compiler/dex/mir_field_info.h - platform/art - Git at Google

 /*
  * 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.
  */

 #ifndef ART_COMPILER_DEX_MIR_FIELD_INFO_H_
 #define ART_COMPILER_DEX_MIR_FIELD_INFO_H_

 #include "base/macros.h"
 #include "dex_file.h"
 #include "dex_instruction_utils.h"
 #include "offsets.h"

 namespace art {

 class CompilerDriver;
 class DexCompilationUnit;
 class ScopedObjectAccess;

 /*
  * Field info is calculated from the perspective of the compilation unit that accesses
  * the field and stored in that unit's MIRGraph. Therefore it does not need to reference the
  * dex file or method for which it has been calculated. However, we do store the declaring
  * field index, class index and dex file of the resolved field to help distinguish between fields.
  */

 class MirFieldInfo {
  public:
   uint16_t FieldIndex() const {
     return field_idx_;
   }
   void SetFieldIndex(uint16_t field_idx) {
     field_idx_ = field_idx;
   }

   bool IsStatic() const {
     return (flags_ & kFlagIsStatic) != 0u;
   }

   bool IsResolved() const {
     return declaring_dex_file_ != nullptr;
   }

   const DexFile* DeclaringDexFile() const {
     return declaring_dex_file_;
   }
   void SetDeclaringDexFile(const DexFile* dex_file) {
     declaring_dex_file_ = dex_file;
   }

   uint16_t DeclaringClassIndex() const {
     return declaring_class_idx_;
   }

   uint16_t DeclaringFieldIndex() const {
     return declaring_field_idx_;
   }

   bool IsVolatile() const {
     return (flags_ & kFlagIsVolatile) != 0u;
   }

   // IGET_QUICK, IGET_BYTE_QUICK, ...
   bool IsQuickened() const {
     return (flags_ & kFlagIsQuickened) != 0u;
   }

   DexMemAccessType MemAccessType() const {
     return static_cast<DexMemAccessType>((flags_ >> kBitMemAccessTypeBegin) & kMemAccessTypeMask);
   }

   void CheckEquals(const MirFieldInfo& other) const {
     CHECK_EQ(field_idx_, other.field_idx_);
     CHECK_EQ(flags_, other.flags_);
     CHECK_EQ(declaring_field_idx_, other.declaring_field_idx_);
     CHECK_EQ(declaring_class_idx_, other.declaring_class_idx_);
     CHECK_EQ(declaring_dex_file_, other.declaring_dex_file_);
   }

  protected:
   enum {
     kBitIsStatic = 0,
     kBitIsVolatile,
     kBitIsQuickened,
     kBitMemAccessTypeBegin,
     kBitMemAccessTypeEnd = kBitMemAccessTypeBegin + 3,  // 3 bits for raw type.
     kFieldInfoBitEnd = kBitMemAccessTypeEnd
   };
   static constexpr uint16_t kFlagIsVolatile = 1u << kBitIsVolatile;
   static constexpr uint16_t kFlagIsStatic = 1u << kBitIsStatic;
   static constexpr uint16_t kFlagIsQuickened = 1u << kBitIsQuickened;
   static constexpr uint16_t kMemAccessTypeMask = 7u;
   static_assert((1u << (kBitMemAccessTypeEnd - kBitMemAccessTypeBegin)) - 1u == kMemAccessTypeMask,
                 "Invalid raw type mask");

   MirFieldInfo(uint16_t field_idx, uint16_t flags, DexMemAccessType type)
       : field_idx_(field_idx),
         flags_(flags | static_cast<uint16_t>(type) << kBitMemAccessTypeBegin),
         declaring_field_idx_(0u),
         declaring_class_idx_(0u),
         declaring_dex_file_(nullptr) {
   }

   // Make copy-ctor/assign/dtor protected to avoid slicing.
   MirFieldInfo(const MirFieldInfo& other) = default;
   MirFieldInfo& operator=(const MirFieldInfo& other) = default;
   ~MirFieldInfo() = default;

   // The field index in the compiling method's dex file.
   uint16_t field_idx_;
   // Flags, for volatility and derived class data.
   uint16_t flags_;
   // The field index in the dex file that defines field, 0 if unresolved.
   uint16_t declaring_field_idx_;
   // The type index of the class declaring the field, 0 if unresolved.
   uint16_t declaring_class_idx_;
   // The dex file that defines the class containing the field and the field, null if unresolved.
   const DexFile* declaring_dex_file_;
 };

 class MirIFieldLoweringInfo : public MirFieldInfo {
  public:
   // For each requested instance field retrieve the field's declaring location (dex file, class
   // index and field index) and volatility and compute whether we can fast path the access
   // with IGET/IPUT. For fast path fields, retrieve the field offset.
   static void Resolve(const ScopedObjectAccess& soa,
                       CompilerDriver* compiler_driver,
                       const DexCompilationUnit* mUnit,
                       MirIFieldLoweringInfo* field_infos,
                       size_t count)
       SHARED_REQUIRES(Locks::mutator_lock_);

   // Construct an unresolved instance field lowering info.
   MirIFieldLoweringInfo(uint16_t field_idx, DexMemAccessType type, bool is_quickened)
       : MirFieldInfo(field_idx,
                      kFlagIsVolatile | (is_quickened ? kFlagIsQuickened : 0u),
                      type),  // Without kFlagIsStatic.
         field_offset_(0u) {
   }

   bool FastGet() const {
     return (flags_ & kFlagFastGet) != 0u;
   }

   bool FastPut() const {
     return (flags_ & kFlagFastPut) != 0u;
   }

   MemberOffset FieldOffset() const {
     return field_offset_;
   }

   void CheckEquals(const MirIFieldLoweringInfo& other) const {
     MirFieldInfo::CheckEquals(other);
     CHECK_EQ(field_offset_.Uint32Value(), other.field_offset_.Uint32Value());
   }

  private:
   enum {
     kBitFastGet = kFieldInfoBitEnd,
     kBitFastPut,
     kIFieldLoweringInfoBitEnd
   };
   static_assert(kIFieldLoweringInfoBitEnd <= 16, "Too many flags");
   static constexpr uint16_t kFlagFastGet = 1u << kBitFastGet;
   static constexpr uint16_t kFlagFastPut = 1u << kBitFastPut;

   // The member offset of the field, 0u if unresolved.
   MemberOffset field_offset_;

   friend class NullCheckEliminationTest;
   friend class GlobalValueNumberingTest;
   friend class GvnDeadCodeEliminationTest;
   friend class LocalValueNumberingTest;
   friend class TypeInferenceTest;
 };

 class MirSFieldLoweringInfo : public MirFieldInfo {
  public:
   // For each requested static field retrieve the field's declaring location (dex file, class
   // index and field index) and volatility and compute whether we can fast path the access with
   // IGET/IPUT. For fast path fields (at least for IGET), retrieve the information needed for
   // the field access, i.e. the field offset, whether the field is in the same class as the
   // method being compiled, whether the declaring class can be safely assumed to be initialized
   // and the type index of the declaring class in the compiled method's dex file.
   static void Resolve(CompilerDriver* compiler_driver, const DexCompilationUnit* mUnit,
                       MirSFieldLoweringInfo* field_infos, size_t count)
       REQUIRES(!Locks::mutator_lock_);

   // Construct an unresolved static field lowering info.
   MirSFieldLoweringInfo(uint16_t field_idx, DexMemAccessType type)
       : MirFieldInfo(field_idx, kFlagIsVolatile | kFlagIsStatic, type),
         field_offset_(0u),
         storage_index_(DexFile::kDexNoIndex) {
   }

   bool FastGet() const {
     return (flags_ & kFlagFastGet) != 0u;
   }

   bool FastPut() const {
     return (flags_ & kFlagFastPut) != 0u;
   }

   bool IsReferrersClass() const {
     return (flags_ & kFlagIsReferrersClass) != 0u;
   }

   bool IsClassInitialized() const {
     return (flags_ & kFlagClassIsInitialized) != 0u;
   }

   bool IsClassInDexCache() const {
     return (flags_ & kFlagClassIsInDexCache) != 0u;
   }

   MemberOffset FieldOffset() const {
     return field_offset_;
   }

   uint32_t StorageIndex() const {
     return storage_index_;
   }

  private:
   enum {
     kBitFastGet = kFieldInfoBitEnd,
     kBitFastPut,
     kBitIsReferrersClass,
     kBitClassIsInitialized,
     kBitClassIsInDexCache,
     kSFieldLoweringInfoBitEnd
   };
   static_assert(kSFieldLoweringInfoBitEnd <= 16, "Too many flags");
   static constexpr uint16_t kFlagFastGet = 1u << kBitFastGet;
   static constexpr uint16_t kFlagFastPut = 1u << kBitFastPut;
   static constexpr uint16_t kFlagIsReferrersClass = 1u << kBitIsReferrersClass;
   static constexpr uint16_t kFlagClassIsInitialized = 1u << kBitClassIsInitialized;
   static constexpr uint16_t kFlagClassIsInDexCache = 1u << kBitClassIsInDexCache;

   // The member offset of the field, 0u if unresolved.
   MemberOffset field_offset_;
   // The type index of the declaring class in the compiling method's dex file,
   // -1 if the field is unresolved or there's no appropriate TypeId in that dex file.
   uint32_t storage_index_;

   friend class ClassInitCheckEliminationTest;
   friend class GlobalValueNumberingTest;
   friend class GvnDeadCodeEliminationTest;
   friend class LocalValueNumberingTest;
   friend class TypeInferenceTest;
 };

 }  // namespace art

 #endif  // ART_COMPILER_DEX_MIR_FIELD_INFO_H_
	/*
	* 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.
	*/

	#ifndef ART_COMPILER_DEX_MIR_FIELD_INFO_H_
	#define ART_COMPILER_DEX_MIR_FIELD_INFO_H_

	#include "base/macros.h"
	#include "dex_file.h"
	#include "dex_instruction_utils.h"
	#include "offsets.h"

	namespace art {

	class CompilerDriver;
	class DexCompilationUnit;
	class ScopedObjectAccess;

	/*
	* Field info is calculated from the perspective of the compilation unit that accesses
	* the field and stored in that unit's MIRGraph. Therefore it does not need to reference the
	* dex file or method for which it has been calculated. However, we do store the declaring
	* field index, class index and dex file of the resolved field to help distinguish between fields.
	*/

	class MirFieldInfo {
	public:
	uint16_t FieldIndex() const {
	return field_idx_;
	}
	void SetFieldIndex(uint16_t field_idx) {
	field_idx_ = field_idx;
	}

	bool IsStatic() const {
	return (flags_ & kFlagIsStatic) != 0u;
	}

	bool IsResolved() const {
	return declaring_dex_file_ != nullptr;
	}

	const DexFile* DeclaringDexFile() const {
	return declaring_dex_file_;
	}
	void SetDeclaringDexFile(const DexFile* dex_file) {
	declaring_dex_file_ = dex_file;
	}

	uint16_t DeclaringClassIndex() const {
	return declaring_class_idx_;
	}

	uint16_t DeclaringFieldIndex() const {
	return declaring_field_idx_;
	}

	bool IsVolatile() const {
	return (flags_ & kFlagIsVolatile) != 0u;
	}

	// IGET_QUICK, IGET_BYTE_QUICK, ...
	bool IsQuickened() const {
	return (flags_ & kFlagIsQuickened) != 0u;
	}

	DexMemAccessType MemAccessType() const {
	return static_cast<DexMemAccessType>((flags_ >> kBitMemAccessTypeBegin) & kMemAccessTypeMask);
	}

	void CheckEquals(const MirFieldInfo& other) const {
	CHECK_EQ(field_idx_, other.field_idx_);
	CHECK_EQ(flags_, other.flags_);
	CHECK_EQ(declaring_field_idx_, other.declaring_field_idx_);
	CHECK_EQ(declaring_class_idx_, other.declaring_class_idx_);
	CHECK_EQ(declaring_dex_file_, other.declaring_dex_file_);
	}

	protected:
	enum {
	kBitIsStatic = 0,
	kBitIsVolatile,
	kBitIsQuickened,
	kBitMemAccessTypeBegin,
	kBitMemAccessTypeEnd = kBitMemAccessTypeBegin + 3, // 3 bits for raw type.
	kFieldInfoBitEnd = kBitMemAccessTypeEnd
	};
	static constexpr uint16_t kFlagIsVolatile = 1u << kBitIsVolatile;
	static constexpr uint16_t kFlagIsStatic = 1u << kBitIsStatic;
	static constexpr uint16_t kFlagIsQuickened = 1u << kBitIsQuickened;
	static constexpr uint16_t kMemAccessTypeMask = 7u;
	static_assert((1u << (kBitMemAccessTypeEnd - kBitMemAccessTypeBegin)) - 1u == kMemAccessTypeMask,
	"Invalid raw type mask");

	MirFieldInfo(uint16_t field_idx, uint16_t flags, DexMemAccessType type)
	: field_idx_(field_idx),
	flags_(flags \| static_cast<uint16_t>(type) << kBitMemAccessTypeBegin),
	declaring_field_idx_(0u),
	declaring_class_idx_(0u),
	declaring_dex_file_(nullptr) {
	}

	// Make copy-ctor/assign/dtor protected to avoid slicing.
	MirFieldInfo(const MirFieldInfo& other) = default;
	MirFieldInfo& operator=(const MirFieldInfo& other) = default;
	~MirFieldInfo() = default;

	// The field index in the compiling method's dex file.
	uint16_t field_idx_;
	// Flags, for volatility and derived class data.
	uint16_t flags_;
	// The field index in the dex file that defines field, 0 if unresolved.
	uint16_t declaring_field_idx_;
	// The type index of the class declaring the field, 0 if unresolved.
	uint16_t declaring_class_idx_;
	// The dex file that defines the class containing the field and the field, null if unresolved.
	const DexFile* declaring_dex_file_;
	};

	class MirIFieldLoweringInfo : public MirFieldInfo {
	public:
	// For each requested instance field retrieve the field's declaring location (dex file, class
	// index and field index) and volatility and compute whether we can fast path the access
	// with IGET/IPUT. For fast path fields, retrieve the field offset.
	static void Resolve(const ScopedObjectAccess& soa,
	CompilerDriver* compiler_driver,
	const DexCompilationUnit* mUnit,
	MirIFieldLoweringInfo* field_infos,
	size_t count)
	SHARED_REQUIRES(Locks::mutator_lock_);

	// Construct an unresolved instance field lowering info.
	MirIFieldLoweringInfo(uint16_t field_idx, DexMemAccessType type, bool is_quickened)
	: MirFieldInfo(field_idx,
	kFlagIsVolatile \| (is_quickened ? kFlagIsQuickened : 0u),
	type), // Without kFlagIsStatic.
	field_offset_(0u) {
	}

	bool FastGet() const {
	return (flags_ & kFlagFastGet) != 0u;
	}

	bool FastPut() const {
	return (flags_ & kFlagFastPut) != 0u;
	}

	MemberOffset FieldOffset() const {
	return field_offset_;
	}

	void CheckEquals(const MirIFieldLoweringInfo& other) const {
	MirFieldInfo::CheckEquals(other);
	CHECK_EQ(field_offset_.Uint32Value(), other.field_offset_.Uint32Value());
	}

	private:
	enum {
	kBitFastGet = kFieldInfoBitEnd,
	kBitFastPut,
	kIFieldLoweringInfoBitEnd
	};
	static_assert(kIFieldLoweringInfoBitEnd <= 16, "Too many flags");
	static constexpr uint16_t kFlagFastGet = 1u << kBitFastGet;
	static constexpr uint16_t kFlagFastPut = 1u << kBitFastPut;

	// The member offset of the field, 0u if unresolved.
	MemberOffset field_offset_;

	friend class NullCheckEliminationTest;
	friend class GlobalValueNumberingTest;
	friend class GvnDeadCodeEliminationTest;
	friend class LocalValueNumberingTest;
	friend class TypeInferenceTest;
	};

	class MirSFieldLoweringInfo : public MirFieldInfo {
	public:
	// For each requested static field retrieve the field's declaring location (dex file, class
	// index and field index) and volatility and compute whether we can fast path the access with
	// IGET/IPUT. For fast path fields (at least for IGET), retrieve the information needed for
	// the field access, i.e. the field offset, whether the field is in the same class as the
	// method being compiled, whether the declaring class can be safely assumed to be initialized
	// and the type index of the declaring class in the compiled method's dex file.
	static void Resolve(CompilerDriver* compiler_driver, const DexCompilationUnit* mUnit,
	MirSFieldLoweringInfo* field_infos, size_t count)
	REQUIRES(!Locks::mutator_lock_);

	// Construct an unresolved static field lowering info.
	MirSFieldLoweringInfo(uint16_t field_idx, DexMemAccessType type)
	: MirFieldInfo(field_idx, kFlagIsVolatile \| kFlagIsStatic, type),
	field_offset_(0u),
	storage_index_(DexFile::kDexNoIndex) {
	}

	bool FastGet() const {
	return (flags_ & kFlagFastGet) != 0u;
	}

	bool FastPut() const {
	return (flags_ & kFlagFastPut) != 0u;
	}

	bool IsReferrersClass() const {
	return (flags_ & kFlagIsReferrersClass) != 0u;
	}

	bool IsClassInitialized() const {
	return (flags_ & kFlagClassIsInitialized) != 0u;
	}

	bool IsClassInDexCache() const {
	return (flags_ & kFlagClassIsInDexCache) != 0u;
	}

	MemberOffset FieldOffset() const {
	return field_offset_;
	}

	uint32_t StorageIndex() const {
	return storage_index_;
	}

	private:
	enum {
	kBitFastGet = kFieldInfoBitEnd,
	kBitFastPut,
	kBitIsReferrersClass,
	kBitClassIsInitialized,
	kBitClassIsInDexCache,
	kSFieldLoweringInfoBitEnd
	};
	static_assert(kSFieldLoweringInfoBitEnd <= 16, "Too many flags");
	static constexpr uint16_t kFlagFastGet = 1u << kBitFastGet;
	static constexpr uint16_t kFlagFastPut = 1u << kBitFastPut;
	static constexpr uint16_t kFlagIsReferrersClass = 1u << kBitIsReferrersClass;
	static constexpr uint16_t kFlagClassIsInitialized = 1u << kBitClassIsInitialized;
	static constexpr uint16_t kFlagClassIsInDexCache = 1u << kBitClassIsInDexCache;

	// The member offset of the field, 0u if unresolved.
	MemberOffset field_offset_;
	// The type index of the declaring class in the compiling method's dex file,
	// -1 if the field is unresolved or there's no appropriate TypeId in that dex file.
	uint32_t storage_index_;

	friend class ClassInitCheckEliminationTest;
	friend class GlobalValueNumberingTest;
	friend class GvnDeadCodeEliminationTest;
	friend class LocalValueNumberingTest;
	friend class TypeInferenceTest;
	};

	} // namespace art

	#endif // ART_COMPILER_DEX_MIR_FIELD_INFO_H_