[builtins] Unify the various versions of [[Call]] with a Call builtin.

src/mips/builtins-mips.cc

Index: src/mips/builtins-mips.cc
diff --git a/src/mips/builtins-mips.cc b/src/mips/builtins-mips.cc
index bd8c85285af4574d7d72e5e25c2cef13161a6564..6e51b0764e9c5dc0fcbebdb125a5c2782905be40 100644
--- a/src/mips/builtins-mips.cc
+++ b/src/mips/builtins-mips.cc
@@ -1252,129 +1252,31 @@ void Builtins::Generate_OsrAfterStackCheck(MacroAssembler* masm) {
 }
 
 
+// static
 void Builtins::Generate_FunctionCall(MacroAssembler* masm) {
   // 1. Make sure we have at least one argument.
   // a0: actual number of arguments
-  { Label done;
+  {
+    Label done;
     __ Branch(&done, ne, a0, Operand(zero_reg));
-    __ LoadRoot(t2, Heap::kUndefinedValueRootIndex);
-    __ push(t2);
+    __ PushRoot(Heap::kUndefinedValueRootIndex);
     __ Addu(a0, a0, Operand(1));
     __ bind(&done);
   }
 
-  // 2. Get the function to call (passed as receiver) from the stack, check
-  //    if it is a function.
+  // 2. Get the function to call (passed as receiver) from the stack.
   // a0: actual number of arguments
-  Label slow, non_function;
   __ sll(at, a0, kPointerSizeLog2);
   __ addu(at, sp, at);
   __ lw(a1, MemOperand(at));
-  __ JumpIfSmi(a1, &non_function);
-  __ GetObjectType(a1, a2, a2);
-  __ Branch(&slow, ne, a2, Operand(JS_FUNCTION_TYPE));
-
-  // 3a. Patch the first argument if necessary when calling a function.
-  // a0: actual number of arguments
-  // a1: function
-  Label shift_arguments;
-  __ li(t0, Operand(0, RelocInfo::NONE32));  // Indicate regular JS_FUNCTION.
-  { Label convert_to_object, use_global_proxy, patch_receiver;
-    // Change context eagerly in case we need the global receiver.
-    __ lw(cp, FieldMemOperand(a1, JSFunction::kContextOffset));
-
-    // Do not transform the receiver for strict mode functions.
-    __ lw(a2, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
-    __ lw(a3, FieldMemOperand(a2, SharedFunctionInfo::kCompilerHintsOffset));
-    __ And(t3, a3, Operand(1 << (SharedFunctionInfo::kStrictModeFunction +
-                                 kSmiTagSize)));
-    __ Branch(&shift_arguments, ne, t3, Operand(zero_reg));
-
-    // Do not transform the receiver for native (Compilerhints already in a3).
-    __ And(t3, a3, Operand(1 << (SharedFunctionInfo::kNative + kSmiTagSize)));
-    __ Branch(&shift_arguments, ne, t3, Operand(zero_reg));
-
-    // Compute the receiver in sloppy mode.
-    // Load first argument in a2. a2 = -kPointerSize(sp + n_args << 2).
-    __ sll(at, a0, kPointerSizeLog2);
-    __ addu(a2, sp, at);
-    __ lw(a2, MemOperand(a2, -kPointerSize));
-    // a0: actual number of arguments
-    // a1: function
-    // a2: first argument
-    __ JumpIfSmi(a2, &convert_to_object, t2);
-
-    __ LoadRoot(a3, Heap::kUndefinedValueRootIndex);
-    __ Branch(&use_global_proxy, eq, a2, Operand(a3));
-    __ LoadRoot(a3, Heap::kNullValueRootIndex);
-    __ Branch(&use_global_proxy, eq, a2, Operand(a3));
 
-    STATIC_ASSERT(LAST_SPEC_OBJECT_TYPE == LAST_TYPE);
-    __ GetObjectType(a2, a3, a3);
-    __ Branch(&shift_arguments, ge, a3, Operand(FIRST_SPEC_OBJECT_TYPE));
-
-    __ bind(&convert_to_object);
-    // Enter an internal frame in order to preserve argument count.
-    {
-      FrameScope scope(masm, StackFrame::INTERNAL);
-      __ sll(a0, a0, kSmiTagSize);  // Smi tagged.
-      __ push(a0);
-      __ mov(a0, a2);
-      ToObjectStub stub(masm->isolate());
-      __ CallStub(&stub);
-      __ mov(a2, v0);
-
-      __ pop(a0);
-      __ sra(a0, a0, kSmiTagSize);  // Un-tag.
-      // Leave internal frame.
-    }
-
-    // Restore the function to a1, and the flag to t0.
-    __ sll(at, a0, kPointerSizeLog2);
-    __ addu(at, sp, at);
-    __ lw(a1, MemOperand(at));
-    __ Branch(USE_DELAY_SLOT, &patch_receiver);
-    __ li(t0, Operand(0, RelocInfo::NONE32));  // In delay slot.
-
-    __ bind(&use_global_proxy);
-    __ lw(a2, ContextOperand(cp, Context::GLOBAL_OBJECT_INDEX));
-    __ lw(a2, FieldMemOperand(a2, GlobalObject::kGlobalProxyOffset));
-
-    __ bind(&patch_receiver);
-    __ sll(at, a0, kPointerSizeLog2);
-    __ addu(a3, sp, at);
-    __ sw(a2, MemOperand(a3, -kPointerSize));
-
-    __ Branch(&shift_arguments);
-  }
-
-  // 3b. Check for function proxy.
-  __ bind(&slow);
-  __ li(t0, Operand(1, RelocInfo::NONE32));  // Indicate function proxy.
-  __ Branch(&shift_arguments, eq, a2, Operand(JS_FUNCTION_PROXY_TYPE));
-
-  __ bind(&non_function);
-  __ li(t0, Operand(2, RelocInfo::NONE32));  // Indicate non-function.
-
-  // 3c. Patch the first argument when calling a non-function.  The
-  //     CALL_NON_FUNCTION builtin expects the non-function callee as
-  //     receiver, so overwrite the first argument which will ultimately
-  //     become the receiver.
-  // a0: actual number of arguments
-  // a1: function
-  // t0: call type (0: JS function, 1: function proxy, 2: non-function)
-  __ sll(at, a0, kPointerSizeLog2);
-  __ addu(a2, sp, at);
-  __ sw(a1, MemOperand(a2, -kPointerSize));
-
-  // 4. Shift arguments and return address one slot down on the stack
+  // 3. Shift arguments and return address one slot down on the stack
   //    (overwriting the original receiver).  Adjust argument count to make
   //    the original first argument the new receiver.
   // a0: actual number of arguments
   // a1: function
-  // t0: call type (0: JS function, 1: function proxy, 2: non-function)
-  __ bind(&shift_arguments);
-  { Label loop;
+  {
+    Label loop;
     // Calculate the copy start address (destination). Copy end address is sp.
     __ sll(at, a0, kPointerSizeLog2);
     __ addu(a2, sp, at);
@@ -1390,46 +1292,8 @@ void Builtins::Generate_FunctionCall(MacroAssembler* masm) {
     __ Pop();
   }
 
-  // 5a. Call non-function via tail call to CALL_NON_FUNCTION builtin,
-  //     or a function proxy via CALL_FUNCTION_PROXY.
-  // a0: actual number of arguments
-  // a1: function
-  // t0: call type (0: JS function, 1: function proxy, 2: non-function)
-  { Label function, non_proxy;
-    __ Branch(&function, eq, t0, Operand(zero_reg));
-    // Expected number of arguments is 0 for CALL_NON_FUNCTION.
-    __ mov(a2, zero_reg);
-    __ Branch(&non_proxy, ne, t0, Operand(1));
-
-    __ push(a1);  // Re-add proxy object as additional argument.
-    __ Addu(a0, a0, Operand(1));
-    __ GetBuiltinFunction(a1, Context::CALL_FUNCTION_PROXY_BUILTIN_INDEX);
-    __ Jump(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
-            RelocInfo::CODE_TARGET);
-
-    __ bind(&non_proxy);
-    __ GetBuiltinFunction(a1, Context::CALL_NON_FUNCTION_BUILTIN_INDEX);
-    __ Jump(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
-            RelocInfo::CODE_TARGET);
-    __ bind(&function);
-  }
-
-  // 5b. Get the code to call from the function and check that the number of
-  //     expected arguments matches what we're providing.  If so, jump
-  //     (tail-call) to the code in register edx without checking arguments.
-  // a0: actual number of arguments
-  // a1: function
-  __ lw(a3, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
-  __ lw(a2,
-         FieldMemOperand(a3, SharedFunctionInfo::kFormalParameterCountOffset));
-  __ sra(a2, a2, kSmiTagSize);
-  // Check formal and actual parameter counts.
-  __ Jump(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
-          RelocInfo::CODE_TARGET, ne, a2, Operand(a0));
-
-  __ lw(a3, FieldMemOperand(a1, JSFunction::kCodeEntryOffset));
-  ParameterCount expected(0);
-  __ InvokeCode(a3, expected, expected, JUMP_FUNCTION, NullCallWrapper());
+  // 4. Call the callable.
+  __ Jump(masm->isolate()->builtins()->Call(), RelocInfo::CODE_TARGET);
 }
 
 
@@ -1493,9 +1357,8 @@ static void Generate_ApplyHelper(MacroAssembler* masm, bool targetIsArgument) {
     const int kFunctionOffset = kReceiverOffset + kPointerSize;
 
     __ lw(a0, MemOperand(fp, kFunctionOffset));  // Get the function.
-    __ push(a0);
-    __ lw(a0, MemOperand(fp, kArgumentsOffset));  // Get the args array.
-    __ push(a0);
+    __ lw(a1, MemOperand(fp, kArgumentsOffset));  // Get the args array.
+    __ Push(a0, a1);
     // Returns (in v0) number of arguments to copy to stack as Smi.
     if (targetIsArgument) {
       __ InvokeBuiltin(Context::REFLECT_APPLY_PREPARE_BUILTIN_INDEX,
@@ -1513,89 +1376,18 @@ static void Generate_ApplyHelper(MacroAssembler* masm, bool targetIsArgument) {
     const int kLimitOffset =
         StandardFrameConstants::kExpressionsOffset - (1 * kPointerSize);
     __ mov(a1, zero_reg);
-    __ Push(v0, a1);  // Limit and initial index.
-
-    // Get the receiver.
-    __ lw(a0, MemOperand(fp, kReceiverOffset));
-
-    // Check that the function is a JS function (otherwise it must be a proxy).
-    Label push_receiver;
-    __ lw(a1, MemOperand(fp, kFunctionOffset));
-    __ GetObjectType(a1, a2, a2);
-    __ Branch(&push_receiver, ne, a2, Operand(JS_FUNCTION_TYPE));
-
-    // Change context eagerly to get the right global object if necessary.
-    __ lw(cp, FieldMemOperand(a1, JSFunction::kContextOffset));
-    // Load the shared function info while the function is still in a1.
-    __ lw(a2, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
-
-    // Compute the receiver.
-    // Do not transform the receiver for strict mode functions.
-    Label call_to_object, use_global_proxy;
-    __ lw(a2, FieldMemOperand(a2, SharedFunctionInfo::kCompilerHintsOffset));
-    __ And(t3, a2, Operand(1 << (SharedFunctionInfo::kStrictModeFunction +
-                                 kSmiTagSize)));
-    __ Branch(&push_receiver, ne, t3, Operand(zero_reg));
-
-    // Do not transform the receiver for native (Compilerhints already in a2).
-    __ And(t3, a2, Operand(1 << (SharedFunctionInfo::kNative + kSmiTagSize)));
-    __ Branch(&push_receiver, ne, t3, Operand(zero_reg));
-
-    // Compute the receiver in sloppy mode.
-    __ JumpIfSmi(a0, &call_to_object);
-    __ LoadRoot(a1, Heap::kNullValueRootIndex);
-    __ Branch(&use_global_proxy, eq, a0, Operand(a1));
-    __ LoadRoot(a2, Heap::kUndefinedValueRootIndex);
-    __ Branch(&use_global_proxy, eq, a0, Operand(a2));
-
-    // Check if the receiver is already a JavaScript object.
-    // a0: receiver
-    STATIC_ASSERT(LAST_SPEC_OBJECT_TYPE == LAST_TYPE);
-    __ GetObjectType(a0, a1, a1);
-    __ Branch(&push_receiver, ge, a1, Operand(FIRST_SPEC_OBJECT_TYPE));
-
-    // Convert the receiver to a regular object.
-    // a0: receiver
-    __ bind(&call_to_object);
-    ToObjectStub stub(masm->isolate());
-    __ CallStub(&stub);
-    __ mov(a0, v0);  // Put object in a0 to match other paths to push_receiver.
-    __ Branch(&push_receiver);
-
-    __ bind(&use_global_proxy);
-    __ lw(a0, ContextOperand(cp, Context::GLOBAL_OBJECT_INDEX));
-    __ lw(a0, FieldMemOperand(a0, GlobalObject::kGlobalProxyOffset));
-
-    // Push the receiver.
-    // a0: receiver
-    __ bind(&push_receiver);
-    __ push(a0);
+    __ lw(a2, MemOperand(fp, kReceiverOffset));
+    __ Push(v0, a1, a2);  // limit, initial index and receiver.
 
     // Copy all arguments from the array to the stack.
-    Generate_PushAppliedArguments(
-        masm, kArgumentsOffset, kIndexOffset, kLimitOffset);
+    Generate_PushAppliedArguments(masm, kArgumentsOffset, kIndexOffset,
+                                  kLimitOffset);
 
-    // Call the function.
-    Label call_proxy;
-    ParameterCount actual(a0);
+    // Call the callable.
+    // TODO(bmeurer): This should be a tail call according to ES6.
     __ lw(a1, MemOperand(fp, kFunctionOffset));
-    __ GetObjectType(a1, a2, a2);
-    __ Branch(&call_proxy, ne, a2, Operand(JS_FUNCTION_TYPE));
-
-    __ InvokeFunction(a1, actual, CALL_FUNCTION, NullCallWrapper());
-
-    frame_scope.GenerateLeaveFrame();
-    __ Ret(USE_DELAY_SLOT);
-    __ Addu(sp, sp, Operand(kStackSize * kPointerSize));  // In delay slot.
+    __ Call(masm->isolate()->builtins()->Call(), RelocInfo::CODE_TARGET);
 
-    // Call the function proxy.
-    __ bind(&call_proxy);
-    __ push(a1);  // Add function proxy as last argument.
-    __ Addu(a0, a0, Operand(1));
-    __ li(a2, Operand(0, RelocInfo::NONE32));
-    __ GetBuiltinFunction(a1, Context::CALL_FUNCTION_PROXY_BUILTIN_INDEX);
-    __ Call(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
-            RelocInfo::CODE_TARGET);
     // Tear down the internal frame and remove function, receiver and args.
   }
 
@@ -1731,6 +1523,147 @@ static void LeaveArgumentsAdaptorFrame(MacroAssembler* masm) {
 }
 
 
+// static
+void Builtins::Generate_CallFunction(MacroAssembler* masm) {
+  // ----------- S t a t e -------------
+  //  -- a0 : the number of arguments (not including the receiver)
+  //  -- a1 : the function to call (checked to be a JSFunction)
+  // -----------------------------------
+
+  Label convert, convert_global_proxy, convert_to_object, done_convert;
+  __ AssertFunction(a1);
+  // TODO(bmeurer): Throw a TypeError if function's [[FunctionKind]] internal
+  // slot is "classConstructor".
+  // Enter the context of the function; ToObject has to run in the function
+  // context, and we also need to take the global proxy from the function
+  // context in case of conversion.
+  // See ES6 section 9.2.1 [[Call]] ( thisArgument, argumentsList)
+  STATIC_ASSERT(SharedFunctionInfo::kNativeByteOffset ==
+                SharedFunctionInfo::kStrictModeByteOffset);
+  __ lw(cp, FieldMemOperand(a1, JSFunction::kContextOffset));
+  __ lw(a2, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
+  // We need to convert the receiver for non-native sloppy mode functions.
+  __ lbu(a3, FieldMemOperand(a2, SharedFunctionInfo::kNativeByteOffset));
+  __ And(at, a3, Operand((1 << SharedFunctionInfo::kNativeBitWithinByte) |
+                         (1 << SharedFunctionInfo::kStrictModeBitWithinByte)));
+  __ Branch(&done_convert, ne, at, Operand(zero_reg));
+  {
+    __ sll(at, a0, kPointerSizeLog2);
+    __ addu(at, sp, at);
+    __ lw(a3, MemOperand(at));
+
+    // ----------- S t a t e -------------
+    //  -- a0 : the number of arguments (not including the receiver)
+    //  -- a1 : the function to call (checked to be a JSFunction)
+    //  -- a2 : the shared function info.
+    //  -- a3 : the receiver
+    //  -- cp : the function context.
+    // -----------------------------------
+
+    Label convert_receiver;
+    __ JumpIfSmi(a3, &convert_to_object);
+    STATIC_ASSERT(LAST_JS_RECEIVER_TYPE == LAST_TYPE);
+    __ GetObjectType(a3, t0, t0);
+    __ Branch(&done_convert, hs, t0, Operand(FIRST_JS_RECEIVER_TYPE));
+    __ JumpIfRoot(a3, Heap::kUndefinedValueRootIndex, &convert_global_proxy);
+    __ JumpIfNotRoot(a3, Heap::kNullValueRootIndex, &convert_to_object);
+    __ bind(&convert_global_proxy);
+    {
+      // Patch receiver to global proxy.
+      __ LoadGlobalProxy(a3);
+    }
+    __ Branch(&convert_receiver);
+    __ bind(&convert_to_object);
+    {
+      // Convert receiver using ToObject.
+      // TODO(bmeurer): Inline the allocation here to avoid building the frame
+      // in the fast case? (fall back to AllocateInNewSpace?)
+      FrameScope scope(masm, StackFrame::INTERNAL);
+      __ sll(a0, a0, kSmiTagSize);  // Smi tagged.
+      __ Push(a0, a1);
+      __ mov(a0, a3);
+      ToObjectStub stub(masm->isolate());
+      __ CallStub(&stub);
+      __ mov(a3, v0);
+      __ Pop(a0, a1);
+      __ sra(a0, a0, kSmiTagSize);  // Un-tag.
+    }
+    __ lw(a2, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
+    __ bind(&convert_receiver);
+    __ sll(at, a0, kPointerSizeLog2);
+    __ addu(at, sp, at);
+    __ sw(a3, MemOperand(at));
+  }
+  __ bind(&done_convert);
+
+  // ----------- S t a t e -------------
+  //  -- a0 : the number of arguments (not including the receiver)
+  //  -- a1 : the function to call (checked to be a JSFunction)
+  //  -- a2 : the shared function info.
+  //  -- cp : the function context.
+  // -----------------------------------
+
+  __ lw(a2,
+        FieldMemOperand(a2, SharedFunctionInfo::kFormalParameterCountOffset));
+  __ sra(a2, a2, kSmiTagSize);  // Un-tag.
+  __ lw(a3, FieldMemOperand(a1, JSFunction::kCodeEntryOffset));
+  ParameterCount actual(a0);
+  ParameterCount expected(a2);
+  __ InvokeCode(a3, expected, actual, JUMP_FUNCTION, NullCallWrapper());
+}
+
+
+// static
+void Builtins::Generate_Call(MacroAssembler* masm) {
+  // ----------- S t a t e -------------
+  //  -- a0 : the number of arguments (not including the receiver)
+  //  -- a1 : the target to call (can be any Object).
+  // -----------------------------------
+
+  Label non_smi, non_function;
+  __ JumpIfSmi(a1, &non_function);
+  __ bind(&non_smi);
+  __ GetObjectType(a1, a2, a2);
+  __ Jump(masm->isolate()->builtins()->CallFunction(), RelocInfo::CODE_TARGET,
+          eq, a2, Operand(JS_FUNCTION_TYPE));
+  __ Branch(&non_function, ne, a2, Operand(JS_FUNCTION_PROXY_TYPE));
+
+
+  // 1. Call to function proxy.
+  // TODO(neis): This doesn't match the ES6 spec for [[Call]] on proxies.
+  __ lw(a1, FieldMemOperand(a1, JSFunctionProxy::kCallTrapOffset));
+  __ AssertNotSmi(a1);
+  __ Branch(&non_smi);
+
+  // 2. Call to something else, which might have a [[Call]] internal method (if
+  // not we raise an exception).
+  __ bind(&non_function);
+  // TODO(bmeurer): I wonder why we prefer to have slow API calls? This could
+  // be awesome instead; i.e. a trivial improvement would be to call into the
+  // runtime and just deal with the API function there instead of returning a
+  // delegate from a runtime call that just jumps back to the runtime once
+  // called. Or, bonus points, call directly into the C API function here, as
+  // we do in some Crankshaft fast cases.
+  // Overwrite the original receiver with the (original) target.
+  __ sll(at, a0, kPointerSizeLog2);
+  __ addu(at, sp, at);
+  __ sw(a1, MemOperand(at));
+  {
+    // Determine the delegate for the target (if any).
+    FrameScope scope(masm, StackFrame::INTERNAL);
+    __ sll(a0, a0, kSmiTagSize);  // Smi tagged.
+    __ Push(a0, a1);
+    __ CallRuntime(Runtime::kGetFunctionDelegate, 1);
+    __ mov(a1, v0);
+    __ Pop(a0);
+    __ sra(a0, a0, kSmiTagSize);  // Un-tag.
+  }
+  // The delegate is always a regular function.
+  __ AssertFunction(a1);
+  __ Jump(masm->isolate()->builtins()->CallFunction(), RelocInfo::CODE_TARGET);
+}
+
+
 void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
   // State setup as expected by MacroAssembler::InvokePrologue.
   // ----------- S t a t e -------------