VM: Load allocation-top and -end via Thread.

runtime/vm/assembler_arm64.cc

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // NOLINT
 #if defined(TARGET_ARCH_ARM64)
 
 #include "vm/assembler.h"
 #include "vm/cpu.h"
 #include "vm/longjump.h"
@@ skipping 1313 matching lines @@
 void Assembler::TryAllocate(const Class& cls,
                             Label* failure,
                             Register instance_reg,
                             Register temp_reg,
                             Register pp) {
   ASSERT(failure != NULL);
   if (FLAG_inline_alloc) {
     // If this allocation is traced, program will jump to failure path
     // (i.e. the allocation stub) which will allocate the object and trace the
     // allocation call site.
-    MaybeTraceAllocation(cls.id(), temp_reg, pp, failure);
+    MaybeTraceAllocation(cls.id(), temp_reg, pp, failure,
+                         /* inline_isolate = */ false);
     const intptr_t instance_size = cls.instance_size();
-    Heap* heap = Isolate::Current()->heap();
-    Heap::Space space = heap->SpaceForAllocation(cls.id());
-    const uword top_address = heap->TopAddress(space);
-    LoadImmediate(temp_reg, top_address, pp);
-    ldr(instance_reg, Address(temp_reg));
+    Heap::Space space = Heap::SpaceForAllocation(cls.id());
+    ldr(temp_reg, Address(THR, Thread::heap_offset()));
+    ldr(instance_reg, Address(temp_reg, Heap::TopOffset(space)));
     // TODO(koda): Protect against unsigned overflow here.
     AddImmediateSetFlags(instance_reg, instance_reg, instance_size, pp);
 
     // instance_reg: potential next object start.
-    const uword end_address = heap->EndAddress(space);
-    ASSERT(top_address < end_address);
-    // Could use ldm to load (top, end), but no benefit seen experimentally.
-    ldr(TMP, Address(temp_reg, end_address - top_address));
+    ldr(TMP, Address(temp_reg, Heap::EndOffset(space)));
     CompareRegisters(TMP, instance_reg);
     // fail if heap end unsigned less than or equal to instance_reg.
     b(failure, LS);
 
     // Successfully allocated the object, now update top to point to
     // next object start and store the class in the class field of object.
-    str(instance_reg, Address(temp_reg));
+    str(instance_reg, Address(temp_reg, Heap::TopOffset(space)));
 
     ASSERT(instance_size >= kHeapObjectTag);
     AddImmediate(
         instance_reg, instance_reg, -instance_size + kHeapObjectTag, pp);
-    UpdateAllocationStats(cls.id(), pp, space);
+    UpdateAllocationStats(cls.id(), pp, space, /* inline_isolate = */ false);
 
     uword tags = 0;
     tags = RawObject::SizeTag::update(instance_size, tags);
     ASSERT(cls.id() != kIllegalCid);
     tags = RawObject::ClassIdTag::update(cls.id(), tags);
     LoadImmediate(TMP, tags, pp);
     StoreFieldToOffset(TMP, instance_reg, Object::tags_offset(), pp);
   } else {
     b(failure);
   }
 }
 
 
 void Assembler::TryAllocateArray(intptr_t cid,
                                  intptr_t instance_size,
                                  Label* failure,
                                  Register instance,
                                  Register end_address,
                                  Register temp1,
                                  Register temp2) {
   if (FLAG_inline_alloc) {
     // If this allocation is traced, program will jump to failure path
     // (i.e. the allocation stub) which will allocate the object and trace the
     // allocation call site.
-    MaybeTraceAllocation(cid, temp1, PP, failure);
-    Isolate* isolate = Isolate::Current();
-    Heap* heap = isolate->heap();
-    Heap::Space space = heap->SpaceForAllocation(cid);
-    LoadImmediate(temp1, heap->TopAddress(space), PP);
-    ldr(instance, Address(temp1, 0));  // Potential new object start.
+    MaybeTraceAllocation(cid, temp1, PP, failure, /* inline_isolate = */ false);
+    Heap::Space space = Heap::SpaceForAllocation(cid);
+    ldr(temp1, Address(THR, Thread::heap_offset()));
+    // Potential new object start.
+    ldr(instance, Address(temp1, Heap::TopOffset(space)));
     AddImmediateSetFlags(end_address, instance, instance_size, PP);
     b(failure, CS);  // Fail on unsigned overflow.
 
     // Check if the allocation fits into the remaining space.
     // instance: potential new object start.
     // end_address: potential next object start.
-    LoadImmediate(temp2, heap->EndAddress(space), PP);
-    ldr(temp2, Address(temp2, 0));
+    ldr(temp2, Address(temp1, Heap::EndOffset(space)));
     cmp(end_address, Operand(temp2));
     b(failure, CS);
 
     // Successfully allocated the object(s), now update top to point to
     // next object start and initialize the object.
-    str(end_address, Address(temp1, 0));
+    str(end_address, Address(temp1, Heap::TopOffset(space)));
     add(instance, instance, Operand(kHeapObjectTag));
     LoadImmediate(temp2, instance_size, PP);
-    UpdateAllocationStatsWithSize(cid, temp2, PP, space);
+    UpdateAllocationStatsWithSize(cid, temp2, PP, space,
+                                  /* inline_isolate = */ false);
 
     // Initialize the tags.
     // instance: new object start as a tagged pointer.
     uword tags = 0;
     tags = RawObject::ClassIdTag::update(cid, tags);
     tags = RawObject::SizeTag::update(instance_size, tags);
     LoadImmediate(temp2, tags, PP);
     str(temp2, FieldAddress(instance, Array::tags_offset()));  // Store tags.
   } else {
     b(failure);
@@ skipping 37 matching lines @@
     add(base, array, Operand(index, LSL, shift));
   }
   const OperandSize size = Address::OperandSizeFor(cid);
   ASSERT(Address::CanHoldOffset(offset, Address::Offset, size));
   return Address(base, offset, Address::Offset, size);
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64