ART: Enable basic optimizations for try/catch

Generating code for try/catch methods requires having run at least the
instruction simplifier to remove redundant suspend checks. This patch
enables the first group of optimizations when try/catch is present.

Enabled optimizations:
1) IntrinsicsRecognizer
Does not modify the graph, only sets HInvoke::intrinsic_.

2) ConstantFolding
Does not deal with throwing instructions.

3) InstructionSimplifier
May remove a throwing instruction (e.g. LoadClass in VisitCheckCast),
or may turn a throwing instruction into a non-throwing one (ArraySet).
Their corresponding catch phi inputs are not removed but correctness
is preserved.

4) ReferenceTypePropagation
Does not modify the graph, only sets type properties. Typing of
LoadException from catch handler information was added.

5) DeadCodeElimination
Removing individual instructions is fine (same as 3). Removal of dead
blocks was disabled for try/catch.

Change-Id: I2722c3229eb8aaf326391e07f522dbf5186774b8

1 files changed, 17 insertions, 18 deletions

diff --git a/compiler/optimizing/optimizing_compiler.cc b/compiler/optimizing/optimizing_compiler.cc
index 866e71705f..bd40c9f639 100644
--- a/compiler/optimizing/optimizing_compiler.cc
+++ b/compiler/optimizing/optimizing_compiler.cc
@@ -359,11 +359,6 @@ static bool IsInstructionSetSupported(InstructionSet instruction_set) {
       || instruction_set == kX86_64;
 }
 
-static bool CanOptimize(const DexFile::CodeItem& code_item) {
-  // TODO: We currently cannot optimize methods with try/catch.
-  return code_item.tries_size_ == 0;
-}
-
 static void RunOptimizations(HOptimization* optimizations[],
                              size_t length,
                              PassObserver* pass_observer) {
@@ -470,6 +465,13 @@ static void RunOptimizations(HGraph* graph,
 
   RunOptimizations(optimizations1, arraysize(optimizations1), pass_observer);
 
+  if (graph->HasTryCatch()) {
+    // TODO: Update the optimizations below to work correctly under try/catch
+    //       semantics. The optimizations above suffice for running codegen
+    //       in the meanwhile.
+    return;
+  }
+
   MaybeRunInliner(graph, driver, stats, dex_compilation_unit, pass_observer, handles);
 
   HOptimization* optimizations2[] = {
@@ -529,6 +531,10 @@ CompiledMethod* OptimizingCompiler::CompileOptimized(HGraph* graph,
   RunOptimizations(graph, compiler_driver, compilation_stats_.get(),
                    dex_compilation_unit, pass_observer, &handles);
 
+  if (graph->HasTryCatch()) {
+    return nullptr;
+  }
+
   AllocateRegisters(graph, codegen, pass_observer);
 
   CodeVectorAllocator allocator;
@@ -717,7 +723,6 @@ CompiledMethod* OptimizingCompiler::TryCompile(const DexFile::CodeItem* code_ite
     }
   }
 
-  bool can_optimize = CanOptimize(*code_item);
   bool can_allocate_registers = RegisterAllocator::CanAllocateRegistersFor(*graph, instruction_set);
 
   // `run_optimizations_` is set explicitly (either through a compiler filter
@@ -738,16 +743,12 @@ CompiledMethod* OptimizingCompiler::TryCompile(const DexFile::CodeItem* code_ite
       }
     }
 
-    if (can_optimize) {
-      return CompileOptimized(graph,
-                              codegen.get(),
-                              compiler_driver,
-                              dex_compilation_unit,
-                              &pass_observer);
-    }
-  }
-
-  if (shouldOptimize && can_allocate_registers) {
+    return CompileOptimized(graph,
+                            codegen.get(),
+                            compiler_driver,
+                            dex_compilation_unit,
+                            &pass_observer);
+  } else if (shouldOptimize && can_allocate_registers) {
     LOG(FATAL) << "Could not allocate registers in optimizing compiler";
     UNREACHABLE();
   } else if (can_use_baseline) {
@@ -755,8 +756,6 @@ CompiledMethod* OptimizingCompiler::TryCompile(const DexFile::CodeItem* code_ite
 
     if (!run_optimizations_) {
       MaybeRecordStat(MethodCompilationStat::kNotOptimizedDisabled);
-    } else if (!can_optimize) {
-      MaybeRecordStat(MethodCompilationStat::kNotOptimizedTryCatch);
     } else if (!can_allocate_registers) {
       MaybeRecordStat(MethodCompilationStat::kNotOptimizedRegisterAllocator);
     }