Keep list of dex files for oat file in CompilerDriver.

Use this list to improve invoke-static/-direct dispatch for
intra-oat calls.

Also fix a latent ArmBaseRelativePatcher::ReserveSpaceEnd()
bug exposed by a buggy early version of this CL: when we
have unresolved patches at the end of all code, we need to
emit a final thunk. Though the OatWriter will try to patch
the unresolved call to a trampoline at the beginning of the
oat file, that trampoline may be too far and the relative
patcher doesn't know about it anyway, so it needs to assume
that a thunk is needed.

This reduces the overall size of oat files present in dalvik
cache on Nexus 9 after first boot by over 1MiB, AOSP ToT,
aosp_flounder-userdebug build.

Change-Id: I98604b70cb17377eed057c1c23971865cf344e43

2 files changed, 20 insertions, 3 deletions

diff --git a/compiler/driver/compiler_driver.cc b/compiler/driver/compiler_driver.cc
index 8750aa8e4e..fb116bb3da 100644
--- a/compiler/driver/compiler_driver.cc
+++ b/compiler/driver/compiler_driver.cc
@@ -375,6 +375,7 @@ CompilerDriver::CompilerDriver(const CompilerOptions* compiler_options,
       timings_logger_(timer),
       compiler_context_(nullptr),
       support_boot_image_fixup_(instruction_set != kMips && instruction_set != kMips64),
+      dex_files_for_oat_file_(nullptr),
       compiled_method_storage_(swap_fd) {
   DCHECK(compiler_options_ != nullptr);
   DCHECK(verification_results_ != nullptr);
@@ -1371,8 +1372,7 @@ uint32_t CompilerDriver::GetReferenceDisableFlagOffset() const {
 }
 
 DexCacheArraysLayout CompilerDriver::GetDexCacheArraysLayout(const DexFile* dex_file) {
-  // Currently only image dex caches have fixed array layout.
-  return IsImage() && GetSupportBootImageFixup()
+  return ContainsElement(GetDexFilesForOatFile(), dex_file)
       ? DexCacheArraysLayout(GetInstructionSetPointerSize(instruction_set_), dex_file)
       : DexCacheArraysLayout();
 }
diff --git a/compiler/driver/compiler_driver.h b/compiler/driver/compiler_driver.h
index 485cdcfb1b..4ed4dc60d2 100644
--- a/compiler/driver/compiler_driver.h
+++ b/compiler/driver/compiler_driver.h
@@ -39,6 +39,7 @@
 #include "runtime.h"
 #include "safe_map.h"
 #include "thread_pool.h"
+#include "utils/array_ref.h"
 #include "utils/dex_cache_arrays_layout.h"
 
 namespace art {
@@ -101,7 +102,20 @@ class CompilerDriver {
 
   ~CompilerDriver();
 
-  void CompileAll(jobject class_loader, const std::vector<const DexFile*>& dex_files,
+  // Set dex files that will be stored in the oat file after being compiled.
+  void SetDexFilesForOatFile(const std::vector<const DexFile*>& dex_files) {
+    dex_files_for_oat_file_ = &dex_files;
+  }
+
+  // Get dex file that will be stored in the oat file after being compiled.
+  ArrayRef<const DexFile* const> GetDexFilesForOatFile() const {
+    return (dex_files_for_oat_file_ != nullptr)
+        ? ArrayRef<const DexFile* const>(*dex_files_for_oat_file_)
+        : ArrayRef<const DexFile* const>();
+  }
+
+  void CompileAll(jobject class_loader,
+                  const std::vector<const DexFile*>& dex_files,
                   TimingLogger* timings)
       REQUIRES(!Locks::mutator_lock_, !compiled_classes_lock_);
 
@@ -661,6 +675,9 @@ class CompilerDriver {
 
   bool support_boot_image_fixup_;
 
+  // List of dex files that will be stored in the oat file.
+  const std::vector<const DexFile*>* dex_files_for_oat_file_;
+
   CompiledMethodStorage compiled_method_storage_;
 
   friend class CompileClassVisitor;