::G1BarrierSet)) {
+    cardtable_start_address = nullptr;
+    cardtable_shift = CardTable::card_shift();
+  } else
+#endif
+#if INCLUDE_SHENANDOAHGC
+  if (bs->is_a(BarrierSet::ShenandoahBarrierSet)) {
+    cardtable_start_address = nullptr;
+    cardtable_shift = CardTable::card_shift();
+  } else
+#endif
   if (bs->is_a(BarrierSet::CardTableBarrierSet)) {
-    CardTable::CardValue* base = ci_card_table_address();
+    CardTable::CardValue* base = ci_card_table_address_const();
     assert(base != nullptr, "unexpected byte_map_base");
     cardtable_start_address = base;
     cardtable_shift = CardTable::card_shift();
-#if INCLUDE_SHENANDOAHGC
-  } else if (bs->is_a(BarrierSet::ShenandoahBarrierSet)) {
-    cardtable_start_address = nullptr;
-    cardtable_shift = CardTable::card_shift();
-#endif
   } else {
     // No card mark barriers
     cardtable_start_address = nullptr;