ART: Move InlineMethodAnalyzer into compiler

Move the infrastructure, which is now only used by the compiler.

Test: mmma art
Change-Id: I4a61e35f23736b226523d7349f49208ad852ad2f

1 files changed, 758 insertions, 0 deletions

diff --git a/compiler/dex/inline_method_analyser.cc b/compiler/dex/inline_method_analyser.cc
new file mode 100644
index 0000000000..3347070468
--- /dev/null
+++ b/compiler/dex/inline_method_analyser.cc
@@ -0,0 +1,758 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "inline_method_analyser.h"
+
+#include "art_field-inl.h"
+#include "art_method-inl.h"
+#include "base/enums.h"
+#include "class_linker-inl.h"
+#include "dex_file-inl.h"
+#include "dex_instruction.h"
+#include "dex_instruction-inl.h"
+#include "dex_instruction_utils.h"
+#include "mirror/class-inl.h"
+#include "mirror/dex_cache-inl.h"
+#include "verifier/method_verifier-inl.h"
+
+/*
+ * NOTE: This code is part of the quick compiler. It lives in the runtime
+ * only to allow the debugger to check whether a method has been inlined.
+ */
+
+namespace art {
+
+namespace {  // anonymous namespace
+
+// Helper class for matching a pattern.
+class Matcher {
+ public:
+  // Match function type.
+  typedef bool MatchFn(Matcher* matcher);
+
+  template <size_t size>
+  static bool Match(const DexFile::CodeItem* code_item, MatchFn* const (&pattern)[size]);
+
+  // Match and advance.
+
+  static bool Mark(Matcher* matcher);
+
+  template <bool (Matcher::*Fn)()>
+  static bool Required(Matcher* matcher);
+
+  template <bool (Matcher::*Fn)()>
+  static bool Repeated(Matcher* matcher);  // On match, returns to the mark.
+
+  // Match an individual instruction.
+
+  template <Instruction::Code opcode> bool Opcode();
+  bool Const0();
+  bool IPutOnThis();
+
+ private:
+  explicit Matcher(const DexFile::CodeItem* code_item)
+      : code_item_(code_item),
+        instruction_(Instruction::At(code_item->insns_)),
+        pos_(0u),
+        mark_(0u) { }
+
+  static bool DoMatch(const DexFile::CodeItem* code_item, MatchFn* const* pattern, size_t size);
+
+  const DexFile::CodeItem* const code_item_;
+  const Instruction* instruction_;
+  size_t pos_;
+  size_t mark_;
+};
+
+template <size_t size>
+bool Matcher::Match(const DexFile::CodeItem* code_item, MatchFn* const (&pattern)[size]) {
+  return DoMatch(code_item, pattern, size);
+}
+
+bool Matcher::Mark(Matcher* matcher) {
+  matcher->pos_ += 1u;  // Advance to the next match function before marking.
+  matcher->mark_ = matcher->pos_;
+  return true;
+}
+
+template <bool (Matcher::*Fn)()>
+bool Matcher::Required(Matcher* matcher) {
+  if (!(matcher->*Fn)()) {
+    return false;
+  }
+  matcher->pos_ += 1u;
+  matcher->instruction_ = matcher->instruction_->Next();
+  return true;
+}
+
+template <bool (Matcher::*Fn)()>
+bool Matcher::Repeated(Matcher* matcher) {
+  if (!(matcher->*Fn)()) {
+    // Didn't match optional instruction, try the next match function.
+    matcher->pos_ += 1u;
+    return true;
+  }
+  matcher->pos_ = matcher->mark_;
+  matcher->instruction_ = matcher->instruction_->Next();
+  return true;
+}
+
+template <Instruction::Code opcode>
+bool Matcher::Opcode() {
+  return instruction_->Opcode() == opcode;
+}
+
+// Match const 0.
+bool Matcher::Const0() {
+  return IsInstructionDirectConst(instruction_->Opcode()) &&
+      (instruction_->Opcode() == Instruction::CONST_WIDE ? instruction_->VRegB_51l() == 0
+                                                         : instruction_->VRegB() == 0);
+}
+
+bool Matcher::IPutOnThis() {
+  DCHECK_NE(code_item_->ins_size_, 0u);
+  return IsInstructionIPut(instruction_->Opcode()) &&
+      instruction_->VRegB_22c() == code_item_->registers_size_ - code_item_->ins_size_;
+}
+
+bool Matcher::DoMatch(const DexFile::CodeItem* code_item, MatchFn* const* pattern, size_t size) {
+  Matcher matcher(code_item);
+  while (matcher.pos_ != size) {
+    if (!pattern[matcher.pos_](&matcher)) {
+      return false;
+    }
+  }
+  return true;
+}
+
+// Used for a single invoke in a constructor. In that situation, the method verifier makes
+// sure we invoke a constructor either in the same class or superclass with at least "this".
+ArtMethod* GetTargetConstructor(ArtMethod* method, const Instruction* invoke_direct)
+    REQUIRES_SHARED(Locks::mutator_lock_) {
+  DCHECK_EQ(invoke_direct->Opcode(), Instruction::INVOKE_DIRECT);
+  DCHECK_EQ(invoke_direct->VRegC_35c(),
+            method->GetCodeItem()->registers_size_ - method->GetCodeItem()->ins_size_);
+  uint32_t method_index = invoke_direct->VRegB_35c();
+  PointerSize pointer_size = Runtime::Current()->GetClassLinker()->GetImagePointerSize();
+  ArtMethod* target_method =
+      method->GetDexCache()->GetResolvedMethod(method_index, pointer_size);
+  if (kIsDebugBuild && target_method != nullptr) {
+    CHECK(!target_method->IsStatic());
+    CHECK(target_method->IsConstructor());
+    CHECK(target_method->GetDeclaringClass() == method->GetDeclaringClass() ||
+          target_method->GetDeclaringClass() == method->GetDeclaringClass()->GetSuperClass());
+  }
+  return target_method;
+}
+
+// Return the forwarded arguments and check that all remaining arguments are zero.
+// If the check fails, return static_cast<size_t>(-1).
+size_t CountForwardedConstructorArguments(const DexFile::CodeItem* code_item,
+                                          const Instruction* invoke_direct,
+                                          uint16_t zero_vreg_mask) {
+  DCHECK_EQ(invoke_direct->Opcode(), Instruction::INVOKE_DIRECT);
+  size_t number_of_args = invoke_direct->VRegA_35c();
+  DCHECK_NE(number_of_args, 0u);
+  uint32_t args[Instruction::kMaxVarArgRegs];
+  invoke_direct->GetVarArgs(args);
+  uint16_t this_vreg = args[0];
+  DCHECK_EQ(this_vreg, code_item->registers_size_ - code_item->ins_size_);  // Checked by verifier.
+  size_t forwarded = 1u;
+  while (forwarded < number_of_args &&
+      args[forwarded] == this_vreg + forwarded &&
+      (zero_vreg_mask & (1u << args[forwarded])) == 0) {
+    ++forwarded;
+  }
+  for (size_t i = forwarded; i != number_of_args; ++i) {
+    if ((zero_vreg_mask & (1u << args[i])) == 0) {
+      return static_cast<size_t>(-1);
+    }
+  }
+  return forwarded;
+}
+
+uint16_t GetZeroVRegMask(const Instruction* const0) {
+  DCHECK(IsInstructionDirectConst(const0->Opcode()));
+  DCHECK((const0->Opcode() == Instruction::CONST_WIDE) ? const0->VRegB_51l() == 0u
+                                                       : const0->VRegB() == 0);
+  uint16_t base_mask = IsInstructionConstWide(const0->Opcode()) ? 3u : 1u;
+  return base_mask << const0->VRegA();
+}
+
+// We limit the number of IPUTs storing parameters. There can be any number
+// of IPUTs that store the value 0 as they are useless in a constructor as
+// the object always starts zero-initialized. We also eliminate all but the
+// last store to any field as they are not observable; not even if the field
+// is volatile as no reference to the object can escape from a constructor
+// with this pattern.
+static constexpr size_t kMaxConstructorIPuts = 3u;
+
+struct ConstructorIPutData {
+  ConstructorIPutData() : field_index(DexFile::kDexNoIndex16), arg(0u) { }
+
+  uint16_t field_index;
+  uint16_t arg;
+};
+
+bool RecordConstructorIPut(ArtMethod* method,
+                           const Instruction* new_iput,
+                           uint16_t this_vreg,
+                           uint16_t zero_vreg_mask,
+                           /*inout*/ ConstructorIPutData (&iputs)[kMaxConstructorIPuts])
+    REQUIRES_SHARED(Locks::mutator_lock_) {
+  DCHECK(IsInstructionIPut(new_iput->Opcode()));
+  uint32_t field_index = new_iput->VRegC_22c();
+  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
+  ArtField* field = class_linker->LookupResolvedField(field_index, method, /* is_static */ false);
+  if (UNLIKELY(field == nullptr)) {
+    return false;
+  }
+  // Remove previous IPUT to the same field, if any. Different field indexes may refer
+  // to the same field, so we need to compare resolved fields from the dex cache.
+  for (size_t old_pos = 0; old_pos != arraysize(iputs); ++old_pos) {
+    if (iputs[old_pos].field_index == DexFile::kDexNoIndex16) {
+      break;
+    }
+    ArtField* f = class_linker->LookupResolvedField(iputs[old_pos].field_index,
+                                                    method,
+                                                    /* is_static */ false);
+    DCHECK(f != nullptr);
+    if (f == field) {
+      auto back_it = std::copy(iputs + old_pos + 1, iputs + arraysize(iputs), iputs + old_pos);
+      *back_it = ConstructorIPutData();
+      break;
+    }
+  }
+  // If the stored value isn't zero, record the IPUT.
+  if ((zero_vreg_mask & (1u << new_iput->VRegA_22c())) == 0u) {
+    size_t new_pos = 0;
+    while (new_pos != arraysize(iputs) && iputs[new_pos].field_index != DexFile::kDexNoIndex16) {
+      ++new_pos;
+    }
+    if (new_pos == arraysize(iputs)) {
+      return false;  // Exceeded capacity of the output array.
+    }
+    iputs[new_pos].field_index = field_index;
+    iputs[new_pos].arg = new_iput->VRegA_22c() - this_vreg;
+  }
+  return true;
+}
+
+bool DoAnalyseConstructor(const DexFile::CodeItem* code_item,
+                          ArtMethod* method,
+                          /*inout*/ ConstructorIPutData (&iputs)[kMaxConstructorIPuts])
+    REQUIRES_SHARED(Locks::mutator_lock_) {
+  // On entry we should not have any IPUTs yet.
+  DCHECK_EQ(0, std::count_if(
+      iputs,
+      iputs + arraysize(iputs),
+      [](const ConstructorIPutData& iput_data) {
+        return iput_data.field_index != DexFile::kDexNoIndex16;
+      }));
+
+  // Limit the maximum number of code units we're willing to match.
+  static constexpr size_t kMaxCodeUnits = 16u;
+
+  // Limit the number of registers that the constructor may use to 16.
+  // Given that IPUTs must use low 16 registers and we do not match MOVEs,
+  // this is a reasonable limitation.
+  static constexpr size_t kMaxVRegs = 16u;
+
+  // We try to match a constructor that calls another constructor (either in
+  // superclass or in the same class) with the same parameters, or with some
+  // parameters truncated (allowed only for calls to superclass constructor)
+  // or with extra parameters with value 0 (with any type, including null).
+  // This call can be followed by optional IPUTs on "this" storing either one
+  // of the parameters or 0 and the code must then finish with RETURN_VOID.
+  // The called constructor must be either java.lang.Object.<init>() or it
+  // must also match the same pattern.
+  static Matcher::MatchFn* const kConstructorPattern[] = {
+      &Matcher::Mark,
+      &Matcher::Repeated<&Matcher::Const0>,
+      &Matcher::Required<&Matcher::Opcode<Instruction::INVOKE_DIRECT>>,
+      &Matcher::Mark,
+      &Matcher::Repeated<&Matcher::Const0>,
+      &Matcher::Repeated<&Matcher::IPutOnThis>,
+      &Matcher::Required<&Matcher::Opcode<Instruction::RETURN_VOID>>,
+  };
+
+  DCHECK(method != nullptr);
+  DCHECK(!method->IsStatic());
+  DCHECK(method->IsConstructor());
+  DCHECK(code_item != nullptr);
+  if (!method->GetDeclaringClass()->IsVerified() ||
+      code_item->insns_size_in_code_units_ > kMaxCodeUnits ||
+      code_item->registers_size_ > kMaxVRegs ||
+      !Matcher::Match(code_item, kConstructorPattern)) {
+    return false;
+  }
+
+  // Verify the invoke, prevent a few odd cases and collect IPUTs.
+  uint16_t this_vreg = code_item->registers_size_ - code_item->ins_size_;
+  uint16_t zero_vreg_mask = 0u;
+  for (const Instruction* instruction = Instruction::At(code_item->insns_);
+      instruction->Opcode() != Instruction::RETURN_VOID;
+      instruction = instruction->Next()) {
+    if (instruction->Opcode() == Instruction::INVOKE_DIRECT) {
+      ArtMethod* target_method = GetTargetConstructor(method, instruction);
+      if (target_method == nullptr) {
+        return false;
+      }
+      // We allow forwarding constructors only if they pass more arguments
+      // to prevent infinite recursion.
+      if (target_method->GetDeclaringClass() == method->GetDeclaringClass() &&
+          instruction->VRegA_35c() <= code_item->ins_size_) {
+        return false;
+      }
+      size_t forwarded = CountForwardedConstructorArguments(code_item, instruction, zero_vreg_mask);
+      if (forwarded == static_cast<size_t>(-1)) {
+        return false;
+      }
+      if (target_method->GetDeclaringClass()->IsObjectClass()) {
+        DCHECK_EQ(Instruction::At(target_method->GetCodeItem()->insns_)->Opcode(),
+                  Instruction::RETURN_VOID);
+      } else {
+        const DexFile::CodeItem* target_code_item = target_method->GetCodeItem();
+        if (target_code_item == nullptr) {
+          return false;  // Native constructor?
+        }
+        if (!DoAnalyseConstructor(target_code_item, target_method, iputs)) {
+          return false;
+        }
+        // Prune IPUTs with zero input.
+        auto kept_end = std::remove_if(
+            iputs,
+            iputs + arraysize(iputs),
+            [forwarded](const ConstructorIPutData& iput_data) {
+              return iput_data.arg >= forwarded;
+            });
+        std::fill(kept_end, iputs + arraysize(iputs), ConstructorIPutData());
+        // If we have any IPUTs from the call, check that the target method is in the same
+        // dex file (compare DexCache references), otherwise field_indexes would be bogus.
+        if (iputs[0].field_index != DexFile::kDexNoIndex16 &&
+            target_method->GetDexCache() != method->GetDexCache()) {
+          return false;
+        }
+      }
+    } else if (IsInstructionDirectConst(instruction->Opcode())) {
+      zero_vreg_mask |= GetZeroVRegMask(instruction);
+      if ((zero_vreg_mask & (1u << this_vreg)) != 0u) {
+        return false;  // Overwriting `this` is unsupported.
+      }
+    } else {
+      DCHECK(IsInstructionIPut(instruction->Opcode()));
+      DCHECK_EQ(instruction->VRegB_22c(), this_vreg);
+      if (!RecordConstructorIPut(method, instruction, this_vreg, zero_vreg_mask, iputs)) {
+        return false;
+      }
+    }
+  }
+  return true;
+}
+
+}  // anonymous namespace
+
+bool AnalyseConstructor(const DexFile::CodeItem* code_item,
+                        ArtMethod* method,
+                        InlineMethod* result)
+    REQUIRES_SHARED(Locks::mutator_lock_) {
+  ConstructorIPutData iputs[kMaxConstructorIPuts];
+  if (!DoAnalyseConstructor(code_item, method, iputs)) {
+    return false;
+  }
+  static_assert(kMaxConstructorIPuts == 3, "Unexpected limit");  // Code below depends on this.
+  DCHECK(iputs[0].field_index != DexFile::kDexNoIndex16 ||
+         iputs[1].field_index == DexFile::kDexNoIndex16);
+  DCHECK(iputs[1].field_index != DexFile::kDexNoIndex16 ||
+         iputs[2].field_index == DexFile::kDexNoIndex16);
+
+#define STORE_IPUT(n)                                                         \
+  do {                                                                        \
+    result->d.constructor_data.iput##n##_field_index = iputs[n].field_index;  \
+    result->d.constructor_data.iput##n##_arg = iputs[n].arg;                  \
+  } while (false)
+
+  STORE_IPUT(0);
+  STORE_IPUT(1);
+  STORE_IPUT(2);
+#undef STORE_IPUT
+
+  result->opcode = kInlineOpConstructor;
+  result->flags = kInlineSpecial;
+  result->d.constructor_data.reserved = 0u;
+  return true;
+}
+
+static_assert(InlineMethodAnalyser::IsInstructionIGet(Instruction::IGET), "iget type");
+static_assert(InlineMethodAnalyser::IsInstructionIGet(Instruction::IGET_WIDE), "iget_wide type");
+static_assert(InlineMethodAnalyser::IsInstructionIGet(Instruction::IGET_OBJECT),
+              "iget_object type");
+static_assert(InlineMethodAnalyser::IsInstructionIGet(Instruction::IGET_BOOLEAN),
+              "iget_boolean type");
+static_assert(InlineMethodAnalyser::IsInstructionIGet(Instruction::IGET_BYTE), "iget_byte type");
+static_assert(InlineMethodAnalyser::IsInstructionIGet(Instruction::IGET_CHAR), "iget_char type");
+static_assert(InlineMethodAnalyser::IsInstructionIGet(Instruction::IGET_SHORT), "iget_short type");
+static_assert(InlineMethodAnalyser::IsInstructionIPut(Instruction::IPUT), "iput type");
+static_assert(InlineMethodAnalyser::IsInstructionIPut(Instruction::IPUT_WIDE), "iput_wide type");
+static_assert(InlineMethodAnalyser::IsInstructionIPut(Instruction::IPUT_OBJECT),
+              "iput_object type");
+static_assert(InlineMethodAnalyser::IsInstructionIPut(Instruction::IPUT_BOOLEAN),
+              "iput_boolean type");
+static_assert(InlineMethodAnalyser::IsInstructionIPut(Instruction::IPUT_BYTE), "iput_byte type");
+static_assert(InlineMethodAnalyser::IsInstructionIPut(Instruction::IPUT_CHAR), "iput_char type");
+static_assert(InlineMethodAnalyser::IsInstructionIPut(Instruction::IPUT_SHORT), "iput_short type");
+static_assert(InlineMethodAnalyser::IGetVariant(Instruction::IGET) ==
+    InlineMethodAnalyser::IPutVariant(Instruction::IPUT), "iget/iput variant");
+static_assert(InlineMethodAnalyser::IGetVariant(Instruction::IGET_WIDE) ==
+    InlineMethodAnalyser::IPutVariant(Instruction::IPUT_WIDE), "iget/iput_wide variant");
+static_assert(InlineMethodAnalyser::IGetVariant(Instruction::IGET_OBJECT) ==
+    InlineMethodAnalyser::IPutVariant(Instruction::IPUT_OBJECT), "iget/iput_object variant");
+static_assert(InlineMethodAnalyser::IGetVariant(Instruction::IGET_BOOLEAN) ==
+    InlineMethodAnalyser::IPutVariant(Instruction::IPUT_BOOLEAN), "iget/iput_boolean variant");
+static_assert(InlineMethodAnalyser::IGetVariant(Instruction::IGET_BYTE) ==
+    InlineMethodAnalyser::IPutVariant(Instruction::IPUT_BYTE), "iget/iput_byte variant");
+static_assert(InlineMethodAnalyser::IGetVariant(Instruction::IGET_CHAR) ==
+    InlineMethodAnalyser::IPutVariant(Instruction::IPUT_CHAR), "iget/iput_char variant");
+static_assert(InlineMethodAnalyser::IGetVariant(Instruction::IGET_SHORT) ==
+    InlineMethodAnalyser::IPutVariant(Instruction::IPUT_SHORT), "iget/iput_short variant");
+
+// This is used by compiler and debugger. We look into the dex cache for resolved methods and
+// fields. However, in the context of the debugger, not all methods and fields are resolved. Since
+// we need to be able to detect possibly inlined method, we pass a null inline method to indicate
+// we don't want to take unresolved methods and fields into account during analysis.
+bool InlineMethodAnalyser::AnalyseMethodCode(verifier::MethodVerifier* verifier,
+                                             InlineMethod* result) {
+  DCHECK(verifier != nullptr);
+  if (!Runtime::Current()->UseJitCompilation()) {
+    DCHECK_EQ(verifier->CanLoadClasses(), result != nullptr);
+  }
+
+  // Note: verifier->GetMethod() may be null.
+  return AnalyseMethodCode(verifier->CodeItem(),
+                           verifier->GetMethodReference(),
+                           (verifier->GetAccessFlags() & kAccStatic) != 0u,
+                           verifier->GetMethod(),
+                           result);
+}
+
+bool InlineMethodAnalyser::AnalyseMethodCode(ArtMethod* method, InlineMethod* result) {
+  const DexFile::CodeItem* code_item = method->GetCodeItem();
+  if (code_item == nullptr) {
+    // Native or abstract.
+    return false;
+  }
+  return AnalyseMethodCode(
+      code_item, method->ToMethodReference(), method->IsStatic(), method, result);
+}
+
+bool InlineMethodAnalyser::AnalyseMethodCode(const DexFile::CodeItem* code_item,
+                                             const MethodReference& method_ref,
+                                             bool is_static,
+                                             ArtMethod* method,
+                                             InlineMethod* result) {
+  // We currently support only plain return or 2-instruction methods.
+
+  DCHECK_NE(code_item->insns_size_in_code_units_, 0u);
+  const Instruction* instruction = Instruction::At(code_item->insns_);
+  Instruction::Code opcode = instruction->Opcode();
+
+  switch (opcode) {
+    case Instruction::RETURN_VOID:
+      if (result != nullptr) {
+        result->opcode = kInlineOpNop;
+        result->flags = kInlineSpecial;
+        result->d.data = 0u;
+      }
+      return true;
+    case Instruction::RETURN:
+    case Instruction::RETURN_OBJECT:
+    case Instruction::RETURN_WIDE:
+      return AnalyseReturnMethod(code_item, result);
+    case Instruction::CONST:
+    case Instruction::CONST_4:
+    case Instruction::CONST_16:
+    case Instruction::CONST_HIGH16:
+      // TODO: Support wide constants (RETURN_WIDE).
+      if (AnalyseConstMethod(code_item, result)) {
+        return true;
+      }
+      FALLTHROUGH_INTENDED;
+    case Instruction::CONST_WIDE:
+    case Instruction::CONST_WIDE_16:
+    case Instruction::CONST_WIDE_32:
+    case Instruction::CONST_WIDE_HIGH16:
+    case Instruction::INVOKE_DIRECT:
+      if (method != nullptr && !method->IsStatic() && method->IsConstructor()) {
+        return AnalyseConstructor(code_item, method, result);
+      }
+      return false;
+    case Instruction::IGET:
+    case Instruction::IGET_OBJECT:
+    case Instruction::IGET_BOOLEAN:
+    case Instruction::IGET_BYTE:
+    case Instruction::IGET_CHAR:
+    case Instruction::IGET_SHORT:
+    case Instruction::IGET_WIDE:
+    // TODO: Add handling for JIT.
+    // case Instruction::IGET_QUICK:
+    // case Instruction::IGET_WIDE_QUICK:
+    // case Instruction::IGET_OBJECT_QUICK:
+      return AnalyseIGetMethod(code_item, method_ref, is_static, method, result);
+    case Instruction::IPUT:
+    case Instruction::IPUT_OBJECT:
+    case Instruction::IPUT_BOOLEAN:
+    case Instruction::IPUT_BYTE:
+    case Instruction::IPUT_CHAR:
+    case Instruction::IPUT_SHORT:
+    case Instruction::IPUT_WIDE:
+      // TODO: Add handling for JIT.
+    // case Instruction::IPUT_QUICK:
+    // case Instruction::IPUT_WIDE_QUICK:
+    // case Instruction::IPUT_OBJECT_QUICK:
+      return AnalyseIPutMethod(code_item, method_ref, is_static, method, result);
+    default:
+      return false;
+  }
+}
+
+bool InlineMethodAnalyser::IsSyntheticAccessor(MethodReference ref) {
+  const DexFile::MethodId& method_id = ref.dex_file->GetMethodId(ref.dex_method_index);
+  const char* method_name = ref.dex_file->GetMethodName(method_id);
+  // javac names synthetic accessors "access$nnn",
+  // jack names them "-getN", "-putN", "-wrapN".
+  return strncmp(method_name, "access$", strlen("access$")) == 0 ||
+      strncmp(method_name, "-", strlen("-")) == 0;
+}
+
+bool InlineMethodAnalyser::AnalyseReturnMethod(const DexFile::CodeItem* code_item,
+                                               InlineMethod* result) {
+  const Instruction* return_instruction = Instruction::At(code_item->insns_);
+  Instruction::Code return_opcode = return_instruction->Opcode();
+  uint32_t reg = return_instruction->VRegA_11x();
+  uint32_t arg_start = code_item->registers_size_ - code_item->ins_size_;
+  DCHECK_GE(reg, arg_start);
+  DCHECK_LT((return_opcode == Instruction::RETURN_WIDE) ? reg + 1 : reg,
+      code_item->registers_size_);
+
+  if (result != nullptr) {
+    result->opcode = kInlineOpReturnArg;
+    result->flags = kInlineSpecial;
+    InlineReturnArgData* data = &result->d.return_data;
+    data->arg = reg - arg_start;
+    data->is_wide = (return_opcode == Instruction::RETURN_WIDE) ? 1u : 0u;
+    data->is_object = (return_opcode == Instruction::RETURN_OBJECT) ? 1u : 0u;
+    data->reserved = 0u;
+    data->reserved2 = 0u;
+  }
+  return true;
+}
+
+bool InlineMethodAnalyser::AnalyseConstMethod(const DexFile::CodeItem* code_item,
+                                              InlineMethod* result) {
+  const Instruction* instruction = Instruction::At(code_item->insns_);
+  const Instruction* return_instruction = instruction->Next();
+  Instruction::Code return_opcode = return_instruction->Opcode();
+  if (return_opcode != Instruction::RETURN &&
+      return_opcode != Instruction::RETURN_OBJECT) {
+    return false;
+  }
+
+  int32_t return_reg = return_instruction->VRegA_11x();
+  DCHECK_LT(return_reg, code_item->registers_size_);
+
+  int32_t const_value = instruction->VRegB();
+  if (instruction->Opcode() == Instruction::CONST_HIGH16) {
+    const_value <<= 16;
+  }
+  DCHECK_LT(instruction->VRegA(), code_item->registers_size_);
+  if (instruction->VRegA() != return_reg) {
+    return false;  // Not returning the value set by const?
+  }
+  if (return_opcode == Instruction::RETURN_OBJECT && const_value != 0) {
+    return false;  // Returning non-null reference constant?
+  }
+  if (result != nullptr) {
+    result->opcode = kInlineOpNonWideConst;
+    result->flags = kInlineSpecial;
+    result->d.data = static_cast<uint64_t>(const_value);
+  }
+  return true;
+}
+
+bool InlineMethodAnalyser::AnalyseIGetMethod(const DexFile::CodeItem* code_item,
+                                             const MethodReference& method_ref,
+                                             bool is_static,
+                                             ArtMethod* method,
+                                             InlineMethod* result) {
+  const Instruction* instruction = Instruction::At(code_item->insns_);
+  Instruction::Code opcode = instruction->Opcode();
+  DCHECK(IsInstructionIGet(opcode));
+
+  const Instruction* return_instruction = instruction->Next();
+  Instruction::Code return_opcode = return_instruction->Opcode();
+  if (!(return_opcode == Instruction::RETURN_WIDE && opcode == Instruction::IGET_WIDE) &&
+      !(return_opcode == Instruction::RETURN_OBJECT && opcode == Instruction::IGET_OBJECT) &&
+      !(return_opcode == Instruction::RETURN && opcode != Instruction::IGET_WIDE &&
+          opcode != Instruction::IGET_OBJECT)) {
+    return false;
+  }
+
+  uint32_t return_reg = return_instruction->VRegA_11x();
+  DCHECK_LT(return_opcode == Instruction::RETURN_WIDE ? return_reg + 1 : return_reg,
+            code_item->registers_size_);
+
+  uint32_t dst_reg = instruction->VRegA_22c();
+  uint32_t object_reg = instruction->VRegB_22c();
+  uint32_t field_idx = instruction->VRegC_22c();
+  uint32_t arg_start = code_item->registers_size_ - code_item->ins_size_;
+  DCHECK_GE(object_reg, arg_start);
+  DCHECK_LT(object_reg, code_item->registers_size_);
+  uint32_t object_arg = object_reg - arg_start;
+
+  DCHECK_LT(opcode == Instruction::IGET_WIDE ? dst_reg + 1 : dst_reg, code_item->registers_size_);
+  if (dst_reg != return_reg) {
+    return false;  // Not returning the value retrieved by IGET?
+  }
+
+  if (is_static || object_arg != 0u) {
+    // TODO: Implement inlining of IGET on non-"this" registers (needs correct stack trace for NPE).
+    // Allow synthetic accessors. We don't care about losing their stack frame in NPE.
+    if (!IsSyntheticAccessor(method_ref)) {
+      return false;
+    }
+  }
+
+  // InlineIGetIPutData::object_arg is only 4 bits wide.
+  static constexpr uint16_t kMaxObjectArg = 15u;
+  if (object_arg > kMaxObjectArg) {
+    return false;
+  }
+
+  if (result != nullptr) {
+    InlineIGetIPutData* data = &result->d.ifield_data;
+    if (!ComputeSpecialAccessorInfo(method, field_idx, false, data)) {
+      return false;
+    }
+    result->opcode = kInlineOpIGet;
+    result->flags = kInlineSpecial;
+    data->op_variant = IGetVariant(opcode);
+    data->method_is_static = is_static ? 1u : 0u;
+    data->object_arg = object_arg;  // Allow IGET on any register, not just "this".
+    data->src_arg = 0u;
+    data->return_arg_plus1 = 0u;
+  }
+  return true;
+}
+
+bool InlineMethodAnalyser::AnalyseIPutMethod(const DexFile::CodeItem* code_item,
+                                             const MethodReference& method_ref,
+                                             bool is_static,
+                                             ArtMethod* method,
+                                             InlineMethod* result) {
+  const Instruction* instruction = Instruction::At(code_item->insns_);
+  Instruction::Code opcode = instruction->Opcode();
+  DCHECK(IsInstructionIPut(opcode));
+
+  const Instruction* return_instruction = instruction->Next();
+  Instruction::Code return_opcode = return_instruction->Opcode();
+  uint32_t arg_start = code_item->registers_size_ - code_item->ins_size_;
+  uint16_t return_arg_plus1 = 0u;
+  if (return_opcode != Instruction::RETURN_VOID) {
+    if (return_opcode != Instruction::RETURN &&
+        return_opcode != Instruction::RETURN_OBJECT &&
+        return_opcode != Instruction::RETURN_WIDE) {
+      return false;
+    }
+    // Returning an argument.
+    uint32_t return_reg = return_instruction->VRegA_11x();
+    DCHECK_GE(return_reg, arg_start);
+    DCHECK_LT(return_opcode == Instruction::RETURN_WIDE ? return_reg + 1u : return_reg,
+              code_item->registers_size_);
+    return_arg_plus1 = return_reg - arg_start + 1u;
+  }
+
+  uint32_t src_reg = instruction->VRegA_22c();
+  uint32_t object_reg = instruction->VRegB_22c();
+  uint32_t field_idx = instruction->VRegC_22c();
+  DCHECK_GE(object_reg, arg_start);
+  DCHECK_LT(object_reg, code_item->registers_size_);
+  DCHECK_GE(src_reg, arg_start);
+  DCHECK_LT(opcode == Instruction::IPUT_WIDE ? src_reg + 1 : src_reg, code_item->registers_size_);
+  uint32_t object_arg = object_reg - arg_start;
+  uint32_t src_arg = src_reg - arg_start;
+
+  if (is_static || object_arg != 0u) {
+    // TODO: Implement inlining of IPUT on non-"this" registers (needs correct stack trace for NPE).
+    // Allow synthetic accessors. We don't care about losing their stack frame in NPE.
+    if (!IsSyntheticAccessor(method_ref)) {
+      return false;
+    }
+  }
+
+  // InlineIGetIPutData::object_arg/src_arg/return_arg_plus1 are each only 4 bits wide.
+  static constexpr uint16_t kMaxObjectArg = 15u;
+  static constexpr uint16_t kMaxSrcArg = 15u;
+  static constexpr uint16_t kMaxReturnArgPlus1 = 15u;
+  if (object_arg > kMaxObjectArg || src_arg > kMaxSrcArg || return_arg_plus1 > kMaxReturnArgPlus1) {
+    return false;
+  }
+
+  if (result != nullptr) {
+    InlineIGetIPutData* data = &result->d.ifield_data;
+    if (!ComputeSpecialAccessorInfo(method, field_idx, true, data)) {
+      return false;
+    }
+    result->opcode = kInlineOpIPut;
+    result->flags = kInlineSpecial;
+    data->op_variant = IPutVariant(opcode);
+    data->method_is_static = is_static ? 1u : 0u;
+    data->object_arg = object_arg;  // Allow IPUT on any register, not just "this".
+    data->src_arg = src_arg;
+    data->return_arg_plus1 = return_arg_plus1;
+  }
+  return true;
+}
+
+bool InlineMethodAnalyser::ComputeSpecialAccessorInfo(ArtMethod* method,
+                                                      uint32_t field_idx,
+                                                      bool is_put,
+                                                      InlineIGetIPutData* result) {
+  if (method == nullptr) {
+    return false;
+  }
+  ObjPtr<mirror::DexCache> dex_cache = method->GetDexCache();
+  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
+  ArtField* field = class_linker->LookupResolvedField(field_idx, method, /* is_static */ false);
+  if (field == nullptr || field->IsStatic()) {
+    return false;
+  }
+  ObjPtr<mirror::Class> method_class = method->GetDeclaringClass();
+  ObjPtr<mirror::Class> field_class = field->GetDeclaringClass();
+  if (!method_class->CanAccessResolvedField(field_class, field, dex_cache, field_idx) ||
+      (is_put && field->IsFinal() && method_class != field_class)) {
+    return false;
+  }
+  DCHECK_GE(field->GetOffset().Int32Value(), 0);
+  // Do not interleave function calls with bit field writes to placate valgrind. Bug: 27552451.
+  uint32_t field_offset = field->GetOffset().Uint32Value();
+  bool is_volatile = field->IsVolatile();
+  result->field_idx = field_idx;
+  result->field_offset = field_offset;
+  result->is_volatile = is_volatile ? 1u : 0u;
+  return true;
+}
+
+}  // namespace art