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

1 files changed, 76 insertions, 16 deletions

diff --git a/compiler/optimizing/graph_checker.cc b/compiler/optimizing/graph_checker.cc
index c88baa8610..fbcbe3608e 100644
--- a/compiler/optimizing/graph_checker.cc
+++ b/compiler/optimizing/graph_checker.cc
@@ -25,6 +25,11 @@
 #include "base/bit_vector-inl.h"
 #include "base/scoped_arena_allocator.h"
 #include "base/scoped_arena_containers.h"
+#include "handle.h"
+#include "mirror/class.h"
+#include "obj_ptr-inl.h"
+#include "scoped_thread_state_change-inl.h"
+#include "subtype_check.h"
 
 namespace art {
 
@@ -548,30 +553,85 @@ void GraphChecker::VisitReturnVoid(HReturnVoid* ret) {
   }
 }
 
-void GraphChecker::VisitCheckCast(HCheckCast* check) {
-  VisitInstruction(check);
-  HInstruction* input = check->InputAt(1);
-  if (!input->IsLoadClass()) {
-    AddError(StringPrintf("%s:%d expects a HLoadClass as second input, not %s:%d.",
+void GraphChecker::CheckTypeCheckBitstringInput(HTypeCheckInstruction* check,
+                                                size_t input_pos,
+                                                bool check_value,
+                                                uint32_t expected_value,
+                                                const char* name) {
+  if (!check->InputAt(input_pos)->IsIntConstant()) {
+    AddError(StringPrintf("%s:%d (bitstring) expects a HIntConstant input %zu (%s), not %s:%d.",
                           check->DebugName(),
                           check->GetId(),
-                          input->DebugName(),
-                          input->GetId()));
+                          input_pos,
+                          name,
+                          check->InputAt(2)->DebugName(),
+                          check->InputAt(2)->GetId()));
+  } else if (check_value) {
+    uint32_t actual_value =
+        static_cast<uint32_t>(check->InputAt(input_pos)->AsIntConstant()->GetValue());
+    if (actual_value != expected_value) {
+      AddError(StringPrintf("%s:%d (bitstring) has %s 0x%x, not 0x%x as expected.",
+                            check->DebugName(),
+                            check->GetId(),
+                            name,
+                            actual_value,
+                            expected_value));
+    }
   }
 }
 
-void GraphChecker::VisitInstanceOf(HInstanceOf* instruction) {
-  VisitInstruction(instruction);
-  HInstruction* input = instruction->InputAt(1);
-  if (!input->IsLoadClass()) {
-    AddError(StringPrintf("%s:%d expects a HLoadClass as second input, not %s:%d.",
-                          instruction->DebugName(),
-                          instruction->GetId(),
-                          input->DebugName(),
-                          input->GetId()));
+void GraphChecker::HandleTypeCheckInstruction(HTypeCheckInstruction* check) {
+  VisitInstruction(check);
+  HInstruction* input = check->InputAt(1);
+  if (check->GetTypeCheckKind() == TypeCheckKind::kBitstringCheck) {
+    if (!input->IsNullConstant()) {
+      AddError(StringPrintf("%s:%d (bitstring) expects a HNullConstant as second input, not %s:%d.",
+                            check->DebugName(),
+                            check->GetId(),
+                            input->DebugName(),
+                            input->GetId()));
+    }
+    bool check_values = false;
+    BitString::StorageType expected_path_to_root = 0u;
+    BitString::StorageType expected_mask = 0u;
+    {
+      ScopedObjectAccess soa(Thread::Current());
+      ObjPtr<mirror::Class> klass = check->GetClass().Get();
+      MutexLock subtype_check_lock(Thread::Current(), *Locks::subtype_check_lock_);
+      SubtypeCheckInfo::State state = SubtypeCheck<ObjPtr<mirror::Class>>::GetState(klass);
+      if (state == SubtypeCheckInfo::kAssigned) {
+        expected_path_to_root =
+            SubtypeCheck<ObjPtr<mirror::Class>>::GetEncodedPathToRootForTarget(klass);
+        expected_mask = SubtypeCheck<ObjPtr<mirror::Class>>::GetEncodedPathToRootMask(klass);
+        check_values = true;
+      } else {
+        AddError(StringPrintf("%s:%d (bitstring) references a class with unassigned bitstring.",
+                              check->DebugName(),
+                              check->GetId()));
+      }
+    }
+    CheckTypeCheckBitstringInput(
+        check, /* input_pos */ 2, check_values, expected_path_to_root, "path_to_root");
+    CheckTypeCheckBitstringInput(check, /* input_pos */ 3, check_values, expected_mask, "mask");
+  } else {
+    if (!input->IsLoadClass()) {
+      AddError(StringPrintf("%s:%d (classic) expects a HLoadClass as second input, not %s:%d.",
+                            check->DebugName(),
+                            check->GetId(),
+                            input->DebugName(),
+                            input->GetId()));
+    }
   }
 }
 
+void GraphChecker::VisitCheckCast(HCheckCast* check) {
+  HandleTypeCheckInstruction(check);
+}
+
+void GraphChecker::VisitInstanceOf(HInstanceOf* instruction) {
+  HandleTypeCheckInstruction(instruction);
+}
+
 void GraphChecker::HandleLoop(HBasicBlock* loop_header) {
   int id = loop_header->GetBlockId();
   HLoopInformation* loop_information = loop_header->GetLoopInformation();