/**
 ******************************************************************************
 * Xenia : Xbox 360 Emulator Research Project                                 *
 ******************************************************************************
 * Copyright 2013 Ben Vanik. All rights reserved.                             *
 * Released under the BSD license - see LICENSE in the root for more details. *
 ******************************************************************************
 */

#ifndef ALLOY_BACKEND_X64_X64_EMITTER_H_
#define ALLOY_BACKEND_X64_X64_EMITTER_H_

#include <alloy/core.h>

#include <alloy/hir/value.h>

#include <third_party/xbyak/xbyak/xbyak.h>

XEDECLARECLASS2(alloy, hir, HIRBuilder);
XEDECLARECLASS2(alloy, hir, Instr);
XEDECLARECLASS2(alloy, runtime, DebugInfo);
XEDECLARECLASS2(alloy, runtime, FunctionInfo);
XEDECLARECLASS2(alloy, runtime, Runtime);
XEDECLARECLASS2(alloy, runtime, SymbolInfo);

namespace alloy {
namespace backend {
namespace x64 {

class X64Backend;
class X64CodeCache;

enum RegisterFlags {
  REG_DEST = (1 << 0),
  REG_ABCD = (1 << 1),
};

enum XmmConst {
  XMMZero = 0,
  XMMOne,
  XMMNegativeOne,
  XMMMaskX16Y16,
  XMMFlipX16Y16,
  XMMFixX16Y16,
  XMMNormalizeX16Y16,
  XMM0001,
  XMM3301,
  XMMSignMaskPS,
  XMMSignMaskPD,
  XMMAbsMaskPS,
  XMMAbsMaskPD,
  XMMByteSwapMask,
  XMMPermuteControl15,
  XMMPackD3DCOLOR,
  XMMUnpackD3DCOLOR,
  XMMOneOver255,
  XMMMaskEvenPI16,
  XMMShiftMaskEvenPI16,
  XMMShiftMaskPS,
  XMMShiftByteMask,
  XMMUnsignedDwordMax,
  XMM255,
  XMMSignMaskI8,
  XMMSignMaskI16,
  XMMSignMaskI32,
  XMMSignMaskF32,
};

// Unfortunately due to the design of xbyak we have to pass this to the ctor.
class XbyakAllocator : public Xbyak::Allocator {
 public:
  virtual bool useProtect() const { return false; }
};

class X64Emitter : public Xbyak::CodeGenerator {
 public:
  X64Emitter(X64Backend* backend, XbyakAllocator* allocator);
  virtual ~X64Emitter();

  runtime::Runtime* runtime() const { return runtime_; }
  X64Backend* backend() const { return backend_; }

  int Initialize();

  int Emit(hir::HIRBuilder* builder, uint32_t debug_info_flags,
           runtime::DebugInfo* debug_info, void*& out_code_address,
           size_t& out_code_size);

 public:
  // Reserved:  rsp
  // Scratch:   rax/rcx/rdx
  //            xmm0-2 (could be only xmm0 with some trickery)
  // Available: rbx, r12-r15 (save to get r8-r11, rbp, rsi, rdi?)
  //            xmm6-xmm15 (save to get xmm3-xmm5)
  static const int GPR_COUNT = 5;
  static const int XMM_COUNT = 10;

  static void SetupReg(const hir::Value* v, Xbyak::Reg8& r) {
    auto idx = gpr_reg_map_[v->reg.index];
    r = Xbyak::Reg8(idx);
  }
  static void SetupReg(const hir::Value* v, Xbyak::Reg16& r) {
    auto idx = gpr_reg_map_[v->reg.index];
    r = Xbyak::Reg16(idx);
  }
  static void SetupReg(const hir::Value* v, Xbyak::Reg32& r) {
    auto idx = gpr_reg_map_[v->reg.index];
    r = Xbyak::Reg32(idx);
  }
  static void SetupReg(const hir::Value* v, Xbyak::Reg64& r) {
    auto idx = gpr_reg_map_[v->reg.index];
    r = Xbyak::Reg64(idx);
  }
  static void SetupReg(const hir::Value* v, Xbyak::Xmm& r) {
    auto idx = xmm_reg_map_[v->reg.index];
    r = Xbyak::Xmm(idx);
  }

  void MarkSourceOffset(const hir::Instr* i);

  void DebugBreak();
  void Trap(uint16_t trap_type = 0);
  void UnimplementedInstr(const hir::Instr* i);
  void UnimplementedExtern(const hir::Instr* i);

  void Call(const hir::Instr* instr, runtime::FunctionInfo* symbol_info);
  void CallIndirect(const hir::Instr* instr, const Xbyak::Reg64& reg);
  void CallExtern(const hir::Instr* instr,
                  const runtime::FunctionInfo* symbol_info);
  void CallNative(void* fn);
  void CallNative(uint64_t (*fn)(void* raw_context));
  void CallNative(uint64_t (*fn)(void* raw_context, uint64_t arg0));
  void CallNative(uint64_t (*fn)(void* raw_context, uint64_t arg0),
                  uint64_t arg0);
  void CallNativeSafe(void* fn);
  void SetReturnAddress(uint64_t value);
  void ReloadECX();
  void ReloadEDX();

  // TODO(benvanik): Label for epilog (don't use strings).

  void LoadEflags();
  void StoreEflags();

  uint32_t page_table_address() const;

  // Moves a 64bit immediate into memory.
  bool ConstantFitsIn32Reg(uint64_t v);
  void MovMem64(const Xbyak::RegExp& addr, uint64_t v);

  Xbyak::Address GetXmmConstPtr(XmmConst id);
  void LoadConstantXmm(Xbyak::Xmm dest, float v);
  void LoadConstantXmm(Xbyak::Xmm dest, double v);
  void LoadConstantXmm(Xbyak::Xmm dest, const vec128_t& v);
  Xbyak::Address StashXmm(const Xbyak::Xmm& r);
  Xbyak::Address StashXmm(const vec128_t& v);

  size_t stack_size() const { return stack_size_; }

 protected:
  void* Emplace(size_t stack_size);
  int Emit(hir::HIRBuilder* builder, size_t& out_stack_size);

 protected:
  runtime::Runtime* runtime_;
  X64Backend* backend_;
  X64CodeCache* code_cache_;
  XbyakAllocator* allocator_;

  hir::Instr* current_instr_;

  size_t source_map_count_;
  Arena source_map_arena_;

  size_t stack_size_;

  static const uint32_t gpr_reg_map_[GPR_COUNT];
  static const uint32_t xmm_reg_map_[XMM_COUNT];
};

}  // namespace x64
}  // namespace backend
}  // namespace alloy

#endif  // ALLOY_BACKEND_X64_X64_EMITTER_H_