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

runtime/vm/intrinsifier_x64.cc

 // Copyright (c) 2013, 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"  // Needed here to get TARGET_ARCH_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/intrinsifier.h"
 
 #include "vm/assembler.h"
@@ skipping 148 matching lines @@
   if (scale_factor == TIMES_16) {                                              \
     /* double length of array. */                                              \
     __ addq(RDI, RDI);                                                         \
     /* only scale by 8. */                                                     \
     scale_factor = TIMES_8;                                                    \
   }                                                                            \
   const intptr_t fixed_size_plus_alignment_padding =                           \
       sizeof(Raw##type_name) + kObjectAlignment - 1;                           \
   __ leaq(RDI, Address(RDI, scale_factor, fixed_size_plus_alignment_padding)); \
   __ andq(RDI, Immediate(-kObjectAlignment));                                  \
-  Heap::Space space = Heap::kNew;                                              \
-  __ movq(R13, Address(THR, Thread::heap_offset()));                           \
-  __ movq(RAX, Address(R13, Heap::TopOffset(space)));                          \
+  NOT_IN_PRODUCT(Heap::Space space = Heap::kNew);                              \
+  __ movq(RAX, Address(THR, Thread::top_offset()));                            \
   __ movq(RCX, RAX);                                                           \
                                                                                \
   /* RDI: allocation size. */                                                  \
   __ addq(RCX, RDI);                                                           \
   __ j(CARRY, &fall_through);                                                  \
                                                                                \
   /* Check if the allocation fits into the remaining space. */                 \
   /* RAX: potential new object start. */                                       \
   /* RCX: potential next object start. */                                      \
   /* RDI: allocation size. */                                                  \
-  /* R13: heap. */                                                             \
-  __ cmpq(RCX, Address(R13, Heap::EndOffset(space)));                          \
+  __ cmpq(RCX, Address(THR, Thread::end_offset()));                            \
   __ j(ABOVE_EQUAL, &fall_through);                                            \
                                                                                \
   /* Successfully allocated the object(s), now update top to point to */       \
   /* next object start and initialize the object. */                           \
-  __ movq(Address(R13, Heap::TopOffset(space)), RCX);                          \
+  __ movq(Address(THR, Thread::top_offset()), RCX);                            \
   __ addq(RAX, Immediate(kHeapObjectTag));                                     \
   NOT_IN_PRODUCT(__ UpdateAllocationStatsWithSize(cid, RDI, space));           \
   /* Initialize the tags. */                                                   \
   /* RAX: new object start as a tagged pointer. */                             \
   /* RCX: new object end address. */                                           \
   /* RDI: allocation size. */                                                  \
   /* R13: scratch register. */                                                 \
   {                                                                            \
     Label size_tag_overflow, done;                                             \
     __ cmpq(RDI, Immediate(RawObject::SizeTag::kMaxSizeTag));                  \
@@ skipping 1735 matching lines @@
   // return a static zero length string here instead.
   __ j(NOT_ZERO, &not_zero_length);
   __ addq(RDI, Immediate(1));
   __ Bind(&not_zero_length);
   const intptr_t fixed_size_plus_alignment_padding =
       sizeof(RawString) + kObjectAlignment - 1;
   __ addq(RDI, Immediate(fixed_size_plus_alignment_padding));
   __ andq(RDI, Immediate(-kObjectAlignment));
 
   const intptr_t cid = kOneByteStringCid;
-  Heap::Space space = Heap::kNew;
-  __ movq(R13, Address(THR, Thread::heap_offset()));
-  __ movq(RAX, Address(R13, Heap::TopOffset(space)));
+  NOT_IN_PRODUCT(Heap::Space space = Heap::kNew);
+  __ movq(RAX, Address(THR, Thread::top_offset()));
 
   // RDI: allocation size.
   __ movq(RCX, RAX);
   __ addq(RCX, RDI);
   __ j(CARRY, &pop_and_fail);
 
   // Check if the allocation fits into the remaining space.
   // RAX: potential new object start.
   // RCX: potential next object start.
   // RDI: allocation size.
-  // R13: heap.
-  __ cmpq(RCX, Address(R13, Heap::EndOffset(space)));
+  __ cmpq(RCX, Address(THR, Thread::end_offset()));
   __ j(ABOVE_EQUAL, &pop_and_fail);
 
   // Successfully allocated the object(s), now update top to point to
   // next object start and initialize the object.
-  __ movq(Address(R13, Heap::TopOffset(space)), RCX);
+  __ movq(Address(THR, Thread::top_offset()), RCX);
   __ addq(RAX, Immediate(kHeapObjectTag));
   NOT_IN_PRODUCT(__ UpdateAllocationStatsWithSize(cid, RDI, space));
 
   // Initialize the tags.
   // RAX: new object start as a tagged pointer.
   // RDI: allocation size.
   {
     Label size_tag_overflow, done;
     __ cmpq(RDI, Immediate(RawObject::SizeTag::kMaxSizeTag));
     __ j(ABOVE, &size_tag_overflow, Assembler::kNearJump);
@@ skipping 249 matching lines @@
   __ movq(Address(THR, Thread::async_stack_trace_offset()), RAX);
   __ LoadObject(RAX, Object::null_object());
   __ ret();
 }
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64