src/third_party/v8/src/execution/ia32/frame-constants-ia32.h

// Copyright 2012 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_IA32_FRAME_CONSTANTS_IA32_H_
#define V8_EXECUTION_IA32_FRAME_CONSTANTS_IA32_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 = -6 * kSystemPointerSize;

  // EntryFrame is used by JSEntry, JSConstructEntry and JSRunMicrotasksEntry.
  // All of them take |root_register_value| as the first parameter.
  static constexpr int kRootRegisterValueOffset = +2 * kSystemPointerSize;

  // Rest of parameters passed to JSEntry and JSConstructEntry.
  static constexpr int kNewTargetArgOffset = +3 * kSystemPointerSize;
  static constexpr int kFunctionArgOffset = +4 * kSystemPointerSize;
  static constexpr int kReceiverArgOffset = +5 * kSystemPointerSize;
  static constexpr int kArgcOffset = +6 * kSystemPointerSize;
  static constexpr int kArgvOffset = +7 * kSystemPointerSize;

  // Rest of parameters passed to JSRunMicrotasksEntry.
  static constexpr int kMicrotaskQueueArgOffset = +3 * kSystemPointerSize;
};

class WasmCompileLazyFrameConstants : public TypedFrameConstants {
 public:
  static constexpr int kNumberOfSavedGpParamRegs = 4;
  static constexpr int kNumberOfSavedFpParamRegs = 6;

  // FP-relative.
  static constexpr int kWasmInstanceOffset = TYPED_FRAME_PUSHED_VALUE_OFFSET(0);
  static constexpr int kFixedFrameSizeFromFp =
      TypedFrameConstants::kFixedFrameSizeFromFp +
      kNumberOfSavedGpParamRegs * kSystemPointerSize +
      kNumberOfSavedFpParamRegs * kSimd128Size;
};

// 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:
  // {eax, ecx, edx, esi, edi}
  static constexpr uint32_t kPushedGpRegs = 0b11000111;
  // {xmm0, xmm1, xmm2, xmm3, xmm4, xmm5, xmm6}
  static constexpr uint32_t kPushedFpRegs = 0b01111111;

  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 * kSimd128Size;

  // 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) * kSimd128Size;
  }
};

}  // namespace internal
}  // namespace v8

#endif  // V8_EXECUTION_IA32_FRAME_CONSTANTS_IA32_H_