Compiler changes for bitstring based type checks.

We guard the use of this feature with a compile-time flag,
set to true in this CL.

Boot image size for aosp_taimen-userdebug in AOSP master:
  - before:
    arm boot*.oat: 63604740
    arm64 boot*.oat: 74237864
  - after:
    arm boot*.oat: 63531172 (-72KiB, -0.1%)
    arm64 boot*.oat: 74135008 (-100KiB, -0.1%)

The new TypeCheckBenchmark yields the following changes
using the little cores of taimen fixed at 1.4016GHz:
                               32-bit        64-bit
  timeCheckCastLevel1ToLevel1  11.48->15.80 11.47->15.78
  timeCheckCastLevel2ToLevel1  15.08->15.79 15.08->15.79
  timeCheckCastLevel3ToLevel1  19.01->15.82 17.94->15.81
  timeCheckCastLevel9ToLevel1  42.55->15.79 42.63->15.81
  timeCheckCastLevel9ToLevel2  39.70->14.36 39.70->14.35
  timeInstanceOfLevel1ToLevel1 13.74->17.93 13.76->17.95
  timeInstanceOfLevel2ToLevel1 17.02->17.95 16.99->17.93
  timeInstanceOfLevel3ToLevel1 24.03->17.95 24.45->17.95
  timeInstanceOfLevel9ToLevel1 47.13->17.95 47.14->18.00
  timeInstanceOfLevel9ToLevel2 44.19->16.52 44.27->16.51
This suggests that the bitstring typecheck should not be
used for exact type checks which would be equivalent to the
"Level1ToLevel1" benchmark. Whether the implementation is
a beneficial replacement for the kClassHierarchyCheck and
kAbstractClassCheck on average depends on how many levels
from the target class (or Object for a negative result) is
a typical object's class.

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing --jit
Test: testrunner.py --host -t 670-bitstring-type-check
Test: Pixel 2 XL boots.
Test: testrunner.py --target --optimizing --jit
Test: testrunner.py --target -t 670-bitstring-type-check
Bug: 64692057
Bug: 71853552
Bug: 26687569
Change-Id: I538d7e036b5a8ae2cc3fe77662a5903d74854562
diff --git a/compiler/optimizing/graph_visualizer.cc b/compiler/optimizing/graph_visualizer.cc
index 12c6988..5519121 100644
--- a/compiler/optimizing/graph_visualizer.cc
+++ b/compiler/optimizing/graph_visualizer.cc
@@ -389,16 +389,23 @@
     StartAttributeStream("load_kind") << load_string->GetLoadKind();
   }
 
-  void VisitCheckCast(HCheckCast* check_cast) OVERRIDE {
-    StartAttributeStream("check_kind") << check_cast->GetTypeCheckKind();
+  void HandleTypeCheckInstruction(HTypeCheckInstruction* check) {
+    StartAttributeStream("check_kind") << check->GetTypeCheckKind();
     StartAttributeStream("must_do_null_check") << std::boolalpha
-        << check_cast->MustDoNullCheck() << std::noboolalpha;
+        << check->MustDoNullCheck() << std::noboolalpha;
+    if (check->GetTypeCheckKind() == TypeCheckKind::kBitstringCheck) {
+      StartAttributeStream("path_to_root") << std::hex
+          << "0x" << check->GetBitstringPathToRoot() << std::dec;
+      StartAttributeStream("mask") << std::hex << "0x" << check->GetBitstringMask() << std::dec;
+    }
+  }
+
+  void VisitCheckCast(HCheckCast* check_cast) OVERRIDE {
+    HandleTypeCheckInstruction(check_cast);
   }
 
   void VisitInstanceOf(HInstanceOf* instance_of) OVERRIDE {
-    StartAttributeStream("check_kind") << instance_of->GetTypeCheckKind();
-    StartAttributeStream("must_do_null_check") << std::boolalpha
-        << instance_of->MustDoNullCheck() << std::noboolalpha;
+    HandleTypeCheckInstruction(instance_of);
   }
 
   void VisitArrayLength(HArrayLength* array_length) OVERRIDE {
@@ -648,20 +655,32 @@
           << std::boolalpha << loop_info->IsIrreducible() << std::noboolalpha;
     }
 
+    // For the builder and the inliner, we want to add extra information on HInstructions
+    // that have reference types, and also HInstanceOf/HCheckcast.
     if ((IsPass(HGraphBuilder::kBuilderPassName)
         || IsPass(HInliner::kInlinerPassName))
-        && (instruction->GetType() == DataType::Type::kReference)) {
-      ReferenceTypeInfo info = instruction->IsLoadClass()
-        ? instruction->AsLoadClass()->GetLoadedClassRTI()
-        : instruction->GetReferenceTypeInfo();
+        && (instruction->GetType() == DataType::Type::kReference ||
+            instruction->IsInstanceOf() ||
+            instruction->IsCheckCast())) {
+      ReferenceTypeInfo info = (instruction->GetType() == DataType::Type::kReference)
+          ? instruction->IsLoadClass()
+              ? instruction->AsLoadClass()->GetLoadedClassRTI()
+              : instruction->GetReferenceTypeInfo()
+          : instruction->IsInstanceOf()
+              ? instruction->AsInstanceOf()->GetTargetClassRTI()
+              : instruction->AsCheckCast()->GetTargetClassRTI();
       ScopedObjectAccess soa(Thread::Current());
       if (info.IsValid()) {
         StartAttributeStream("klass")
             << mirror::Class::PrettyDescriptor(info.GetTypeHandle().Get());
-        StartAttributeStream("can_be_null")
-            << std::boolalpha << instruction->CanBeNull() << std::noboolalpha;
+        if (instruction->GetType() == DataType::Type::kReference) {
+          StartAttributeStream("can_be_null")
+              << std::boolalpha << instruction->CanBeNull() << std::noboolalpha;
+        }
         StartAttributeStream("exact") << std::boolalpha << info.IsExact() << std::noboolalpha;
-      } else if (instruction->IsLoadClass()) {
+      } else if (instruction->IsLoadClass() ||
+                 instruction->IsInstanceOf() ||
+                 instruction->IsCheckCast()) {
         StartAttributeStream("klass") << "unresolved";
       } else {
         // The NullConstant may be added to the graph during other passes that happen between