add context save for GenerateFastApiCall

src/arm/macro-assembler-arm.cc

Index: src/arm/macro-assembler-arm.cc
diff --git a/src/arm/macro-assembler-arm.cc b/src/arm/macro-assembler-arm.cc
index 7df785776dd50a7ed56993b9b7043e6ac1373b63..07900d3e17ad8ef4763605b02df63bdd7a7a619f 100644
--- a/src/arm/macro-assembler-arm.cc
+++ b/src/arm/macro-assembler-arm.cc
@@ -1020,7 +1020,8 @@ int MacroAssembler::ActivationFrameAlignment() {
 
 
 void MacroAssembler::LeaveExitFrame(bool save_doubles,
-                                    Register argument_count) {
+                                    Register argument_count,
+                                    bool restore_context) {
   // Optionally restore all double registers.
   if (save_doubles) {
     // Calculate the stack location of the saved doubles and restore them.
@@ -1035,10 +1036,14 @@ void MacroAssembler::LeaveExitFrame(bool save_doubles,
   mov(ip, Operand(ExternalReference(Isolate::kCEntryFPAddress, isolate())));
   str(r3, MemOperand(ip));
 
+
   // Restore current context from top and clear it in debug mode.
-  mov(ip, Operand(ExternalReference(Isolate::kContextAddress, isolate())));
-  ldr(cp, MemOperand(ip));
+  if (restore_context) {
+    mov(ip, Operand(ExternalReference(Isolate::kContextAddress, isolate())));
+    ldr(cp, MemOperand(ip));
+  }
 #ifdef DEBUG
+  mov(ip, Operand(ExternalReference(Isolate::kContextAddress, isolate())));
   str(r3, MemOperand(ip));
 #endif
 
@@ -2280,12 +2285,14 @@ static int AddressOffset(ExternalReference ref0, ExternalReference ref1) {
 }
 
 
-void MacroAssembler::CallApiFunctionAndReturn(ExternalReference function,
-                                              Address function_address,
-                                              ExternalReference thunk_ref,
-                                              Register thunk_last_arg,
-                                              int stack_space,
-                                              int return_value_offset) {
+void MacroAssembler::CallApiFunctionAndReturn(
+    ExternalReference function,
+    Address function_address,
+    ExternalReference thunk_ref,
+    Register thunk_last_arg,
+    int stack_space,
+    MemOperand return_value_operand,
+    MemOperand* context_restore_operand) {
   ExternalReference next_address =
       ExternalReference::handle_scope_next_address(isolate());
   const int kNextOffset = 0;
@@ -2349,12 +2356,13 @@ void MacroAssembler::CallApiFunctionAndReturn(ExternalReference function,
   }
 
   Label promote_scheduled_exception;
+  Label exception_handled;
   Label delete_allocated_handles;
   Label leave_exit_frame;
   Label return_value_loaded;
 
   // load value from ReturnValue
-  ldr(r0, MemOperand(fp, return_value_offset*kPointerSize));
+  ldr(r0, return_value_operand);
   bind(&return_value_loaded);
   // No more valid handles (the result handle was the last one). Restore
   // previous handle scope.
@@ -2377,17 +2385,22 @@ void MacroAssembler::CallApiFunctionAndReturn(ExternalReference function,
   ldr(r5, MemOperand(ip));
   cmp(r4, r5);
   b(ne, &promote_scheduled_exception);
+  bind(&exception_handled);
 
+  bool restore_context = context_restore_operand != NULL;
+  if (restore_context) {
+    ldr(cp, *context_restore_operand);
+  }
   // LeaveExitFrame expects unwind space to be in a register.
   mov(r4, Operand(stack_space));
-  LeaveExitFrame(false, r4);
+  LeaveExitFrame(false, r4, !restore_context);
   mov(pc, lr);
 
   bind(&promote_scheduled_exception);
-  TailCallExternalReference(
+  CallExternalReference(
       ExternalReference(Runtime::kPromoteScheduledException, isolate()),
-      0,
-      1);
+      0);
+  jmp(&exception_handled);
 
   // HandleScope limit has changed. Delete allocated extensions.
   bind(&delete_allocated_handles);