Fast elements conversions in crankshaft using generated code.

src/x64/code-stubs-x64.cc

Index: src/x64/code-stubs-x64.cc
diff --git a/src/x64/code-stubs-x64.cc b/src/x64/code-stubs-x64.cc
index 63aaee116b6cbd1efd580a9593ad0f10f2a2386d..615388b1d6cb35666a63cc16b5f33ddef9863b4a 100644
--- a/src/x64/code-stubs-x64.cc
+++ b/src/x64/code-stubs-x64.cc
@@ -5963,7 +5963,7 @@ void FastElementsConversionStub::GenerateSmiOnlyToObject(MacroAssembler* masm) {
 
 
 void FastElementsConversionStub::GenerateSmiOnlyToDouble(
-    MacroAssembler* masm, StrictModeFlag strict_mode) {
+    MacroAssembler* masm, Type type, StrictModeFlag strict_mode) {
   // ----------- S t a t e -------------
   //  -- rax    : value
   //  -- rbx    : target map
@@ -6013,11 +6013,16 @@ void FastElementsConversionStub::GenerateSmiOnlyToDouble(
   __ bind(&entry);
   __ testq(r9, r9);
   __ j(not_zero, &loop);
+
+  if (type == TRANSITION_ONLY) {
+    __ movq(rax, rdx);
+    __ Ret();
+  }
 }
 
 
 void FastElementsConversionStub::GenerateDoubleToObject(
-    MacroAssembler* masm, StrictModeFlag strict_mode) {
+    MacroAssembler* masm, Type type, StrictModeFlag strict_mode) {
   // ----------- S t a t e -------------
   //  -- rax    : value
   //  -- rbx    : target map
@@ -6051,7 +6056,15 @@ void FastElementsConversionStub::GenerateDoubleToObject(
   __ bind(&gc_required);
   __ pop(rax);
   __ movq(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
-  KeyedStoreIC::GenerateRuntimeSetProperty(masm, strict_mode);
+  if (type == TRANSITION_ONLY) {
+    __ pop(rbx);
+    __ push(rdx);
+    __ push(rbx);  // return address
+    __ TailCallRuntime(Runtime::kTransitionElementsDoubleToObject, 1, 1);
+  } else {
+    ASSERT(type == TRANSITION_AND_STORE);
+    KeyedStoreIC::GenerateRuntimeSetProperty(masm, strict_mode);
+  }
 
   // Box doubles into heap numbers.
   __ bind(&loop);
@@ -6115,6 +6128,11 @@ void FastElementsConversionStub::GenerateDoubleToObject(
                       OMIT_SMI_CHECK);
   __ pop(rax);
   __ movq(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
+
+  if (type == TRANSITION_ONLY) {
+    __ movq(rax, rdx);
+    __ Ret();
+  }
 }
 
 #undef __