Revert "Moves the top_ and end_ words of the Scavenger into mutator thread."

runtime/vm/stub_code_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"
 #if defined(TARGET_ARCH_ARM64)
 
 #include "vm/assembler.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
@@ skipping 703 matching lines @@
 
   // Check for maximum allowed length.
   const intptr_t max_len =
       reinterpret_cast<intptr_t>(Smi::New(Array::kMaxElements));
   __ CompareImmediate(R2, max_len);
   __ b(&slow_case, GT);
 
   const intptr_t cid = kArrayCid;
   NOT_IN_PRODUCT(__ MaybeTraceAllocation(kArrayCid, R4, &slow_case));
 
-  NOT_IN_PRODUCT(Heap::Space space = Heap::kNew);
+  Heap::Space space = Heap::kNew;
+  __ ldr(R8, Address(THR, Thread::heap_offset()));
 
   // Calculate and align allocation size.
   // Load new object start and calculate next object start.
   // R1: array element type.
   // R2: array length as Smi.
-  __ ldr(R0, Address(THR, Thread::top_offset()));
+  // R8: heap.
+  __ LoadFromOffset(R0, R8, Heap::TopOffset(space));
   intptr_t fixed_size_plus_alignment_padding =
       sizeof(RawArray) + kObjectAlignment - 1;
   __ LoadImmediate(R3, fixed_size_plus_alignment_padding);
   __ add(R3, R3, Operand(R2, LSL, 2));  // R2 is Smi.
   ASSERT(kSmiTagShift == 1);
   __ andi(R3, R3, Immediate(~(kObjectAlignment - 1)));
   // R0: potential new object start.
   // R3: object size in bytes.
   __ adds(R7, R3, Operand(R0));
   __ b(&slow_case, CS);  // Branch if unsigned overflow.
 
   // Check if the allocation fits into the remaining space.
   // R0: potential new object start.
   // R1: array element type.
   // R2: array length as Smi.
   // R3: array size.
   // R7: potential next object start.
-  __ LoadFromOffset(TMP, THR, Thread::end_offset());
+  // R8: heap.
+  __ LoadFromOffset(TMP, R8, Heap::EndOffset(space));
   __ CompareRegisters(R7, TMP);
   __ b(&slow_case, CS);  // Branch if unsigned higher or equal.
 
   // Successfully allocated the object(s), now update top to point to
   // next object start and initialize the object.
   // R0: potential new object start.
   // R3: array size.
   // R7: potential next object start.
-  __ str(R7, Address(THR, Thread::top_offset()));
+  // R8: heap.
+  __ StoreToOffset(R7, R8, Heap::TopOffset(space));
   __ add(R0, R0, Operand(kHeapObjectTag));
   NOT_IN_PRODUCT(__ UpdateAllocationStatsWithSize(cid, R3, space));
 
   // R0: new object start as a tagged pointer.
   // R1: array element type.
   // R2: array length as Smi.
   // R3: array size.
   // R7: new object end address.
 
   // Store the type argument field.
@@ skipping 211 matching lines @@
     __ LoadImmediate(R2, fixed_size_plus_alignment_padding);
     __ add(R2, R2, Operand(R1, LSL, 3));
     ASSERT(kSmiTagShift == 1);
     __ andi(R2, R2, Immediate(~(kObjectAlignment - 1)));
 
     NOT_IN_PRODUCT(__ MaybeTraceAllocation(kContextCid, R4, &slow_case));
     // Now allocate the object.
     // R1: number of context variables.
     // R2: object size.
     const intptr_t cid = kContextCid;
-    NOT_IN_PRODUCT(Heap::Space space = Heap::kNew);
-    __ ldr(R0, Address(THR, Thread::top_offset()));
+    Heap::Space space = Heap::kNew;
+    __ ldr(R5, Address(THR, Thread::heap_offset()));
+    __ ldr(R0, Address(R5, Heap::TopOffset(space)));
     __ add(R3, R2, Operand(R0));
     // Check if the allocation fits into the remaining space.
     // R0: potential new object.
     // R1: number of context variables.
     // R2: object size.
     // R3: potential next object start.
-    __ ldr(TMP, Address(THR, Thread::end_offset()));
+    // R5: heap.
+    __ ldr(TMP, Address(R5, Heap::EndOffset(space)));
     __ CompareRegisters(R3, TMP);
     if (FLAG_use_slow_path) {
       __ b(&slow_case);
     } else {
       __ b(&slow_case, CS);  // Branch if unsigned higher or equal.
     }
 
     // Successfully allocated the object, now update top to point to
     // next object start and initialize the object.
     // R0: new object.
     // R1: number of context variables.
     // R2: object size.
     // R3: next object start.
-    __ str(R3, Address(THR, Thread::top_offset()));
+    // R5: heap.
+    __ str(R3, Address(R5, Heap::TopOffset(space)));
     __ add(R0, R0, Operand(kHeapObjectTag));
     NOT_IN_PRODUCT(__ UpdateAllocationStatsWithSize(cid, R2, space));
 
     // Calculate the size tag.
     // R0: new object.
     // R1: number of context variables.
     // R2: object size.
     const intptr_t shift = RawObject::kSizeTagPos - kObjectAlignmentLog2;
     __ CompareImmediate(R2, RawObject::SizeTag::kMaxSizeTag);
     // If no size tag overflow, shift R2 left, else set R2 to zero.
@@ skipping 140 matching lines @@
     __ ldr(R1, Address(SP));
     // R1: instantiated type arguments.
   }
   Isolate* isolate = Isolate::Current();
   if (FLAG_inline_alloc && Heap::IsAllocatableInNewSpace(instance_size) &&
       !cls.TraceAllocation(isolate)) {
     Label slow_case;
     // Allocate the object and update top to point to
     // next object start and initialize the allocated object.
     // R1: instantiated type arguments (if is_cls_parameterized).
-    NOT_IN_PRODUCT(Heap::Space space = Heap::kNew);
-    __ ldr(R2, Address(THR, Thread::top_offset()));
+    Heap::Space space = Heap::kNew;
+    __ ldr(R5, Address(THR, Thread::heap_offset()));
+    __ ldr(R2, Address(R5, Heap::TopOffset(space)));
     __ AddImmediate(R3, R2, instance_size);
     // Check if the allocation fits into the remaining space.
     // R2: potential new object start.
     // R3: potential next object start.
-    __ ldr(TMP, Address(THR, Thread::end_offset()));
+    // R5: heap.
+    __ ldr(TMP, Address(R5, Heap::EndOffset(space)));
     __ CompareRegisters(R3, TMP);
     if (FLAG_use_slow_path) {
       __ b(&slow_case);
     } else {
       __ b(&slow_case, CS);  // Unsigned higher or equal.
     }
-    __ str(R3, Address(THR, Thread::top_offset()));
+    __ str(R3, Address(R5, Heap::TopOffset(space)));
     NOT_IN_PRODUCT(__ UpdateAllocationStats(cls.id(), space));
 
     // R2: new object start.
     // R3: next object start.
     // R1: new object type arguments (if is_cls_parameterized).
     // Set the tags.
     uint32_t tags = 0;
     tags = RawObject::SizeTag::update(instance_size, tags);
     ASSERT(cls.id() != kIllegalCid);
     tags = RawObject::ClassIdTag::update(cls.id(), tags);
@@ skipping 1175 matching lines @@
 }
 
 
 void StubCode::GenerateAsynchronousGapMarkerStub(Assembler* assembler) {
   __ brk(0);
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64