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

runtime/vm/intrinsifier_ia32.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.
 //
 // The intrinsic code below is executed before a method has built its frame.
 // The return address is on the stack and the arguments below it.
 // Registers EDX (arguments descriptor) and ECX (function) must be preserved.
 // Each intrinsification method returns true if the corresponding
 // Dart method was intrinsified.
 
@@ skipping 198 matching lines @@
   if (scale_factor == TIMES_16) {                                              \
     /* double length of array. */                                              \
     __ addl(EDI, EDI);                                                         \
     /* only scale by 8. */                                                     \
     scale_factor = TIMES_8;                                                    \
   }                                                                            \
   const intptr_t fixed_size_plus_alignment_padding =                           \
       sizeof(Raw##type_name) + kObjectAlignment - 1;                           \
   __ leal(EDI, Address(EDI, scale_factor, fixed_size_plus_alignment_padding)); \
   __ andl(EDI, Immediate(-kObjectAlignment));                                  \
-  Heap::Space space = Heap::kNew;                                              \
-  __ movl(ECX, Address(THR, Thread::heap_offset()));                           \
-  __ movl(EAX, Address(ECX, Heap::TopOffset(space)));                          \
+  NOT_IN_PRODUCT(Heap::Space space = Heap::kNew);                              \
+  __ movl(EAX, Address(THR, Thread::top_offset()));                            \
   __ movl(EBX, EAX);                                                           \
                                                                                \
   /* EDI: allocation size. */                                                  \
   __ addl(EBX, EDI);                                                           \
   __ j(CARRY, &fall_through);                                                  \
                                                                                \
   /* Check if the allocation fits into the remaining space. */                 \
   /* EAX: potential new object start. */                                       \
   /* EBX: potential next object start. */                                      \
   /* EDI: allocation size. */                                                  \
-  /* ECX: heap. */                                                             \
-  __ cmpl(EBX, Address(ECX, Heap::EndOffset(space)));                          \
+  __ cmpl(EBX, 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. */                           \
-  __ movl(Address(ECX, Heap::TopOffset(space)), EBX);                          \
+  __ movl(Address(THR, Thread::top_offset()), EBX);                            \
   __ addl(EAX, Immediate(kHeapObjectTag));                                     \
   NOT_IN_PRODUCT(__ UpdateAllocationStatsWithSize(cid, EDI, ECX, space));      \
                                                                                \
   /* Initialize the tags. */                                                   \
   /* EAX: new object start as a tagged pointer. */                             \
   /* EBX: new object end address. */                                           \
   /* EDI: allocation size. */                                                  \
   {                                                                            \
     Label size_tag_overflow, done;                                             \
     __ cmpl(EDI, Immediate(RawObject::SizeTag::kMaxSizeTag));                  \
@@ skipping 1789 matching lines @@
   Label pop_and_fail;
   __ pushl(EDI);  // Preserve length.
   __ SmiUntag(EDI);
   const intptr_t fixed_size_plus_alignment_padding =
       sizeof(RawString) + kObjectAlignment - 1;
   __ leal(EDI, Address(EDI, TIMES_1,
                        fixed_size_plus_alignment_padding));  // EDI is untagged.
   __ andl(EDI, Immediate(-kObjectAlignment));
 
   const intptr_t cid = kOneByteStringCid;
-  Heap::Space space = Heap::kNew;
-  __ movl(ECX, Address(THR, Thread::heap_offset()));
-  __ movl(EAX, Address(ECX, Heap::TopOffset(space)));
+  NOT_IN_PRODUCT(Heap::Space space = Heap::kNew);
+  __ movl(EAX, Address(THR, Thread::top_offset()));
   __ movl(EBX, EAX);
 
   // EDI: allocation size.
   __ addl(EBX, EDI);
   __ j(CARRY, &pop_and_fail);
 
   // Check if the allocation fits into the remaining space.
   // EAX: potential new object start.
   // EBX: potential next object start.
   // EDI: allocation size.
-  // ECX: heap.
-  __ cmpl(EBX, Address(ECX, Heap::EndOffset(space)));
+  __ cmpl(EBX, 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.
-  __ movl(Address(ECX, Heap::TopOffset(space)), EBX);
+  __ movl(Address(THR, Thread::top_offset()), EBX);
   __ addl(EAX, Immediate(kHeapObjectTag));
 
   NOT_IN_PRODUCT(__ UpdateAllocationStatsWithSize(cid, EDI, ECX, space));
 
   // Initialize the tags.
   // EAX: new object start as a tagged pointer.
   // EBX: new object end address.
   // EDI: allocation size.
   {
     Label size_tag_overflow, done;
@@ skipping 263 matching lines @@
   __ movl(Address(THR, Thread::async_stack_trace_offset()), EAX);
   __ LoadObject(EAX, Object::null_object());
   __ ret();
 }
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32