compiler/compiled_method.h - platform/art - Gitiles

 /*
  * Copyright (C) 2011 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.
  */

 #ifndef ART_COMPILER_COMPILED_METHOD_H_
 #define ART_COMPILER_COMPILED_METHOD_H_

 #include <memory>
 #include <iosfwd>
 #include <string>
 #include <vector>

 #include "arch/instruction_set.h"
 #include "base/array_ref.h"
 #include "base/bit_utils.h"
 #include "base/length_prefixed_array.h"
 #include "method_reference.h"

 namespace art {

 class CompilerDriver;
 class CompiledMethodStorage;

 class CompiledCode {
  public:
   // For Quick to supply an code blob
   CompiledCode(CompilerDriver* compiler_driver, InstructionSet instruction_set,
                const ArrayRef<const uint8_t>& quick_code);

   virtual ~CompiledCode();

   InstructionSet GetInstructionSet() const {
     return instruction_set_;
   }

   ArrayRef<const uint8_t> GetQuickCode() const {
     return GetArray(quick_code_);
   }

   bool operator==(const CompiledCode& rhs) const;

   // To align an offset from a page-aligned value to make it suitable
   // for code storage. For example on ARM, to ensure that PC relative
   // valu computations work out as expected.
   size_t AlignCode(size_t offset) const;
   static size_t AlignCode(size_t offset, InstructionSet instruction_set);

   // returns the difference between the code address and a usable PC.
   // mainly to cope with kThumb2 where the lower bit must be set.
   size_t CodeDelta() const;
   static size_t CodeDelta(InstructionSet instruction_set);

   // Returns a pointer suitable for invoking the code at the argument
   // code_pointer address.  Mainly to cope with kThumb2 where the
   // lower bit must be set to indicate Thumb mode.
   static const void* CodePointer(const void* code_pointer,
                                  InstructionSet instruction_set);

  protected:
   template <typename T>
   static ArrayRef<const T> GetArray(const LengthPrefixedArray<T>* array) {
     if (array == nullptr) {
       return ArrayRef<const T>();
     }
     DCHECK_NE(array->size(), 0u);
     return ArrayRef<const T>(&array->At(0), array->size());
   }

   CompilerDriver* GetCompilerDriver() {
     return compiler_driver_;
   }

  private:
   CompilerDriver* const compiler_driver_;

   const InstructionSet instruction_set_;

   // Used to store the PIC code for Quick.
   const LengthPrefixedArray<uint8_t>* const quick_code_;
 };

 class SrcMapElem {
  public:
   uint32_t from_;
   int32_t to_;
 };

 inline bool operator<(const SrcMapElem& lhs, const SrcMapElem& rhs) {
   if (lhs.from_ != rhs.from_) {
     return lhs.from_ < rhs.from_;
   }
   return lhs.to_ < rhs.to_;
 }

 inline bool operator==(const SrcMapElem& lhs, const SrcMapElem& rhs) {
   return lhs.from_ == rhs.from_ && lhs.to_ == rhs.to_;
 }

 template <class Allocator>
 class SrcMap FINAL : public std::vector<SrcMapElem, Allocator> {
  public:
   using std::vector<SrcMapElem, Allocator>::begin;
   using typename std::vector<SrcMapElem, Allocator>::const_iterator;
   using std::vector<SrcMapElem, Allocator>::empty;
   using std::vector<SrcMapElem, Allocator>::end;
   using std::vector<SrcMapElem, Allocator>::resize;
   using std::vector<SrcMapElem, Allocator>::shrink_to_fit;
   using std::vector<SrcMapElem, Allocator>::size;

   explicit SrcMap() {}
   explicit SrcMap(const Allocator& alloc) : std::vector<SrcMapElem, Allocator>(alloc) {}

   template <class InputIt>
   SrcMap(InputIt first, InputIt last, const Allocator& alloc)
       : std::vector<SrcMapElem, Allocator>(first, last, alloc) {}

   void push_back(const SrcMapElem& elem) {
     if (!empty()) {
       // Check that the addresses are inserted in sorted order.
       DCHECK_GE(elem.from_, this->back().from_);
       // If two consequitive entries map to the same value, ignore the later.
       // E.g. for map {{0, 1}, {4, 1}, {8, 2}}, all values in [0,8) map to 1.
       if (elem.to_ == this->back().to_) {
         return;
       }
     }
     std::vector<SrcMapElem, Allocator>::push_back(elem);
   }

   // Returns true and the corresponding "to" value if the mapping is found.
   // Oterwise returns false and 0.
   std::pair<bool, int32_t> Find(uint32_t from) const {
     // Finds first mapping such that lb.from_ >= from.
     auto lb = std::lower_bound(begin(), end(), SrcMapElem {from, INT32_MIN});
     if (lb != end() && lb->from_ == from) {
       // Found exact match.
       return std::make_pair(true, lb->to_);
     } else if (lb != begin()) {
       // The previous mapping is still in effect.
       return std::make_pair(true, (--lb)->to_);
     } else {
       // Not found because 'from' is smaller than first entry in the map.
       return std::make_pair(false, 0);
     }
   }
 };

 using DefaultSrcMap = SrcMap<std::allocator<SrcMapElem>>;

 class LinkerPatch {
  public:
   // Note: We explicitly specify the underlying type of the enum because GCC
   // would otherwise select a bigger underlying type and then complain that
   //     'art::LinkerPatch::patch_type_' is too small to hold all
   //     values of 'enum class art::LinkerPatch::Type'
   // which is ridiculous given we have only a handful of values here. If we
   // choose to squeeze the Type into fewer than 8 bits, we'll have to declare
   // patch_type_ as an uintN_t and do explicit static_cast<>s.
   enum class Type : uint8_t {
     kRecordPosition,   // Just record patch position for patchoat.
     kMethod,
     kCall,
     kCallRelative,     // NOTE: Actual patching is instruction_set-dependent.
     kType,
     kTypeRelative,     // NOTE: Actual patching is instruction_set-dependent.
     kString,
     kStringRelative,   // NOTE: Actual patching is instruction_set-dependent.
     kStringBssEntry,   // NOTE: Actual patching is instruction_set-dependent.
     kDexCacheArray,    // NOTE: Actual patching is instruction_set-dependent.
   };

   static LinkerPatch RecordPosition(size_t literal_offset) {
     return LinkerPatch(literal_offset, Type::kRecordPosition, /* target_dex_file */ nullptr);
   }

   static LinkerPatch MethodPatch(size_t literal_offset,
                                  const DexFile* target_dex_file,
                                  uint32_t target_method_idx) {
     LinkerPatch patch(literal_offset, Type::kMethod, target_dex_file);
     patch.method_idx_ = target_method_idx;
     return patch;
   }

   static LinkerPatch CodePatch(size_t literal_offset,
                                const DexFile* target_dex_file,
                                uint32_t target_method_idx) {
     LinkerPatch patch(literal_offset, Type::kCall, target_dex_file);
     patch.method_idx_ = target_method_idx;
     return patch;
   }

   static LinkerPatch RelativeCodePatch(size_t literal_offset,
                                        const DexFile* target_dex_file,
                                        uint32_t target_method_idx) {
     LinkerPatch patch(literal_offset, Type::kCallRelative, target_dex_file);
     patch.method_idx_ = target_method_idx;
     return patch;
   }

   static LinkerPatch TypePatch(size_t literal_offset,
                                const DexFile* target_dex_file,
                                uint32_t target_type_idx) {
     LinkerPatch patch(literal_offset, Type::kType, target_dex_file);
     patch.type_idx_ = target_type_idx;
     return patch;
   }

   static LinkerPatch RelativeTypePatch(size_t literal_offset,
                                        const DexFile* target_dex_file,
                                        uint32_t pc_insn_offset,
                                        uint32_t target_type_idx) {
     LinkerPatch patch(literal_offset, Type::kTypeRelative, target_dex_file);
     patch.type_idx_ = target_type_idx;
     patch.pc_insn_offset_ = pc_insn_offset;
     return patch;
   }

   static LinkerPatch StringPatch(size_t literal_offset,
                                  const DexFile* target_dex_file,
                                  uint32_t target_string_idx) {
     LinkerPatch patch(literal_offset, Type::kString, target_dex_file);
     patch.string_idx_ = target_string_idx;
     return patch;
   }

   static LinkerPatch RelativeStringPatch(size_t literal_offset,
                                          const DexFile* target_dex_file,
                                          uint32_t pc_insn_offset,
                                          uint32_t target_string_idx) {
     LinkerPatch patch(literal_offset, Type::kStringRelative, target_dex_file);
     patch.string_idx_ = target_string_idx;
     patch.pc_insn_offset_ = pc_insn_offset;
     return patch;
   }

   static LinkerPatch StringBssEntryPatch(size_t literal_offset,
                                          const DexFile* target_dex_file,
                                          uint32_t pc_insn_offset,
                                          uint32_t target_string_idx) {
     LinkerPatch patch(literal_offset, Type::kStringBssEntry, target_dex_file);
     patch.string_idx_ = target_string_idx;
     patch.pc_insn_offset_ = pc_insn_offset;
     return patch;
   }

   static LinkerPatch DexCacheArrayPatch(size_t literal_offset,
                                         const DexFile* target_dex_file,
                                         uint32_t pc_insn_offset,
                                         uint32_t element_offset) {
     DCHECK(IsUint<32>(element_offset));
     LinkerPatch patch(literal_offset, Type::kDexCacheArray, target_dex_file);
     patch.pc_insn_offset_ = pc_insn_offset;
     patch.element_offset_ = element_offset;
     return patch;
   }

   LinkerPatch(const LinkerPatch& other) = default;
   LinkerPatch& operator=(const LinkerPatch& other) = default;

   size_t LiteralOffset() const {
     return literal_offset_;
   }

   Type GetType() const {
     return patch_type_;
   }

   bool IsPcRelative() const {
     switch (GetType()) {
       case Type::kCallRelative:
       case Type::kTypeRelative:
       case Type::kStringRelative:
       case Type::kStringBssEntry:
       case Type::kDexCacheArray:
         return true;
       default:
         return false;
     }
   }

   MethodReference TargetMethod() const {
     DCHECK(patch_type_ == Type::kMethod ||
            patch_type_ == Type::kCall ||
            patch_type_ == Type::kCallRelative);
     return MethodReference(target_dex_file_, method_idx_);
   }

   const DexFile* TargetTypeDexFile() const {
     DCHECK(patch_type_ == Type::kType || patch_type_ == Type::kTypeRelative);
     return target_dex_file_;
   }

   uint32_t TargetTypeIndex() const {
     DCHECK(patch_type_ == Type::kType || patch_type_ == Type::kTypeRelative);
     return type_idx_;
   }

   const DexFile* TargetStringDexFile() const {
     DCHECK(patch_type_ == Type::kString ||
            patch_type_ == Type::kStringRelative ||
            patch_type_ == Type::kStringBssEntry);
     return target_dex_file_;
   }

   uint32_t TargetStringIndex() const {
     DCHECK(patch_type_ == Type::kString ||
            patch_type_ == Type::kStringRelative ||
            patch_type_ == Type::kStringBssEntry);
     return string_idx_;
   }

   const DexFile* TargetDexCacheDexFile() const {
     DCHECK(patch_type_ == Type::kDexCacheArray);
     return target_dex_file_;
   }

   size_t TargetDexCacheElementOffset() const {
     DCHECK(patch_type_ == Type::kDexCacheArray);
     return element_offset_;
   }

   uint32_t PcInsnOffset() const {
     DCHECK(patch_type_ == Type::kTypeRelative ||
            patch_type_ == Type::kStringRelative ||
            patch_type_ == Type::kStringBssEntry ||
            patch_type_ == Type::kDexCacheArray);
     return pc_insn_offset_;
   }

  private:
   LinkerPatch(size_t literal_offset, Type patch_type, const DexFile* target_dex_file)
       : target_dex_file_(target_dex_file),
         literal_offset_(literal_offset),
         patch_type_(patch_type) {
     cmp1_ = 0u;
     cmp2_ = 0u;
     // The compiler rejects methods that are too big, so the compiled code
     // of a single method really shouln't be anywhere close to 16MiB.
     DCHECK(IsUint<24>(literal_offset));
   }

   const DexFile* target_dex_file_;
   uint32_t literal_offset_ : 24;  // Method code size up to 16MiB.
   Type patch_type_ : 8;
   union {
     uint32_t cmp1_;             // Used for relational operators.
     uint32_t method_idx_;       // Method index for Call/Method patches.
     uint32_t type_idx_;         // Type index for Type patches.
     uint32_t string_idx_;       // String index for String patches.
     uint32_t element_offset_;   // Element offset in the dex cache arrays.
     static_assert(sizeof(method_idx_) == sizeof(cmp1_), "needed by relational operators");
     static_assert(sizeof(type_idx_) == sizeof(cmp1_), "needed by relational operators");
     static_assert(sizeof(string_idx_) == sizeof(cmp1_), "needed by relational operators");
     static_assert(sizeof(element_offset_) == sizeof(cmp1_), "needed by relational operators");
   };
   union {
     // Note: To avoid uninitialized padding on 64-bit systems, we use `size_t` for `cmp2_`.
     // This allows a hashing function to treat an array of linker patches as raw memory.
     size_t cmp2_;             // Used for relational operators.
     // Literal offset of the insn loading PC (same as literal_offset if it's the same insn,
     // may be different if the PC-relative addressing needs multiple insns).
     uint32_t pc_insn_offset_;
     static_assert(sizeof(pc_insn_offset_) <= sizeof(cmp2_), "needed by relational operators");
   };

   friend bool operator==(const LinkerPatch& lhs, const LinkerPatch& rhs);
   friend bool operator<(const LinkerPatch& lhs, const LinkerPatch& rhs);
 };
 std::ostream& operator<<(std::ostream& os, const LinkerPatch::Type& type);

 inline bool operator==(const LinkerPatch& lhs, const LinkerPatch& rhs) {
   return lhs.literal_offset_ == rhs.literal_offset_ &&
       lhs.patch_type_ == rhs.patch_type_ &&
       lhs.target_dex_file_ == rhs.target_dex_file_ &&
       lhs.cmp1_ == rhs.cmp1_ &&
       lhs.cmp2_ == rhs.cmp2_;
 }

 inline bool operator<(const LinkerPatch& lhs, const LinkerPatch& rhs) {
   return (lhs.literal_offset_ != rhs.literal_offset_) ? lhs.literal_offset_ < rhs.literal_offset_
       : (lhs.patch_type_ != rhs.patch_type_) ? lhs.patch_type_ < rhs.patch_type_
       : (lhs.target_dex_file_ != rhs.target_dex_file_) ? lhs.target_dex_file_ < rhs.target_dex_file_
       : (lhs.cmp1_ != rhs.cmp1_) ? lhs.cmp1_ < rhs.cmp1_
       : lhs.cmp2_ < rhs.cmp2_;
 }

 class CompiledMethod FINAL : public CompiledCode {
  public:
   // Constructs a CompiledMethod.
   // Note: Consider using the static allocation methods below that will allocate the CompiledMethod
   //       in the swap space.
   CompiledMethod(CompilerDriver* driver,
                  InstructionSet instruction_set,
                  const ArrayRef<const uint8_t>& quick_code,
                  const size_t frame_size_in_bytes,
                  const uint32_t core_spill_mask,
                  const uint32_t fp_spill_mask,
                  const ArrayRef<const SrcMapElem>& src_mapping_table,
                  const ArrayRef<const uint8_t>& vmap_table,
                  const ArrayRef<const uint8_t>& cfi_info,
                  const ArrayRef<const LinkerPatch>& patches);

   virtual ~CompiledMethod();

   static CompiledMethod* SwapAllocCompiledMethod(
       CompilerDriver* driver,
       InstructionSet instruction_set,
       const ArrayRef<const uint8_t>& quick_code,
       const size_t frame_size_in_bytes,
       const uint32_t core_spill_mask,
       const uint32_t fp_spill_mask,
       const ArrayRef<const SrcMapElem>& src_mapping_table,
       const ArrayRef<const uint8_t>& vmap_table,
       const ArrayRef<const uint8_t>& cfi_info,
       const ArrayRef<const LinkerPatch>& patches);

   static void ReleaseSwapAllocatedCompiledMethod(CompilerDriver* driver, CompiledMethod* m);

   size_t GetFrameSizeInBytes() const {
     return frame_size_in_bytes_;
   }

   uint32_t GetCoreSpillMask() const {
     return core_spill_mask_;
   }

   uint32_t GetFpSpillMask() const {
     return fp_spill_mask_;
   }

   ArrayRef<const SrcMapElem> GetSrcMappingTable() const {
     return GetArray(src_mapping_table_);
   }

   ArrayRef<const uint8_t> GetVmapTable() const {
     return GetArray(vmap_table_);
   }

   ArrayRef<const uint8_t> GetCFIInfo() const {
     return GetArray(cfi_info_);
   }

   ArrayRef<const LinkerPatch> GetPatches() const {
     return GetArray(patches_);
   }

  private:
   // For quick code, the size of the activation used by the code.
   const size_t frame_size_in_bytes_;
   // For quick code, a bit mask describing spilled GPR callee-save registers.
   const uint32_t core_spill_mask_;
   // For quick code, a bit mask describing spilled FPR callee-save registers.
   const uint32_t fp_spill_mask_;
   // For quick code, a set of pairs (PC, DEX) mapping from native PC offset to DEX offset.
   const LengthPrefixedArray<SrcMapElem>* const src_mapping_table_;
   // For quick code, a uleb128 encoded map from GPR/FPR register to dex register. Size prefixed.
   const LengthPrefixedArray<uint8_t>* const vmap_table_;
   // For quick code, a FDE entry for the debug_frame section.
   const LengthPrefixedArray<uint8_t>* const cfi_info_;
   // For quick code, linker patches needed by the method.
   const LengthPrefixedArray<LinkerPatch>* const patches_;
 };

 }  // namespace art

 #endif  // ART_COMPILER_COMPILED_METHOD_H_
	/*
	* Copyright (C) 2011 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.
	*/

	#ifndef ART_COMPILER_COMPILED_METHOD_H_
	#define ART_COMPILER_COMPILED_METHOD_H_

	#include <memory>
	#include <iosfwd>
	#include <string>
	#include <vector>

	#include "arch/instruction_set.h"
	#include "base/array_ref.h"
	#include "base/bit_utils.h"
	#include "base/length_prefixed_array.h"
	#include "method_reference.h"

	namespace art {

	class CompilerDriver;
	class CompiledMethodStorage;

	class CompiledCode {
	public:
	// For Quick to supply an code blob
	CompiledCode(CompilerDriver* compiler_driver, InstructionSet instruction_set,
	const ArrayRef<const uint8_t>& quick_code);

	virtual ~CompiledCode();

	InstructionSet GetInstructionSet() const {
	return instruction_set_;
	}

	ArrayRef<const uint8_t> GetQuickCode() const {
	return GetArray(quick_code_);
	}

	bool operator==(const CompiledCode& rhs) const;

	// To align an offset from a page-aligned value to make it suitable
	// for code storage. For example on ARM, to ensure that PC relative
	// valu computations work out as expected.
	size_t AlignCode(size_t offset) const;
	static size_t AlignCode(size_t offset, InstructionSet instruction_set);

	// returns the difference between the code address and a usable PC.
	// mainly to cope with kThumb2 where the lower bit must be set.
	size_t CodeDelta() const;
	static size_t CodeDelta(InstructionSet instruction_set);

	// Returns a pointer suitable for invoking the code at the argument
	// code_pointer address. Mainly to cope with kThumb2 where the
	// lower bit must be set to indicate Thumb mode.
	static const void* CodePointer(const void* code_pointer,
	InstructionSet instruction_set);

	protected:
	template <typename T>
	static ArrayRef<const T> GetArray(const LengthPrefixedArray<T>* array) {
	if (array == nullptr) {
	return ArrayRef<const T>();
	}
	DCHECK_NE(array->size(), 0u);
	return ArrayRef<const T>(&array->At(0), array->size());
	}

	CompilerDriver* GetCompilerDriver() {
	return compiler_driver_;
	}

	private:
	CompilerDriver* const compiler_driver_;

	const InstructionSet instruction_set_;

	// Used to store the PIC code for Quick.
	const LengthPrefixedArray<uint8_t>* const quick_code_;
	};

	class SrcMapElem {
	public:
	uint32_t from_;
	int32_t to_;
	};

	inline bool operator<(const SrcMapElem& lhs, const SrcMapElem& rhs) {
	if (lhs.from_ != rhs.from_) {
	return lhs.from_ < rhs.from_;
	}
	return lhs.to_ < rhs.to_;
	}

	inline bool operator==(const SrcMapElem& lhs, const SrcMapElem& rhs) {
	return lhs.from_ == rhs.from_ && lhs.to_ == rhs.to_;
	}

	template <class Allocator>
	class SrcMap FINAL : public std::vector<SrcMapElem, Allocator> {
	public:
	using std::vector<SrcMapElem, Allocator>::begin;
	using typename std::vector<SrcMapElem, Allocator>::const_iterator;
	using std::vector<SrcMapElem, Allocator>::empty;
	using std::vector<SrcMapElem, Allocator>::end;
	using std::vector<SrcMapElem, Allocator>::resize;
	using std::vector<SrcMapElem, Allocator>::shrink_to_fit;
	using std::vector<SrcMapElem, Allocator>::size;

	explicit SrcMap() {}
	explicit SrcMap(const Allocator& alloc) : std::vector<SrcMapElem, Allocator>(alloc) {}

	template <class InputIt>
	SrcMap(InputIt first, InputIt last, const Allocator& alloc)
	: std::vector<SrcMapElem, Allocator>(first, last, alloc) {}

	void push_back(const SrcMapElem& elem) {
	if (!empty()) {
	// Check that the addresses are inserted in sorted order.
	DCHECK_GE(elem.from_, this->back().from_);
	// If two consequitive entries map to the same value, ignore the later.
	// E.g. for map {{0, 1}, {4, 1}, {8, 2}}, all values in [0,8) map to 1.
	if (elem.to_ == this->back().to_) {
	return;
	}
	}
	std::vector<SrcMapElem, Allocator>::push_back(elem);
	}

	// Returns true and the corresponding "to" value if the mapping is found.
	// Oterwise returns false and 0.
	std::pair<bool, int32_t> Find(uint32_t from) const {
	// Finds first mapping such that lb.from_ >= from.
	auto lb = std::lower_bound(begin(), end(), SrcMapElem {from, INT32_MIN});
	if (lb != end() && lb->from_ == from) {
	// Found exact match.
	return std::make_pair(true, lb->to_);
	} else if (lb != begin()) {
	// The previous mapping is still in effect.
	return std::make_pair(true, (--lb)->to_);
	} else {
	// Not found because 'from' is smaller than first entry in the map.
	return std::make_pair(false, 0);
	}
	}
	};

	using DefaultSrcMap = SrcMap<std::allocator<SrcMapElem>>;

	class LinkerPatch {
	public:
	// Note: We explicitly specify the underlying type of the enum because GCC
	// would otherwise select a bigger underlying type and then complain that
	// 'art::LinkerPatch::patch_type_' is too small to hold all
	// values of 'enum class art::LinkerPatch::Type'
	// which is ridiculous given we have only a handful of values here. If we
	// choose to squeeze the Type into fewer than 8 bits, we'll have to declare
	// patch_type_ as an uintN_t and do explicit static_cast<>s.
	enum class Type : uint8_t {
	kRecordPosition, // Just record patch position for patchoat.
	kMethod,
	kCall,
	kCallRelative, // NOTE: Actual patching is instruction_set-dependent.
	kType,
	kTypeRelative, // NOTE: Actual patching is instruction_set-dependent.
	kString,
	kStringRelative, // NOTE: Actual patching is instruction_set-dependent.
	kStringBssEntry, // NOTE: Actual patching is instruction_set-dependent.
	kDexCacheArray, // NOTE: Actual patching is instruction_set-dependent.
	};

	static LinkerPatch RecordPosition(size_t literal_offset) {
	return LinkerPatch(literal_offset, Type::kRecordPosition, /* target_dex_file */ nullptr);
	}

	static LinkerPatch MethodPatch(size_t literal_offset,
	const DexFile* target_dex_file,
	uint32_t target_method_idx) {
	LinkerPatch patch(literal_offset, Type::kMethod, target_dex_file);
	patch.method_idx_ = target_method_idx;
	return patch;
	}

	static LinkerPatch CodePatch(size_t literal_offset,
	const DexFile* target_dex_file,
	uint32_t target_method_idx) {
	LinkerPatch patch(literal_offset, Type::kCall, target_dex_file);
	patch.method_idx_ = target_method_idx;
	return patch;
	}

	static LinkerPatch RelativeCodePatch(size_t literal_offset,
	const DexFile* target_dex_file,
	uint32_t target_method_idx) {
	LinkerPatch patch(literal_offset, Type::kCallRelative, target_dex_file);
	patch.method_idx_ = target_method_idx;
	return patch;
	}

	static LinkerPatch TypePatch(size_t literal_offset,
	const DexFile* target_dex_file,
	uint32_t target_type_idx) {
	LinkerPatch patch(literal_offset, Type::kType, target_dex_file);
	patch.type_idx_ = target_type_idx;
	return patch;
	}

	static LinkerPatch RelativeTypePatch(size_t literal_offset,
	const DexFile* target_dex_file,
	uint32_t pc_insn_offset,
	uint32_t target_type_idx) {
	LinkerPatch patch(literal_offset, Type::kTypeRelative, target_dex_file);
	patch.type_idx_ = target_type_idx;
	patch.pc_insn_offset_ = pc_insn_offset;
	return patch;
	}

	static LinkerPatch StringPatch(size_t literal_offset,
	const DexFile* target_dex_file,
	uint32_t target_string_idx) {
	LinkerPatch patch(literal_offset, Type::kString, target_dex_file);
	patch.string_idx_ = target_string_idx;
	return patch;
	}

	static LinkerPatch RelativeStringPatch(size_t literal_offset,
	const DexFile* target_dex_file,
	uint32_t pc_insn_offset,
	uint32_t target_string_idx) {
	LinkerPatch patch(literal_offset, Type::kStringRelative, target_dex_file);
	patch.string_idx_ = target_string_idx;
	patch.pc_insn_offset_ = pc_insn_offset;
	return patch;
	}

	static LinkerPatch StringBssEntryPatch(size_t literal_offset,
	const DexFile* target_dex_file,
	uint32_t pc_insn_offset,
	uint32_t target_string_idx) {
	LinkerPatch patch(literal_offset, Type::kStringBssEntry, target_dex_file);
	patch.string_idx_ = target_string_idx;
	patch.pc_insn_offset_ = pc_insn_offset;
	return patch;
	}

	static LinkerPatch DexCacheArrayPatch(size_t literal_offset,
	const DexFile* target_dex_file,
	uint32_t pc_insn_offset,
	uint32_t element_offset) {
	DCHECK(IsUint<32>(element_offset));
	LinkerPatch patch(literal_offset, Type::kDexCacheArray, target_dex_file);
	patch.pc_insn_offset_ = pc_insn_offset;
	patch.element_offset_ = element_offset;
	return patch;
	}

	LinkerPatch(const LinkerPatch& other) = default;
	LinkerPatch& operator=(const LinkerPatch& other) = default;

	size_t LiteralOffset() const {
	return literal_offset_;
	}

	Type GetType() const {
	return patch_type_;
	}

	bool IsPcRelative() const {
	switch (GetType()) {
	case Type::kCallRelative:
	case Type::kTypeRelative:
	case Type::kStringRelative:
	case Type::kStringBssEntry:
	case Type::kDexCacheArray:
	return true;
	default:
	return false;
	}
	}

	MethodReference TargetMethod() const {
	DCHECK(patch_type_ == Type::kMethod \|\|
	patch_type_ == Type::kCall \|\|
	patch_type_ == Type::kCallRelative);
	return MethodReference(target_dex_file_, method_idx_);
	}

	const DexFile* TargetTypeDexFile() const {
	DCHECK(patch_type_ == Type::kType \|\| patch_type_ == Type::kTypeRelative);
	return target_dex_file_;
	}

	uint32_t TargetTypeIndex() const {
	DCHECK(patch_type_ == Type::kType \|\| patch_type_ == Type::kTypeRelative);
	return type_idx_;
	}

	const DexFile* TargetStringDexFile() const {
	DCHECK(patch_type_ == Type::kString \|\|
	patch_type_ == Type::kStringRelative \|\|
	patch_type_ == Type::kStringBssEntry);
	return target_dex_file_;
	}

	uint32_t TargetStringIndex() const {
	DCHECK(patch_type_ == Type::kString \|\|
	patch_type_ == Type::kStringRelative \|\|
	patch_type_ == Type::kStringBssEntry);
	return string_idx_;
	}

	const DexFile* TargetDexCacheDexFile() const {
	DCHECK(patch_type_ == Type::kDexCacheArray);
	return target_dex_file_;
	}

	size_t TargetDexCacheElementOffset() const {
	DCHECK(patch_type_ == Type::kDexCacheArray);
	return element_offset_;
	}

	uint32_t PcInsnOffset() const {
	DCHECK(patch_type_ == Type::kTypeRelative \|\|
	patch_type_ == Type::kStringRelative \|\|
	patch_type_ == Type::kStringBssEntry \|\|
	patch_type_ == Type::kDexCacheArray);
	return pc_insn_offset_;
	}

	private:
	LinkerPatch(size_t literal_offset, Type patch_type, const DexFile* target_dex_file)
	: target_dex_file_(target_dex_file),
	literal_offset_(literal_offset),
	patch_type_(patch_type) {
	cmp1_ = 0u;
	cmp2_ = 0u;
	// The compiler rejects methods that are too big, so the compiled code
	// of a single method really shouln't be anywhere close to 16MiB.
	DCHECK(IsUint<24>(literal_offset));
	}

	const DexFile* target_dex_file_;
	uint32_t literal_offset_ : 24; // Method code size up to 16MiB.
	Type patch_type_ : 8;
	union {
	uint32_t cmp1_; // Used for relational operators.
	uint32_t method_idx_; // Method index for Call/Method patches.
	uint32_t type_idx_; // Type index for Type patches.
	uint32_t string_idx_; // String index for String patches.
	uint32_t element_offset_; // Element offset in the dex cache arrays.
	static_assert(sizeof(method_idx_) == sizeof(cmp1_), "needed by relational operators");
	static_assert(sizeof(type_idx_) == sizeof(cmp1_), "needed by relational operators");
	static_assert(sizeof(string_idx_) == sizeof(cmp1_), "needed by relational operators");
	static_assert(sizeof(element_offset_) == sizeof(cmp1_), "needed by relational operators");
	};
	union {
	// Note: To avoid uninitialized padding on 64-bit systems, we use `size_t` for `cmp2_`.
	// This allows a hashing function to treat an array of linker patches as raw memory.
	size_t cmp2_; // Used for relational operators.
	// Literal offset of the insn loading PC (same as literal_offset if it's the same insn,
	// may be different if the PC-relative addressing needs multiple insns).
	uint32_t pc_insn_offset_;
	static_assert(sizeof(pc_insn_offset_) <= sizeof(cmp2_), "needed by relational operators");
	};

	friend bool operator==(const LinkerPatch& lhs, const LinkerPatch& rhs);
	friend bool operator<(const LinkerPatch& lhs, const LinkerPatch& rhs);
	};
	std::ostream& operator<<(std::ostream& os, const LinkerPatch::Type& type);

	inline bool operator==(const LinkerPatch& lhs, const LinkerPatch& rhs) {
	return lhs.literal_offset_ == rhs.literal_offset_ &&
	lhs.patch_type_ == rhs.patch_type_ &&
	lhs.target_dex_file_ == rhs.target_dex_file_ &&
	lhs.cmp1_ == rhs.cmp1_ &&
	lhs.cmp2_ == rhs.cmp2_;
	}

	inline bool operator<(const LinkerPatch& lhs, const LinkerPatch& rhs) {
	return (lhs.literal_offset_ != rhs.literal_offset_) ? lhs.literal_offset_ < rhs.literal_offset_
	: (lhs.patch_type_ != rhs.patch_type_) ? lhs.patch_type_ < rhs.patch_type_
	: (lhs.target_dex_file_ != rhs.target_dex_file_) ? lhs.target_dex_file_ < rhs.target_dex_file_
	: (lhs.cmp1_ != rhs.cmp1_) ? lhs.cmp1_ < rhs.cmp1_
	: lhs.cmp2_ < rhs.cmp2_;
	}

	class CompiledMethod FINAL : public CompiledCode {
	public:
	// Constructs a CompiledMethod.
	// Note: Consider using the static allocation methods below that will allocate the CompiledMethod
	// in the swap space.
	CompiledMethod(CompilerDriver* driver,
	InstructionSet instruction_set,
	const ArrayRef<const uint8_t>& quick_code,
	const size_t frame_size_in_bytes,
	const uint32_t core_spill_mask,
	const uint32_t fp_spill_mask,
	const ArrayRef<const SrcMapElem>& src_mapping_table,
	const ArrayRef<const uint8_t>& vmap_table,
	const ArrayRef<const uint8_t>& cfi_info,
	const ArrayRef<const LinkerPatch>& patches);

	virtual ~CompiledMethod();

	static CompiledMethod* SwapAllocCompiledMethod(
	CompilerDriver* driver,
	InstructionSet instruction_set,
	const ArrayRef<const uint8_t>& quick_code,
	const size_t frame_size_in_bytes,
	const uint32_t core_spill_mask,
	const uint32_t fp_spill_mask,
	const ArrayRef<const SrcMapElem>& src_mapping_table,
	const ArrayRef<const uint8_t>& vmap_table,
	const ArrayRef<const uint8_t>& cfi_info,
	const ArrayRef<const LinkerPatch>& patches);

	static void ReleaseSwapAllocatedCompiledMethod(CompilerDriver* driver, CompiledMethod* m);

	size_t GetFrameSizeInBytes() const {
	return frame_size_in_bytes_;
	}

	uint32_t GetCoreSpillMask() const {
	return core_spill_mask_;
	}

	uint32_t GetFpSpillMask() const {
	return fp_spill_mask_;
	}

	ArrayRef<const SrcMapElem> GetSrcMappingTable() const {
	return GetArray(src_mapping_table_);
	}

	ArrayRef<const uint8_t> GetVmapTable() const {
	return GetArray(vmap_table_);
	}

	ArrayRef<const uint8_t> GetCFIInfo() const {
	return GetArray(cfi_info_);
	}

	ArrayRef<const LinkerPatch> GetPatches() const {
	return GetArray(patches_);
	}

	private:
	// For quick code, the size of the activation used by the code.
	const size_t frame_size_in_bytes_;
	// For quick code, a bit mask describing spilled GPR callee-save registers.
	const uint32_t core_spill_mask_;
	// For quick code, a bit mask describing spilled FPR callee-save registers.
	const uint32_t fp_spill_mask_;
	// For quick code, a set of pairs (PC, DEX) mapping from native PC offset to DEX offset.
	const LengthPrefixedArray<SrcMapElem>* const src_mapping_table_;
	// For quick code, a uleb128 encoded map from GPR/FPR register to dex register. Size prefixed.
	const LengthPrefixedArray<uint8_t>* const vmap_table_;
	// For quick code, a FDE entry for the debug_frame section.
	const LengthPrefixedArray<uint8_t>* const cfi_info_;
	// For quick code, linker patches needed by the method.
	const LengthPrefixedArray<LinkerPatch>* const patches_;
	};

	} // namespace art

	#endif // ART_COMPILER_COMPILED_METHOD_H_