Compilation filter

This CL introduces a static compilation filter mechanism intended
to allow us to reduce compilation time and space requirements until
we have a profiling mechanism in place.

It supports 5 modes of filtering:

   o interpret-only (compile nothing)
   o deferred-compilation (compile only those methods believe to be
     compute-intensive)
   o space (optimized for space)
   o balanced (best return on space investment)
   o speed (compile everything)

A future CL will allow the default filtering mode to be set
via system property.  For now, you can pass it in via command
line as follows:

   dalvikvm -compiler-filter:[interpret-only|defer-compilation|
                              space|balanced|speed]

or dex2oat --runtime-arg -compiler-filter:[one of the above modes]

Creating a file named art/SMALL_ART will force the filter
default to interpret-only.  Later on we'll move this capability
to a persistent system property.

or modify kDefaultCompilerFilter in runtime.h

It also changes the compiler driver to allow the compilers to
decline to compile a method by return NULL.

Change-Id: Ic73411818f8bb845a4a19a05b0395c50902c534f
(cherry picked from commit a024a0686c3b0fea13f362bff70d65981e5febc5)

1 files changed, 7 insertions, 3 deletions

diff --git a/compiler/driver/compiler_driver.cc b/compiler/driver/compiler_driver.cc
index 38d00a0804..e7ba402b21 100644
--- a/compiler/driver/compiler_driver.cc
+++ b/compiler/driver/compiler_driver.cc
@@ -334,8 +334,8 @@ extern "C" void compilerLLVMSetBitcodeFileName(art::CompilerDriver& driver,
                                                std::string const& filename);
 
 CompilerDriver::CompilerDriver(CompilerBackend compiler_backend, InstructionSet instruction_set,
-                               bool image, DescriptorSet* image_classes,
-                               size_t thread_count, bool dump_stats)
+                               bool image, DescriptorSet* image_classes, size_t thread_count,
+                               bool dump_stats)
     : compiler_backend_(compiler_backend),
       instruction_set_(instruction_set),
       freezing_constructor_lock_("freezing constructor lock"),
@@ -2253,6 +2253,10 @@ void CompilerDriver::CompileMethod(const DexFile::CodeItem* code_item, uint32_t
   } else {
     bool compile = verifier::MethodVerifier::IsCandidateForCompilation(code_item, access_flags);
     if (compile) {
+      // If we're doing the image, override the compiler filter to force full compilation.
+      if ((image_classes_.get() != NULL) && (image_classes_->size() != 0)) {
+        Runtime::Current()->SetCompilerFilter(Runtime::kSpeed);
+      }
       CompilerFn compiler = compiler_;
 #ifdef ART_SEA_IR_MODE
       bool use_sea = Runtime::Current()->IsSeaIRMode();
@@ -2261,9 +2265,9 @@ void CompilerDriver::CompileMethod(const DexFile::CodeItem* code_item, uint32_t
         compiler = sea_ir_compiler_;
       }
 #endif
+      // NOTE: if compiler declines to compile this method, it will return NULL.
       compiled_method = (*compiler)(*this, code_item, access_flags, invoke_type, class_def_idx,
                                     method_idx, class_loader, dex_file);
-      CHECK(compiled_method != NULL) << PrettyMethod(method_idx, dex_file);
     } else if (dex_to_dex_compilation_level != kDontDexToDexCompile) {
       // TODO: add a mode to disable DEX-to-DEX compilation ?
       (*dex_to_dex_compiler_)(*this, code_item, access_flags,