Use register parameters in ElementsTransitionGenerator.

src/x64/codegen-x64.cc

Index: src/x64/codegen-x64.cc
diff --git a/src/x64/codegen-x64.cc b/src/x64/codegen-x64.cc
index d30ca498f04c249fef010713138fdfd5ac98b67a..939051b0f0c9d45fff4d20ad067215d28237489c 100644
--- a/src/x64/codegen-x64.cc
+++ b/src/x64/codegen-x64.cc
@@ -184,26 +184,29 @@ ModuloFunction CreateModuloFunction() {
 #define __ ACCESS_MASM(masm)
 
 void ElementsTransitionGenerator::GenerateMapChangeElementsTransition(
-    MacroAssembler* masm, AllocationSiteMode mode,
+    MacroAssembler* masm,
+    Register receiver,
+    Register key,
+    Register value,
+    Register target_map,
+    AllocationSiteMode mode,
     Label* allocation_memento_found) {
-  // ----------- S t a t e -------------
-  //  -- rax    : value
-  //  -- rbx    : target map
-  //  -- rcx    : key
-  //  -- rdx    : receiver
-  //  -- rsp[0] : return address
-  // -----------------------------------
+  // Return address is on the stack.
+  Register scratch = rdi;
+  ASSERT(!AreAliased(receiver, key, value, target_map, scratch));
+
   if (mode == TRACK_ALLOCATION_SITE) {
     ASSERT(allocation_memento_found != NULL);
-    __ JumpIfJSArrayHasAllocationMemento(rdx, rdi, allocation_memento_found);
+    __ JumpIfJSArrayHasAllocationMemento(
+        receiver, scratch, allocation_memento_found);
   }
 
   // Set transitioned map.
-  __ movp(FieldOperand(rdx, HeapObject::kMapOffset), rbx);
-  __ RecordWriteField(rdx,
+  __ movp(FieldOperand(receiver, HeapObject::kMapOffset), target_map);
+  __ RecordWriteField(receiver,
                       HeapObject::kMapOffset,
-                      rbx,
-                      rdi,
+                      target_map,
+                      scratch,
                       kDontSaveFPRegs,
                       EMIT_REMEMBERED_SET,
                       OMIT_SMI_CHECK);
@@ -211,14 +214,19 @@ void ElementsTransitionGenerator::GenerateMapChangeElementsTransition(
 
 
 void ElementsTransitionGenerator::GenerateSmiToDouble(
-    MacroAssembler* masm, AllocationSiteMode mode, Label* fail) {
-  // ----------- S t a t e -------------
-  //  -- rax    : value
-  //  -- rbx    : target map
-  //  -- rcx    : key
-  //  -- rdx    : receiver
-  //  -- rsp[0] : return address
-  // -----------------------------------
+    MacroAssembler* masm,
+    Register receiver,
+    Register key,
+    Register value,
+    Register target_map,
+    AllocationSiteMode mode,
+    Label* fail) {
+  // Return address is on the stack.
+  ASSERT(receiver.is(rdx));
+  ASSERT(key.is(rcx));
+  ASSERT(value.is(rax));
+  ASSERT(target_map.is(rbx));
+
   // The fail label is not actually used since we do not allocate.
   Label allocated, new_backing_store, only_change_map, done;
 
@@ -345,14 +353,19 @@ void ElementsTransitionGenerator::GenerateSmiToDouble(
 
 
 void ElementsTransitionGenerator::GenerateDoubleToObject(
-    MacroAssembler* masm, AllocationSiteMode mode, Label* fail) {
-  // ----------- S t a t e -------------
-  //  -- rax    : value
-  //  -- rbx    : target map
-  //  -- rcx    : key
-  //  -- rdx    : receiver
-  //  -- rsp[0] : return address
-  // -----------------------------------
+    MacroAssembler* masm,
+    Register receiver,
+    Register key,
+    Register value,
+    Register target_map,
+    AllocationSiteMode mode,
+    Label* fail) {
+  // Return address is on the stack.
+  ASSERT(receiver.is(rdx));
+  ASSERT(key.is(rcx));
+  ASSERT(value.is(rax));
+  ASSERT(target_map.is(rbx));
+
   Label loop, entry, convert_hole, gc_required, only_change_map;
 
   if (mode == TRACK_ALLOCATION_SITE) {