[fullcodegen] Avoid arguments juggling when calling a JS runtime function.

src/full-codegen/x64/full-codegen-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/ast/scopes.h"
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
@@ skipping 3212 matching lines @@
 
   __ bind(&runtime);
   CallRuntimeWithOperands(Runtime::kCreateIterResultObject);
 
   __ bind(&done);
   context()->Plug(rax);
 }
 
 
 void FullCodeGenerator::EmitLoadJSRuntimeFunction(CallRuntime* expr) {
-  // Push the builtins object as receiver.
+  // Push function.
+  __ LoadNativeContextSlot(expr->context_index(), rax);
+  PushOperand(rax);
+
+  // Push undefined as receiver.
   OperandStackDepthIncrement(1);
   __ PushRoot(Heap::kUndefinedValueRootIndex);
-
-  __ LoadNativeContextSlot(expr->context_index(), rax);
 }
 
 
 void FullCodeGenerator::EmitCallJSRuntimeFunction(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   int arg_count = args->length();
 
   SetCallPosition(expr);
   __ movp(rdi, Operand(rsp, (arg_count + 1) * kPointerSize));
   __ Set(rax, arg_count);
   __ Call(isolate()->builtins()->Call(ConvertReceiverMode::kNullOrUndefined),
           RelocInfo::CODE_TARGET);
   OperandStackDepthDecrement(arg_count + 1);
 }
 
 
 void FullCodeGenerator::VisitCallRuntime(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   int arg_count = args->length();
 
   if (expr->is_jsruntime()) {
     Comment cmnt(masm_, "[ CallRuntime");
-
     EmitLoadJSRuntimeFunction(expr);
 
-    // Push the target function under the receiver.
-    PushOperand(Operand(rsp, 0));
-    __ movp(Operand(rsp, kPointerSize), rax);
-
     // Push the arguments ("left-to-right").
     for (int i = 0; i < arg_count; i++) {
       VisitForStackValue(args->at(i));
     }
 
     PrepareForBailoutForId(expr->CallId(), NO_REGISTERS);
     EmitCallJSRuntimeFunction(expr);
 
     // Restore context register.
     __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
@@ skipping 753 matching lines @@
   DCHECK_EQ(
       isolate->builtins()->OnStackReplacement()->entry(),
       Assembler::target_address_at(call_target_address, unoptimized_code));
   return ON_STACK_REPLACEMENT;
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64