PPC: [stubs] Introduce a dedicated FastNewObjectStub.

src/ppc/code-stubs-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.
 
 #if V8_TARGET_ARCH_PPC
 
 #include "src/base/bits.h"
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
@@ skipping 4686 matching lines @@
 
   Label fast_elements_case;
   __ cmpi(r6, Operand(FAST_ELEMENTS));
   __ beq(&fast_elements_case);
   GenerateCase(masm, FAST_HOLEY_ELEMENTS);
 
   __ bind(&fast_elements_case);
   GenerateCase(masm, FAST_ELEMENTS);
 }
 
+void FastNewObjectStub::Generate(MacroAssembler* masm) {
+  // ----------- S t a t e -------------
+  //  -- r4 : target
+  //  -- r6 : new target
+  //  -- cp : context
+  //  -- lr : return address
+  // -----------------------------------
+  __ AssertFunction(r4);
+  __ AssertReceiver(r6);
+
+  // Verify that the new target is a JSFunction.
+  Label new_object;
+  __ CompareObjectType(r6, r5, r5, JS_FUNCTION_TYPE);
+  __ bne(&new_object);
+
+  // Load the initial map and verify that it's in fact a map.
+  __ LoadP(r5, FieldMemOperand(r6, JSFunction::kPrototypeOrInitialMapOffset));
+  __ JumpIfSmi(r5, &new_object);
+  __ CompareObjectType(r5, r3, r3, MAP_TYPE);
+  __ bne(&new_object);
+
+  // Fall back to runtime if the target differs from the new target's
+  // initial map constructor.
+  __ LoadP(r3, FieldMemOperand(r5, Map::kConstructorOrBackPointerOffset));
+  __ cmp(r3, r4);
+  __ bne(&new_object);
+
+  // Allocate the JSObject on the heap.
+  Label allocate, done_allocate;
+  __ lbz(r7, FieldMemOperand(r5, Map::kInstanceSizeOffset));
+  __ Allocate(r7, r3, r8, r9, &allocate, SIZE_IN_WORDS);
+  __ bind(&done_allocate);
+
+  // Initialize the JSObject fields.
+  __ StoreP(r5, MemOperand(r3, JSObject::kMapOffset));
+  __ LoadRoot(r6, Heap::kEmptyFixedArrayRootIndex);
+  __ StoreP(r6, MemOperand(r3, JSObject::kPropertiesOffset));
+  __ StoreP(r6, MemOperand(r3, JSObject::kElementsOffset));
+  STATIC_ASSERT(JSObject::kHeaderSize == 3 * kPointerSize);
+  __ addi(r4, r3, Operand(JSObject::kHeaderSize));
+
+  // ----------- S t a t e -------------
+  //  -- r3 : result (untagged)
+  //  -- r4 : result fields (untagged)
+  //  -- r8 : result end (untagged)
+  //  -- r5 : initial map
+  //  -- cp : context
+  //  -- lr : return address
+  // -----------------------------------
+
+  // Perform in-object slack tracking if requested.
+  Label slack_tracking;
+  STATIC_ASSERT(Map::kNoSlackTracking == 0);
+  __ LoadRoot(r9, Heap::kUndefinedValueRootIndex);
+  __ lwz(r6, FieldMemOperand(r5, Map::kBitField3Offset));
+  __ DecodeField<Map::ConstructionCounter>(r10, r6, SetRC);
+  __ bne(&slack_tracking, cr0);
+  {
+    // Initialize all in-object fields with undefined.
+    __ InitializeFieldsWithFiller(r4, r8, r9);
+
+    // Add the object tag to make the JSObject real.
+    __ addi(r3, r3, Operand(kHeapObjectTag));
+    __ Ret();
+  }
+  __ bind(&slack_tracking);
+  {
+    // Decrease generous allocation count.
+    STATIC_ASSERT(Map::ConstructionCounter::kNext == 32);
+    __ Add(r6, r6, -(1 << Map::ConstructionCounter::kShift), r0);
+    __ stw(r6, FieldMemOperand(r5, Map::kBitField3Offset));
+
+    // Initialize the in-object fields with undefined.
+    __ lbz(r7, FieldMemOperand(r5, Map::kUnusedPropertyFieldsOffset));
+    __ ShiftLeftImm(r7, r7, Operand(kPointerSizeLog2));
+    __ sub(r7, r8, r7);
+    __ InitializeFieldsWithFiller(r4, r7, r9);
+
+    // Initialize the remaining (reserved) fields with one pointer filler map.
+    __ LoadRoot(r9, Heap::kOnePointerFillerMapRootIndex);
+    __ InitializeFieldsWithFiller(r4, r8, r9);
+
+    // Add the object tag to make the JSObject real.
+    __ addi(r3, r3, Operand(kHeapObjectTag));
+
+    // Check if we can finalize the instance size.
+    __ cmpi(r10, Operand(Map::kSlackTrackingCounterEnd));
+    __ Ret(ne);
+
+    // Finalize the instance size.
+    {
+      FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
+      __ Push(r3, r5);
+      __ CallRuntime(Runtime::kFinalizeInstanceSize);
+      __ Pop(r3);
+    }
+    __ Ret();
+  }
+
+  // Fall back to %AllocateInNewSpace.
+  __ bind(&allocate);
+  {
+    FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
+    STATIC_ASSERT(kSmiTag == 0);
+    __ ShiftLeftImm(r7, r7,
+                    Operand(kPointerSizeLog2 + kSmiTagSize + kSmiShiftSize));
+    __ Push(r5, r7);
+    __ CallRuntime(Runtime::kAllocateInNewSpace);
+    __ Pop(r5);
+  }
+  __ subi(r3, r3, Operand(kHeapObjectTag));
+  __ lbz(r8, FieldMemOperand(r5, Map::kInstanceSizeOffset));
+  __ ShiftLeftImm(r8, r8, Operand(kPointerSizeLog2));
+  __ add(r8, r3, r8);
+  __ b(&done_allocate);
+
+  // Fall back to %NewObject.
+  __ bind(&new_object);
+  __ Push(r4, r6);
+  __ TailCallRuntime(Runtime::kNewObject);
+}
+
 void FastNewRestParameterStub::Generate(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- r4 : function
   //  -- cp : context
   //  -- fp : frame pointer
   //  -- lr : return address
   // -----------------------------------
   __ AssertFunction(r4);
 
   // For Ignition we need to skip all possible handler/stub frames until
@@ skipping 1016 matching lines @@
   CallApiFunctionAndReturn(masm, api_function_address, thunk_ref,
                            kStackUnwindSpace, NULL, return_value_operand, NULL);
 }
 
 
 #undef __
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_PPC