/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef jit_arm64_MoveEmitter_arm64_h
#define jit_arm64_MoveEmitter_arm64_h

#include "mozilla/Assertions.h"

#include <stdint.h>

#include "jit/arm64/Assembler-arm64.h"
#include "jit/MacroAssembler.h"
#include "jit/MoveResolver.h"
#include "jit/Registers.h"

namespace js {
namespace jit {

class CodeGenerator;

class MoveEmitterARM64 {
  bool inCycle_;
  MacroAssembler& masm;

  // A scratch general register used to break cycles.
  ARMRegister cycleGeneralReg_;

  // Original stack push value.
  uint32_t pushedAtStart_;

  // This stores a stack offset to a spill location, snapshotting
  // `masm.framePushed()` at the time it was allocated. It is -1 if no
  // stack space has been allocated for that particular spill.
  int32_t pushedAtCycle_;

  void assertDone() { MOZ_ASSERT(!inCycle_); }

  MemOperand cycleSlot();
  MemOperand toMemOperand(const MoveOperand& operand) const;
  ARMRegister toARMReg32(const MoveOperand& operand) const {
    MOZ_ASSERT(operand.isGeneralReg());
    return ARMRegister(operand.reg(), 32);
  }
  ARMRegister toARMReg64(const MoveOperand& operand) const {
    if (operand.isGeneralReg()) {
      return ARMRegister(operand.reg(), 64);
    } else {
      return ARMRegister(operand.base(), 64);
    }
  }
  ARMFPRegister toFPReg(const MoveOperand& operand, MoveOp::Type t) const {
    MOZ_ASSERT(operand.isFloatReg());
    switch (t) {
      case MoveOp::FLOAT32:
        return ARMFPRegister(operand.floatReg().encoding(), 32);
      case MoveOp::DOUBLE:
        return ARMFPRegister(operand.floatReg().encoding(), 64);
      case MoveOp::SIMD128:
        return ARMFPRegister(operand.floatReg().encoding(), 128);
      default:
        MOZ_MAKE_COMPILER_ASSUME_IS_UNREACHABLE("Bad register type");
    }
  }

  void emitFloat32Move(const MoveOperand& from, const MoveOperand& to);
  void emitDoubleMove(const MoveOperand& from, const MoveOperand& to);
  void emitSimd128Move(const MoveOperand& from, const MoveOperand& to);
  void emitInt32Move(const MoveOperand& from, const MoveOperand& to);
  void emitGeneralMove(const MoveOperand& from, const MoveOperand& to);

  void emitMove(const MoveOp& move);
  void breakCycle(const MoveOperand& to, MoveOp::Type type);
  void completeCycle(const MoveOperand& from, const MoveOperand& to,
                     MoveOp::Type type);

 public:
  explicit MoveEmitterARM64(MacroAssembler& masm)
      : inCycle_(false),
        masm(masm),
        pushedAtStart_(masm.framePushed()),
        pushedAtCycle_(-1) {}

  ~MoveEmitterARM64() { assertDone(); }

  void emit(const MoveResolver& moves);
  void finish();
};

using MoveEmitter = MoveEmitterARM64;

}  // namespace jit
}  // namespace js

#endif /* jit_arm64_MoveEmitter_arm64_h */