src/hotspot/cpu/sparc/templateTable_sparc.cpp

rev 47680 : [mq]: x86_tlab
rev 47682 : [mq]: sparc2

@@ -3256,15 +3256,22 @@
   // make sure klass does not have has_finalizer, or is abstract, or interface or java/lang/Class
   __ btst(Klass::_lh_instance_slow_path_bit, Roffset);
   __ br(Assembler::notZero, false, Assembler::pn, slow_case);
   __ delayed()->nop();
 
-  // allocate the instance
-  // 1) Try to allocate in the TLAB
-  // 2) if fail, and the TLAB is not full enough to discard, allocate in the shared Eden
-  // 3) if the above fails (or is not applicable), go to a slow case
-  // (creates a new TLAB, etc.)
+  // Allocate the instance:
+  // 1) If TLAB is enabled:
+  //  a) Try to allocate in the TLAB
+  //  b) If fails, go to the slow path.
+  // 2) Else TLAB is disabled:
+  //  a) If inline contiguous allocations are enabled:
+  //    i) Try to allocate in eden
+  //    ii) If fails due to heap end, go to slow path.
+  // 3) If TLAB is enabled OR inline contiguous is enabled:
+  //  a) Initialize the allocation
+  //  b) Exit.
+  // 4) If neither 1 OR 2 are applicable, go to slow path.
 
   const bool allow_shared_alloc =
     Universe::heap()->supports_inline_contig_alloc();
 
   if(UseTLAB) {

@@ -3288,34 +3295,13 @@
       // initialize both the header and fields
       __ brx(Assembler::lessEqualUnsigned, true, Assembler::pt, initialize_object);
     }
     __ delayed()->st_ptr(RnewTopValue, G2_thread, in_bytes(JavaThread::tlab_top_offset()));
 
-    if (allow_shared_alloc) {
-      // Check if tlab should be discarded (refill_waste_limit >= free)
-      __ ld_ptr(G2_thread, in_bytes(JavaThread::tlab_refill_waste_limit_offset()), RtlabWasteLimitValue);
-      __ sub(RendValue, RoldTopValue, RfreeValue);
-      __ srlx(RfreeValue, LogHeapWordSize, RfreeValue);
-      __ cmp_and_brx_short(RtlabWasteLimitValue, RfreeValue, Assembler::greaterEqualUnsigned, Assembler::pt, slow_case); // tlab waste is small
-
-      // increment waste limit to prevent getting stuck on this slow path
-      if (Assembler::is_simm13(ThreadLocalAllocBuffer::refill_waste_limit_increment())) {
-        __ add(RtlabWasteLimitValue, ThreadLocalAllocBuffer::refill_waste_limit_increment(), RtlabWasteLimitValue);
-      } else {
-        // set64 does not use the temp register if the given constant is 32 bit. So
-        // we can just use any register; using G0 results in ignoring of the upper 32 bit
-        // of that value.
-        __ set64(ThreadLocalAllocBuffer::refill_waste_limit_increment(), G4_scratch, G0);
-        __ add(RtlabWasteLimitValue, G4_scratch, RtlabWasteLimitValue);
-      }
-      __ st_ptr(RtlabWasteLimitValue, G2_thread, in_bytes(JavaThread::tlab_refill_waste_limit_offset()));
-    } else {
-      // No allocation in the shared eden.
+    // Allocation does not fit in the TLAB.
       __ ba_short(slow_case);
-    }
-  }
-
+  } else {
   // Allocation in the shared Eden
   if (allow_shared_alloc) {
     Register RoldTopValue = G1_scratch;
     Register RtopAddr = G3_scratch;
     Register RnewTopValue = RallocatedObject;

@@ -3341,12 +3327,15 @@
 
     // bump total bytes allocated by this thread
     // RoldTopValue and RtopAddr are dead, so can use G1 and G3
     __ incr_allocated_bytes(Roffset, G1_scratch, G3_scratch);
   }
+  }
 
-  if (UseTLAB || Universe::heap()->supports_inline_contig_alloc()) {
+  // If UseTLAB or allow_shared_alloc are true, the object is created above and
+  // there is an initialize need. Otherwise, skip and go to the slow path.
+  if (UseTLAB || allow_shared_alloc) {
     // clear object fields
     __ bind(initialize_object);
     __ deccc(Roffset, sizeof(oopDesc));
     __ br(Assembler::zero, false, Assembler::pt, initialize_header);
     __ delayed()->add(RallocatedObject, sizeof(oopDesc), G3_scratch);