PPC: Cleanup Generate_JSConstructStubHelper a bit.

src/ppc/builtins-ppc.cc

 // Copyright 2014 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_PPC
 
 #include "src/codegen.h"
 #include "src/debug.h"
@@ skipping 289 matching lines @@
   __ bge(&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) {
-  // ----------- S t a t e -------------
-  //  -- r4: argument for Runtime_NewObject
-  // -----------------------------------
-  Register result = r7;
-
-  if (create_memento) {
-    // Get the cell or allocation site.
-    __ LoadP(r5, MemOperand(sp, 3 * kPointerSize));
-    __ Push(r5, r4, original_constructor);
-    __ CallRuntime(Runtime::kNewObjectWithAllocationSite, 3);
-    __ mr(result, r3);
-    // Runtime_NewObjectWithAllocationSite increments allocation count.
-    // Skip the increment.
-    __ b(count_incremented);
-  } else {
-    __ Push(r4, original_constructor);
-    __ CallRuntime(Runtime::kNewObject, 2);
-    __ mr(result, r3);
-    __ b(allocated);
-  }
-}
-
-
 static void Generate_JSConstructStubHelper(MacroAssembler* masm,
                                            bool is_api_function,
                                            bool create_memento) {
   // ----------- S t a t e -------------
   //  -- r3     : number of arguments
   //  -- r4     : constructor function
   //  -- r5     : allocation site or undefined
   //  -- r6     : original constructor
   //  -- lr     : return address
   //  -- sp[...]: constructor arguments
@@ skipping 10 matching lines @@
 
     if (create_memento) {
       __ AssertUndefinedOrAllocationSite(r5, r7);
       __ push(r5);
     }
 
     // Preserve the incoming parameters on the stack.
     __ SmiTag(r3);
     __ Push(r3, r4, r6);
 
-    Label rt_call, allocated, normal_new, count_incremented;
-    __ cmp(r4, r6);
-    __ beq(&normal_new);
-
-    // Original constructor and function are different.
-    Generate_Runtime_NewObject(masm, create_memento, r6, &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(r5, Operand(debug_step_in_fp));
       __ LoadP(r5, MemOperand(r5));
       __ cmpi(r5, Operand::Zero());
       __ bne(&rt_call);
 
+      // Fall back to runtime if the original constructor and function differ.
+      __ cmp(r4, r6);
+      __ bne(&rt_call);
+
       // Load the initial map and verify that it is in fact a map.
       // r4: constructor function
       __ LoadP(r5,
                FieldMemOperand(r4, JSFunction::kPrototypeOrInitialMapOffset));
       __ JumpIfSmi(r5, &rt_call);
-      __ CompareObjectType(r5, r6, r7, MAP_TYPE);
+      __ CompareObjectType(r5, r8, r7, MAP_TYPE);
       __ bne(&rt_call);
 
       // 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.
       // r4: constructor function
       // r5: initial map
-      __ CompareInstanceType(r5, r6, JS_FUNCTION_TYPE);
+      __ CompareInstanceType(r5, r8, JS_FUNCTION_TYPE);
       __ beq(&rt_call);
 
       if (!is_api_function) {
         Label allocate;
         MemOperand bit_field3 = FieldMemOperand(r5, Map::kBitField3Offset);
         // Check if slack tracking is enabled.
         __ lwz(r7, bit_field3);
         __ DecodeField<Map::Counter>(r11, r7);
         __ cmpi(r11, Operand(Map::kSlackTrackingCounterEnd));
         __ blt(&allocate);
         // Decrease generous allocation count.
         __ Add(r7, r7, -(1 << Map::Counter::kShift), r0);
         __ stw(r7, bit_field3);
         __ cmpi(r11, Operand(Map::kSlackTrackingCounterEnd));
         __ bne(&allocate);
 
         __ push(r4);
 
         __ Push(r5, r4);  // r4 = constructor
         __ CallRuntime(Runtime::kFinalizeInstanceSize, 1);
 
         __ Pop(r4, r5);
 
         __ bind(&allocate);
       }
 
       // Now allocate the JSObject on the heap.
       // r4: constructor function
       // r5: initial map
+      Label rt_call_reload_new_target;
       __ lbz(r6, FieldMemOperand(r5, Map::kInstanceSizeOffset));
       if (create_memento) {
         __ addi(r6, r6, Operand(AllocationMemento::kSize / kPointerSize));
       }
 
-      __ Allocate(r6, r7, r8, r9, &rt_call, SIZE_IN_WORDS);
+      __ Allocate(r6, r7, r8, r9, &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.
       // r4: constructor function
       // r5: initial map
       // r6: object size (including memento if create_memento)
       // r7: JSObject (not tagged)
       __ LoadRoot(r9, Heap::kEmptyFixedArrayRootIndex);
       __ mr(r8, r7);
       __ StoreP(r5, MemOperand(r8, JSObject::kMapOffset));
@@ skipping 64 matching lines @@
         __ InitializeFieldsWithFiller(r8, r9, r10);
       }
 
       // 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.
       __ addi(r7, r7, Operand(kHeapObjectTag));
 
       // Continue with JSObject being successfully allocated
       // r7: JSObject
       __ b(&allocated);
+
+      // Reload the original constructor and fall-through.
+      __ bind(&rt_call_reload_new_target);
+      __ LoadP(r6, MemOperand(sp, 0 * kPointerSize));
     }
 
     // Allocate the new receiver object using the runtime call.
     // r4: constructor function
+    // r6: original constructor
     __ bind(&rt_call);
-    Generate_Runtime_NewObject(masm, create_memento, r4, &count_incremented,
-                               &allocated);
+    if (create_memento) {
+      // Get the cell or allocation site.
+      __ LoadP(r5, MemOperand(sp, 3 * kPointerSize));
+      __ Push(r5, r4, r6);
+      __ CallRuntime(Runtime::kNewObjectWithAllocationSite, 3);
+    } else {
+      __ Push(r4, r6);
+      __ CallRuntime(Runtime::kNewObject, 2);
+    }
+    __ mr(r7, r3);
+
+    // Runtime_NewObjectWithAllocationSite increments allocation count.
+    // Skip the increment.
+    Label count_incremented;
+    if (create_memento) {
+      __ b(&count_incremented);
+    }
 
     // Receiver for constructor call allocated.
     // r7: JSObject
     __ bind(&allocated);
 
     if (create_memento) {
       __ LoadP(r5, MemOperand(sp, 3 * kPointerSize));
       __ LoadRoot(r8, Heap::kUndefinedValueRootIndex);
       __ cmp(r5, r8);
       __ beq(&count_incremented);
@@ skipping 66 matching lines @@
     // sp[2]: number of arguments (smi-tagged)
     __ LoadP(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
 
     // If the result is an object (in the ECMA sense), we should get rid
     // of the receiver and use the result; see ECMA-262 section 13.2.2-7
     // on page 74.
     Label use_receiver, exit;
 
     // If the result is a smi, it is *not* an object in the ECMA sense.
     // r3: result
-    // sp[0]: receiver (newly allocated object)
+    // sp[0]: receiver
     // sp[1]: new.target
     // sp[2]: number of arguments (smi-tagged)
     __ JumpIfSmi(r3, &use_receiver);
 
     // If the type of the result (stored in its map) is less than
     // FIRST_SPEC_OBJECT_TYPE, it is not an object in the ECMA sense.
     __ CompareObjectType(r3, r4, r6, FIRST_SPEC_OBJECT_TYPE);
     __ bge(&exit);
 
     // Throw away the result of the constructor invocation and use the
@@ skipping 1172 matching lines @@
     __ bkpt(0);
   }
 }
 
 
 #undef __
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_PPC