[promises] Move promise constructor to TFS

src/builtins/x64/builtins-x64.cc

Index: src/builtins/x64/builtins-x64.cc
diff --git a/src/builtins/x64/builtins-x64.cc b/src/builtins/x64/builtins-x64.cc
index 21071017c5299a0d63c8050681ec155def7b3986..f6e33dfe4ed37b4786aa957cad3a8d8523b7697d 100644
--- a/src/builtins/x64/builtins-x64.cc
+++ b/src/builtins/x64/builtins-x64.cc
@@ -2839,6 +2839,59 @@ void Builtins::Generate_ConstructProxy(MacroAssembler* masm) {
 }
 
 // static
+void Builtins::Generate_PromiseConstructorHelper(MacroAssembler* masm) {

[Benedikt Meurer, 2016/11/22 06:03:28]

Unless I'm missing something, this is 100% identical to the
JSBuiltinsConstructStub. Please just use that instead.

+  // ----------- S t a t e -------------
+  //  -- rax: number of arguments
+  //  -- rsi: context
+  //  -- rdi: constructor function
+  //  -- rdx: new target
+  // -----------------------------------
+
+  // Enter a construct frame.
+  {
+    FrameScope scope(masm, StackFrame::CONSTRUCT);
+
+    // Preserve the incoming parameters on the stack.
+    __ Integer32ToSmi(rcx, rax);
+    __ Push(rsi);
+    __ Push(rcx);
+    __ PushRoot(Heap::kTheHoleValueRootIndex);
+
+    // Set up pointer to last argument.
+    __ leap(rbx, Operand(rbp, StandardFrameConstants::kCallerSPOffset));
+
+    // Copy arguments and receiver to the expression stack.
+    Label loop, entry;
+    __ movp(rcx, rax);
+    __ jmp(&entry);
+    __ bind(&loop);
+    __ Push(Operand(rbx, rcx, times_pointer_size, 0));
+    __ bind(&entry);
+    __ decp(rcx);
+    __ j(greater_equal, &loop);
+
+    // Call the function.
+    ParameterCount actual(rax);
+    __ InvokeFunction(rdi, rdx, actual, CALL_FUNCTION,
+                      CheckDebugStepCallWrapper());
+
+    // Restore context from the frame.
+    __ movp(rsi, Operand(rbp, ConstructFrameConstants::kContextOffset));
+
+    __ movp(rbx, Operand(rsp, 0));
+
+    // Leave construct frame.
+  }
+
+  // Remove caller arguments from the stack and return.
+  __ PopReturnAddressTo(rcx);
+  SmiIndex index = masm->SmiToIndex(rbx, rbx, kPointerSizeLog2);
+  __ leap(rsp, Operand(rsp, index.reg, index.scale, 1 * kPointerSize));
+  __ PushReturnAddressFrom(rcx);
+  __ ret(0);
+}
+
+// static
 void Builtins::Generate_Construct(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- rax : the number of arguments (not including the receiver)