add context save for GenerateFastApiCall

src/x64/macro-assembler-x64.cc

Index: src/x64/macro-assembler-x64.cc
diff --git a/src/x64/macro-assembler-x64.cc b/src/x64/macro-assembler-x64.cc
index fa8cf18fe1365e4fcfeec7b87351020f1912a844..4ff379138bd47013b09e19a0188f052078718b32 100644
--- a/src/x64/macro-assembler-x64.cc
+++ b/src/x64/macro-assembler-x64.cc
@@ -691,13 +691,16 @@ void MacroAssembler::PrepareCallApiFunction(int arg_stack_space) {
 }
 
 
-void MacroAssembler::CallApiFunctionAndReturn(Address function_address,
-                                              Address thunk_address,
-                                              Register thunk_last_arg,
-                                              int stack_space,
-                                              int return_value_offset) {
+void MacroAssembler::CallApiFunctionAndReturn(
+    Address function_address,
+    Address thunk_address,
+    Register thunk_last_arg,
+    int stack_space,
+    Operand return_value_operand,
+    Operand* context_restore_operand) {
   Label prologue;
   Label promote_scheduled_exception;
+  Label exception_handled;
   Label delete_allocated_handles;
   Label leave_exit_frame;
   Label write_back;
@@ -768,7 +771,7 @@ void MacroAssembler::CallApiFunctionAndReturn(Address function_address,
   }
 
   // Load the value from ReturnValue
-  movq(rax, Operand(rbp, return_value_offset * kPointerSize));
+  movq(rax, return_value_operand);
   bind(&prologue);
 
   // No more valid handles (the result handle was the last one). Restore
@@ -783,6 +786,7 @@ void MacroAssembler::CallApiFunctionAndReturn(Address function_address,
   movq(rsi, scheduled_exception_address);
   Cmp(Operand(rsi, 0), factory->the_hole_value());
   j(not_equal, &promote_scheduled_exception);
+  bind(&exception_handled);
 
 #if ENABLE_EXTRA_CHECKS
   // Check if the function returned a valid JavaScript value.
@@ -819,11 +823,16 @@ void MacroAssembler::CallApiFunctionAndReturn(Address function_address,
   bind(&ok);
 #endif
 
-  LeaveApiExitFrame();
+  bool restore_context = context_restore_operand != NULL;
+  if (restore_context) {
+    movq(rsi, *context_restore_operand);
+  }
+  LeaveApiExitFrame(!restore_context);
   ret(stack_space * kPointerSize);
 
   bind(&promote_scheduled_exception);
-  TailCallRuntime(Runtime::kPromoteScheduledException, 0, 1);
+  CallRuntime(Runtime::kPromoteScheduledException, 0);
+  jmp(&exception_handled);
 
   // HandleScope limit has changed. Delete allocated extensions.
   bind(&delete_allocated_handles);
@@ -3695,23 +3704,25 @@ void MacroAssembler::LeaveExitFrame(bool save_doubles) {
 
   PushReturnAddressFrom(rcx);
 
-  LeaveExitFrameEpilogue();
+  LeaveExitFrameEpilogue(true);
 }
 
 
-void MacroAssembler::LeaveApiExitFrame() {
+void MacroAssembler::LeaveApiExitFrame(bool restore_context) {
   movq(rsp, rbp);
   pop(rbp);
 
-  LeaveExitFrameEpilogue();
+  LeaveExitFrameEpilogue(restore_context);
 }
 
 
-void MacroAssembler::LeaveExitFrameEpilogue() {
+void MacroAssembler::LeaveExitFrameEpilogue(bool restore_context) {
   // Restore current context from top and clear it in debug mode.
   ExternalReference context_address(Isolate::kContextAddress, isolate());
   Operand context_operand = ExternalOperand(context_address);
-  movq(rsi, context_operand);
+  if (restore_context) {
+    movq(rsi, context_operand);
+  }
 #ifdef DEBUG
   movq(context_operand, Immediate(0));
 #endif