Revert "Fast-path for `HInstanceOf`/`kInterfaceCheck`."

This reverts commit 20668496dda44e4877d3c29afc22cd098701d461.

Reason for revert: DroidMonitor. Potential culprit for b/337042605 - verifying through ABTD before submission. 

Change-Id: I64db3d0e0e701a174add7787c8fa0dbf593fbb4b

5 files changed, 56 insertions, 287 deletions

diff --git a/compiler/optimizing/code_generator.h b/compiler/optimizing/code_generator.h
index 3ac4bd7dcc..970da76c43 100644
--- a/compiler/optimizing/code_generator.h
+++ b/compiler/optimizing/code_generator.h
@@ -461,13 +461,11 @@ class CodeGenerator : public DeletableArenaObject<kArenaAllocCodeGenerator> {
                          DataType::Type type2);
 
   bool InstanceOfNeedsReadBarrier(HInstanceOf* instance_of) {
-    // Used only for `kExactCheck`, `kAbstractClassCheck`, `kClassHierarchyCheck`,
-    // `kArrayObjectCheck` and `kInterfaceCheck`.
+    // Used only for kExactCheck, kAbstractClassCheck, kClassHierarchyCheck and kArrayObjectCheck.
     DCHECK(instance_of->GetTypeCheckKind() == TypeCheckKind::kExactCheck ||
            instance_of->GetTypeCheckKind() == TypeCheckKind::kAbstractClassCheck ||
            instance_of->GetTypeCheckKind() == TypeCheckKind::kClassHierarchyCheck ||
-           instance_of->GetTypeCheckKind() == TypeCheckKind::kArrayObjectCheck ||
-           instance_of->GetTypeCheckKind() == TypeCheckKind::kInterfaceCheck)
+           instance_of->GetTypeCheckKind() == TypeCheckKind::kArrayObjectCheck)
         << instance_of->GetTypeCheckKind();
     // If the target class is in the boot or app image, it's non-moveable and it doesn't matter
     // if we compare it with a from-space or to-space reference, the result is the same.
diff --git a/compiler/optimizing/code_generator_arm64.cc b/compiler/optimizing/code_generator_arm64.cc
index cfa28eda25..8a4b069e19 100644
--- a/compiler/optimizing/code_generator_arm64.cc
+++ b/compiler/optimizing/code_generator_arm64.cc
@@ -4135,16 +4135,15 @@ void LocationsBuilderARM64::VisitInstanceOf(HInstanceOf* instruction) {
     case TypeCheckKind::kExactCheck:
     case TypeCheckKind::kAbstractClassCheck:
     case TypeCheckKind::kClassHierarchyCheck:
-    case TypeCheckKind::kArrayObjectCheck:
-    case TypeCheckKind::kInterfaceCheck: {
+    case TypeCheckKind::kArrayObjectCheck: {
       bool needs_read_barrier = codegen_->InstanceOfNeedsReadBarrier(instruction);
       call_kind = needs_read_barrier ? LocationSummary::kCallOnSlowPath : LocationSummary::kNoCall;
-      baker_read_barrier_slow_path = (kUseBakerReadBarrier && needs_read_barrier) &&
-                                     (type_check_kind != TypeCheckKind::kInterfaceCheck);
+      baker_read_barrier_slow_path = kUseBakerReadBarrier && needs_read_barrier;
       break;
     }
     case TypeCheckKind::kArrayCheck:
     case TypeCheckKind::kUnresolvedCheck:
+    case TypeCheckKind::kInterfaceCheck:
       call_kind = LocationSummary::kCallOnSlowPath;
       break;
     case TypeCheckKind::kBitstringCheck:
@@ -4185,14 +4184,10 @@ void InstructionCodeGeneratorARM64::VisitInstanceOf(HInstanceOf* instruction) {
   const size_t num_temps = NumberOfInstanceOfTemps(codegen_->EmitReadBarrier(), type_check_kind);
   DCHECK_LE(num_temps, 1u);
   Location maybe_temp_loc = (num_temps >= 1) ? locations->GetTemp(0) : Location::NoLocation();
-  const uint32_t class_offset = mirror::Object::ClassOffset().Int32Value();
-  const uint32_t super_offset = mirror::Class::SuperClassOffset().Int32Value();
-  const uint32_t component_offset = mirror::Class::ComponentTypeOffset().Int32Value();
-  const uint32_t primitive_offset = mirror::Class::PrimitiveTypeOffset().Int32Value();
-  const uint32_t iftable_offset = mirror::Class::IfTableOffset().Uint32Value();
-  const uint32_t array_length_offset = mirror::Array::LengthOffset().Uint32Value();
-  const uint32_t object_array_data_offset =
-      mirror::Array::DataOffset(kHeapReferenceSize).Uint32Value();
+  uint32_t class_offset = mirror::Object::ClassOffset().Int32Value();
+  uint32_t super_offset = mirror::Class::SuperClassOffset().Int32Value();
+  uint32_t component_offset = mirror::Class::ComponentTypeOffset().Int32Value();
+  uint32_t primitive_offset = mirror::Class::PrimitiveTypeOffset().Int32Value();
 
   vixl::aarch64::Label done, zero;
   SlowPathCodeARM64* slow_path = nullptr;
@@ -4339,54 +4334,11 @@ void InstructionCodeGeneratorARM64::VisitInstanceOf(HInstanceOf* instruction) {
       break;
     }
 
+    case TypeCheckKind::kUnresolvedCheck:
     case TypeCheckKind::kInterfaceCheck: {
-      if (codegen_->InstanceOfNeedsReadBarrier(instruction)) {
-        DCHECK(locations->OnlyCallsOnSlowPath());
-        slow_path = new (codegen_->GetScopedAllocator()) TypeCheckSlowPathARM64(
-            instruction, /* is_fatal= */ false);
-        codegen_->AddSlowPath(slow_path);
-        if (codegen_->EmitNonBakerReadBarrier()) {
-          __ B(slow_path->GetEntryLabel());
-          break;
-        }
-        // For Baker read barrier, take the slow path while marking.
-        __ Cbnz(mr, slow_path->GetEntryLabel());
-      }
-
-      // Fast-path without read barriers.
-      UseScratchRegisterScope temps(GetVIXLAssembler());
-      Register temp = temps.AcquireW();
-      Register temp2 = temps.AcquireW();
-      // /* HeapReference<Class> */ temp = obj->klass_
-      __ Ldr(temp, HeapOperand(obj, class_offset));
-      GetAssembler()->MaybeUnpoisonHeapReference(temp);
-      // /* HeapReference<Class> */ temp = temp->iftable_
-      __ Ldr(temp, HeapOperand(temp, iftable_offset));
-      GetAssembler()->MaybeUnpoisonHeapReference(temp);
-      // Load the size of the `IfTable`. The `Class::iftable_` is never null.
-      __ Ldr(out, HeapOperand(temp, array_length_offset));
-      // Loop through the `IfTable` and check if any class matches.
-      vixl::aarch64::Label loop;
-      __ Bind(&loop);
-      __ Cbz(out, &done);  // If taken, the result in `out` is already 0 (false).
-      __ Ldr(temp2, HeapOperand(temp, object_array_data_offset));
-      GetAssembler()->MaybeUnpoisonHeapReference(temp2);
-      // Go to next interface.
-      __ Add(temp, temp, 2 * kHeapReferenceSize);
-      __ Sub(out, out, 2);
-      // Compare the classes and continue the loop if they do not match.
-      __ Cmp(cls, temp2);
-      __ B(ne, &loop);
-      __ Mov(out, 1);
-      if (zero.IsLinked()) {
-        __ B(&done);
-      }
-      break;
-    }
-
-    case TypeCheckKind::kUnresolvedCheck: {
       // Note that we indeed only call on slow path, but we always go
-      // into the slow path for the unresolved check case.
+      // into the slow path for the unresolved and interface check
+      // cases.
       //
       // We cannot directly call the InstanceofNonTrivial runtime
       // entry point without resorting to a type checking slow path
@@ -4629,7 +4581,7 @@ void InstructionCodeGeneratorARM64::VisitCheckCast(HCheckCast* instruction) {
                                        iftable_offset,
                                        maybe_temp2_loc,
                                        kWithoutReadBarrier);
-      // Load the size of the `IfTable`. The `Class::iftable_` is never null.
+      // Iftable is never null.
       __ Ldr(WRegisterFrom(maybe_temp2_loc), HeapOperand(temp.W(), array_length_offset));
       // Loop through the iftable and check if any class matches.
       vixl::aarch64::Label start_loop;
diff --git a/compiler/optimizing/code_generator_arm_vixl.cc b/compiler/optimizing/code_generator_arm_vixl.cc
index a7cc5a6d12..eb5fbc4364 100644
--- a/compiler/optimizing/code_generator_arm_vixl.cc
+++ b/compiler/optimizing/code_generator_arm_vixl.cc
@@ -8061,9 +8061,6 @@ void InstructionCodeGeneratorARMVIXL::VisitThrow(HThrow* instruction) {
 
 // Temp is used for read barrier.
 static size_t NumberOfInstanceOfTemps(bool emit_read_barrier, TypeCheckKind type_check_kind) {
-  if (type_check_kind == TypeCheckKind::kInterfaceCheck) {
-    return 1;
-  }
   if (emit_read_barrier &&
        (kUseBakerReadBarrier ||
           type_check_kind == TypeCheckKind::kAbstractClassCheck ||
@@ -8092,16 +8089,15 @@ void LocationsBuilderARMVIXL::VisitInstanceOf(HInstanceOf* instruction) {
     case TypeCheckKind::kExactCheck:
     case TypeCheckKind::kAbstractClassCheck:
     case TypeCheckKind::kClassHierarchyCheck:
-    case TypeCheckKind::kArrayObjectCheck:
-    case TypeCheckKind::kInterfaceCheck: {
+    case TypeCheckKind::kArrayObjectCheck: {
       bool needs_read_barrier = codegen_->InstanceOfNeedsReadBarrier(instruction);
       call_kind = needs_read_barrier ? LocationSummary::kCallOnSlowPath : LocationSummary::kNoCall;
-      baker_read_barrier_slow_path = (kUseBakerReadBarrier && needs_read_barrier) &&
-                                     (type_check_kind != TypeCheckKind::kInterfaceCheck);
+      baker_read_barrier_slow_path = kUseBakerReadBarrier && needs_read_barrier;
       break;
     }
     case TypeCheckKind::kArrayCheck:
     case TypeCheckKind::kUnresolvedCheck:
+    case TypeCheckKind::kInterfaceCheck:
       call_kind = LocationSummary::kCallOnSlowPath;
       break;
     case TypeCheckKind::kBitstringCheck:
@@ -8141,14 +8137,10 @@ void InstructionCodeGeneratorARMVIXL::VisitInstanceOf(HInstanceOf* instruction)
   const size_t num_temps = NumberOfInstanceOfTemps(codegen_->EmitReadBarrier(), type_check_kind);
   DCHECK_LE(num_temps, 1u);
   Location maybe_temp_loc = (num_temps >= 1) ? locations->GetTemp(0) : Location::NoLocation();
-  const uint32_t class_offset = mirror::Object::ClassOffset().Int32Value();
-  const uint32_t super_offset = mirror::Class::SuperClassOffset().Int32Value();
-  const uint32_t component_offset = mirror::Class::ComponentTypeOffset().Int32Value();
-  const uint32_t primitive_offset = mirror::Class::PrimitiveTypeOffset().Int32Value();
-  const uint32_t iftable_offset = mirror::Class::IfTableOffset().Uint32Value();
-  const uint32_t array_length_offset = mirror::Array::LengthOffset().Uint32Value();
-  const uint32_t object_array_data_offset =
-      mirror::Array::DataOffset(kHeapReferenceSize).Uint32Value();
+  uint32_t class_offset = mirror::Object::ClassOffset().Int32Value();
+  uint32_t super_offset = mirror::Class::SuperClassOffset().Int32Value();
+  uint32_t component_offset = mirror::Class::ComponentTypeOffset().Int32Value();
+  uint32_t primitive_offset = mirror::Class::PrimitiveTypeOffset().Int32Value();
   vixl32::Label done;
   vixl32::Label* const final_label = codegen_->GetFinalLabel(instruction, &done);
   SlowPathCodeARMVIXL* slow_path = nullptr;
@@ -8352,52 +8344,11 @@ void InstructionCodeGeneratorARMVIXL::VisitInstanceOf(HInstanceOf* instruction)
       break;
     }
 
+    case TypeCheckKind::kUnresolvedCheck:
     case TypeCheckKind::kInterfaceCheck: {
-      if (codegen_->InstanceOfNeedsReadBarrier(instruction)) {
-        DCHECK(locations->OnlyCallsOnSlowPath());
-        slow_path = new (codegen_->GetScopedAllocator()) TypeCheckSlowPathARMVIXL(
-            instruction, /* is_fatal= */ false);
-        codegen_->AddSlowPath(slow_path);
-        if (codegen_->EmitNonBakerReadBarrier()) {
-          __ B(slow_path->GetEntryLabel());
-          break;
-        }
-        // For Baker read barrier, take the slow path while marking.
-        __ CompareAndBranchIfNonZero(mr, slow_path->GetEntryLabel());
-      }
-
-      // Fast-path without read barriers.
-      UseScratchRegisterScope temps(GetVIXLAssembler());
-      vixl32::Register temp = RegisterFrom(maybe_temp_loc);
-      vixl32::Register temp2 = temps.Acquire();
-      // /* HeapReference<Class> */ temp = obj->klass_
-      __ Ldr(temp, MemOperand(obj, class_offset));
-      GetAssembler()->MaybeUnpoisonHeapReference(temp);
-      // /* HeapReference<Class> */ temp = temp->iftable_
-      __ Ldr(temp, MemOperand(temp, iftable_offset));
-      GetAssembler()->MaybeUnpoisonHeapReference(temp);
-      // Load the size of the `IfTable`. The `Class::iftable_` is never null.
-      __ Ldr(out, MemOperand(temp, array_length_offset));
-      // Loop through the `IfTable` and check if any class matches.
-      vixl32::Label loop;
-      __ Bind(&loop);
-      // If taken, the result in `out` is already 0 (false).
-      __ CompareAndBranchIfZero(out, &done, /* is_far_target= */ false);
-      __ Ldr(temp2, MemOperand(temp, object_array_data_offset));
-      GetAssembler()->MaybeUnpoisonHeapReference(temp2);
-      // Go to next interface.
-      __ Add(temp, temp, static_cast<uint32_t>(2 * kHeapReferenceSize));
-      __ Sub(out, out, 2);
-      // Compare the classes and continue the loop if they do not match.
-      __ Cmp(cls, temp2);
-      __ B(ne, &loop);
-      __ Mov(out, 1);
-      break;
-    }
-
-    case TypeCheckKind::kUnresolvedCheck: {
       // Note that we indeed only call on slow path, but we always go
-      // into the slow path for the unresolved check case.
+      // into the slow path for the unresolved and interface check
+      // cases.
       //
       // We cannot directly call the InstanceofNonTrivial runtime
       // entry point without resorting to a type checking slow path
@@ -8642,7 +8593,7 @@ void InstructionCodeGeneratorARMVIXL::VisitCheckCast(HCheckCast* instruction) {
                                        iftable_offset,
                                        maybe_temp2_loc,
                                        kWithoutReadBarrier);
-      // Load the size of the `IfTable`. The `Class::iftable_` is never null.
+      // Iftable is never null.
       __ Ldr(RegisterFrom(maybe_temp2_loc), MemOperand(temp, array_length_offset));
       // Loop through the iftable and check if any class matches.
       vixl32::Label start_loop;
diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index 5ad818dd53..5460a1bb07 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -7666,9 +7666,6 @@ void InstructionCodeGeneratorX86::VisitThrow(HThrow* instruction) {
 
 // Temp is used for read barrier.
 static size_t NumberOfInstanceOfTemps(bool emit_read_barrier, TypeCheckKind type_check_kind) {
-  if (type_check_kind == TypeCheckKind::kInterfaceCheck) {
-    return 1;
-  }
   if (emit_read_barrier &&
       !kUseBakerReadBarrier &&
       (type_check_kind == TypeCheckKind::kAbstractClassCheck ||
@@ -7683,6 +7680,9 @@ static size_t NumberOfInstanceOfTemps(bool emit_read_barrier, TypeCheckKind type
 // interface pointer, the current interface is compared in memory.
 // The other checks have one temp for loading the object's class.
 static size_t NumberOfCheckCastTemps(bool emit_read_barrier, TypeCheckKind type_check_kind) {
+  if (type_check_kind == TypeCheckKind::kInterfaceCheck) {
+    return 2;
+  }
   return 1 + NumberOfInstanceOfTemps(emit_read_barrier, type_check_kind);
 }
 
@@ -7694,16 +7694,15 @@ void LocationsBuilderX86::VisitInstanceOf(HInstanceOf* instruction) {
     case TypeCheckKind::kExactCheck:
     case TypeCheckKind::kAbstractClassCheck:
     case TypeCheckKind::kClassHierarchyCheck:
-    case TypeCheckKind::kArrayObjectCheck:
-    case TypeCheckKind::kInterfaceCheck: {
+    case TypeCheckKind::kArrayObjectCheck: {
       bool needs_read_barrier = codegen_->InstanceOfNeedsReadBarrier(instruction);
       call_kind = needs_read_barrier ? LocationSummary::kCallOnSlowPath : LocationSummary::kNoCall;
-      baker_read_barrier_slow_path = (kUseBakerReadBarrier && needs_read_barrier) &&
-                                     (type_check_kind != TypeCheckKind::kInterfaceCheck);
+      baker_read_barrier_slow_path = kUseBakerReadBarrier && needs_read_barrier;
       break;
     }
     case TypeCheckKind::kArrayCheck:
     case TypeCheckKind::kUnresolvedCheck:
+    case TypeCheckKind::kInterfaceCheck:
       call_kind = LocationSummary::kCallOnSlowPath;
       break;
     case TypeCheckKind::kBitstringCheck:
@@ -7720,8 +7719,6 @@ void LocationsBuilderX86::VisitInstanceOf(HInstanceOf* instruction) {
     locations->SetInAt(1, Location::ConstantLocation(instruction->InputAt(1)));
     locations->SetInAt(2, Location::ConstantLocation(instruction->InputAt(2)));
     locations->SetInAt(3, Location::ConstantLocation(instruction->InputAt(3)));
-  } else if (type_check_kind == TypeCheckKind::kInterfaceCheck) {
-    locations->SetInAt(1, Location::RequiresRegister());
   } else {
     locations->SetInAt(1, Location::Any());
   }
@@ -7743,14 +7740,10 @@ void InstructionCodeGeneratorX86::VisitInstanceOf(HInstanceOf* instruction) {
   const size_t num_temps = NumberOfInstanceOfTemps(codegen_->EmitReadBarrier(), type_check_kind);
   DCHECK_LE(num_temps, 1u);
   Location maybe_temp_loc = (num_temps >= 1) ? locations->GetTemp(0) : Location::NoLocation();
-  const uint32_t class_offset = mirror::Object::ClassOffset().Int32Value();
-  const uint32_t super_offset = mirror::Class::SuperClassOffset().Int32Value();
-  const uint32_t component_offset = mirror::Class::ComponentTypeOffset().Int32Value();
-  const uint32_t primitive_offset = mirror::Class::PrimitiveTypeOffset().Int32Value();
-  const uint32_t iftable_offset = mirror::Class::IfTableOffset().Uint32Value();
-  const uint32_t array_length_offset = mirror::Array::LengthOffset().Uint32Value();
-  const uint32_t object_array_data_offset =
-      mirror::Array::DataOffset(kHeapReferenceSize).Uint32Value();
+  uint32_t class_offset = mirror::Object::ClassOffset().Int32Value();
+  uint32_t super_offset = mirror::Class::SuperClassOffset().Int32Value();
+  uint32_t component_offset = mirror::Class::ComponentTypeOffset().Int32Value();
+  uint32_t primitive_offset = mirror::Class::PrimitiveTypeOffset().Int32Value();
   SlowPathCode* slow_path = nullptr;
   NearLabel done, zero;
 
@@ -7920,69 +7913,11 @@ void InstructionCodeGeneratorX86::VisitInstanceOf(HInstanceOf* instruction) {
       break;
     }
 
+    case TypeCheckKind::kUnresolvedCheck:
     case TypeCheckKind::kInterfaceCheck: {
-      if (codegen_->InstanceOfNeedsReadBarrier(instruction)) {
-        DCHECK(locations->OnlyCallsOnSlowPath());
-        slow_path = new (codegen_->GetScopedAllocator()) TypeCheckSlowPathX86(
-            instruction, /* is_fatal= */ false);
-        codegen_->AddSlowPath(slow_path);
-        if (codegen_->EmitNonBakerReadBarrier()) {
-          __ jmp(slow_path->GetEntryLabel());
-          break;
-        }
-        // For Baker read barrier, take the slow path while marking.
-        __ fs()->cmpl(Address::Absolute(Thread::IsGcMarkingOffset<kX86PointerSize>()),
-                      Immediate(0));
-        __ j(kNotEqual, slow_path->GetEntryLabel());
-      }
-
-      // Fast-path without read barriers.
-      Register temp = maybe_temp_loc.AsRegister<Register>();
-      // /* HeapReference<Class> */ temp = obj->klass_
-      __ movl(temp, Address(obj, class_offset));
-      __ MaybeUnpoisonHeapReference(temp);
-      // /* HeapReference<Class> */ temp = temp->iftable_
-      __ movl(temp, Address(temp, iftable_offset));
-      __ MaybeUnpoisonHeapReference(temp);
-      // Load the size of the `IfTable`. The `Class::iftable_` is never null.
-      __ movl(out, Address(temp, array_length_offset));
-      // Maybe poison the `cls` for direct comparison with memory.
-      __ MaybePoisonHeapReference(cls.AsRegister<Register>());
-      // Loop through the iftable and check if any class matches.
-      NearLabel loop, end;
-      __ Bind(&loop);
-      // Check if we still have an entry to compare.
-      __ subl(out, Immediate(2));
-      __ j(kNegative, (zero.IsLinked() && !kPoisonHeapReferences) ? &zero : &end);
-      // Go to next interface if the classes do not match.
-      __ cmpl(cls.AsRegister<Register>(),
-              CodeGeneratorX86::ArrayAddress(temp, out_loc, TIMES_4, object_array_data_offset));
-      __ j(kNotEqual, &loop);
-      if (zero.IsLinked()) {
-        __ movl(out, Immediate(1));
-        // If `cls` was poisoned above, unpoison it.
-        __ MaybeUnpoisonHeapReference(cls.AsRegister<Register>());
-        __ jmp(&done);
-        if (kPoisonHeapReferences) {
-          // The false case needs to unpoison the class before jumping to `zero`.
-          __ Bind(&end);
-          __ UnpoisonHeapReference(cls.AsRegister<Register>());
-          __ jmp(&zero);
-        }
-      } else {
-        // To reduce branching, use the fact that the false case branches with a `-2` in `out`.
-        __ movl(out, Immediate(-1));
-        __ Bind(&end);
-        __ addl(out, Immediate(2));
-        // If `cls` was poisoned above, unpoison it.
-        __ MaybeUnpoisonHeapReference(cls.AsRegister<Register>());
-      }
-      break;
-    }
-
-    case TypeCheckKind::kUnresolvedCheck: {
       // Note that we indeed only call on slow path, but we always go
-      // into the slow path for the unresolved check case.
+      // into the slow path for the unresolved and interface check
+      // cases.
       //
       // We cannot directly call the InstanceofNonTrivial runtime
       // entry point without resorting to a type checking slow path
@@ -8245,14 +8180,14 @@ void InstructionCodeGeneratorX86::VisitCheckCast(HCheckCast* instruction) {
                                        iftable_offset,
                                        maybe_temp2_loc,
                                        kWithoutReadBarrier);
-      // Load the size of the `IfTable`. The `Class::iftable_` is never null.
+      // Iftable is never null.
       __ movl(maybe_temp2_loc.AsRegister<Register>(), Address(temp, array_length_offset));
       // Maybe poison the `cls` for direct comparison with memory.
       __ MaybePoisonHeapReference(cls.AsRegister<Register>());
       // Loop through the iftable and check if any class matches.
       NearLabel start_loop;
       __ Bind(&start_loop);
-      // Check if we still have an entry to compare.
+      // Need to subtract first to handle the empty array case.
       __ subl(maybe_temp2_loc.AsRegister<Register>(), Immediate(2));
       __ j(kNegative, type_check_slow_path->GetEntryLabel());
       // Go to next interface if the classes do not match.
diff --git a/compiler/optimizing/code_generator_x86_64.cc b/compiler/optimizing/code_generator_x86_64.cc
index 4d23062100..c495d48406 100644
--- a/compiler/optimizing/code_generator_x86_64.cc
+++ b/compiler/optimizing/code_generator_x86_64.cc
@@ -6267,9 +6267,8 @@ void CodeGeneratorX86_64::CheckGCCardIsValid(CpuRegister temp,
   // assert (!clean || !self->is_gc_marking)
   __ cmpb(Address(temp, card, TIMES_1, 0), Immediate(gc::accounting::CardTable::kCardClean));
   __ j(kNotEqual, &done);
-  __ gs()->cmpl(
-      Address::Absolute(Thread::IsGcMarkingOffset<kX86_64PointerSize>(), /* no_rip= */ true),
-      Immediate(0));
+  __ gs()->cmpl(Address::Absolute(Thread::IsGcMarkingOffset<kX86_64PointerSize>(), true),
+                Immediate(0));
   __ j(kEqual, &done);
   __ int3();
   __ Bind(&done);
@@ -7008,9 +7007,6 @@ void InstructionCodeGeneratorX86_64::VisitThrow(HThrow* instruction) {
 
 // Temp is used for read barrier.
 static size_t NumberOfInstanceOfTemps(bool emit_read_barrier, TypeCheckKind type_check_kind) {
-  if (type_check_kind == TypeCheckKind::kInterfaceCheck) {
-    return 1;
-  }
   if (emit_read_barrier &&
       !kUseBakerReadBarrier &&
       (type_check_kind == TypeCheckKind::kAbstractClassCheck ||
@@ -7025,6 +7021,9 @@ static size_t NumberOfInstanceOfTemps(bool emit_read_barrier, TypeCheckKind type
 // interface pointer, the current interface is compared in memory.
 // The other checks have one temp for loading the object's class.
 static size_t NumberOfCheckCastTemps(bool emit_read_barrier, TypeCheckKind type_check_kind) {
+  if (type_check_kind == TypeCheckKind::kInterfaceCheck) {
+    return 2;
+  }
   return 1 + NumberOfInstanceOfTemps(emit_read_barrier, type_check_kind);
 }
 
@@ -7036,16 +7035,15 @@ void LocationsBuilderX86_64::VisitInstanceOf(HInstanceOf* instruction) {
     case TypeCheckKind::kExactCheck:
     case TypeCheckKind::kAbstractClassCheck:
     case TypeCheckKind::kClassHierarchyCheck:
-    case TypeCheckKind::kArrayObjectCheck:
-    case TypeCheckKind::kInterfaceCheck: {
+    case TypeCheckKind::kArrayObjectCheck: {
       bool needs_read_barrier = codegen_->InstanceOfNeedsReadBarrier(instruction);
       call_kind = needs_read_barrier ? LocationSummary::kCallOnSlowPath : LocationSummary::kNoCall;
-      baker_read_barrier_slow_path = (kUseBakerReadBarrier && needs_read_barrier) &&
-                                     (type_check_kind == TypeCheckKind::kInterfaceCheck);
+      baker_read_barrier_slow_path = kUseBakerReadBarrier && needs_read_barrier;
       break;
     }
     case TypeCheckKind::kArrayCheck:
     case TypeCheckKind::kUnresolvedCheck:
+    case TypeCheckKind::kInterfaceCheck:
       call_kind = LocationSummary::kCallOnSlowPath;
       break;
     case TypeCheckKind::kBitstringCheck:
@@ -7062,8 +7060,6 @@ void LocationsBuilderX86_64::VisitInstanceOf(HInstanceOf* instruction) {
     locations->SetInAt(1, Location::ConstantLocation(instruction->InputAt(1)));
     locations->SetInAt(2, Location::ConstantLocation(instruction->InputAt(2)));
     locations->SetInAt(3, Location::ConstantLocation(instruction->InputAt(3)));
-  } else if (type_check_kind == TypeCheckKind::kInterfaceCheck) {
-    locations->SetInAt(1, Location::RequiresRegister());
   } else {
     locations->SetInAt(1, Location::Any());
   }
@@ -7084,14 +7080,10 @@ void InstructionCodeGeneratorX86_64::VisitInstanceOf(HInstanceOf* instruction) {
   const size_t num_temps = NumberOfInstanceOfTemps(codegen_->EmitReadBarrier(), type_check_kind);
   DCHECK_LE(num_temps, 1u);
   Location maybe_temp_loc = (num_temps >= 1u) ? locations->GetTemp(0) : Location::NoLocation();
-  const uint32_t class_offset = mirror::Object::ClassOffset().Int32Value();
-  const uint32_t super_offset = mirror::Class::SuperClassOffset().Int32Value();
-  const uint32_t component_offset = mirror::Class::ComponentTypeOffset().Int32Value();
-  const uint32_t primitive_offset = mirror::Class::PrimitiveTypeOffset().Int32Value();
-  const uint32_t iftable_offset = mirror::Class::IfTableOffset().Uint32Value();
-  const uint32_t array_length_offset = mirror::Array::LengthOffset().Uint32Value();
-  const uint32_t object_array_data_offset =
-      mirror::Array::DataOffset(kHeapReferenceSize).Uint32Value();
+  uint32_t class_offset = mirror::Object::ClassOffset().Int32Value();
+  uint32_t super_offset = mirror::Class::SuperClassOffset().Int32Value();
+  uint32_t component_offset = mirror::Class::ComponentTypeOffset().Int32Value();
+  uint32_t primitive_offset = mirror::Class::PrimitiveTypeOffset().Int32Value();
   SlowPathCode* slow_path = nullptr;
   NearLabel done, zero;
 
@@ -7266,70 +7258,11 @@ void InstructionCodeGeneratorX86_64::VisitInstanceOf(HInstanceOf* instruction) {
       break;
     }
 
+    case TypeCheckKind::kUnresolvedCheck:
     case TypeCheckKind::kInterfaceCheck: {
-      if (codegen_->InstanceOfNeedsReadBarrier(instruction)) {
-        DCHECK(locations->OnlyCallsOnSlowPath());
-        slow_path = new (codegen_->GetScopedAllocator()) TypeCheckSlowPathX86_64(
-            instruction, /* is_fatal= */ false);
-        codegen_->AddSlowPath(slow_path);
-        if (codegen_->EmitNonBakerReadBarrier()) {
-          __ jmp(slow_path->GetEntryLabel());
-          break;
-        }
-        // For Baker read barrier, take the slow path while marking.
-        __ gs()->cmpl(
-            Address::Absolute(Thread::IsGcMarkingOffset<kX86_64PointerSize>(), /* no_rip= */ true),
-            Immediate(0));
-        __ j(kNotEqual, slow_path->GetEntryLabel());
-      }
-
-      // Fast-path without read barriers.
-      CpuRegister temp = maybe_temp_loc.AsRegister<CpuRegister>();
-      // /* HeapReference<Class> */ temp = obj->klass_
-      __ movl(temp, Address(obj, class_offset));
-      __ MaybeUnpoisonHeapReference(temp);
-      // /* HeapReference<Class> */ temp = temp->iftable_
-      __ movl(temp, Address(temp, iftable_offset));
-      __ MaybeUnpoisonHeapReference(temp);
-      // Load the size of the `IfTable`. The `Class::iftable_` is never null.
-      __ movl(out, Address(temp, array_length_offset));
-      // Maybe poison the `cls` for direct comparison with memory.
-      __ MaybePoisonHeapReference(cls.AsRegister<CpuRegister>());
-      // Loop through the iftable and check if any class matches.
-      NearLabel loop, end;
-      __ Bind(&loop);
-      // Check if we still have an entry to compare.
-      __ subl(out, Immediate(2));
-      __ j(kNegative, (zero.IsLinked() && !kPoisonHeapReferences) ? &zero : &end);
-      // Go to next interface if the classes do not match.
-      __ cmpl(cls.AsRegister<CpuRegister>(),
-              CodeGeneratorX86_64::ArrayAddress(temp, out_loc, TIMES_4, object_array_data_offset));
-      __ j(kNotEqual, &loop);
-      if (zero.IsLinked()) {
-        __ movl(out, Immediate(1));
-        // If `cls` was poisoned above, unpoison it.
-        __ MaybeUnpoisonHeapReference(cls.AsRegister<CpuRegister>());
-        __ jmp(&done);
-        if (kPoisonHeapReferences) {
-          // The false case needs to unpoison the class before jumping to `zero`.
-          __ Bind(&end);
-          __ UnpoisonHeapReference(cls.AsRegister<CpuRegister>());
-          __ jmp(&zero);
-        }
-      } else {
-        // To reduce branching, use the fact that the false case branches with a `-2` in `out`.
-        __ movl(out, Immediate(-1));
-        __ Bind(&end);
-        __ addl(out, Immediate(2));
-        // If `cls` was poisoned above, unpoison it.
-        __ MaybeUnpoisonHeapReference(cls.AsRegister<CpuRegister>());
-      }
-      break;
-    }
-
-    case TypeCheckKind::kUnresolvedCheck: {
       // Note that we indeed only call on slow path, but we always go
-      // into the slow path for the unresolved check case.
+      // into the slow path for the unresolved and interface check
+      // cases.
       //
       // We cannot directly call the InstanceofNonTrivial runtime
       // entry point without resorting to a type checking slow path
@@ -7599,14 +7532,14 @@ void InstructionCodeGeneratorX86_64::VisitCheckCast(HCheckCast* instruction) {
                                        iftable_offset,
                                        maybe_temp2_loc,
                                        kWithoutReadBarrier);
-      // Load the size of the `IfTable`. The `Class::iftable_` is never null.
+      // Iftable is never null.
       __ movl(maybe_temp2_loc.AsRegister<CpuRegister>(), Address(temp, array_length_offset));
       // Maybe poison the `cls` for direct comparison with memory.
       __ MaybePoisonHeapReference(cls.AsRegister<CpuRegister>());
       // Loop through the iftable and check if any class matches.
       NearLabel start_loop;
       __ Bind(&start_loop);
-      // Check if we still have an entry to compare.
+      // Need to subtract first to handle the empty array case.
       __ subl(maybe_temp2_loc.AsRegister<CpuRegister>(), Immediate(2));
       __ j(kNegative, type_check_slow_path->GetEntryLabel());
       // Go to next interface if the classes do not match.