X64: Optimize access to external references.

src/x64/macro-assembler-x64.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 26 matching lines @@
 #include "debug.h"
 #include "heap.h"
 
 namespace v8 {
 namespace internal {
 
 MacroAssembler::MacroAssembler(void* buffer, int size)
     : Assembler(buffer, size),
       generating_stub_(false),
       allow_stub_calls_(true),
+      root_array_available_(true),
       code_object_(HEAP->undefined_value()) {
 }
 
 
+static intptr_t RootRegisterDelta(ExternalReference other) {
+  Address roots_register_value = kRootRegisterBias +
+      reinterpret_cast<Address>(Isolate::Current()->heap()->roots_address());
+  intptr_t delta = other.address() - roots_register_value;
+  return delta;
+}
+
+
+Operand MacroAssembler::ExternalOperand(ExternalReference target,
+                                        Register scratch) {
+  if (root_array_available_ && !Serializer::enabled()) {
+    intptr_t delta = RootRegisterDelta(target);
+    if (is_int32(delta)) {
+      Serializer::TooLateToEnableNow();
+      return Operand(kRootRegister, delta);
+    }
+  }
+  movq(scratch, target);
+  return Operand(scratch, 0);
+}
+
+
+void MacroAssembler::Load(Register destination, ExternalReference source) {
+  if (root_array_available_ && !Serializer::enabled()) {
+    intptr_t delta = RootRegisterDelta(source);
+    if (is_int32(delta)) {
+      Serializer::TooLateToEnableNow();
+      movq(destination, Operand(kRootRegister, static_cast<int32_t>(delta)));
+      return;
+    }
+  }
+  // Safe code.
+  if (destination.is(rax)) {
+    load_rax(source);
+  } else {
+    movq(kScratchRegister, source);
+    movq(destination, Operand(kScratchRegister, 0));
+  }
+}
+
+
+void MacroAssembler::Store(ExternalReference destination, Register source) {
+  if (root_array_available_ && !Serializer::enabled()) {
+    intptr_t delta = RootRegisterDelta(destination);
+    if (is_int32(delta)) {
+      Serializer::TooLateToEnableNow();
+      movq(Operand(kRootRegister, static_cast<int32_t>(delta)), source);
+      return;
+    }
+  }
+  // Safe code.
+  if (source.is(rax)) {
+    store_rax(destination);
+  } else {
+    movq(kScratchRegister, destination);
+    movq(Operand(kScratchRegister, 0), source);
+  }
+}
+
+
+void MacroAssembler::LoadAddress(Register destination,
+                                 ExternalReference source) {
+  if (root_array_available_ && !Serializer::enabled()) {
+    intptr_t delta = RootRegisterDelta(source);
+    if (is_int32(delta)) {
+      Serializer::TooLateToEnableNow();
+      lea(destination, Operand(kRootRegister, static_cast<int32_t>(delta)));
+      return;
+    }
+  }
+  // Safe code.
+  movq(destination, source);
+}
+
+
+int MacroAssembler::LoadAddressSize(ExternalReference source) {
+  if (root_array_available_ && !Serializer::enabled()) {
+    // This calculation depends on the internals of LoadAddress.
+    // It's correctness is ensured by the asserts in the Call
+    // instruction below.
+    intptr_t delta = RootRegisterDelta(source);
+    if (is_int32(delta)) {
+      Serializer::TooLateToEnableNow();
+      // Operand is lea(scratch, Operand(kRootRegister, delta));
+      // Opcodes : REX.W 8D ModRM Disp8/Disp32  - 4 or 7.
+      int size = 4;
+      if (!is_int8(static_cast<int32_t>(delta))) {
+        size += 3;  // Need full four-byte displacement in lea.
+      }
+      return size;
+    }
+  }
+  // Size of movq(destination, src);
+  return 10;
+}
+
+
 void MacroAssembler::LoadRoot(Register destination, Heap::RootListIndex index) {
+  ASSERT(root_array_available_);
   movq(destination, Operand(kRootRegister,
                             (index << kPointerSizeLog2) - kRootRegisterBias));
 }
 
 
 void MacroAssembler::LoadRootIndexed(Register destination,
                                      Register variable_offset,
                                      int fixed_offset) {
+  ASSERT(root_array_available_);
   movq(destination,
        Operand(kRootRegister,
                variable_offset, times_pointer_size,
                (fixed_offset << kPointerSizeLog2) - kRootRegisterBias));
 }
 
 
 void MacroAssembler::StoreRoot(Register source, Heap::RootListIndex index) {
+  ASSERT(root_array_available_);
   movq(Operand(kRootRegister, (index << kPointerSizeLog2) - kRootRegisterBias),
        source);
 }
 
 
 void MacroAssembler::PushRoot(Heap::RootListIndex index) {
+  ASSERT(root_array_available_);
   push(Operand(kRootRegister, (index << kPointerSizeLog2) - kRootRegisterBias));
 }
 
 
 void MacroAssembler::CompareRoot(Register with, Heap::RootListIndex index) {
+  ASSERT(root_array_available_);
   cmpq(with, Operand(kRootRegister,
                      (index << kPointerSizeLog2) - kRootRegisterBias));
 }
 
 
 void MacroAssembler::CompareRoot(const Operand& with,
                                  Heap::RootListIndex index) {
+  ASSERT(root_array_available_);
   ASSERT(!with.AddressUsesRegister(kScratchRegister));
   LoadRoot(kScratchRegister, index);
   cmpq(with, kScratchRegister);
 }
 
 
 void MacroAssembler::RecordWriteHelper(Register object,
                                        Register addr,
                                        Register scratch) {
   if (emit_debug_code()) {
@@ skipping 290 matching lines @@
 
 
 void MacroAssembler::CallRuntime(Runtime::FunctionId id, int num_arguments) {
   CallRuntime(Runtime::FunctionForId(id), num_arguments);
 }
 
 
 void MacroAssembler::CallRuntimeSaveDoubles(Runtime::FunctionId id) {
   const Runtime::Function* function = Runtime::FunctionForId(id);
   Set(rax, function->nargs);
-  movq(rbx, ExternalReference(function));
+  LoadAddress(rbx, ExternalReference(function));
   CEntryStub ces(1);
   ces.SaveDoubles();
   CallStub(&ces);
 }
 
 
 MaybeObject* MacroAssembler::TryCallRuntime(Runtime::FunctionId id,
                                             int num_arguments) {
   return TryCallRuntime(Runtime::FunctionForId(id), num_arguments);
 }
 
 
 void MacroAssembler::CallRuntime(const Runtime::Function* f,
                                  int num_arguments) {
   // If the expected number of arguments of the runtime function is
   // constant, we check that the actual number of arguments match the
   // expectation.
   if (f->nargs >= 0 && f->nargs != num_arguments) {
     IllegalOperation(num_arguments);
     return;
   }
 
   // TODO(1236192): Most runtime routines don't need the number of
   // arguments passed in because it is constant. At some point we
   // should remove this need and make the runtime routine entry code
   // smarter.
   Set(rax, num_arguments);
-  movq(rbx, ExternalReference(f));
+  LoadAddress(rbx, ExternalReference(f));
   CEntryStub ces(f->result_size);
   CallStub(&ces);
 }
 
 
 MaybeObject* MacroAssembler::TryCallRuntime(const Runtime::Function* f,
                                             int num_arguments) {
   if (f->nargs >= 0 && f->nargs != num_arguments) {
     IllegalOperation(num_arguments);
     // Since we did not call the stub, there was no allocation failure.
     // Return some non-failure object.
     return HEAP->undefined_value();
   }
 
   // TODO(1236192): Most runtime routines don't need the number of
   // arguments passed in because it is constant. At some point we
   // should remove this need and make the runtime routine entry code
   // smarter.
   Set(rax, num_arguments);
-  movq(rbx, ExternalReference(f));
+  LoadAddress(rbx, ExternalReference(f));
   CEntryStub ces(f->result_size);
   return TryCallStub(&ces);
 }
 
 
 void MacroAssembler::CallExternalReference(const ExternalReference& ext,
                                            int num_arguments) {
   Set(rax, num_arguments);
-  movq(rbx, ext);
+  LoadAddress(rbx, ext);
 
   CEntryStub stub(1);
   CallStub(&stub);
 }
 
 
 void MacroAssembler::TailCallExternalReference(const ExternalReference& ext,
                                                int num_arguments,
                                                int result_size) {
   // ----------- S t a t e -------------
@@ skipping 140 matching lines @@
   bind(&empty_result);
   // It was zero; the result is undefined.
   Move(rax, FACTORY->undefined_value());
   jmp(&prologue);
 
   // HandleScope limit has changed. Delete allocated extensions.
   bind(&delete_allocated_handles);
   movq(Operand(base_reg, kLimitOffset), prev_limit_reg);
   movq(prev_limit_reg, rax);
 #ifdef _WIN64
-  movq(rcx, ExternalReference::isolate_address());
+  LoadAddress(rcx, ExternalReference::isolate_address());
 #else
-  movq(rdi, ExternalReference::isolate_address());
+  LoadAddress(rdi, ExternalReference::isolate_address());
 #endif
-  movq(rax, ExternalReference::delete_handle_scope_extensions());
+  LoadAddress(rax, ExternalReference::delete_handle_scope_extensions());
   call(rax);
   movq(rax, prev_limit_reg);
   jmp(&leave_exit_frame);
 
   return result;
 }
 
 
 void MacroAssembler::JumpToExternalReference(const ExternalReference& ext,
                                              int result_size) {
   // Set the entry point and jump to the C entry runtime stub.
-  movq(rbx, ext);
+  LoadAddress(rbx, ext);
   CEntryStub ces(result_size);
   jmp(ces.GetCode(), RelocInfo::CODE_TARGET);
 }
 
 
 MaybeObject* MacroAssembler::TryJumpToExternalReference(
     const ExternalReference& ext, int result_size) {
   // Set the entry point and jump to the C entry runtime stub.
-  movq(rbx, ext);
+  LoadAddress(rbx, ext);
   CEntryStub ces(result_size);
   return TryTailCallStub(&ces);
 }
 
 
 void MacroAssembler::InvokeBuiltin(Builtins::JavaScript id,
                                    InvokeFlag flag,
                                    CallWrapper* call_wrapper) {
   // Calls are not allowed in some stubs.
   ASSERT(flag == JUMP_FUNCTION || allow_stub_calls());
@@ skipping 786 matching lines @@
   }
 }
 
 
 void MacroAssembler::Test(const Operand& src, Smi* source) {
   testl(Operand(src, kIntSize), Immediate(source->value()));
 }
 
 
 void MacroAssembler::Jump(ExternalReference ext) {
-  movq(kScratchRegister, ext);
+  LoadAddress(kScratchRegister, ext);
   jmp(kScratchRegister);
 }
 
 
 void MacroAssembler::Jump(Address destination, RelocInfo::Mode rmode) {
   movq(kScratchRegister, destination, rmode);
   jmp(kScratchRegister);
 }
 
 
 void MacroAssembler::Jump(Handle<Code> code_object, RelocInfo::Mode rmode) {
   // TODO(X64): Inline this
   jmp(code_object, rmode);
 }
 
 
+int MacroAssembler::CallSize(ExternalReference ext) {
+  // Opcode for call kScratchRegister is: Rex.B FF D4 (three bytes).
+  const int kCallInstructionSize = 3;
+  return LoadAddressSize(ext) + kCallInstructionSize;
+}
+
+
 void MacroAssembler::Call(ExternalReference ext) {
 #ifdef DEBUG
-  int pre_position = pc_offset();
+  int end_position = pc_offset() + CallSize(ext);
 #endif
-  movq(kScratchRegister, ext);
+  LoadAddress(kScratchRegister, ext);
   call(kScratchRegister);
 #ifdef DEBUG
-  int post_position = pc_offset();
-  CHECK_EQ(pre_position + CallSize(ext), post_position);
+  CHECK_EQ(end_position, pc_offset());
 #endif
 }
 
 
 void MacroAssembler::Call(Address destination, RelocInfo::Mode rmode) {
 #ifdef DEBUG
-  int pre_position = pc_offset();
+  int end_position = pc_offset() + CallSize(destination, rmode);
 #endif
   movq(kScratchRegister, destination, rmode);
   call(kScratchRegister);
 #ifdef DEBUG
-  int post_position = pc_offset();
-  CHECK_EQ(pre_position + CallSize(destination, rmode), post_position);
+  CHECK_EQ(pc_offset(), end_position);
 #endif
 }
 
 
 void MacroAssembler::Call(Handle<Code> code_object, RelocInfo::Mode rmode) {
 #ifdef DEBUG
-  int pre_position = pc_offset();
+  int end_position = pc_offset() + CallSize(code_object);
 #endif
   ASSERT(RelocInfo::IsCodeTarget(rmode));
   call(code_object, rmode);
 #ifdef DEBUG
-  int post_position = pc_offset();
-  CHECK_EQ(pre_position + CallSize(code_object), post_position);
+  CHECK_EQ(end_position, pc_offset());
 #endif
 }
 
 
 void MacroAssembler::Pushad() {
   push(rax);
   push(rcx);
   push(rdx);
   push(rbx);
   // Not pushing rsp or rbp.
@@ skipping 100 matching lines @@
     push(rbp);
   } else {
     ASSERT(try_location == IN_JS_ENTRY);
     // The frame pointer does not point to a JS frame so we save NULL
     // for rbp. We expect the code throwing an exception to check rbp
     // before dereferencing it to restore the context.
     push(Immediate(StackHandler::ENTRY));
     push(Immediate(0));  // NULL frame pointer.
   }
   // Save the current handler.
-  movq(kScratchRegister, ExternalReference(Isolate::k_handler_address));
-  push(Operand(kScratchRegister, 0));
+  Operand handler_operand =
+      ExternalOperand(ExternalReference(Isolate::k_handler_address));
+  push(handler_operand);
   // Link this handler.
-  movq(Operand(kScratchRegister, 0), rsp);
+  movq(handler_operand, rsp);
 }
 
 
 void MacroAssembler::PopTryHandler() {
   ASSERT_EQ(0, StackHandlerConstants::kNextOffset);
   // Unlink this handler.
-  movq(kScratchRegister, ExternalReference(Isolate::k_handler_address));
-  pop(Operand(kScratchRegister, 0));
+  Operand handler_operand =
+      ExternalOperand(ExternalReference(Isolate::k_handler_address));
+  pop(handler_operand);
   // Remove the remaining fields.
   addq(rsp, Immediate(StackHandlerConstants::kSize - kPointerSize));
 }
 
 
 void MacroAssembler::Throw(Register value) {
   // Check that stack should contain next handler, frame pointer, state and
   // return address in that order.
   STATIC_ASSERT(StackHandlerConstants::kFPOffset + kPointerSize ==
             StackHandlerConstants::kStateOffset);
   STATIC_ASSERT(StackHandlerConstants::kStateOffset + kPointerSize ==
             StackHandlerConstants::kPCOffset);
   // Keep thrown value in rax.
   if (!value.is(rax)) {
     movq(rax, value);
   }
 
   ExternalReference handler_address(Isolate::k_handler_address);
-  movq(kScratchRegister, handler_address);
-  movq(rsp, Operand(kScratchRegister, 0));
+  Operand handler_operand = ExternalOperand(handler_address);
+  movq(rsp, handler_operand);
   // get next in chain
-  pop(rcx);
-  movq(Operand(kScratchRegister, 0), rcx);
+  pop(handler_operand);
   pop(rbp);  // pop frame pointer
   pop(rdx);  // remove state
 
   // Before returning we restore the context from the frame pointer if not NULL.
   // The frame pointer is NULL in the exception handler of a JS entry frame.
   Set(rsi, 0);  // Tentatively set context pointer to NULL
   NearLabel skip;
   cmpq(rbp, Immediate(0));
   j(equal, &skip);
   movq(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
   bind(&skip);
   ret(0);
 }
 
 
 void MacroAssembler::ThrowUncatchable(UncatchableExceptionType type,
                                       Register value) {
   // Keep thrown value in rax.
   if (!value.is(rax)) {
     movq(rax, value);
   }
   // Fetch top stack handler.
   ExternalReference handler_address(Isolate::k_handler_address);
-  movq(kScratchRegister, handler_address);
-  movq(rsp, Operand(kScratchRegister, 0));
+  Load(rsp, handler_address);
 
   // Unwind the handlers until the ENTRY handler is found.
   NearLabel loop, done;
   bind(&loop);
   // Load the type of the current stack handler.
   const int kStateOffset = StackHandlerConstants::kStateOffset;
   cmpq(Operand(rsp, kStateOffset), Immediate(StackHandler::ENTRY));
   j(equal, &done);
   // Fetch the next handler in the list.
   const int kNextOffset = StackHandlerConstants::kNextOffset;
   movq(rsp, Operand(rsp, kNextOffset));
   jmp(&loop);
   bind(&done);
 
   // Set the top handler address to next handler past the current ENTRY handler.
-  movq(kScratchRegister, handler_address);
-  pop(Operand(kScratchRegister, 0));
+  Operand handler_operand = ExternalOperand(handler_address);
+  pop(handler_operand);
 
   if (type == OUT_OF_MEMORY) {
     // Set external caught exception to false.
     ExternalReference external_caught(
         Isolate::k_external_caught_exception_address);
     movq(rax, Immediate(false));
-    store_rax(external_caught);
+    Store(external_caught, rax);
 
     // Set pending exception and rax to out of memory exception.
     ExternalReference pending_exception(Isolate::k_pending_exception_address);
     movq(rax, Failure::OutOfMemoryException(), RelocInfo::NONE);
-    store_rax(pending_exception);
+    Store(pending_exception, rax);
   }
 
   // Clear the context pointer.
   Set(rsi, 0);
 
   // Restore registers from handler.
   STATIC_ASSERT(StackHandlerConstants::kNextOffset + kPointerSize ==
-            StackHandlerConstants::kFPOffset);
+                StackHandlerConstants::kFPOffset);
   pop(rbp);  // FP
   STATIC_ASSERT(StackHandlerConstants::kFPOffset + kPointerSize ==
-            StackHandlerConstants::kStateOffset);
+                StackHandlerConstants::kStateOffset);
   pop(rdx);  // State
 
   STATIC_ASSERT(StackHandlerConstants::kStateOffset + kPointerSize ==
-            StackHandlerConstants::kPCOffset);
+                StackHandlerConstants::kPCOffset);
   ret(0);
 }
 
 
 void MacroAssembler::Ret() {
   ret(0);
 }
 
 
 void MacroAssembler::Ret(int bytes_dropped, Register scratch) {
@@ skipping 144 matching lines @@
   bind(&non_instance);
   movq(result, FieldOperand(result, Map::kConstructorOffset));
 
   // All done.
   bind(&done);
 }
 
 
 void MacroAssembler::SetCounter(StatsCounter* counter, int value) {
   if (FLAG_native_code_counters && counter->Enabled()) {
-    movq(kScratchRegister, ExternalReference(counter));
-    movl(Operand(kScratchRegister, 0), Immediate(value));
+    Operand counter_operand = ExternalOperand(ExternalReference(counter));
+    movq(counter_operand, Immediate(value));
   }
 }
 
 
 void MacroAssembler::IncrementCounter(StatsCounter* counter, int value) {
   ASSERT(value > 0);
   if (FLAG_native_code_counters && counter->Enabled()) {
-    movq(kScratchRegister, ExternalReference(counter));
-    Operand operand(kScratchRegister, 0);
+    Operand counter_operand = ExternalOperand(ExternalReference(counter));
     if (value == 1) {
-      incl(operand);
+      incl(counter_operand);
     } else {
-      addl(operand, Immediate(value));
+      addl(counter_operand, Immediate(value));
     }
   }
 }
 
 
 void MacroAssembler::DecrementCounter(StatsCounter* counter, int value) {
   ASSERT(value > 0);
   if (FLAG_native_code_counters && counter->Enabled()) {
-    movq(kScratchRegister, ExternalReference(counter));
-    Operand operand(kScratchRegister, 0);
+    Operand counter_operand = ExternalOperand(ExternalReference(counter));
     if (value == 1) {
-      decl(operand);
+      decl(counter_operand);
     } else {
-      subl(operand, Immediate(value));
+      subl(counter_operand, Immediate(value));
     }
   }
 }
 
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
 void MacroAssembler::DebugBreak() {
   ASSERT(allow_stub_calls());
   Set(rax, 0);  // No arguments.
-  movq(rbx, ExternalReference(Runtime::kDebugBreak));
+  LoadAddress(rbx, ExternalReference(Runtime::kDebugBreak));
   CEntryStub ces(1);
   Call(ces.GetCode(), RelocInfo::DEBUG_BREAK);
 }
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 
 void MacroAssembler::InvokeCode(Register code,
                                 const ParameterCount& expected,
                                 const ParameterCount& actual,
                                 InvokeFlag flag,
@@ skipping 133 matching lines @@
   ASSERT(ExitFrameConstants::kSPOffset == -1 * kPointerSize);
   push(Immediate(0));  // Saved entry sp, patched before call.
   movq(kScratchRegister, CodeObject(), RelocInfo::EMBEDDED_OBJECT);
   push(kScratchRegister);  // Accessed from EditFrame::code_slot.
 
   // Save the frame pointer and the context in top.
   if (save_rax) {
     movq(r14, rax);  // Backup rax in callee-save register.
   }
 
-  movq(kScratchRegister, ExternalReference(Isolate::k_c_entry_fp_address));
-  movq(Operand(kScratchRegister, 0), rbp);
-
-  movq(kScratchRegister, ExternalReference(Isolate::k_context_address));
-  movq(Operand(kScratchRegister, 0), rsi);
+  Store(ExternalReference(Isolate::k_c_entry_fp_address), rbp);
+  Store(ExternalReference(Isolate::k_context_address), rsi);
 }
 
 
 void MacroAssembler::EnterExitFrameEpilogue(int arg_stack_space,
                                             bool save_doubles) {
 #ifdef _WIN64
   const int kShadowSpace = 4;
   arg_stack_space += kShadowSpace;
 #endif
   // Optionally save all XMM registers.
@@ skipping 71 matching lines @@
   movq(rsp, rbp);
   pop(rbp);
 
   LeaveExitFrameEpilogue();
 }
 
 
 void MacroAssembler::LeaveExitFrameEpilogue() {
   // Restore current context from top and clear it in debug mode.
   ExternalReference context_address(Isolate::k_context_address);
-  movq(kScratchRegister, context_address);
-  movq(rsi, Operand(kScratchRegister, 0));
+  Operand context_operand = ExternalOperand(context_address);
+  movq(rsi, context_operand);
 #ifdef DEBUG
-  movq(Operand(kScratchRegister, 0), Immediate(0));
+  movq(context_operand, Immediate(0));
 #endif
 
   // Clear the top frame.
   ExternalReference c_entry_fp_address(Isolate::k_c_entry_fp_address);
-  movq(kScratchRegister, c_entry_fp_address);
-  movq(Operand(kScratchRegister, 0), Immediate(0));
+  Operand c_entry_fp_operand = ExternalOperand(c_entry_fp_address);
+  movq(c_entry_fp_operand, Immediate(0));
 }
 
 
 void MacroAssembler::CheckAccessGlobalProxy(Register holder_reg,
                                             Register scratch,
                                             Label* miss) {
   Label same_contexts;
 
   ASSERT(!holder_reg.is(scratch));
   ASSERT(!scratch.is(kScratchRegister));
@@ skipping 58 matching lines @@
                                              AllocationFlags flags) {
   ExternalReference new_space_allocation_top =
       ExternalReference::new_space_allocation_top_address();
 
   // Just return if allocation top is already known.
   if ((flags & RESULT_CONTAINS_TOP) != 0) {
     // No use of scratch if allocation top is provided.
     ASSERT(!scratch.is_valid());
 #ifdef DEBUG
     // Assert that result actually contains top on entry.
-    movq(kScratchRegister, new_space_allocation_top);
-    cmpq(result, Operand(kScratchRegister, 0));
+    Operand top_operand = ExternalOperand(new_space_allocation_top);
+    cmpq(result, top_operand);
     Check(equal, "Unexpected allocation top");
 #endif
     return;
   }
 
   // Move address of new object to result. Use scratch register if available,
   // and keep address in scratch until call to UpdateAllocationTopHelper.
   if (scratch.is_valid()) {
-    movq(scratch, new_space_allocation_top);
+    LoadAddress(scratch, new_space_allocation_top);
     movq(result, Operand(scratch, 0));
-  } else if (result.is(rax)) {
-    load_rax(new_space_allocation_top);
   } else {
-    movq(kScratchRegister, new_space_allocation_top);
-    movq(result, Operand(kScratchRegister, 0));
+    Load(result, new_space_allocation_top);
   }
 }
 
 
 void MacroAssembler::UpdateAllocationTopHelper(Register result_end,
                                                Register scratch) {
   if (emit_debug_code()) {
     testq(result_end, Immediate(kObjectAlignmentMask));
     Check(zero, "Unaligned allocation in new space");
   }
 
   ExternalReference new_space_allocation_top =
       ExternalReference::new_space_allocation_top_address();
 
   // Update new top.
-  if (result_end.is(rax)) {
-    // rax can be stored directly to a memory location.
-    store_rax(new_space_allocation_top);
+  if (scratch.is_valid()) {
+    // Scratch already contains address of allocation top.
+    movq(Operand(scratch, 0), result_end);
   } else {
-    // Register required - use scratch provided if available.
-    if (scratch.is_valid()) {
-      movq(Operand(scratch, 0), result_end);
-    } else {
-      movq(kScratchRegister, new_space_allocation_top);
-      movq(Operand(kScratchRegister, 0), result_end);
-    }
+    Store(new_space_allocation_top, result_end);
   }
 }
 
 
 void MacroAssembler::AllocateInNewSpace(int object_size,
                                         Register result,
                                         Register result_end,
                                         Register scratch,
                                         Label* gc_required,
                                         AllocationFlags flags) {
@@ skipping 20 matching lines @@
   ExternalReference new_space_allocation_limit =
       ExternalReference::new_space_allocation_limit_address();
 
   Register top_reg = result_end.is_valid() ? result_end : result;
 
   if (!top_reg.is(result)) {
     movq(top_reg, result);
   }
   addq(top_reg, Immediate(object_size));
   j(carry, gc_required);
-  movq(kScratchRegister, new_space_allocation_limit);
-  cmpq(top_reg, Operand(kScratchRegister, 0));
+  Operand limit_operand = ExternalOperand(new_space_allocation_limit);
+  cmpq(top_reg, limit_operand);
   j(above, gc_required);
 
   // Update allocation top.
   UpdateAllocationTopHelper(top_reg, scratch);
 
   if (top_reg.is(result)) {
     if ((flags & TAG_OBJECT) != 0) {
       subq(result, Immediate(object_size - kHeapObjectTag));
     } else {
       subq(result, Immediate(object_size));
@@ skipping 33 matching lines @@
 
   // Calculate new top and bail out if new space is exhausted.
   ExternalReference new_space_allocation_limit =
       ExternalReference::new_space_allocation_limit_address();
 
   // We assume that element_count*element_size + header_size does not
   // overflow.
   lea(result_end, Operand(element_count, element_size, header_size));
   addq(result_end, result);
   j(carry, gc_required);
-  movq(kScratchRegister, new_space_allocation_limit);
-  cmpq(result_end, Operand(kScratchRegister, 0));
+  Operand limit_operand = ExternalOperand(new_space_allocation_limit);
+  cmpq(result_end, limit_operand);
   j(above, gc_required);
 
   // Update allocation top.
   UpdateAllocationTopHelper(result_end, scratch);
 
   // Tag the result if requested.
   if ((flags & TAG_OBJECT) != 0) {
     addq(result, Immediate(kHeapObjectTag));
   }
 }
@@ skipping 24 matching lines @@
   LoadAllocationTopHelper(result, scratch, flags);
 
   // Calculate new top and bail out if new space is exhausted.
   ExternalReference new_space_allocation_limit =
       ExternalReference::new_space_allocation_limit_address();
   if (!object_size.is(result_end)) {
     movq(result_end, object_size);
   }
   addq(result_end, result);
   j(carry, gc_required);
-  movq(kScratchRegister, new_space_allocation_limit);
-  cmpq(result_end, Operand(kScratchRegister, 0));
+  Operand limit_operand = ExternalOperand(new_space_allocation_limit);
+  cmpq(result_end, limit_operand);
   j(above, gc_required);
 
   // Update allocation top.
   UpdateAllocationTopHelper(result_end, scratch);
 
   // Tag the result if requested.
   if ((flags & TAG_OBJECT) != 0) {
     addq(result, Immediate(kHeapObjectTag));
   }
 }
 
 
 void MacroAssembler::UndoAllocationInNewSpace(Register object) {
   ExternalReference new_space_allocation_top =
       ExternalReference::new_space_allocation_top_address();
 
   // Make sure the object has no tag before resetting top.
   and_(object, Immediate(~kHeapObjectTagMask));
-  movq(kScratchRegister, new_space_allocation_top);
+  Operand top_operand = ExternalOperand(new_space_allocation_top);
 #ifdef DEBUG
-  cmpq(object, Operand(kScratchRegister, 0));
+  cmpq(object, top_operand);
   Check(below, "Undo allocation of non allocated memory");
 #endif
-  movq(Operand(kScratchRegister, 0), object);
+  movq(top_operand, object);
 }
 
 
 void MacroAssembler::AllocateHeapNumber(Register result,
                                         Register scratch,
                                         Label* gc_required) {
   // Allocate heap number in new space.
   AllocateInNewSpace(HeapNumber::kSize,
                      result,
                      scratch,
@@ skipping 214 matching lines @@
   int argument_slots_on_stack =
       ArgumentStackSlotsForCFunctionCall(num_arguments);
   subq(rsp, Immediate((argument_slots_on_stack + 1) * kPointerSize));
   and_(rsp, Immediate(-frame_alignment));
   movq(Operand(rsp, argument_slots_on_stack * kPointerSize), kScratchRegister);
 }
 
 
 void MacroAssembler::CallCFunction(ExternalReference function,
                                    int num_arguments) {
-  movq(rax, function);
+  LoadAddress(rax, function);
   CallCFunction(rax, num_arguments);
 }
 
 
 void MacroAssembler::CallCFunction(Register function, int num_arguments) {
   // Pass current isolate address as additional parameter.
   if (num_arguments < kRegisterPassedArguments) {
 #ifdef _WIN64
     // First four arguments are passed in registers on Windows.
     Register arg_to_reg[] = {rcx, rdx, r8, r9};
 #else
     // First six arguments are passed in registers on other platforms.
     Register arg_to_reg[] = {rdi, rsi, rdx, rcx, r8, r9};
 #endif
     Register reg = arg_to_reg[num_arguments];
-    movq(reg, ExternalReference::isolate_address());
+    LoadAddress(reg, ExternalReference::isolate_address());
   } else {
     // Push Isolate pointer after all parameters.
     int argument_slots_on_stack =
         ArgumentStackSlotsForCFunctionCall(num_arguments);
-    movq(kScratchRegister, ExternalReference::isolate_address());
+    LoadAddress(kScratchRegister, ExternalReference::isolate_address());
     movq(Operand(rsp, argument_slots_on_stack * kPointerSize),
          kScratchRegister);
   }
 
   // Check stack alignment.
   if (emit_debug_code()) {
     CheckStackAlignment();
   }
 
   call(function);
@@ skipping 20 matching lines @@
   CPU::FlushICache(address_, size_);
 
   // Check that the code was patched as expected.
   ASSERT(masm_.pc_ == address_ + size_);
   ASSERT(masm_.reloc_info_writer.pos() == address_ + size_ + Assembler::kGap);
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64