Direct call api functions (arm implementation)

src/arm/stub-cache-arm.cc

Index: src/arm/stub-cache-arm.cc
===================================================================
--- src/arm/stub-cache-arm.cc	(revision 6213)
+++ src/arm/stub-cache-arm.cc	(working copy)
@@ -571,6 +571,7 @@
   __ CallStub(&stub);
 }
 
+static const int kFastApiCallArguments = 3;
 
 // Reserves space for the extra arguments to FastHandleApiCall in the
 // caller's frame.
@@ -579,64 +580,85 @@
 static void ReserveSpaceForFastApiCall(MacroAssembler* masm,
                                        Register scratch) {
   __ mov(scratch, Operand(Smi::FromInt(0)));
-  __ push(scratch);
-  __ push(scratch);
-  __ push(scratch);
-  __ push(scratch);
+  for (int i = 0; i < kFastApiCallArguments; i++) {
+    __ push(scratch);
+  }
 }
 
 
 // Undoes the effects of ReserveSpaceForFastApiCall.
 static void FreeSpaceForFastApiCall(MacroAssembler* masm) {
-  __ Drop(4);
+  __ Drop(kFastApiCallArguments);
 }
 
 
-// Generates call to FastHandleApiCall builtin.
-static void GenerateFastApiCall(MacroAssembler* masm,
-                                const CallOptimization& optimization,
-                                int argc) {
+static bool GenerateFastApiDirectCall(MacroAssembler* masm,

[Erik Corry, 2011/01/24 21:45:16]

Instead of returning a bool and using a Failure** to return the failure this
function should return a MaybeObject*.  This is the pattern used throughout V8
for functions that may encounter an allocation failure.  You can return
Heap::undefined_value() in the success cases where there is nothing to return.

[Zaheer, 2011/01/25 07:39:52]

Actually i followed the IA32 return structure. Modified as per suggestion.
Done.

+                                      const CallOptimization& optimization,
+                                      int argc,
+                                      Failure** failure) {
+  // ----------- S t a t e -------------
+  //  -- sp[0]              : holder (set by CheckPrototypes)
+  //  -- sp[4]              : callee js function
+  //  -- sp[8]              : call data
+  //  -- sp[12]             : last js argument
+  //  -- ...
+  //  -- sp[(argc + 3) * 4] : first js argument
+  //  -- sp[(argc + 4) * 4] : receiver
+  // -----------------------------------
   // Get the function and setup the context.
   JSFunction* function = optimization.constant_function();
   __ mov(r5, Operand(Handle<JSFunction>(function)));
   __ ldr(cp, FieldMemOperand(r5, JSFunction::kContextOffset));
 
   // Pass the additional arguments FastHandleApiCall expects.
-  bool info_loaded = false;
-  Object* callback = optimization.api_call_info()->callback();
-  if (Heap::InNewSpace(callback)) {
-    info_loaded = true;
-    __ Move(r0, Handle<CallHandlerInfo>(optimization.api_call_info()));
-    __ ldr(r7, FieldMemOperand(r0, CallHandlerInfo::kCallbackOffset));
-  } else {
-    __ Move(r7, Handle<Object>(callback));
-  }
   Object* call_data = optimization.api_call_info()->data();
+  Handle<CallHandlerInfo> api_call_info_handle(optimization.api_call_info());
   if (Heap::InNewSpace(call_data)) {
-    if (!info_loaded) {
-      __ Move(r0, Handle<CallHandlerInfo>(optimization.api_call_info()));
-    }
+    __ Move(r0, api_call_info_handle);
     __ ldr(r6, FieldMemOperand(r0, CallHandlerInfo::kDataOffset));
   } else {
     __ Move(r6, Handle<Object>(call_data));
   }
+  // Store js function and call data.
+  __ stm(ib, sp, r5.bit() | r6.bit());
 
-  __ add(sp, sp, Operand(1 * kPointerSize));
-  __ stm(ia, sp, r5.bit() | r6.bit() | r7.bit());
-  __ sub(sp, sp, Operand(1 * kPointerSize));
+  // r2 points to call data as expected by Arguments class (refer layout above).
+  __ add(r2, sp, Operand(2 * kPointerSize));
 
-  // Set the number of arguments.
-  __ mov(r0, Operand(argc + 4));
+  Object* callback = optimization.api_call_info()->callback();
+  Address api_function_address = v8::ToCData<Address>(callback);
+  ApiFunction fun(api_function_address);
 
-  // Jump to the fast api call builtin (tail call).
-  Handle<Code> code = Handle<Code>(
-      Builtins::builtin(Builtins::FastHandleApiCall));
-  ParameterCount expected(0);
-  __ InvokeCode(code, expected, expected,
-                RelocInfo::CODE_TARGET, JUMP_FUNCTION);
+  const int kApiStackSpace = 4;
+  __ PrepareCallApiFunction(kApiStackSpace,
+                            argc + kFastApiCallArguments + 1);
+  // v8::Arguments::implicit_args = data
+  __ str(r2, MemOperand(sp));
+  // v8::Arguments::values = last argument
+  __ add(ip, r2, Operand(argc * kPointerSize));
+  __ str(ip, MemOperand(sp, 1 * kPointerSize));
+  // v8::Arguments::length_ = argc
+  __ mov(ip, Operand(argc));
+  __ str(ip, MemOperand(sp, 2 * kPointerSize));
+  // v8::Arguments::is_construct_call = 0
+  __ mov(ip, Operand(0));
+  __ str(ip, MemOperand(sp, 3 * kPointerSize));
+  // r0 = v8::Arguments&
+  __ mov(r0, sp);
+
+  // Emitting a stub call may try to allocate (if the code is not
+  // already generated).  Do not allow the assembler to perform a
+  // garbage collection but instead return the allocation failure
+  // object.
+  MaybeObject* result =
+      masm->TryCallApiFunctionAndReturn(&fun);
+  if (result->IsFailure()) {
+    *failure = Failure::cast(result);
+    return false;
+  }
+  return true;
 }
 
-
 class CallInterceptorCompiler BASE_EMBEDDED {
  public:
   CallInterceptorCompiler(StubCompiler* stub_compiler,
@@ -646,7 +668,7 @@
         arguments_(arguments),
         name_(name) {}
 
-  void Compile(MacroAssembler* masm,
+  bool Compile(MacroAssembler* masm,
                JSObject* object,
                JSObject* holder,
                String* name,
@@ -655,7 +677,8 @@
                Register scratch1,
                Register scratch2,
                Register scratch3,
-               Label* miss) {
+               Label* miss,
+               Failure **failure) {
     ASSERT(holder->HasNamedInterceptor());
     ASSERT(!holder->GetNamedInterceptor()->getter()->IsUndefined());
 
@@ -665,7 +688,7 @@
     CallOptimization optimization(lookup);
 
     if (optimization.is_constant_call()) {
-      CompileCacheable(masm,
+      return CompileCacheable(masm,
                        object,
                        receiver,
                        scratch1,
@@ -675,7 +698,8 @@
                        lookup,
                        name,
                        optimization,
-                       miss);
+                       miss,
+                       failure);
     } else {
       CompileRegular(masm,
                      object,
@@ -686,11 +710,12 @@
                      name,
                      holder,
                      miss);
+      return true;
     }
   }
 
  private:
-  void CompileCacheable(MacroAssembler* masm,
+  bool CompileCacheable(MacroAssembler* masm,
                        JSObject* object,
                        Register receiver,
                        Register scratch1,
@@ -700,7 +725,8 @@
                        LookupResult* lookup,
                        String* name,
                        const CallOptimization& optimization,
-                       Label* miss_label) {
+                       Label* miss_label,
+                       Failure **failure) {
     ASSERT(optimization.is_constant_call());
     ASSERT(!lookup->holder()->IsGlobalObject());
 
@@ -764,7 +790,13 @@
 
     // Invoke function.
     if (can_do_fast_api_call) {
-      GenerateFastApiCall(masm, optimization, arguments_.immediate());
+      bool success = GenerateFastApiDirectCall(masm,
+                                               optimization,
+                                               arguments_.immediate(),
+                                               failure);
+      if (!success) {
+        return false;
+      }
     } else {
       __ InvokeFunction(optimization.constant_function(), arguments_,
                         JUMP_FUNCTION);
@@ -782,6 +814,8 @@
     if (can_do_fast_api_call) {
       FreeSpaceForFastApiCall(masm);
     }
+
+    return true;
   }
 
   void CompileRegular(MacroAssembler* masm,
@@ -2238,7 +2272,14 @@
   }
 
   if (depth != kInvalidProtoDepth) {
-    GenerateFastApiCall(masm(), optimization, argc);
+    Failure* failure;
+    bool success = GenerateFastApiDirectCall(masm(),
+                                             optimization,
+                                             argc,
+                                             &failure);
+    if (!success) {
+      return failure;
+    }
   } else {
     __ InvokeFunction(function, arguments(), JUMP_FUNCTION);
   }
@@ -2282,7 +2323,8 @@
   __ ldr(r1, MemOperand(sp, argc * kPointerSize));
 
   CallInterceptorCompiler compiler(this, arguments(), r2);
-  compiler.Compile(masm(),
+  Failure *failure;
+  bool success =  compiler.Compile(masm(),
                    object,
                    holder,
                    name,
@@ -2291,7 +2333,11 @@
                    r3,
                    r4,
                    r0,
-                   &miss);
+                   &miss,
+                   &failure);
+  if (!success) {
+      return false;
+  }
 
   // Move returned value, the function to call, to r1.
   __ mov(r1, r0);