--- a/hotspot/src/cpu/sparc/vm/assembler_sparc.cpp	Mon Aug 29 17:42:39 2011 -0700
+++ b/hotspot/src/cpu/sparc/vm/assembler_sparc.cpp	Wed Aug 31 10:16:02 2011 -0700
@@ -2161,29 +2161,6 @@
 #endif
 }
 
-void MacroAssembler::br_on_reg_cond( RCondition rc, bool a, Predict p,
-                                     Register s1, address d,
-                                     relocInfo::relocType rt ) {
-  assert_not_delayed();
-  if (VM_Version::v9_instructions_work()) {
-    bpr(rc, a, p, s1, d, rt);
-  } else {
-    tst(s1);
-    br(reg_cond_to_cc_cond(rc), a, p, d, rt);
-  }
-}
-
-void MacroAssembler::br_on_reg_cond( RCondition rc, bool a, Predict p,
-                                     Register s1, Label& L ) {
-  assert_not_delayed();
-  if (VM_Version::v9_instructions_work()) {
-    bpr(rc, a, p, s1, L);
-  } else {
-    tst(s1);
-    br(reg_cond_to_cc_cond(rc), a, p, L);
-  }
-}
-
 // Compare registers and branch with nop in delay slot or cbcond without delay slot.
 
 // Compare integer (32 bit) values (icc only).
@@ -4340,22 +4317,29 @@
   } else {
     pre_val = O0;
   }
+
   int satb_q_index_byte_offset =
     in_bytes(JavaThread::satb_mark_queue_offset() +
              PtrQueue::byte_offset_of_index());
+
   int satb_q_buf_byte_offset =
     in_bytes(JavaThread::satb_mark_queue_offset() +
              PtrQueue::byte_offset_of_buf());
+
   assert(in_bytes(PtrQueue::byte_width_of_index()) == sizeof(intptr_t) &&
          in_bytes(PtrQueue::byte_width_of_buf()) == sizeof(intptr_t),
          "check sizes in assembly below");
 
   __ bind(restart);
+
+  // Load the index into the SATB buffer. PtrQueue::_index is a size_t
+  // so ld_ptr is appropriate.
   __ ld_ptr(G2_thread, satb_q_index_byte_offset, L0);
 
-  __ br_on_reg_cond(Assembler::rc_z, /*annul*/false, Assembler::pn, L0, refill);
-  // If the branch is taken, no harm in executing this in the delay slot.
-  __ delayed()->ld_ptr(G2_thread, satb_q_buf_byte_offset, L1);
+  // index == 0?
+  __ cmp_and_brx_short(L0, G0, Assembler::equal, Assembler::pn, refill);
+
+  __ ld_ptr(G2_thread, satb_q_buf_byte_offset, L1);
   __ sub(L0, oopSize, L0);
 
   __ st_ptr(pre_val, L1, L0);  // [_buf + index] := I0
@@ -4466,9 +4450,8 @@
          tmp);
   }
 
-  // Check on whether to annul.
-  br_on_reg_cond(rc_z, /*annul*/false, Assembler::pt, tmp, filtered);
-  delayed()->nop();
+  // Is marking active?
+  cmp_and_br_short(tmp, G0, Assembler::equal, Assembler::pt, filtered);
 
   // Do we need to load the previous value?
   if (obj != noreg) {
@@ -4490,9 +4473,7 @@
   assert(pre_val != noreg, "must have a real register");
 
   // Is the previous value null?
-  // Check on whether to annul.
-  br_on_reg_cond(rc_z, /*annul*/false, Assembler::pt, pre_val, filtered);
-  delayed()->nop();
+  cmp_and_brx_short(pre_val, G0, Assembler::equal, Assembler::pt, filtered);
 
   // OK, it's not filtered, so we'll need to call enqueue.  In the normal
   // case, pre_val will be a scratch G-reg, but there are some cases in
@@ -4519,39 +4500,6 @@
   bind(filtered);
 }
 
-static jint num_ct_writes = 0;
-static jint num_ct_writes_filtered_in_hr = 0;
-static jint num_ct_writes_filtered_null = 0;
-static G1CollectedHeap* g1 = NULL;
-
-static Thread* count_ct_writes(void* filter_val, void* new_val) {
-  Atomic::inc(&num_ct_writes);
-  if (filter_val == NULL) {
-    Atomic::inc(&num_ct_writes_filtered_in_hr);
-  } else if (new_val == NULL) {
-    Atomic::inc(&num_ct_writes_filtered_null);
-  } else {
-    if (g1 == NULL) {
-      g1 = G1CollectedHeap::heap();
-    }
-  }
-  if ((num_ct_writes % 1000000) == 0) {
-    jint num_ct_writes_filtered =
-      num_ct_writes_filtered_in_hr +
-      num_ct_writes_filtered_null;
-
-    tty->print_cr("%d potential CT writes: %5.2f%% filtered\n"
-                  "   (%5.2f%% intra-HR, %5.2f%% null).",
-                  num_ct_writes,
-                  100.0*(float)num_ct_writes_filtered/(float)num_ct_writes,
-                  100.0*(float)num_ct_writes_filtered_in_hr/
-                  (float)num_ct_writes,
-                  100.0*(float)num_ct_writes_filtered_null/
-                  (float)num_ct_writes);
-  }
-  return Thread::current();
-}
-
 static address dirty_card_log_enqueue = 0;
 static u_char* dirty_card_log_enqueue_end = 0;
 
@@ -4574,11 +4522,8 @@
   __ set(addrlit, O1); // O1 := <card table base>
   __ ldub(O0, O1, O2); // O2 := [O0 + O1]
 
-  __ br_on_reg_cond(Assembler::rc_nz, /*annul*/false, Assembler::pt,
-                      O2, not_already_dirty);
-  // Get O1 + O2 into a reg by itself -- useful in the take-the-branch
-  // case, harmless if not.
-  __ delayed()->add(O0, O1, O3);
+  assert(CardTableModRefBS::dirty_card_val() == 0, "otherwise check this code");
+  __ cmp_and_br_short(O2, G0, Assembler::notEqual, Assembler::pt, not_already_dirty);
 
   // We didn't take the branch, so we're already dirty: return.
   // Use return-from-leaf
@@ -4587,8 +4532,13 @@
 
   // Not dirty.
   __ bind(not_already_dirty);
+
+  // Get O0 + O1 into a reg by itself
+  __ add(O0, O1, O3);
+
   // First, dirty it.
   __ stb(G0, O3, G0);  // [cardPtr] := 0  (i.e., dirty).
+
   int dirty_card_q_index_byte_offset =
     in_bytes(JavaThread::dirty_card_queue_offset() +
              PtrQueue::byte_offset_of_index());
@@ -4596,12 +4546,15 @@
     in_bytes(JavaThread::dirty_card_queue_offset() +
              PtrQueue::byte_offset_of_buf());
   __ bind(restart);
+
+  // Load the index into the update buffer. PtrQueue::_index is
+  // a size_t so ld_ptr is appropriate here.
   __ ld_ptr(G2_thread, dirty_card_q_index_byte_offset, L0);
 
-  __ br_on_reg_cond(Assembler::rc_z, /*annul*/false, Assembler::pn,
-                      L0, refill);
-  // If the branch is taken, no harm in executing this in the delay slot.
-  __ delayed()->ld_ptr(G2_thread, dirty_card_q_buf_byte_offset, L1);
+  // index == 0?
+  __ cmp_and_brx_short(L0, G0, Assembler::equal, Assembler::pn, refill);
+
+  __ ld_ptr(G2_thread, dirty_card_q_buf_byte_offset, L1);
   __ sub(L0, oopSize, L0);
 
   __ st_ptr(O3, L1, L0);  // [_buf + index] := I0
@@ -4664,6 +4617,7 @@
   G1SATBCardTableModRefBS* bs = (G1SATBCardTableModRefBS*) Universe::heap()->barrier_set();
   assert(bs->kind() == BarrierSet::G1SATBCT ||
          bs->kind() == BarrierSet::G1SATBCTLogging, "wrong barrier");
+
   if (G1RSBarrierRegionFilter) {
     xor3(store_addr, new_val, tmp);
 #ifdef _LP64
@@ -4672,33 +4626,8 @@
     srl(tmp, HeapRegion::LogOfHRGrainBytes, tmp);
 #endif
 
-    if (G1PrintCTFilterStats) {
-      guarantee(tmp->is_global(), "Or stats won't work...");
-      // This is a sleazy hack: I'm temporarily hijacking G2, which I
-      // promise to restore.
-      mov(new_val, G2);
-      save_frame(0);
-      mov(tmp, O0);
-      mov(G2, O1);
-      // Save G-regs that target may use.
-      mov(G1, L1);
-      mov(G2, L2);
-      mov(G3, L3);
-      mov(G4, L4);
-      mov(G5, L5);
-      call(CAST_FROM_FN_PTR(address, &count_ct_writes));
-      delayed()->nop();
-      mov(O0, G2);
-      // Restore G-regs that target may have used.
-      mov(L1, G1);
-      mov(L3, G3);
-      mov(L4, G4);
-      mov(L5, G5);
-      restore(G0, G0, G0);
-    }
-    // XXX Should I predict this taken or not?  Does it mattern?
-    br_on_reg_cond(rc_z, /*annul*/false, Assembler::pt, tmp, filtered);
-    delayed()->nop();
+    // XXX Should I predict this taken or not?  Does it matter?
+    cmp_and_brx_short(tmp, G0, Assembler::equal, Assembler::pt, filtered);
   }
 
   // If the "store_addr" register is an "in" or "local" register, move it to
@@ -4723,7 +4652,6 @@
   restore();
 
   bind(filtered);
-
 }
 
 #endif  // SERIALGC

--- a/hotspot/src/cpu/sparc/vm/assembler_sparc.hpp	Mon Aug 29 17:42:39 2011 -0700
+++ b/hotspot/src/cpu/sparc/vm/assembler_sparc.hpp	Wed Aug 31 10:16:02 2011 -0700
@@ -1940,12 +1940,6 @@
   void br_null   ( Register s1, bool a, Predict p, Label& L );
   void br_notnull( Register s1, bool a, Predict p, Label& L );
 
-  // These versions will do the most efficient thing on v8 and v9.  Perhaps
-  // this is what the routine above was meant to do, but it didn't (and
-  // didn't cover both target address kinds.)
-  void br_on_reg_cond( RCondition c, bool a, Predict p, Register s1, address d, relocInfo::relocType rt = relocInfo::none );
-  void br_on_reg_cond( RCondition c, bool a, Predict p, Register s1, Label& L);
-
   //
   // Compare registers and branch with nop in delay slot or cbcond without delay slot.
   //

--- a/hotspot/src/cpu/sparc/vm/c1_CodeStubs_sparc.cpp	Mon Aug 29 17:42:39 2011 -0700
+++ b/hotspot/src/cpu/sparc/vm/c1_CodeStubs_sparc.cpp	Wed Aug 31 10:16:02 2011 -0700
@@ -421,8 +421,7 @@
   }
 
   if (__ is_in_wdisp16_range(_continuation)) {
-    __ br_on_reg_cond(Assembler::rc_z, /*annul*/false, Assembler::pt,
-                      pre_val_reg, _continuation);
+    __ br_null(pre_val_reg, /*annul*/false, Assembler::pt, _continuation);
   } else {
     __ cmp(pre_val_reg, G0);
     __ brx(Assembler::equal, false, Assembler::pn, _continuation);
@@ -458,8 +457,7 @@
     // The original src operand was not a constant.
     // Generate src == null?
     if (__ is_in_wdisp16_range(_continuation)) {
-      __ br_on_reg_cond(Assembler::rc_z, /*annul*/false, Assembler::pt,
-                        src_reg, _continuation);
+      __ br_null(src_reg, /*annul*/false, Assembler::pt, _continuation);
     } else {
       __ cmp(src_reg, G0);
       __ brx(Assembler::equal, false, Assembler::pt, _continuation);
@@ -476,13 +474,9 @@
   Address ref_type_adr(tmp_reg, instanceKlass::reference_type_offset_in_bytes() + sizeof(oopDesc));
   __ ld(ref_type_adr, tmp_reg);
 
-  if (__ is_in_wdisp16_range(_continuation)) {
-    __ br_on_reg_cond(Assembler::rc_z, /*annul*/false, Assembler::pt,
-                      tmp_reg, _continuation);
-  } else {
-    __ cmp(tmp_reg, G0);
-    __ brx(Assembler::equal, false, Assembler::pt, _continuation);
-  }
+  // _reference_type field is of type ReferenceType (enum)
+  assert(REF_NONE == 0, "check this code");
+  __ cmp_zero_and_br(Assembler::equal, tmp_reg, _continuation, /*annul*/false, Assembler::pt);
   __ delayed()->nop();
 
   // Is marking active?
@@ -498,13 +492,8 @@
     assert(in_bytes(PtrQueue::byte_width_of_active()) == 1, "Assumption");
     __ ldsb(in_progress, tmp_reg);
   }
-  if (__ is_in_wdisp16_range(_continuation)) {
-    __ br_on_reg_cond(Assembler::rc_z, /*annul*/false, Assembler::pt,
-                      tmp_reg, _continuation);
-  } else {
-    __ cmp(tmp_reg, G0);
-    __ brx(Assembler::equal, false, Assembler::pt, _continuation);
-  }
+
+  __ cmp_zero_and_br(Assembler::equal, tmp_reg, _continuation, /*annul*/false, Assembler::pt);
   __ delayed()->nop();
 
   // val == null?
@@ -512,8 +501,7 @@
   Register val_reg = val()->as_register();
 
   if (__ is_in_wdisp16_range(_continuation)) {
-    __ br_on_reg_cond(Assembler::rc_z, /*annul*/false, Assembler::pt,
-                      val_reg, _continuation);
+    __ br_null(val_reg, /*annul*/false, Assembler::pt, _continuation);
   } else {
     __ cmp(val_reg, G0);
     __ brx(Assembler::equal, false, Assembler::pt, _continuation);
@@ -542,9 +530,9 @@
   assert(new_val()->is_register(), "Precondition.");
   Register addr_reg = addr()->as_pointer_register();
   Register new_val_reg = new_val()->as_register();
+
   if (__ is_in_wdisp16_range(_continuation)) {
-    __ br_on_reg_cond(Assembler::rc_z, /*annul*/false, Assembler::pt,
-                      new_val_reg, _continuation);
+    __ br_null(new_val_reg, /*annul*/false, Assembler::pt, _continuation);
   } else {
     __ cmp(new_val_reg, G0);
     __ brx(Assembler::equal, false, Assembler::pn, _continuation);

--- a/hotspot/src/cpu/sparc/vm/c1_Runtime1_sparc.cpp	Mon Aug 29 17:42:39 2011 -0700
+++ b/hotspot/src/cpu/sparc/vm/c1_Runtime1_sparc.cpp	Wed Aug 31 10:16:02 2011 -0700
@@ -834,14 +834,16 @@
         int satb_q_buf_byte_offset =
           in_bytes(JavaThread::satb_mark_queue_offset() +
                    PtrQueue::byte_offset_of_buf());
+
         __ bind(restart);
+        // Load the index into the SATB buffer. PtrQueue::_index is a
+        // size_t so ld_ptr is appropriate
         __ ld_ptr(G2_thread, satb_q_index_byte_offset, tmp);
 
-        __ br_on_reg_cond(Assembler::rc_z, /*annul*/false,
-                          Assembler::pn, tmp, refill);
+        // index == 0?
+        __ cmp_and_brx_short(tmp, G0, Assembler::equal, Assembler::pn, refill);
 
-        // If the branch is taken, no harm in executing this in the delay slot.
-        __ delayed()->ld_ptr(G2_thread, satb_q_buf_byte_offset, tmp2);
+        __ ld_ptr(G2_thread, satb_q_buf_byte_offset, tmp2);
         __ sub(tmp, oopSize, tmp);
 
         __ st_ptr(pre_val, tmp2, tmp);  // [_buf + index] := <address_of_card>
@@ -901,11 +903,8 @@
         __ set(rs, cardtable);         // cardtable := <card table base>
         __ ldub(addr, cardtable, tmp); // tmp := [addr + cardtable]
 
-        __ br_on_reg_cond(Assembler::rc_nz, /*annul*/false, Assembler::pt,
-                          tmp, not_already_dirty);
-        // Get cardtable + tmp into a reg by itself -- useful in the take-the-branch
-        // case, harmless if not.
-        __ delayed()->add(addr, cardtable, tmp2);
+        assert(CardTableModRefBS::dirty_card_val() == 0, "otherwise check this code");
+        __ cmp_and_br_short(tmp, G0, Assembler::notEqual, Assembler::pt, not_already_dirty);
 
         // We didn't take the branch, so we're already dirty: return.
         // Use return-from-leaf
@@ -914,6 +913,10 @@
 
         // Not dirty.
         __ bind(not_already_dirty);
+
+        // Get cardtable + tmp into a reg by itself
+        __ add(addr, cardtable, tmp2);
+
         // First, dirty it.
         __ stb(G0, tmp2, 0);  // [cardPtr] := 0  (i.e., dirty).
 
@@ -929,13 +932,17 @@
         int dirty_card_q_buf_byte_offset =
           in_bytes(JavaThread::dirty_card_queue_offset() +
                    PtrQueue::byte_offset_of_buf());
+
         __ bind(restart);
+
+        // Get the index into the update buffer. PtrQueue::_index is
+        // a size_t so ld_ptr is appropriate here.
         __ ld_ptr(G2_thread, dirty_card_q_index_byte_offset, tmp3);
 
-        __ br_on_reg_cond(Assembler::rc_z, /*annul*/false, Assembler::pn,
-                          tmp3, refill);
-        // If the branch is taken, no harm in executing this in the delay slot.
-        __ delayed()->ld_ptr(G2_thread, dirty_card_q_buf_byte_offset, tmp4);
+        // index == 0?
+        __ cmp_and_brx_short(tmp3, G0, Assembler::equal,  Assembler::pn, refill);
+
+        __ ld_ptr(G2_thread, dirty_card_q_buf_byte_offset, tmp4);
         __ sub(tmp3, oopSize, tmp3);
 
         __ st_ptr(tmp2, tmp4, tmp3);  // [_buf + index] := <address_of_card>

--- a/hotspot/src/share/vm/gc_implementation/g1/g1_globals.hpp	Mon Aug 29 17:42:39 2011 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1_globals.hpp	Wed Aug 31 10:16:02 2011 -0700
@@ -124,9 +124,6 @@
   develop(bool, G1RSBarrierNullFilter, true,                                \
           "If true, generate null-pointer filtering code in RS barrier")    \
                                                                             \
-  develop(bool, G1PrintCTFilterStats, false,                                \
-          "If true, print stats on RS filtering effectiveness")             \
-                                                                            \
   develop(bool, G1DeferredRSUpdate, true,                                   \
           "If true, use deferred RS updates")                               \
                                                                             \