Cleanup Generate_JSConstructStubHelper a bit.

src/arm64/builtins-arm64.cc

 // Copyright 2013 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_ARM64
 
 #include "src/codegen.h"
 #include "src/debug.h"
@@ skipping 284 matching lines @@
   __ B(hs, &ok);
 
   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.
-    __ Peek(x4, 3 * kXRegSize);
-    __ Push(x4);
-    __ Push(x1);  // Argument for Runtime_NewObject.
-    __ Push(original_constructor);
-    __ CallRuntime(Runtime::kNewObjectWithAllocationSite, 3);
-    __ Mov(x4, x0);
-    // If we ended up using the runtime, and we want a memento, then the
-    // runtime call made it for us, and we shouldn't do create count
-    // increment.
-    __ jmp(count_incremented);
-  } else {
-    __ Push(x1);  // Argument for Runtime_NewObject.
-    __ Push(original_constructor);
-    __ CallRuntime(Runtime::kNewObject, 2);
-    __ Mov(x4, x0);
-    __ jmp(allocated);
-  }
-}
-
-
 static void Generate_JSConstructStubHelper(MacroAssembler* masm,
                                            bool is_api_function,
                                            bool create_memento) {
   // ----------- S t a t e -------------
   //  -- x0     : number of arguments
   //  -- x1     : constructor function
   //  -- x2     : allocation site or undefined
   //  -- x3    : original constructor
   //  -- lr     : return address
   //  -- sp[...]: constructor arguments
@@ skipping 19 matching lines @@
     Register constructor = x1;
     Register original_constructor = x3;
 
     // Preserve the incoming parameters on the stack.
     __ SmiTag(argc);
     __ Push(argc, constructor, original_constructor);
     // sp[0]: new.target
     // sp[1]: Constructor function.
     // sp[2]: number of arguments (smi-tagged)
 
-    Label rt_call, count_incremented, allocated, normal_new;
-    __ Cmp(constructor, original_constructor);
-    __ B(eq, &normal_new);
-    Generate_Runtime_NewObject(masm, create_memento, original_constructor,
-                               &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);
       __ Mov(x2, Operand(debug_step_in_fp));
       __ Ldr(x2, MemOperand(x2));
       __ Cbnz(x2, &rt_call);
+
+      // Fall back to runtime if the original constructor and function differ.
+      __ Cmp(constructor, original_constructor);
+      __ B(ne, &rt_call);
+
       // Load the initial map and verify that it is in fact a map.
       Register init_map = x2;
       __ Ldr(init_map,
              FieldMemOperand(constructor,
                              JSFunction::kPrototypeOrInitialMapOffset));
       __ JumpIfSmi(init_map, &rt_call);
       __ JumpIfNotObjectType(init_map, x10, x11, MAP_TYPE, &rt_call);
 
       // Check that the constructor is not constructing a JSFunction (see
       // comments in Runtime_NewObject in runtime.cc). In which case the initial
@@ skipping 20 matching lines @@
         // Push the constructor and map to the stack, and the constructor again
         // as argument to the runtime call.
         __ Push(constructor, init_map, constructor);
         __ CallRuntime(Runtime::kFinalizeInstanceSize, 1);
         __ Pop(init_map, constructor);
         __ Mov(constructon_count, Operand(Map::kSlackTrackingCounterEnd - 1));
         __ Bind(&allocate);
       }
 
       // Now allocate the JSObject on the heap.
+      Label rt_call_reload_new_target;
       Register obj_size = x3;
       Register new_obj = x4;
       __ Ldrb(obj_size, FieldMemOperand(init_map, Map::kInstanceSizeOffset));
       if (create_memento) {
         __ Add(x7, obj_size,
                Operand(AllocationMemento::kSize / kPointerSize));
-        __ Allocate(x7, new_obj, x10, x11, &rt_call, SIZE_IN_WORDS);
+        __ Allocate(x7, new_obj, x10, x11, &rt_call_reload_new_target,
+                    SIZE_IN_WORDS);
       } else {
-        __ Allocate(obj_size, new_obj, x10, x11, &rt_call, SIZE_IN_WORDS);
+        __ Allocate(obj_size, new_obj, x10, x11, &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.
       // NB. the object pointer is not tagged, so MemOperand is used.
       Register empty = x5;
       __ LoadRoot(empty, Heap::kEmptyFixedArrayRootIndex);
       __ Str(init_map, MemOperand(new_obj, JSObject::kMapOffset));
       STATIC_ASSERT(JSObject::kElementsOffset ==
           (JSObject::kPropertiesOffset + kPointerSize));
@@ skipping 73 matching lines @@
         first_prop = NoReg;
         prop_fields = NoReg;
       }
 
       // 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.
       __ Add(new_obj, new_obj, kHeapObjectTag);
 
       // Continue with JSObject being successfully allocated.
       __ B(&allocated);
+
+      // Reload the original constructor and fall-through.
+      __ Bind(&rt_call_reload_new_target);
+      __ Peek(x3, 0 * kXRegSize);
     }
 
     // Allocate the new receiver object using the runtime call.
+    // x1: constructor function
+    // x3: original constructor
     __ Bind(&rt_call);
-    Generate_Runtime_NewObject(masm, create_memento, constructor,
-                               &count_incremented, &allocated);
+    Label count_incremented;
+    if (create_memento) {
+      // Get the cell or allocation site.
+      __ Peek(x4, 3 * kXRegSize);
+      __ Push(x4, constructor, original_constructor);  // arguments 1-3
+      __ CallRuntime(Runtime::kNewObjectWithAllocationSite, 3);
+      __ Mov(x4, x0);
+      // If we ended up using the runtime, and we want a memento, then the
+      // runtime call made it for us, and we shouldn't do create count
+      // increment.
+      __ B(&count_incremented);
+    } else {
+      __ Push(constructor, original_constructor);  // arguments 1-2
+      __ CallRuntime(Runtime::kNewObject, 2);
+      __ Mov(x4, x0);
+    }
 
     // Receiver for constructor call allocated.
     // x4: JSObject
     __ Bind(&allocated);
 
     if (create_memento) {
       __ Peek(x10, 3 * kXRegSize);
       __ JumpIfRoot(x10, Heap::kUndefinedValueRootIndex, &count_incremented);
       // r2 is an AllocationSite. We are creating a memento from it, so we
       // need to increment the memento create count.
@@ skipping 1250 matching lines @@
   }
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM