/*
 * 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_OPTIMIZING_CODE_GENERATOR_ARM64_H_
#define ART_COMPILER_OPTIMIZING_CODE_GENERATOR_ARM64_H_

#include "code_generator.h"
#include "common_arm64.h"
#include "dex/compiler_enums.h"
#include "driver/compiler_options.h"
#include "nodes.h"
#include "parallel_move_resolver.h"
#include "utils/arm64/assembler_arm64.h"
#include "vixl/a64/disasm-a64.h"
#include "vixl/a64/macro-assembler-a64.h"
#include "arch/arm64/quick_method_frame_info_arm64.h"

namespace art {
namespace arm64 {

class CodeGeneratorARM64;

// Use a local definition to prevent copying mistakes.
static constexpr size_t kArm64WordSize = kArm64PointerSize;

static const vixl::Register kParameterCoreRegisters[] = {
  vixl::x1, vixl::x2, vixl::x3, vixl::x4, vixl::x5, vixl::x6, vixl::x7
};
static constexpr size_t kParameterCoreRegistersLength = arraysize(kParameterCoreRegisters);
static const vixl::FPRegister kParameterFPRegisters[] = {
  vixl::d0, vixl::d1, vixl::d2, vixl::d3, vixl::d4, vixl::d5, vixl::d6, vixl::d7
};
static constexpr size_t kParameterFPRegistersLength = arraysize(kParameterFPRegisters);

const vixl::Register tr = vixl::x19;                        // Thread Register
static const vixl::Register kArtMethodRegister = vixl::x0;  // Method register on invoke.

const vixl::CPURegList vixl_reserved_core_registers(vixl::ip0, vixl::ip1);
const vixl::CPURegList vixl_reserved_fp_registers(vixl::d31);

const vixl::CPURegList runtime_reserved_core_registers(tr, vixl::lr);

// Callee-saved registers AAPCS64 (without x19 - Thread Register)
const vixl::CPURegList callee_saved_core_registers(vixl::CPURegister::kRegister,
                                                   vixl::kXRegSize,
                                                   vixl::x20.code(),
                                                   vixl::x30.code());
const vixl::CPURegList callee_saved_fp_registers(vixl::CPURegister::kFPRegister,
                                                 vixl::kDRegSize,
                                                 vixl::d8.code(),
                                                 vixl::d15.code());
Location ARM64ReturnLocation(Primitive::Type return_type);

class SlowPathCodeARM64 : public SlowPathCode {
 public:
  SlowPathCodeARM64() : entry_label_(), exit_label_() {}

  vixl::Label* GetEntryLabel() { return &entry_label_; }
  vixl::Label* GetExitLabel() { return &exit_label_; }

  void SaveLiveRegisters(CodeGenerator* codegen, LocationSummary* locations) OVERRIDE;
  void RestoreLiveRegisters(CodeGenerator* codegen, LocationSummary* locations) OVERRIDE;

 private:
  vixl::Label entry_label_;
  vixl::Label exit_label_;

  DISALLOW_COPY_AND_ASSIGN(SlowPathCodeARM64);
};

class JumpTableARM64 : public ArenaObject<kArenaAllocSwitchTable> {
 public:
  explicit JumpTableARM64(HPackedSwitch* switch_instr)
    : switch_instr_(switch_instr), table_start_() {}

  vixl::Label* GetTableStartLabel() { return &table_start_; }

  void EmitTable(CodeGeneratorARM64* codegen);

 private:
  HPackedSwitch* const switch_instr_;
  vixl::Label table_start_;

  DISALLOW_COPY_AND_ASSIGN(JumpTableARM64);
};

static const vixl::Register kRuntimeParameterCoreRegisters[] =
    { vixl::x0, vixl::x1, vixl::x2, vixl::x3, vixl::x4, vixl::x5, vixl::x6, vixl::x7 };
static constexpr size_t kRuntimeParameterCoreRegistersLength =
    arraysize(kRuntimeParameterCoreRegisters);
static const vixl::FPRegister kRuntimeParameterFpuRegisters[] =
    { vixl::d0, vixl::d1, vixl::d2, vixl::d3, vixl::d4, vixl::d5, vixl::d6, vixl::d7 };
static constexpr size_t kRuntimeParameterFpuRegistersLength =
    arraysize(kRuntimeParameterCoreRegisters);

class InvokeRuntimeCallingConvention : public CallingConvention<vixl::Register, vixl::FPRegister> {
 public:
  static constexpr size_t kParameterCoreRegistersLength = arraysize(kParameterCoreRegisters);

  InvokeRuntimeCallingConvention()
      : CallingConvention(kRuntimeParameterCoreRegisters,
                          kRuntimeParameterCoreRegistersLength,
                          kRuntimeParameterFpuRegisters,
                          kRuntimeParameterFpuRegistersLength,
                          kArm64PointerSize) {}

  Location GetReturnLocation(Primitive::Type return_type);

 private:
  DISALLOW_COPY_AND_ASSIGN(InvokeRuntimeCallingConvention);
};

class InvokeDexCallingConvention : public CallingConvention<vixl::Register, vixl::FPRegister> {
 public:
  InvokeDexCallingConvention()
      : CallingConvention(kParameterCoreRegisters,
                          kParameterCoreRegistersLength,
                          kParameterFPRegisters,
                          kParameterFPRegistersLength,
                          kArm64PointerSize) {}

  Location GetReturnLocation(Primitive::Type return_type) const {
    return ARM64ReturnLocation(return_type);
  }


 private:
  DISALLOW_COPY_AND_ASSIGN(InvokeDexCallingConvention);
};

class InvokeDexCallingConventionVisitorARM64 : public InvokeDexCallingConventionVisitor {
 public:
  InvokeDexCallingConventionVisitorARM64() {}
  virtual ~InvokeDexCallingConventionVisitorARM64() {}

  Location GetNextLocation(Primitive::Type type) OVERRIDE;
  Location GetReturnLocation(Primitive::Type return_type) const OVERRIDE {
    return calling_convention.GetReturnLocation(return_type);
  }
  Location GetMethodLocation() const OVERRIDE;

 private:
  InvokeDexCallingConvention calling_convention;

  DISALLOW_COPY_AND_ASSIGN(InvokeDexCallingConventionVisitorARM64);
};

class FieldAccessCallingConventionARM64 : public FieldAccessCallingConvention {
 public:
  FieldAccessCallingConventionARM64() {}

  Location GetObjectLocation() const OVERRIDE {
    return helpers::LocationFrom(vixl::x1);
  }
  Location GetFieldIndexLocation() const OVERRIDE {
    return helpers::LocationFrom(vixl::x0);
  }
  Location GetReturnLocation(Primitive::Type type ATTRIBUTE_UNUSED) const OVERRIDE {
    return helpers::LocationFrom(vixl::x0);
  }
  Location GetSetValueLocation(Primitive::Type type, bool is_instance) const OVERRIDE {
    return Primitive::Is64BitType(type)
        ? helpers::LocationFrom(vixl::x2)
        : (is_instance
            ? helpers::LocationFrom(vixl::x2)
            : helpers::LocationFrom(vixl::x1));
  }
  Location GetFpuLocation(Primitive::Type type ATTRIBUTE_UNUSED) const OVERRIDE {
    return helpers::LocationFrom(vixl::d0);
  }

 private:
  DISALLOW_COPY_AND_ASSIGN(FieldAccessCallingConventionARM64);
};

class InstructionCodeGeneratorARM64 : public InstructionCodeGenerator {
 public:
  InstructionCodeGeneratorARM64(HGraph* graph, CodeGeneratorARM64* codegen);

#define DECLARE_VISIT_INSTRUCTION(name, super) \
  void Visit##name(H##name* instr) OVERRIDE;

  FOR_EACH_CONCRETE_INSTRUCTION_COMMON(DECLARE_VISIT_INSTRUCTION)
  FOR_EACH_CONCRETE_INSTRUCTION_ARM64(DECLARE_VISIT_INSTRUCTION)

#undef DECLARE_VISIT_INSTRUCTION

  void VisitInstruction(HInstruction* instruction) OVERRIDE {
    LOG(FATAL) << "Unreachable instruction " << instruction->DebugName()
               << " (id " << instruction->GetId() << ")";
  }

  Arm64Assembler* GetAssembler() const { return assembler_; }
  vixl::MacroAssembler* GetVIXLAssembler() { return GetAssembler()->vixl_masm_; }

 private:
  void GenerateClassInitializationCheck(SlowPathCodeARM64* slow_path, vixl::Register class_reg);
  void GenerateMemoryBarrier(MemBarrierKind kind);
  void GenerateSuspendCheck(HSuspendCheck* instruction, HBasicBlock* successor);
  void HandleBinaryOp(HBinaryOperation* instr);
  void HandleFieldSet(HInstruction* instruction,
                      const FieldInfo& field_info,
                      bool value_can_be_null);
  void HandleFieldGet(HInstruction* instruction, const FieldInfo& field_info);
  void HandleCondition(HCondition* instruction);
  void HandleShift(HBinaryOperation* instr);
  void GenerateImplicitNullCheck(HNullCheck* instruction);
  void GenerateExplicitNullCheck(HNullCheck* instruction);
  void GenerateTestAndBranch(HInstruction* instruction,
                             size_t condition_input_index,
                             vixl::Label* true_target,
                             vixl::Label* false_target);
  void DivRemOneOrMinusOne(HBinaryOperation* instruction);
  void DivRemByPowerOfTwo(HBinaryOperation* instruction);
  void GenerateDivRemWithAnyConstant(HBinaryOperation* instruction);
  void GenerateDivRemIntegral(HBinaryOperation* instruction);
  void HandleGoto(HInstruction* got, HBasicBlock* successor);

  Arm64Assembler* const assembler_;
  CodeGeneratorARM64* const codegen_;

  DISALLOW_COPY_AND_ASSIGN(InstructionCodeGeneratorARM64);
};

class LocationsBuilderARM64 : public HGraphVisitor {
 public:
  LocationsBuilderARM64(HGraph* graph, CodeGeneratorARM64* codegen)
      : HGraphVisitor(graph), codegen_(codegen) {}

#define DECLARE_VISIT_INSTRUCTION(name, super) \
  void Visit##name(H##name* instr) OVERRIDE;

  FOR_EACH_CONCRETE_INSTRUCTION_COMMON(DECLARE_VISIT_INSTRUCTION)
  FOR_EACH_CONCRETE_INSTRUCTION_ARM64(DECLARE_VISIT_INSTRUCTION)

#undef DECLARE_VISIT_INSTRUCTION

  void VisitInstruction(HInstruction* instruction) OVERRIDE {
    LOG(FATAL) << "Unreachable instruction " << instruction->DebugName()
               << " (id " << instruction->GetId() << ")";
  }

 private:
  void HandleBinaryOp(HBinaryOperation* instr);
  void HandleFieldSet(HInstruction* instruction);
  void HandleFieldGet(HInstruction* instruction);
  void HandleInvoke(HInvoke* instr);
  void HandleCondition(HCondition* instruction);
  void HandleShift(HBinaryOperation* instr);

  CodeGeneratorARM64* const codegen_;
  InvokeDexCallingConventionVisitorARM64 parameter_visitor_;

  DISALLOW_COPY_AND_ASSIGN(LocationsBuilderARM64);
};

class ParallelMoveResolverARM64 : public ParallelMoveResolverNoSwap {
 public:
  ParallelMoveResolverARM64(ArenaAllocator* allocator, CodeGeneratorARM64* codegen)
      : ParallelMoveResolverNoSwap(allocator), codegen_(codegen), vixl_temps_() {}

 protected:
  void PrepareForEmitNativeCode() OVERRIDE;
  void FinishEmitNativeCode() OVERRIDE;
  Location AllocateScratchLocationFor(Location::Kind kind) OVERRIDE;
  void FreeScratchLocation(Location loc) OVERRIDE;
  void EmitMove(size_t index) OVERRIDE;

 private:
  Arm64Assembler* GetAssembler() const;
  vixl::MacroAssembler* GetVIXLAssembler() const {
    return GetAssembler()->vixl_masm_;
  }

  CodeGeneratorARM64* const codegen_;
  vixl::UseScratchRegisterScope vixl_temps_;

  DISALLOW_COPY_AND_ASSIGN(ParallelMoveResolverARM64);
};

class CodeGeneratorARM64 : public CodeGenerator {
 public:
  CodeGeneratorARM64(HGraph* graph,
                     const Arm64InstructionSetFeatures& isa_features,
                     const CompilerOptions& compiler_options,
                     OptimizingCompilerStats* stats = nullptr);
  virtual ~CodeGeneratorARM64() {}

  void GenerateFrameEntry() OVERRIDE;
  void GenerateFrameExit() OVERRIDE;

  vixl::CPURegList GetFramePreservedCoreRegisters() const;
  vixl::CPURegList GetFramePreservedFPRegisters() const;

  void Bind(HBasicBlock* block) OVERRIDE;

  vixl::Label* GetLabelOf(HBasicBlock* block) const {
    return CommonGetLabelOf<vixl::Label>(block_labels_, block);
  }

  void Move(HInstruction* instruction, Location location, HInstruction* move_for) OVERRIDE;

  size_t GetWordSize() const OVERRIDE {
    return kArm64WordSize;
  }

  size_t GetFloatingPointSpillSlotSize() const OVERRIDE {
    // Allocated in D registers, which are word sized.
    return kArm64WordSize;
  }

  uintptr_t GetAddressOf(HBasicBlock* block) const OVERRIDE {
    vixl::Label* block_entry_label = GetLabelOf(block);
    DCHECK(block_entry_label->IsBound());
    return block_entry_label->location();
  }

  HGraphVisitor* GetLocationBuilder() OVERRIDE { return &location_builder_; }
  HGraphVisitor* GetInstructionVisitor() OVERRIDE { return &instruction_visitor_; }
  Arm64Assembler* GetAssembler() OVERRIDE { return &assembler_; }
  const Arm64Assembler& GetAssembler() const OVERRIDE { return assembler_; }
  vixl::MacroAssembler* GetVIXLAssembler() { return GetAssembler()->vixl_masm_; }

  // Emit a write barrier.
  void MarkGCCard(vixl::Register object, vixl::Register value, bool value_can_be_null);

  // Register allocation.

  void SetupBlockedRegisters() const OVERRIDE;

  Location GetStackLocation(HLoadLocal* load) const OVERRIDE;

  size_t SaveCoreRegister(size_t stack_index, uint32_t reg_id) OVERRIDE;
  size_t RestoreCoreRegister(size_t stack_index, uint32_t reg_id) OVERRIDE;
  size_t SaveFloatingPointRegister(size_t stack_index, uint32_t reg_id) OVERRIDE;
  size_t RestoreFloatingPointRegister(size_t stack_index, uint32_t reg_id) OVERRIDE;

  // The number of registers that can be allocated. The register allocator may
  // decide to reserve and not use a few of them.
  // We do not consider registers sp, xzr, wzr. They are either not allocatable
  // (xzr, wzr), or make for poor allocatable registers (sp alignment
  // requirements, etc.). This also facilitates our task as all other registers
  // can easily be mapped via to or from their type and index or code.
  static const int kNumberOfAllocatableRegisters = vixl::kNumberOfRegisters - 1;
  static const int kNumberOfAllocatableFPRegisters = vixl::kNumberOfFPRegisters;
  static constexpr int kNumberOfAllocatableRegisterPairs = 0;

  void DumpCoreRegister(std::ostream& stream, int reg) const OVERRIDE;
  void DumpFloatingPointRegister(std::ostream& stream, int reg) const OVERRIDE;

  InstructionSet GetInstructionSet() const OVERRIDE {
    return InstructionSet::kArm64;
  }

  const Arm64InstructionSetFeatures& GetInstructionSetFeatures() const {
    return isa_features_;
  }

  void Initialize() OVERRIDE {
    block_labels_ = CommonInitializeLabels<vixl::Label>();
  }

  void AddJumpTable(JumpTableARM64* jump_table) {
    jump_tables_.push_back(jump_table);
  }

  void Finalize(CodeAllocator* allocator) OVERRIDE;

  // Code generation helpers.
  void MoveConstant(vixl::CPURegister destination, HConstant* constant);
  void MoveConstant(Location destination, int32_t value) OVERRIDE;
  void MoveLocation(Location dst, Location src, Primitive::Type dst_type) OVERRIDE;
  void AddLocationAsTemp(Location location, LocationSummary* locations) OVERRIDE;

  void Load(Primitive::Type type, vixl::CPURegister dst, const vixl::MemOperand& src);
  void Store(Primitive::Type type, vixl::CPURegister rt, const vixl::MemOperand& dst);
  void LoadAcquire(HInstruction* instruction, vixl::CPURegister dst, const vixl::MemOperand& src);
  void StoreRelease(Primitive::Type type, vixl::CPURegister rt, const vixl::MemOperand& dst);

  // Generate code to invoke a runtime entry point.
  void InvokeRuntime(QuickEntrypointEnum entrypoint,
                     HInstruction* instruction,
                     uint32_t dex_pc,
                     SlowPathCode* slow_path) OVERRIDE;

  void InvokeRuntime(int32_t offset,
                     HInstruction* instruction,
                     uint32_t dex_pc,
                     SlowPathCode* slow_path);

  ParallelMoveResolverARM64* GetMoveResolver() OVERRIDE { return &move_resolver_; }

  bool NeedsTwoRegisters(Primitive::Type type ATTRIBUTE_UNUSED) const OVERRIDE {
    return false;
  }

  // Check if the desired_dispatch_info is supported. If it is, return it,
  // otherwise return a fall-back info that should be used instead.
  HInvokeStaticOrDirect::DispatchInfo GetSupportedInvokeStaticOrDirectDispatch(
      const HInvokeStaticOrDirect::DispatchInfo& desired_dispatch_info,
      MethodReference target_method) OVERRIDE;

  void GenerateStaticOrDirectCall(HInvokeStaticOrDirect* invoke, Location temp) OVERRIDE;
  void GenerateVirtualCall(HInvokeVirtual* invoke, Location temp) OVERRIDE;

  void MoveFromReturnRegister(Location trg ATTRIBUTE_UNUSED,
                              Primitive::Type type ATTRIBUTE_UNUSED) OVERRIDE {
    UNIMPLEMENTED(FATAL);
  }

  void EmitLinkerPatches(ArenaVector<LinkerPatch>* linker_patches) OVERRIDE;

  // Generate a read barrier for a heap reference within `instruction`.
  //
  // A read barrier for an object reference read from the heap is
  // implemented as a call to the artReadBarrierSlow runtime entry
  // point, which is passed the values in locations `ref`, `obj`, and
  // `offset`:
  //
  //   mirror::Object* artReadBarrierSlow(mirror::Object* ref,
  //                                      mirror::Object* obj,
  //                                      uint32_t offset);
  //
  // The `out` location contains the value returned by
  // artReadBarrierSlow.
  //
  // When `index` is provided (i.e. for array accesses), the offset
  // value passed to artReadBarrierSlow is adjusted to take `index`
  // into account.
  void GenerateReadBarrier(HInstruction* instruction,
                           Location out,
                           Location ref,
                           Location obj,
                           uint32_t offset,
                           Location index = Location::NoLocation());

  // If read barriers are enabled, generate a read barrier for a heap reference.
  // If heap poisoning is enabled, also unpoison the reference in `out`.
  void MaybeGenerateReadBarrier(HInstruction* instruction,
                                Location out,
                                Location ref,
                                Location obj,
                                uint32_t offset,
                                Location index = Location::NoLocation());

  // Generate a read barrier for a GC root within `instruction`.
  //
  // A read barrier for an object reference GC root is implemented as
  // a call to the artReadBarrierForRootSlow runtime entry point,
  // which is passed the value in location `root`:
  //
  //   mirror::Object* artReadBarrierForRootSlow(GcRoot<mirror::Object>* root);
  //
  // The `out` location contains the value returned by
  // artReadBarrierForRootSlow.
  void GenerateReadBarrierForRoot(HInstruction* instruction, Location out, Location root);

 private:
  using Uint64ToLiteralMap = ArenaSafeMap<uint64_t, vixl::Literal<uint64_t>*>;
  using MethodToLiteralMap = ArenaSafeMap<MethodReference,
                                          vixl::Literal<uint64_t>*,
                                          MethodReferenceComparator>;

  vixl::Literal<uint64_t>* DeduplicateUint64Literal(uint64_t value);
  vixl::Literal<uint64_t>* DeduplicateMethodLiteral(MethodReference target_method,
                                                    MethodToLiteralMap* map);
  vixl::Literal<uint64_t>* DeduplicateMethodAddressLiteral(MethodReference target_method);
  vixl::Literal<uint64_t>* DeduplicateMethodCodeLiteral(MethodReference target_method);

  struct PcRelativeDexCacheAccessInfo {
    PcRelativeDexCacheAccessInfo(const DexFile& dex_file, uint32_t element_off)
        : target_dex_file(dex_file), element_offset(element_off), label(), pc_insn_label() { }

    const DexFile& target_dex_file;
    uint32_t element_offset;
    vixl::Label label;
    vixl::Label* pc_insn_label;
  };

  void EmitJumpTables();

  // Labels for each block that will be compiled.
  vixl::Label* block_labels_;  // Indexed by block id.
  vixl::Label frame_entry_label_;
  ArenaVector<JumpTableARM64*> jump_tables_;

  LocationsBuilderARM64 location_builder_;
  InstructionCodeGeneratorARM64 instruction_visitor_;
  ParallelMoveResolverARM64 move_resolver_;
  Arm64Assembler assembler_;
  const Arm64InstructionSetFeatures& isa_features_;

  // Deduplication map for 64-bit literals, used for non-patchable method address and method code.
  Uint64ToLiteralMap uint64_literals_;
  // Method patch info, map MethodReference to a literal for method address and method code.
  MethodToLiteralMap method_patches_;
  MethodToLiteralMap call_patches_;
  // Relative call patch info.
  // Using ArenaDeque<> which retains element addresses on push/emplace_back().
  ArenaDeque<MethodPatchInfo<vixl::Label>> relative_call_patches_;
  // PC-relative DexCache access info.
  ArenaDeque<PcRelativeDexCacheAccessInfo> pc_relative_dex_cache_patches_;

  DISALLOW_COPY_AND_ASSIGN(CodeGeneratorARM64);
};

inline Arm64Assembler* ParallelMoveResolverARM64::GetAssembler() const {
  return codegen_->GetAssembler();
}

}  // namespace arm64
}  // namespace art

#endif  // ART_COMPILER_OPTIMIZING_CODE_GENERATOR_ARM64_H_