Clean up aligned allocation code in preparation for SIMD alignments.

src/heap/heap.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"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/base/bits.h"
 #include "src/base/once.h"
@@ skipping 1964 matching lines @@
 STATIC_ASSERT((ConstantPoolArray::kExtendedFirstOffset &
                kDoubleAlignmentMask) == 0);  // NOLINT
 STATIC_ASSERT((FixedTypedArrayBase::kDataOffset & kDoubleAlignmentMask) ==
               0);  // NOLINT
 #ifdef V8_HOST_ARCH_32_BIT
 STATIC_ASSERT((HeapNumber::kValueOffset & kDoubleAlignmentMask) !=
               0);  // NOLINT
 #endif
 
 
-HeapObject* Heap::EnsureAligned(HeapObject* object, int size,
-                                AllocationAlignment alignment) {
-  if (alignment == kDoubleAligned &&
-      (OffsetFrom(object->address()) & kDoubleAlignmentMask) != 0) {
-    CreateFillerObjectAt(object->address(), kPointerSize);
-    return HeapObject::FromAddress(object->address() + kPointerSize);
-  } else if (alignment == kDoubleUnaligned &&
-             (OffsetFrom(object->address()) & kDoubleAlignmentMask) == 0) {
-    CreateFillerObjectAt(object->address(), kPointerSize);
-    return HeapObject::FromAddress(object->address() + kPointerSize);
-  } else {
-    CreateFillerObjectAt(object->address() + size - kPointerSize, kPointerSize);
-    return object;
+int Heap::GetMaximumFillToAlign(AllocationAlignment alignment) {
+  switch (alignment) {
+    case kWordAligned:
+      return 0;
+    case kDoubleAligned:
+    case kDoubleUnaligned:
+      return kDoubleSize - kPointerSize;
+    default:
+      UNREACHABLE();
   }
+  return 0;
 }
 
 
-HeapObject* Heap::PrecedeWithFiller(HeapObject* object) {
-  CreateFillerObjectAt(object->address(), kPointerSize);
-  return HeapObject::FromAddress(object->address() + kPointerSize);
+int Heap::GetFillToAlign(Address address, AllocationAlignment alignment) {
+  intptr_t offset = OffsetFrom(address);
+  if (alignment == kDoubleAligned && (offset & kDoubleAlignmentMask) != 0)
+    return kPointerSize;
+  if (alignment == kDoubleUnaligned && (offset & kDoubleAlignmentMask) == 0)
+    return kDoubleSize - kPointerSize;  // No fill if double is always aligned.
+  return 0;
+}
+
+
+HeapObject* Heap::PrecedeWithFiller(HeapObject* object, int filler_size) {
+  CreateFillerObjectAt(object->address(), filler_size);
+  return HeapObject::FromAddress(object->address() + filler_size);
+}
+
+
+HeapObject* Heap::AlignWithFiller(HeapObject* object, int object_size,
+                                  int allocation_size,
+                                  AllocationAlignment alignment) {
+  int filler_size = allocation_size - object_size;
+  DCHECK(filler_size > 0);
+  int pre_filler = GetFillToAlign(object->address(), alignment);
+  if (pre_filler) {
+    object = PrecedeWithFiller(object, pre_filler);
+    filler_size -= pre_filler;
+  }
+  if (filler_size)
+    CreateFillerObjectAt(object->address() + object_size, filler_size);
+  return object;
 }
 
 
 HeapObject* Heap::DoubleAlignForDeserialization(HeapObject* object, int size) {
-  return EnsureAligned(object, size, kDoubleAligned);
+  return AlignWithFiller(object, size, size + kPointerSize, kDoubleAligned);
 }
 
 
 enum LoggingAndProfiling {
   LOGGING_AND_PROFILING_ENABLED,
   LOGGING_AND_PROFILING_DISABLED
 };
 
 
 enum MarksHandling { TRANSFER_MARKS, IGNORE_MARKS };
@@ skipping 4570 matching lines @@
     *object_type = "CODE_TYPE";                                                \
     *object_sub_type = "CODE_AGE/" #name;                                      \
     return true;
     CODE_AGE_LIST_COMPLETE(COMPARE_AND_RETURN_NAME)
 #undef COMPARE_AND_RETURN_NAME
   }
   return false;
 }
 }
 }  // namespace v8::internal