Clean up aligned allocation code in preparation for SIMD alignments.

test/cctest/test-heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1764 matching lines @@
   // Normally sweeping would not be complete here, but no guarantees.
 
   CHECK_EQ(initial_size, static_cast<int>(CcTest::heap()->SizeOfObjects()));
 
   // Waiting for sweeper threads should not change heap size.
   if (collector->sweeping_in_progress()) {
     collector->EnsureSweepingCompleted();
   }
   CHECK_EQ(initial_size, static_cast<int>(CcTest::heap()->SizeOfObjects()));
 }
 

[Hannes Payer (out of office), 2015/05/26 09:22:29]

It would be nice to have test for all the aligned allocation functions as well.
Unfortunately, we do not have that. Would you mind adding some tests?

 
+TEST(TestAlignmentCalculations) {
+  // Maximum fill amounts should be consistent.
+  int maximum_double_misalignment = kDoubleSize - kPointerSize;
+  int max_word_fill = Heap::GetMaximumFillToAlign(kWordAligned);
+  CHECK_EQ(0, max_word_fill);
+  int max_double_fill = Heap::GetMaximumFillToAlign(kDoubleAligned);
+  CHECK_EQ(maximum_double_misalignment, max_double_fill);
+  int max_double_unaligned_fill = Heap::GetMaximumFillToAlign(kDoubleUnaligned);
+  CHECK_EQ(maximum_double_misalignment, max_double_unaligned_fill);
+
+  Address base = reinterpret_cast<Address>(NULL);
+  int fill = 0;
+
+  // Word alignment never requires fill.
+  fill = Heap::GetFillToAlign(base, kWordAligned);
+  CHECK_EQ(0, fill);
+  fill = Heap::GetFillToAlign(base + kPointerSize, kWordAligned);
+  CHECK_EQ(0, fill);
+
+  // No fill is required when address is double aligned.
+  fill = Heap::GetFillToAlign(base, kDoubleAligned);
+  CHECK_EQ(0, fill);
+  // Fill is required if address is not double aligned.
+  fill = Heap::GetFillToAlign(base + kPointerSize, kDoubleAligned);
+  CHECK_EQ(maximum_double_misalignment, fill);
+  // kDoubleUnaligned has the opposite fill amounts.
+  fill = Heap::GetFillToAlign(base, kDoubleUnaligned);
+  CHECK_EQ(maximum_double_misalignment, fill);
+  fill = Heap::GetFillToAlign(base + kPointerSize, kDoubleUnaligned);
+  CHECK_EQ(0, fill);
+}
+
+
 TEST(TestSizeOfObjectsVsHeapIteratorPrecision) {
   CcTest::InitializeVM();
   HeapIterator iterator(CcTest::heap());
   intptr_t size_of_objects_1 = CcTest::heap()->SizeOfObjects();
   intptr_t size_of_objects_2 = 0;
   for (HeapObject* obj = iterator.next();
        obj != NULL;
        obj = iterator.next()) {
     if (!obj->IsFreeSpace()) {
       size_of_objects_2 += obj->Size();
@@ skipping 3754 matching lines @@
   size_t counter2 = 2000;
   tracer->SampleNewSpaceAllocation(time2, counter2);
   size_t bytes = tracer->NewSpaceAllocatedBytesInLast(1000);
   CHECK_EQ(10000, bytes);
   int time3 = 1000;
   size_t counter3 = 30000;
   tracer->SampleNewSpaceAllocation(time3, counter3);
   bytes = tracer->NewSpaceAllocatedBytesInLast(100);
   CHECK_EQ((counter3 - counter1) * 100 / (time3 - time1), bytes);
 }