Clean up handling of global cell stores in the optimizing compiler.

src/x64/lithium-codegen-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 2010 matching lines @@
 
   __ Move(rcx, instr->name());
   RelocInfo::Mode mode = instr->for_typeof() ? RelocInfo::CODE_TARGET :
                                                RelocInfo::CODE_TARGET_CONTEXT;
   Handle<Code> ic = isolate()->builtins()->LoadIC_Initialize();
   CallCode(ic, mode, instr);
 }
 
 
 void LCodeGen::DoStoreGlobalCell(LStoreGlobalCell* instr) {
-  Register object = ToRegister(instr->TempAt(0));
-  Register address = ToRegister(instr->TempAt(1));
-  Register value = ToRegister(instr->InputAt(0));
-  ASSERT(!value.is(object));
-  Handle<JSGlobalPropertyCell> cell_handle(instr->hydrogen()->cell());
-
-  __ movq(address, cell_handle, RelocInfo::GLOBAL_PROPERTY_CELL);
+  Register value = ToRegister(instr->value());
+  Handle<JSGlobalPropertyCell> cell_handle = instr->hydrogen()->cell();
 
   // If the cell we are storing to contains the hole it could have
   // been deleted from the property dictionary. In that case, we need
   // to update the property details in the property dictionary to mark
   // it as no longer deleted. We deoptimize in that case.
   if (instr->hydrogen()->RequiresHoleCheck()) {
-    __ CompareRoot(Operand(address, 0), Heap::kTheHoleValueRootIndex);
+    // We have a temp because CompareRoot might clobber kScratchRegister.
+    Register cell = ToRegister(instr->TempAt(0));
+    ASSERT(!value.is(cell));
+    __ movq(cell, cell_handle, RelocInfo::GLOBAL_PROPERTY_CELL);
+    __ CompareRoot(Operand(cell, 0), Heap::kTheHoleValueRootIndex);
     DeoptimizeIf(equal, instr->environment());
+    // Store the value.
+    __ movq(Operand(cell, 0), value);
+  } else {
+    // Store the value.
+    __ movq(kScratchRegister, cell_handle, RelocInfo::GLOBAL_PROPERTY_CELL);
+    __ movq(Operand(kScratchRegister, 0), value);
   }
-
-  // Store the value.
-  __ movq(Operand(address, 0), value);
   // Cells are always rescanned, so no write barrier here.
 }
 
 
 void LCodeGen::DoStoreGlobalGeneric(LStoreGlobalGeneric* instr) {
   ASSERT(ToRegister(instr->global_object()).is(rdx));
   ASSERT(ToRegister(instr->value()).is(rax));
 
   __ Move(rcx, instr->name());
   Handle<Code> ic = (instr->strict_mode_flag() == kStrictMode)
@@ skipping 2274 matching lines @@
   RegisterEnvironmentForDeoptimization(environment, Safepoint::kNoLazyDeopt);
   ASSERT(osr_pc_offset_ == -1);
   osr_pc_offset_ = masm()->pc_offset();
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64