/*
 * 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_X86_H_
#define ART_COMPILER_OPTIMIZING_CODE_GENERATOR_X86_H_

#include "code_generator.h"
#include "dex/compiler_enums.h"
#include "driver/compiler_options.h"
#include "nodes.h"
#include "parallel_move_resolver.h"
#include "utils/x86/assembler_x86.h"

namespace art {
namespace x86 {

// Use a local definition to prevent copying mistakes.
static constexpr size_t kX86WordSize = kX86PointerSize;

class CodeGeneratorX86;
class SlowPathCodeX86;

static constexpr Register kParameterCoreRegisters[] = { ECX, EDX, EBX };
static constexpr RegisterPair kParameterCorePairRegisters[] = { ECX_EDX, EDX_EBX };
static constexpr size_t kParameterCoreRegistersLength = arraysize(kParameterCoreRegisters);
static constexpr XmmRegister kParameterFpuRegisters[] = { XMM0, XMM1, XMM2, XMM3 };
static constexpr size_t kParameterFpuRegistersLength = arraysize(kParameterFpuRegisters);

class InvokeDexCallingConvention : public CallingConvention<Register, XmmRegister> {
 public:
  InvokeDexCallingConvention() : CallingConvention(
      kParameterCoreRegisters,
      kParameterCoreRegistersLength,
      kParameterFpuRegisters,
      kParameterFpuRegistersLength) {}

  RegisterPair GetRegisterPairAt(size_t argument_index) {
    DCHECK_LT(argument_index + 1, GetNumberOfRegisters());
    return kParameterCorePairRegisters[argument_index];
  }

 private:
  DISALLOW_COPY_AND_ASSIGN(InvokeDexCallingConvention);
};

class InvokeDexCallingConventionVisitor {
 public:
  InvokeDexCallingConventionVisitor() : gp_index_(0), fp_index_(0), stack_index_(0) {}

  Location GetNextLocation(Primitive::Type type);

 private:
  InvokeDexCallingConvention calling_convention;
  // The current index for cpu registers.
  uint32_t gp_index_;
  // The current index for fpu registers.
  uint32_t fp_index_;
  // The current stack index.
  uint32_t stack_index_;

  DISALLOW_COPY_AND_ASSIGN(InvokeDexCallingConventionVisitor);
};

class ParallelMoveResolverX86 : public ParallelMoveResolver {
 public:
  ParallelMoveResolverX86(ArenaAllocator* allocator, CodeGeneratorX86* codegen)
      : ParallelMoveResolver(allocator), codegen_(codegen) {}

  void EmitMove(size_t index) OVERRIDE;
  void EmitSwap(size_t index) OVERRIDE;
  void SpillScratch(int reg) OVERRIDE;
  void RestoreScratch(int reg) OVERRIDE;

  X86Assembler* GetAssembler() const;

 private:
  void Exchange(Register reg, int mem);
  void Exchange(int mem1, int mem2);
  void Exchange32(XmmRegister reg, int mem);
  void MoveMemoryToMemory32(int dst, int src);
  void MoveMemoryToMemory64(int dst, int src);

  CodeGeneratorX86* const codegen_;

  DISALLOW_COPY_AND_ASSIGN(ParallelMoveResolverX86);
};

class LocationsBuilderX86 : public HGraphVisitor {
 public:
  LocationsBuilderX86(HGraph* graph, CodeGeneratorX86* codegen)
      : HGraphVisitor(graph), codegen_(codegen) {}

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

  FOR_EACH_CONCRETE_INSTRUCTION(DECLARE_VISIT_INSTRUCTION)

#undef DECLARE_VISIT_INSTRUCTION

 private:
  void HandleBitwiseOperation(HBinaryOperation* instruction);
  void HandleInvoke(HInvoke* invoke);
  void HandleShift(HBinaryOperation* instruction);
  void HandleFieldSet(HInstruction* instruction, const FieldInfo& field_info);
  void HandleFieldGet(HInstruction* instruction, const FieldInfo& field_info);

  CodeGeneratorX86* const codegen_;
  InvokeDexCallingConventionVisitor parameter_visitor_;

  DISALLOW_COPY_AND_ASSIGN(LocationsBuilderX86);
};

class InstructionCodeGeneratorX86 : public HGraphVisitor {
 public:
  InstructionCodeGeneratorX86(HGraph* graph, CodeGeneratorX86* codegen);

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

  FOR_EACH_CONCRETE_INSTRUCTION(DECLARE_VISIT_INSTRUCTION)

#undef DECLARE_VISIT_INSTRUCTION

  X86Assembler* GetAssembler() const { return assembler_; }

 private:
  // Generate code for the given suspend check. If not null, `successor`
  // is the block to branch to if the suspend check is not needed, and after
  // the suspend call.
  void GenerateSuspendCheck(HSuspendCheck* check, HBasicBlock* successor);
  void GenerateClassInitializationCheck(SlowPathCodeX86* slow_path, Register class_reg);
  void HandleBitwiseOperation(HBinaryOperation* instruction);
  void GenerateDivRemIntegral(HBinaryOperation* instruction);
  void GenerateRemFP(HRem *rem);
  void HandleShift(HBinaryOperation* instruction);
  void GenerateShlLong(const Location& loc, Register shifter);
  void GenerateShrLong(const Location& loc, Register shifter);
  void GenerateUShrLong(const Location& loc, Register shifter);
  void GenerateMemoryBarrier(MemBarrierKind kind);
  void HandleFieldSet(HInstruction* instruction, const FieldInfo& field_info);
  void HandleFieldGet(HInstruction* instruction, const FieldInfo& field_info);
  void PushOntoFPStack(Location source, uint32_t temp_offset,
                       uint32_t stack_adjustment, bool is_float);

  void GenerateImplicitNullCheck(HNullCheck* instruction);
  void GenerateExplicitNullCheck(HNullCheck* instruction);

  X86Assembler* const assembler_;
  CodeGeneratorX86* const codegen_;

  DISALLOW_COPY_AND_ASSIGN(InstructionCodeGeneratorX86);
};

class CodeGeneratorX86 : public CodeGenerator {
 public:
  CodeGeneratorX86(HGraph* graph, const CompilerOptions& compiler_options);
  virtual ~CodeGeneratorX86() {}

  void GenerateFrameEntry() OVERRIDE;
  void GenerateFrameExit() OVERRIDE;
  void Bind(HBasicBlock* block) OVERRIDE;
  void Move(HInstruction* instruction, Location location, HInstruction* move_for) 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;

  size_t GetWordSize() const OVERRIDE {
    return kX86WordSize;
  }

  size_t GetFloatingPointSpillSlotSize() const OVERRIDE {
    // 8 bytes == 2 words for each spill.
    return 2 * kX86WordSize;
  }

  HGraphVisitor* GetLocationBuilder() OVERRIDE {
    return &location_builder_;
  }

  HGraphVisitor* GetInstructionVisitor() OVERRIDE {
    return &instruction_visitor_;
  }

  X86Assembler* GetAssembler() OVERRIDE {
    return &assembler_;
  }

  uintptr_t GetAddressOf(HBasicBlock* block) const OVERRIDE {
    return GetLabelOf(block)->Position();
  }

  void SetupBlockedRegisters(bool is_baseline) const OVERRIDE;

  Location AllocateFreeRegister(Primitive::Type type) const OVERRIDE;

  Location GetStackLocation(HLoadLocal* load) const OVERRIDE;

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

  // Blocks all register pairs made out of blocked core registers.
  void UpdateBlockedPairRegisters() const;

  ParallelMoveResolverX86* GetMoveResolver() OVERRIDE {
    return &move_resolver_;
  }

  InstructionSet GetInstructionSet() const OVERRIDE {
    return InstructionSet::kX86;
  }

  // Helper method to move a 32bits value between two locations.
  void Move32(Location destination, Location source);
  // Helper method to move a 64bits value between two locations.
  void Move64(Location destination, Location source);

  // Emit a write barrier.
  void MarkGCCard(Register temp, Register card, Register object, Register value);

  void LoadCurrentMethod(Register reg);

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

  void Initialize() OVERRIDE {
    block_labels_.SetSize(GetGraph()->GetBlocks().Size());
  }

  bool NeedsTwoRegisters(Primitive::Type type) const OVERRIDE {
    return type == Primitive::kPrimLong;
  }

  bool ShouldSplitLongMoves() const OVERRIDE { return true; }

  Label* GetFrameEntryLabel() { return &frame_entry_label_; }

 private:
  // Labels for each block that will be compiled.
  GrowableArray<Label> block_labels_;
  Label frame_entry_label_;
  LocationsBuilderX86 location_builder_;
  InstructionCodeGeneratorX86 instruction_visitor_;
  ParallelMoveResolverX86 move_resolver_;
  X86Assembler assembler_;

  DISALLOW_COPY_AND_ASSIGN(CodeGeneratorX86);
};

}  // namespace x86
}  // namespace art

#endif  // ART_COMPILER_OPTIMIZING_CODE_GENERATOR_X86_H_