// Copyright 2021 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef V8_EXECUTION_LOONG64_FRAME_CONSTANTS_LOONG64_H_
#define V8_EXECUTION_LOONG64_FRAME_CONSTANTS_LOONG64_H_

#include "src/base/bits.h"
#include "src/base/macros.h"
#include "src/execution/frame-constants.h"

namespace v8 {
namespace internal {

class EntryFrameConstants : public AllStatic {
 public:
  // This is the offset to where JSEntry pushes the current value of
  // Isolate::c_entry_fp onto the stack.
  static constexpr int kCallerFPOffset = -3 * kSystemPointerSize;
};

class WasmCompileLazyFrameConstants : public TypedFrameConstants {
 public:
  static constexpr int kNumberOfSavedGpParamRegs = 7;
  static constexpr int kNumberOfSavedFpParamRegs = 8;
  static constexpr int kNumberOfSavedAllParamRegs = 15;

  // FP-relative.
  // See Generate_WasmCompileLazy in builtins-loong64.cc.
  static constexpr int kWasmInstanceOffset = TYPED_FRAME_PUSHED_VALUE_OFFSET(6);
  static constexpr int kFixedFrameSizeFromFp =
      TypedFrameConstants::kFixedFrameSizeFromFp +
      kNumberOfSavedGpParamRegs * kPointerSize +
      kNumberOfSavedFpParamRegs * kDoubleSize;
};

// Frame constructed by the {WasmDebugBreak} builtin.
// After pushing the frame type marker, the builtin pushes all Liftoff cache
// registers (see liftoff-assembler-defs.h).
class WasmDebugBreakFrameConstants : public TypedFrameConstants {
 public:
  // {a0, a1, a2, a3, a4, a5, a6, a7, t0, t1, t2, t3, t4, t5, t6, t7, t8, s7}
  static constexpr uint32_t kPushedGpRegs = 0b1000000000111111111111111110000;
  // {f0, f1, f2, ... f27, f28}
  static constexpr uint32_t kPushedFpRegs = 0x1fffffff;

  static constexpr int kNumPushedGpRegisters =
      base::bits::CountPopulation(kPushedGpRegs);
  static constexpr int kNumPushedFpRegisters =
      base::bits::CountPopulation(kPushedFpRegs);

  static constexpr int kLastPushedGpRegisterOffset =
      -kFixedFrameSizeFromFp - kNumPushedGpRegisters * kSystemPointerSize;
  static constexpr int kLastPushedFpRegisterOffset =
      kLastPushedGpRegisterOffset - kNumPushedFpRegisters * kDoubleSize;

  // Offsets are fp-relative.
  static int GetPushedGpRegisterOffset(int reg_code) {
    DCHECK_NE(0, kPushedGpRegs & (1 << reg_code));
    uint32_t lower_regs = kPushedGpRegs & ((uint32_t{1} << reg_code) - 1);
    return kLastPushedGpRegisterOffset +
           base::bits::CountPopulation(lower_regs) * kSystemPointerSize;
  }

  static int GetPushedFpRegisterOffset(int reg_code) {
    DCHECK_NE(0, kPushedFpRegs & (1 << reg_code));
    uint32_t lower_regs = kPushedFpRegs & ((uint32_t{1} << reg_code) - 1);
    return kLastPushedFpRegisterOffset +
           base::bits::CountPopulation(lower_regs) * kDoubleSize;
  }
};

}  // namespace internal
}  // namespace v8

#endif  // V8_EXECUTION_LOONG64_FRAME_CONSTANTS_LOONG64_H_
