8293353: [BACKOUT] G1: Remove redundant is-marking-active checks in C1 barrier

Reviewed-by: kbarrett, mdoerr, tschatzl

Author: albertnetymk

src/hotspot/cpu/aarch64/gc/g1/g1BarrierSetAssembler_aarch64.cpp

@@ -380,6 +380,15 @@ void G1BarrierSetAssembler::generate_c1_pre_barrier_runtime_stub(StubAssembler*
   Label done;
   Label runtime;
 
+  // Is marking still active?
+  if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {
+    __ ldrw(tmp, in_progress);
+  } else {
+    assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
+    __ ldrb(tmp, in_progress);
+  }
+  __ cbzw(tmp, done);
+
   // Can we store original value in the thread's buffer?
   __ ldr(tmp, queue_index);
   __ cbz(tmp, runtime);

src/hotspot/cpu/arm/gc/g1/g1BarrierSetAssembler_arm.cpp

@@ -382,6 +382,11 @@ void G1BarrierSetAssembler::generate_c1_pre_barrier_runtime_stub(StubAssembler*
   Label done;
   Label runtime;
 
+  // Is marking still active?
+  assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
+  __ ldrb(R1, queue_active);
+  __ cbz(R1, done);
+
   __ ldr(r_index_1, queue_index);
   __ ldr(r_pre_val_0, Address(SP, nb_saved_regs*wordSize));
   __ ldr(r_buffer_2, buffer);

src/hotspot/cpu/ppc/gc/g1/g1BarrierSetAssembler_ppc.cpp

@@ -469,6 +469,16 @@ void G1BarrierSetAssembler::generate_c1_pre_barrier_runtime_stub(StubAssembler*
   __ std(tmp, -16, R1_SP);
   __ std(tmp2, -24, R1_SP);
 
+  // Is marking still active?
+  if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {
+    __ lwz(tmp, satb_q_active_byte_offset, R16_thread);
+  } else {
+    assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
+    __ lbz(tmp, satb_q_active_byte_offset, R16_thread);
+  }
+  __ cmpdi(CCR0, tmp, 0);
+  __ beq(CCR0, marking_not_active);
+
   __ bind(restart);
   // Load the index into the SATB buffer. SATBMarkQueue::_index is a
   // size_t so ld_ptr is appropriate.

src/hotspot/cpu/riscv/gc/g1/g1BarrierSetAssembler_riscv.cpp

@@ -369,6 +369,15 @@ void G1BarrierSetAssembler::generate_c1_pre_barrier_runtime_stub(StubAssembler*
   Label done;
   Label runtime;
 
+  // Is marking still active?
+  if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {  // 4-byte width
+    __ lwu(tmp, in_progress);
+  } else {
+    assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
+    __ lbu(tmp, in_progress);
+  }
+  __ beqz(tmp, done);
+
   // Can we store original value in the thread's buffer?
   __ ld(tmp, queue_index);
   __ beqz(tmp, runtime);

src/hotspot/cpu/s390/gc/g1/g1BarrierSetAssembler_s390.cpp

@@ -488,6 +488,15 @@ void G1BarrierSetAssembler::generate_c1_pre_barrier_runtime_stub(StubAssembler*
   __ z_stg(tmp,  0*BytesPerWord + FrameMap::first_available_sp_in_frame, Z_SP);
   __ z_stg(tmp2, 1*BytesPerWord + FrameMap::first_available_sp_in_frame, Z_SP);
 
+  // Is marking still active?
+  if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {
+    __ load_and_test_int(tmp, Address(Z_thread, satb_q_active_byte_offset));
+  } else {
+    assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
+    __ load_and_test_byte(tmp, Address(Z_thread, satb_q_active_byte_offset));
+  }
+  __ z_bre(marking_not_active); // Activity indicator is zero, so there is no marking going on currently.
+
   __ bind(restart);
   // Load the index into the SATB buffer. SATBMarkQueue::_index is a
   // size_t so ld_ptr is appropriate.

src/hotspot/cpu/x86/gc/g1/g1BarrierSetAssembler_x86.cpp

@@ -468,6 +468,15 @@ void G1BarrierSetAssembler::generate_c1_pre_barrier_runtime_stub(StubAssembler*
   Label done;
   Label runtime;
 
+  // Is marking still active?
+  if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {
+    __ cmpl(queue_active, 0);
+  } else {
+    assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
+    __ cmpb(queue_active, 0);
+  }
+  __ jcc(Assembler::equal, done);
+
   // Can we store original value in the thread's buffer?
 
   __ movptr(tmp, queue_index);