Cleanup Generate_JSConstructStubHelper a bit.

src/mips/builtins-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_MIPS
 
@@ skipping 298 matching lines @@
   __ Branch(&ok, hs, sp, Operand(t0));
 
   CallRuntimePassFunction(masm, Runtime::kTryInstallOptimizedCode);
   GenerateTailCallToReturnedCode(masm);
 
   __ bind(&ok);
   GenerateTailCallToSharedCode(masm);
 }
 
 
-static void Generate_Runtime_NewObject(MacroAssembler* masm,
-                                       bool create_memento,
-                                       Register original_constructor,
-                                       Label* count_incremented,
-                                       Label* allocated) {
-  if (create_memento) {
-    // Get the cell or allocation site.
-    __ lw(a2, MemOperand(sp, 3 * kPointerSize));
-    __ push(a2);
-  }
-
-  __ push(a1);                    // argument for Runtime_NewObject
-  __ push(original_constructor);  // original constructor
-  if (create_memento) {
-    __ CallRuntime(Runtime::kNewObjectWithAllocationSite, 3);
-  } else {
-    __ CallRuntime(Runtime::kNewObject, 2);
-  }
-  __ mov(t4, v0);
-
-  // Runtime_NewObjectWithAllocationSite increments allocation count.
-  // Skip the increment.
-  if (create_memento) {
-    __ jmp(count_incremented);
-  } else {
-    __ jmp(allocated);
-  }
-}
-
-
 static void Generate_JSConstructStubHelper(MacroAssembler* masm,
                                            bool is_api_function,
                                            bool create_memento) {
   // ----------- S t a t e -------------
   //  -- a0     : number of arguments
   //  -- a1     : constructor function
   //  -- a2     : allocation site or undefined
   //  -- a3     : original constructor
   //  -- ra     : return address
   //  -- sp[...]: constructor arguments
   // -----------------------------------
 
   // Should never create mementos for api functions.
   DCHECK(!is_api_function || !create_memento);
 
   Isolate* isolate = masm->isolate();
 
-  // ----------- S t a t e -------------
-  //  -- a0     : number of arguments
-  //  -- a1     : constructor function
-  //  -- ra     : return address
-  //  -- sp[...]: constructor arguments
-  // -----------------------------------
-
   // Enter a construct frame.
   {
     FrameScope scope(masm, StackFrame::CONSTRUCT);
 
     if (create_memento) {
       __ AssertUndefinedOrAllocationSite(a2, t0);
       __ push(a2);
     }
 
     // Preserve the incoming parameters on the stack.
     __ SmiTag(a0);
     __ Push(a0, a1, a3);
 
-    Label rt_call, allocated, normal_new, count_incremented;
-    __ Branch(&normal_new, eq, a1, Operand(a3));
-
-    // Original constructor and function are different.
-    Generate_Runtime_NewObject(masm, create_memento, a3, &count_incremented,
-                               &allocated);
-    __ bind(&normal_new);
-
     // Try to allocate the object without transitioning into C code. If any of
     // the preconditions is not met, the code bails out to the runtime call.
+    Label rt_call, allocated;
     if (FLAG_inline_new) {
       ExternalReference debug_step_in_fp =
           ExternalReference::debug_step_in_fp_address(isolate);
       __ li(a2, Operand(debug_step_in_fp));
       __ lw(a2, MemOperand(a2));
       __ Branch(&rt_call, ne, a2, Operand(zero_reg));
 
+      // Fall back to runtime if the original constructor and function differ.
+      __ Branch(&rt_call, ne, a1, Operand(a3));
+
       // Load the initial map and verify that it is in fact a map.
       // a1: constructor function
       __ lw(a2, FieldMemOperand(a1, JSFunction::kPrototypeOrInitialMapOffset));
       __ JumpIfSmi(a2, &rt_call);
-      __ GetObjectType(a2, a3, t4);
+      __ GetObjectType(a2, t5, t4);
       __ Branch(&rt_call, ne, t4, Operand(MAP_TYPE));
 
       // Check that the constructor is not constructing a JSFunction (see
       // comments in Runtime_NewObject in runtime.cc). In which case the
       // initial map's instance type would be JS_FUNCTION_TYPE.
       // a1: constructor function
       // a2: initial map
-      __ lbu(a3, FieldMemOperand(a2, Map::kInstanceTypeOffset));
-      __ Branch(&rt_call, eq, a3, Operand(JS_FUNCTION_TYPE));
+      __ lbu(t5, FieldMemOperand(a2, Map::kInstanceTypeOffset));
+      __ Branch(&rt_call, eq, t5, Operand(JS_FUNCTION_TYPE));
 
       if (!is_api_function) {
         Label allocate;
         MemOperand bit_field3 = FieldMemOperand(a2, Map::kBitField3Offset);
         // Check if slack tracking is enabled.
         __ lw(t0, bit_field3);
         __ DecodeField<Map::Counter>(t2, t0);
         __ Branch(&allocate, lt, t2, Operand(Map::kSlackTrackingCounterEnd));
         // Decrease generous allocation count.
         __ Subu(t0, t0, Operand(1 << Map::Counter::kShift));
         __ Branch(USE_DELAY_SLOT, &allocate, ne, t2,
                   Operand(Map::kSlackTrackingCounterEnd));
         __ sw(t0, bit_field3);  // In delay slot.
 
         __ Push(a1, a2, a1);  // a1 = Constructor.
         __ CallRuntime(Runtime::kFinalizeInstanceSize, 1);
 
         __ Pop(a1, a2);
         __ li(t2, Operand(Map::kSlackTrackingCounterEnd - 1));
 
         __ bind(&allocate);
       }
 
       // Now allocate the JSObject on the heap.
       // a1: constructor function
       // a2: initial map
+      Label rt_call_reload_new_target;
       __ lbu(a3, FieldMemOperand(a2, Map::kInstanceSizeOffset));
       if (create_memento) {
         __ Addu(a3, a3, Operand(AllocationMemento::kSize / kPointerSize));
       }
 
-      __ Allocate(a3, t4, t5, t6, &rt_call, SIZE_IN_WORDS);
+      __ Allocate(a3, t4, t5, t6, &rt_call_reload_new_target, SIZE_IN_WORDS);
 
       // Allocated the JSObject, now initialize the fields. Map is set to
       // initial map and properties and elements are set to empty fixed array.
       // a1: constructor function
       // a2: initial map
       // a3: object size (including memento if create_memento)
       // t4: JSObject (not tagged)
       __ LoadRoot(t6, Heap::kEmptyFixedArrayRootIndex);
       __ mov(t5, t4);
       __ sw(a2, MemOperand(t5, JSObject::kMapOffset));
@@ skipping 67 matching lines @@
         __ InitializeFieldsWithFiller(t5, a0, t7);
       }
 
       // Add the object tag to make the JSObject real, so that we can continue
       // and jump into the continuation code at any time from now on.
       __ Addu(t4, t4, Operand(kHeapObjectTag));
 
       // Continue with JSObject being successfully allocated.
       // t4: JSObject
       __ jmp(&allocated);
+
+      // Reload the original constructor and fall-through.
+      __ bind(&rt_call_reload_new_target);
+      __ lw(a3, MemOperand(sp, 0 * kPointerSize));
     }
 
     // Allocate the new receiver object using the runtime call.
     // a1: constructor function
+    // a3: original constructor
     __ bind(&rt_call);
-    Generate_Runtime_NewObject(masm, create_memento, a1, &count_incremented,
-                               &allocated);
+    if (create_memento) {
+      // Get the cell or allocation site.
+      __ lw(a2, MemOperand(sp, 3 * kPointerSize));
+      __ push(a2);  // argument 1: allocation site
+    }
+
+    __ Push(a1, a3);  // arguments 2-3 / 1-2
+    if (create_memento) {
+      __ CallRuntime(Runtime::kNewObjectWithAllocationSite, 3);
+    } else {
+      __ CallRuntime(Runtime::kNewObject, 2);
+    }
+    __ mov(t4, v0);
+
+    // Runtime_NewObjectWithAllocationSite increments allocation count.
+    // Skip the increment.
+    Label count_incremented;
+    if (create_memento) {
+      __ jmp(&count_incremented);
+    }
 
     // Receiver for constructor call allocated.
     // t4: JSObject
     __ bind(&allocated);
 
     if (create_memento) {
       __ lw(a2, MemOperand(sp, 3 * kPointerSize));
       __ LoadRoot(t5, Heap::kUndefinedValueRootIndex);
       __ Branch(&count_incremented, eq, a2, Operand(t5));
       // a2 is an AllocationSite. We are creating a memento from it, so we
@@ skipping 1201 matching lines @@
   }
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS