commit f0edfc355893d53d1104b05501c99ad5ccf305c4
author Hiroshi Yamauchi <yamauchi@google.com> Thu Sep 25 11:46:46 2014 -0700
committer Hiroshi Yamauchi <yamauchi@google.com> Thu Sep 25 15:53:54 2014 -0700
tree 7e1fa49875759512f5d02b1c45435d3e3366b920
parent 1ed5b27ee329208fd8ae22b8a9a61d708e2c1ffb

Some optimizations for the array alloc path.

- Force Array::Alloc() to be inlined.
- Simplify the array size overflow check.
- Turn fill_usable into a template parameter.
- Remove a branch in Array::DataOffset() and avoid
  Primitive::ComponentSize(), which has a switch, in the array alloc
  path.
- Strength reductions in the array size computation by using component
  size shifts instead of component sizes. Store component size shift
  in the upper 16 bits of primitive_type field.
- Speedup: ~4% (3435->3284) in MemAllocTest on N4.

Bug: 9986565

Change-Id: I4b142ffac4ab8b5b915836f1660a949d6442344c

runtime/mirror/object_test.cc

diff --git a/runtime/mirror/object_test.cc b/runtime/mirror/object_test.cc
index 1290a3d..7fa664d 100644
--- a/runtime/mirror/object_test.cc
+++ b/runtime/mirror/object_test.cc
@@ -162,19 +162,19 @@
   Class* c = class_linker_->FindSystemClass(soa.Self(), "[I");
   StackHandleScope<1> hs(soa.Self());
   MutableHandle<Array> a(
-      hs.NewHandle(Array::Alloc<true>(soa.Self(), c, 1, c->GetComponentSize(),
+      hs.NewHandle(Array::Alloc<true>(soa.Self(), c, 1, c->GetComponentSizeShift(),
                                       Runtime::Current()->GetHeap()->GetCurrentAllocator())));
   EXPECT_TRUE(c == a->GetClass());
   EXPECT_EQ(1, a->GetLength());
 
   c = class_linker_->FindSystemClass(soa.Self(), "[Ljava/lang/Object;");
-  a.Assign(Array::Alloc<true>(soa.Self(), c, 1, c->GetComponentSize(),
+  a.Assign(Array::Alloc<true>(soa.Self(), c, 1, c->GetComponentSizeShift(),
                               Runtime::Current()->GetHeap()->GetCurrentAllocator()));
   EXPECT_TRUE(c == a->GetClass());
   EXPECT_EQ(1, a->GetLength());
 
   c = class_linker_->FindSystemClass(soa.Self(), "[[Ljava/lang/Object;");
-  a.Assign(Array::Alloc<true>(soa.Self(), c, 1, c->GetComponentSize(),
+  a.Assign(Array::Alloc<true>(soa.Self(), c, 1, c->GetComponentSizeShift(),
                               Runtime::Current()->GetHeap()->GetCurrentAllocator()));
   EXPECT_TRUE(c == a->GetClass());
   EXPECT_EQ(1, a->GetLength());
@@ -185,26 +185,26 @@
   Class* c = class_linker_->FindSystemClass(soa.Self(), "[B");
   StackHandleScope<1> hs(soa.Self());
   MutableHandle<Array> a(
-      hs.NewHandle(Array::Alloc<true>(soa.Self(), c, 1, c->GetComponentSize(),
-                                      Runtime::Current()->GetHeap()->GetCurrentAllocator(), true)));
+      hs.NewHandle(Array::Alloc<true, true>(soa.Self(), c, 1, c->GetComponentSizeShift(),
+                                            Runtime::Current()->GetHeap()->GetCurrentAllocator())));
   EXPECT_TRUE(c == a->GetClass());
   EXPECT_LE(1, a->GetLength());
 
   c = class_linker_->FindSystemClass(soa.Self(), "[I");
-  a.Assign(Array::Alloc<true>(soa.Self(), c, 2, c->GetComponentSize(),
-                              Runtime::Current()->GetHeap()->GetCurrentAllocator(), true));
+  a.Assign(Array::Alloc<true, true>(soa.Self(), c, 2, c->GetComponentSizeShift(),
+                                    Runtime::Current()->GetHeap()->GetCurrentAllocator()));
   EXPECT_TRUE(c == a->GetClass());
   EXPECT_LE(2, a->GetLength());
 
   c = class_linker_->FindSystemClass(soa.Self(), "[Ljava/lang/Object;");
-  a.Assign(Array::Alloc<true>(soa.Self(), c, 2, c->GetComponentSize(),
-                              Runtime::Current()->GetHeap()->GetCurrentAllocator(), true));
+  a.Assign(Array::Alloc<true, true>(soa.Self(), c, 2, c->GetComponentSizeShift(),
+                                    Runtime::Current()->GetHeap()->GetCurrentAllocator()));
   EXPECT_TRUE(c == a->GetClass());
   EXPECT_LE(2, a->GetLength());
 
   c = class_linker_->FindSystemClass(soa.Self(), "[[Ljava/lang/Object;");
-  a.Assign(Array::Alloc<true>(soa.Self(), c, 2, c->GetComponentSize(),
-                             Runtime::Current()->GetHeap()->GetCurrentAllocator(), true));
+  a.Assign(Array::Alloc<true, true>(soa.Self(), c, 2, c->GetComponentSizeShift(),
+                                    Runtime::Current()->GetHeap()->GetCurrentAllocator()));
   EXPECT_TRUE(c == a->GetClass());
   EXPECT_LE(2, a->GetLength());
 }