Fixed layout for dex caches in boot image.
Define a fixed layout for dex cache arrays (type, method,
string and field arrays) for dex caches in the boot image.
This gives those arrays fixed offsets from the boot image
code and allows PC-relative addressing of their elements.
Use the PC-relative load on arm64 for relevant instructions,
i.e. invoke-static, invoke-direct, const-string,
const-class, check-cast and instance-of. This reduces the
arm64 boot.oat on Nexus 9 by 1.1MiB.
This CL provides the infrastructure and shows on the arm64
the gains that we can achieve by having fixed dex cache
arrays' layout. To fully use this for the boot images, we
need to implement the PC-relative addressing for other
architectures. To achieve similar gains for apps, we need
to move the dex cache arrays to a .bss section of the oat
file. These changes will be implemented in subsequent CLs.
(Also remove some compiler_driver.h dependencies to reduce
incremental build times.)
Change-Id: Ib1859fa4452d01d983fd92ae22b611f45a85d69b
diff --git a/compiler/utils/dex_cache_arrays_layout-inl.h b/compiler/utils/dex_cache_arrays_layout-inl.h
new file mode 100644
index 0000000..7d02ce3
--- /dev/null
+++ b/compiler/utils/dex_cache_arrays_layout-inl.h
@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_COMPILER_UTILS_DEX_CACHE_ARRAYS_LAYOUT_INL_H_
+#define ART_COMPILER_UTILS_DEX_CACHE_ARRAYS_LAYOUT_INL_H_
+
+#include "dex_cache_arrays_layout.h"
+
+#include "base/logging.h"
+#include "globals.h"
+#include "mirror/array-inl.h"
+#include "primitive.h"
+#include "utils.h"
+
+namespace mirror {
+class ArtField;
+class ArtMethod;
+class Class;
+class String;
+} // namespace mirror
+
+namespace art {
+
+inline DexCacheArraysLayout::DexCacheArraysLayout(const DexFile* dex_file)
+ : /* types_offset_ is always 0u */
+ methods_offset_(types_offset_ + ArraySize<mirror::Class>(dex_file->NumTypeIds())),
+ strings_offset_(methods_offset_ + ArraySize<mirror::ArtMethod>(dex_file->NumMethodIds())),
+ fields_offset_(strings_offset_ + ArraySize<mirror::String>(dex_file->NumStringIds())),
+ size_(fields_offset_ + ArraySize<mirror::ArtField>(dex_file->NumFieldIds())) {
+}
+
+inline size_t DexCacheArraysLayout::TypeOffset(uint32_t type_idx) const {
+ return types_offset_ + ElementOffset<mirror::Class>(type_idx);
+}
+
+inline size_t DexCacheArraysLayout::MethodOffset(uint32_t method_idx) const {
+ return methods_offset_ + ElementOffset<mirror::ArtMethod>(method_idx);
+}
+
+inline size_t DexCacheArraysLayout::StringOffset(uint32_t string_idx) const {
+ return strings_offset_ + ElementOffset<mirror::String>(string_idx);
+}
+
+inline size_t DexCacheArraysLayout::FieldOffset(uint32_t field_idx) const {
+ return fields_offset_ + ElementOffset<mirror::ArtField>(field_idx);
+}
+
+template <typename MirrorType>
+inline size_t DexCacheArraysLayout::ElementOffset(uint32_t idx) {
+ return mirror::Array::DataOffset(sizeof(mirror::HeapReference<MirrorType>)).Uint32Value() +
+ sizeof(mirror::HeapReference<MirrorType>) * idx;
+}
+
+template <typename MirrorType>
+inline size_t DexCacheArraysLayout::ArraySize(uint32_t num_elements) {
+ size_t array_size = mirror::ComputeArraySize(
+ num_elements, ComponentSizeShiftWidth<sizeof(mirror::HeapReference<MirrorType>)>());
+ DCHECK_NE(array_size, 0u); // No overflow expected for dex cache arrays.
+ return RoundUp(array_size, kObjectAlignment);
+}
+
+} // namespace art
+
+#endif // ART_COMPILER_UTILS_DEX_CACHE_ARRAYS_LAYOUT_INL_H_