text: // Copyright 2011 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_MIPS_FRAME_CONSTANTS_MIPS_H_
  #define V8_EXECUTION_MIPS_FRAME_CONSTANTS_MIPS_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;
  
    // Stack offsets for arguments passed to JSEntry.
    static constexpr int kArgcOffset = +0 * kSystemPointerSize;
    static constexpr int kArgvOffset = +1 * kSystemPointerSize;
  };
  
  class WasmCompileLazyFrameConstants : public TypedFrameConstants {
   public:
    static constexpr int kNumberOfSavedGpParamRegs = 3;
    static constexpr int kNumberOfSavedFpParamRegs = 7;
  
    // FP-relative.
    static constexpr int kWasmInstanceOffset = TYPED_FRAME_PUSHED_VALUE_OFFSET(3);
    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:
    // {v0, v1, a0, a1, a2, a3, t0, t1, t2, t3, t4, t5, t6, s7}
    static constexpr uint32_t kPushedGpRegs = 0b111111111111100 + (1 << 23);
    // {f0, f2, f4, f6, f8, f10, f12, f14, f16, f18, f20, f22, f24}
    static constexpr uint32_t kPushedFpRegs = 0b1010101010101010101010101;
  
    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_MIPS_FRAME_CONSTANTS_MIPS_H_
  