Remove unused byte from Map::instance_sizes field.

src/mips64/builtins-mips64.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_MIPS64
 
@@ skipping 375 matching lines @@
     __ 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.
     if (FLAG_inline_new) {
-      Label undo_allocation;
       ExternalReference debug_step_in_fp =
           ExternalReference::debug_step_in_fp_address(isolate);
       __ li(a2, Operand(debug_step_in_fp));
       __ ld(a2, MemOperand(a2));
       __ Branch(&rt_call, ne, a2, Operand(zero_reg));
 
       // Load the initial map and verify that it is in fact a map.
       // a1: constructor function
       __ ld(a2, FieldMemOperand(a1, JSFunction::kPrototypeOrInitialMapOffset));
       __ JumpIfSmi(a2, &rt_call);
@@ skipping 71 matching lines @@
 
       if (!is_api_function) {
         Label no_inobject_slack_tracking;
 
         // Check if slack tracking is enabled.
         __ Branch(&no_inobject_slack_tracking, lt, a6,
                   Operand(static_cast<int64_t>(Map::kSlackTrackingCounterEnd)));
 
         // Allocate object with a slack.
         __ lwu(a0, FieldMemOperand(a2, Map::kInstanceSizesOffset));
-        __ Ext(a0, a0, Map::kPreAllocatedPropertyFieldsByte * kBitsPerByte,
-                kBitsPerByte);
+        __ Ext(a0, a0, Map::kInObjectPropertiesByte * kBitsPerByte,
+               kBitsPerByte);
+        __ lwu(a2, FieldMemOperand(a2, Map::kInstanceAttributesOffset));
+        __ Ext(a2, a2, Map::kUnusedPropertyFieldsByte * kBitsPerByte,
+               kBitsPerByte);
+        __ dsubu(a0, a0, a2);
         __ dsll(at, a0, kPointerSizeLog2);
         __ daddu(a0, t1, at);
         // a0: offset of first field after pre-allocated fields
         if (FLAG_debug_code) {
           __ dsll(at, a3, kPointerSizeLog2);
           __ Daddu(t2, t0, Operand(at));   // End of object.
           __ Assert(le, kUnexpectedNumberOfPreAllocatedPropertyFields,
               a0, Operand(t2));
         }
         __ InitializeFieldsWithFiller(t1, a0, t3);
@@ skipping 21 matching lines @@
         DCHECK_EQ(1 * kPointerSize, AllocationMemento::kAllocationSiteOffset);
         __ sd(t3, MemOperand(t1));
         __ Daddu(t1, t1, kPointerSize);
       } else {
         __ dsll(at, a3, kPointerSizeLog2);
         __ Daddu(a0, t0, Operand(at));  // End of object.
         __ InitializeFieldsWithFiller(t1, a0, t3);
       }
 
       // 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. Any
-      // failures need to undo the allocation, so that the heap is in a
-      // consistent state and verifiable.
+      // and jump into the continuation code at any time from now on.
       __ Daddu(t0, t0, Operand(kHeapObjectTag));
 
-      // Check if a non-empty properties array is needed. Continue with
-      // allocated object if not; allocate and initialize a FixedArray if yes.
-      // a1: constructor function
-      // t0: JSObject
-      // t1: start of next object (not tagged)
-      __ lbu(a3, FieldMemOperand(a2, Map::kUnusedPropertyFieldsOffset));
-      // The field instance sizes contains both pre-allocated property fields
-      // and in-object properties.
-      __ lw(a0, FieldMemOperand(a2, Map::kInstanceSizesOffset));
-      __ Ext(t2, a0, Map::kPreAllocatedPropertyFieldsByte * kBitsPerByte,
-             kBitsPerByte);
-      __ Daddu(a3, a3, Operand(t2));
-      __ Ext(t2, a0, Map::kInObjectPropertiesByte * kBitsPerByte,
-              kBitsPerByte);
-      __ dsubu(a3, a3, t2);
-
-      // Done if no extra properties are to be allocated.
-      __ Branch(&allocated, eq, a3, Operand(zero_reg));
-      __ Assert(greater_equal, kPropertyAllocationCountFailed,
-          a3, Operand(zero_reg));
-
-      // Scale the number of elements by pointer size and add the header for
-      // FixedArrays to the start of the next object calculation from above.
-      // a1: constructor
-      // a3: number of elements in properties array
-      // t0: JSObject
-      // t1: start of next object
-      __ Daddu(a0, a3, Operand(FixedArray::kHeaderSize / kPointerSize));
-      __ Allocate(
-          a0,
-          t1,
-          t2,
-          a2,
-          &undo_allocation,
-          static_cast<AllocationFlags>(RESULT_CONTAINS_TOP | SIZE_IN_WORDS));
-
-      // Initialize the FixedArray.
-      // a1: constructor
-      // a3: number of elements in properties array (untagged)
-      // t0: JSObject
-      // t1: start of FixedArray (untagged)
-      __ LoadRoot(t2, Heap::kFixedArrayMapRootIndex);
-      __ mov(a2, t1);
-      __ sd(t2, MemOperand(a2, JSObject::kMapOffset));
-      // Tag number of elements.
-      __ dsll32(a0, a3, 0);
-      __ sd(a0, MemOperand(a2, FixedArray::kLengthOffset));
-      __ Daddu(a2, a2, Operand(2 * kPointerSize));
-
-      DCHECK_EQ(0 * kPointerSize, JSObject::kMapOffset);
-      DCHECK_EQ(1 * kPointerSize, FixedArray::kLengthOffset);
-
-      // Initialize the fields to undefined.
-      // a1: constructor
-      // a2: First element of FixedArray (not tagged)
-      // a3: number of elements in properties array
-      // t0: JSObject
-      // t1: FixedArray (not tagged)
-      __ dsll(a7, a3, kPointerSizeLog2);
-      __ daddu(t2, a2, a7);  // End of object.
-      DCHECK_EQ(2 * kPointerSize, FixedArray::kHeaderSize);
-      if (!is_api_function || create_memento) {
-        __ LoadRoot(t3, Heap::kUndefinedValueRootIndex);
-      } else if (FLAG_debug_code) {
-        __ LoadRoot(a6, Heap::kUndefinedValueRootIndex);
-        __ Assert(eq, kUndefinedValueNotLoaded, t3, Operand(a6));
-      }
-      __ InitializeFieldsWithFiller(a2, t2, t3);
-
-      // Store the initialized FixedArray into the properties field of
-      // the JSObject.
-      // a1: constructor function
-      // t0: JSObject
-      // t1: FixedArray (not tagged)
-      __ Daddu(t1, t1, Operand(kHeapObjectTag));  // Add the heap tag.
-      __ sd(t1, FieldMemOperand(t0, JSObject::kPropertiesOffset));
-
       // Continue with JSObject being successfully allocated.
-      // a1: constructor function
       // a4: JSObject
       __ jmp(&allocated);
-
-      // Undo the setting of the new top so that the heap is verifiable. For
-      // example, the map's unused properties potentially do not match the
-      // allocated objects unused properties.
-      // t0: JSObject (previous new top)
-      __ bind(&undo_allocation);
-      __ UndoAllocationInNewSpace(t0, t1);
     }
 
     // Allocate the new receiver object using the runtime call.
     // a1: constructor function
     __ bind(&rt_call);
     Generate_Runtime_NewObject(masm, create_memento, a1, &count_incremented,
                                &allocated);
 
 
     // Receiver for constructor call allocated.
@@ skipping 1208 matching lines @@
   }
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS64