v8/test/cctest/test-utils-arm64.h

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#ifndef V8_ARM64_TEST_UTILS_ARM64_H_
#define V8_ARM64_TEST_UTILS_ARM64_H_

#include "src/codegen/macro-assembler.h"

namespace v8 {
namespace internal {

// Structure representing Q registers in a RegisterDump.
struct vec128_t {
  uint64_t l;
  uint64_t h;
};

// RegisterDump: Object allowing integer, floating point and flags registers
// to be saved to itself for future reference.
class RegisterDump {
 public:
  RegisterDump() : completed_(false) {}

  // The Dump method generates code to store a snapshot of the register values.
  // It needs to be able to use the stack temporarily.
  //
  // The dumping code is generated though the given MacroAssembler. No registers
  // are corrupted in the process, but the stack is used briefly. The flags will
  // be corrupted during this call.
  void Dump(MacroAssembler* assm);

  // Register accessors.
  inline int32_t wreg(unsigned code) const {
    if (code == kSPRegInternalCode) {
      return wspreg();
    }
    CHECK(RegAliasesMatch(code));
    return dump_.w_[code];
  }

  inline int64_t xreg(unsigned code) const {
    if (code == kSPRegInternalCode) {
      return spreg();
    }
    CHECK(RegAliasesMatch(code));
    return dump_.x_[code];
  }

  // VRegister accessors.
  inline uint32_t sreg_bits(unsigned code) const {
    CHECK(FPRegAliasesMatch(code));
    return dump_.s_[code];
  }

  inline float sreg(unsigned code) const {
    return base::bit_cast<float>(sreg_bits(code));
  }

  inline uint64_t dreg_bits(unsigned code) const {
    CHECK(FPRegAliasesMatch(code));
    return dump_.d_[code];
  }

  inline double dreg(unsigned code) const {
    return base::bit_cast<double>(dreg_bits(code));
  }

  inline vec128_t qreg(unsigned code) const { return dump_.q_[code]; }

  // Stack pointer accessors.
  inline int64_t spreg() const {
    CHECK(SPRegAliasesMatch());
    return dump_.sp_;
  }

  inline int32_t wspreg() const {
    CHECK(SPRegAliasesMatch());
    return static_cast<int32_t>(dump_.wsp_);
  }

  // Flags accessors.
  inline uint32_t flags_nzcv() const {
    CHECK(IsComplete());
    CHECK_EQ(dump_.flags_ & ~Flags_mask, 0);
    return dump_.flags_ & Flags_mask;
  }

  inline bool IsComplete() const {
    return completed_;
  }

 private:
  // Indicate whether the dump operation has been completed.
  bool completed_;

  // Check that the lower 32 bits of x<code> exactly match the 32 bits of
  // w<code>. A failure of this test most likely represents a failure in the
  // ::Dump method, or a failure in the simulator.
  bool RegAliasesMatch(unsigned code) const {
    CHECK(IsComplete());
    CHECK_LT(code, kNumberOfRegisters);
    return ((dump_.x_[code] & kWRegMask) == dump_.w_[code]);
  }

  // As RegAliasesMatch, but for the stack pointer.
  bool SPRegAliasesMatch() const {
    CHECK(IsComplete());
    return ((dump_.sp_ & kWRegMask) == dump_.wsp_);
  }

  // As RegAliasesMatch, but for floating-point registers.
  bool FPRegAliasesMatch(unsigned code) const {
    CHECK(IsComplete());
    CHECK_LT(code, kNumberOfVRegisters);
    return (dump_.d_[code] & kSRegMask) == dump_.s_[code];
  }

  // Store all the dumped elements in a simple struct so the implementation can
  // use offsetof to quickly find the correct field.
  struct dump_t {
    // Core registers.
    uint64_t x_[kNumberOfRegisters];
    uint32_t w_[kNumberOfRegisters];

    // Floating-point registers, as raw bits.
    uint64_t d_[kNumberOfVRegisters];
    uint32_t s_[kNumberOfVRegisters];

    // Vector registers.
    vec128_t q_[kNumberOfVRegisters];

    // The stack pointer.
    uint64_t sp_;
    uint64_t wsp_;

    // NZCV flags, stored in bits 28 to 31.
    // bit[31] : Negative
    // bit[30] : Zero
    // bit[29] : Carry
    // bit[28] : oVerflow
    uint64_t flags_;
  } dump_;

  static dump_t for_sizeof();
  static_assert(kXRegSize == kDRegSize, "X and D registers must be same size.");
  static_assert(kWRegSize == kSRegSize, "W and S registers must be same size.");
  static_assert(sizeof(for_sizeof().q_[0]) == kQRegSize,
                "Array elements must be size of Q register.");
  static_assert(sizeof(for_sizeof().d_[0]) == kDRegSize,
                "Array elements must be size of D register.");
  static_assert(sizeof(for_sizeof().s_[0]) == kSRegSize,
                "Array elements must be size of S register.");
  static_assert(sizeof(for_sizeof().x_[0]) == kXRegSize,
                "Array elements must be size of X register.");
  static_assert(sizeof(for_sizeof().w_[0]) == kWRegSize,
                "Array elements must be size of W register.");
};

// Some of these methods don't use the RegisterDump argument, but they have to
// accept them so that they can overload those that take register arguments.
bool Equal32(uint32_t expected, const RegisterDump*, uint32_t result);
bool Equal64(uint64_t expected, const RegisterDump*, uint64_t result);

bool EqualFP32(float expected, const RegisterDump*, float result);
bool EqualFP64(double expected, const RegisterDump*, double result);

bool Equal32(uint32_t expected, const RegisterDump* core, const Register& reg);
bool Equal64(uint64_t expected, const RegisterDump* core, const Register& reg);

bool EqualFP32(float expected, const RegisterDump* core,
               const VRegister& fpreg);
bool EqualFP64(double expected, const RegisterDump* core,
               const VRegister& fpreg);

bool Equal64(const Register& reg0, const RegisterDump* core,
             const Register& reg1);
bool Equal128(uint64_t expected_h, uint64_t expected_l,
              const RegisterDump* core, const VRegister& reg);

bool EqualNzcv(uint32_t expected, uint32_t result);

// Compares two RegisterDumps, only comparing registers that V8 uses.
bool EqualV8Registers(const RegisterDump* a, const RegisterDump* b);

// Create an array of type {RegType}, size {Size}, filled with {NoReg}.
template <typename RegType, size_t Size>
std::array<RegType, Size> CreateRegisterArray() {
  return base::make_array<Size>([](size_t) { return RegType::no_reg(); });
}

// Populate the w, x and r arrays with registers from the 'allowed' mask. The
// r array will be populated with <reg_size>-sized registers,
//
// This allows for tests which use large, parameterized blocks of registers
// (such as the push and pop tests), but where certain registers must be
// avoided as they are used for other purposes.
//
// Any of w, x, or r can be nullptr if they are not required.
//
// The return value is a RegList indicating which registers were allocated.
RegList PopulateRegisterArray(Register* w, Register* x, Register* r,
                              int reg_size, int reg_count, RegList allowed);

// As PopulateRegisterArray, but for floating-point registers.
DoubleRegList PopulateVRegisterArray(VRegister* s, VRegister* d, VRegister* v,
                                     int reg_size, int reg_count,
                                     DoubleRegList allowed);

// Ovewrite the contents of the specified registers. This enables tests to
// check that register contents are written in cases where it's likely that the
// correct outcome could already be stored in the register.
//
// This always overwrites X-sized registers. If tests are operating on W
// registers, a subsequent write into an aliased W register should clear the
// top word anyway, so clobbering the full X registers should make tests more
// rigorous.
void Clobber(MacroAssembler* masm, RegList reg_list,
             uint64_t const value = 0xFEDCBA9876543210UL);

// As Clobber, but for FP registers.
void ClobberFP(MacroAssembler* masm, DoubleRegList reg_list,
               double const value = kFP64SignallingNaN);

// As Clobber, but for a CPURegList with either FP or integer registers. When
// using this method, the clobber value is always the default for the basic
// Clobber or ClobberFP functions.
void Clobber(MacroAssembler* masm, CPURegList reg_list);

}  // namespace internal
}  // namespace v8

#endif  // V8_ARM64_TEST_UTILS_ARM64_H_