text: /*
   * Copyright (C) 2015-2017 Apple Inc. All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
   * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
   * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
   * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
   * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
   */
  
  #pragma once
  
  #if ENABLE(B3_JIT)
  
  #include "CPU.h"
  #include "GPRInfo.h"
  #include "JSExportMacros.h"
  #include "Options.h"
  #include <wtf/Optional.h>
  
  namespace JSC { namespace B3 {
  
  enum B3ComplitationMode {
      B3Mode,
      AirMode
  };
  
  JS_EXPORT_PRIVATE bool shouldDumpIR(B3ComplitationMode);
  bool shouldDumpIRAtEachPhase(B3ComplitationMode);
  bool shouldValidateIR();
  bool shouldValidateIRAtEachPhase();
  bool shouldSaveIRBeforePhase();
  bool shouldMeasurePhaseTiming();
  
  template<typename BitsType, typename InputType>
  inline bool isIdentical(InputType left, InputType right)
  {
      BitsType leftBits = bitwise_cast<BitsType>(left);
      BitsType rightBits = bitwise_cast<BitsType>(right);
      return leftBits == rightBits;
  }
  
  inline bool isIdentical(int32_t left, int32_t right)
  {
      return isIdentical<int32_t>(left, right);
  }
  
  inline bool isIdentical(int64_t left, int64_t right)
  {
      return isIdentical<int64_t>(left, right);
  }
  
  inline bool isIdentical(double left, double right)
  {
      return isIdentical<int64_t>(left, right);
  }
  
  inline bool isIdentical(float left, float right)
  {
      return isIdentical<int32_t>(left, right);
  }
  
  template<typename ResultType, typename InputType, typename BitsType>
  inline bool isRepresentableAsImpl(InputType originalValue)
  {
      // Convert the original value to the desired result type.
      ResultType result = static_cast<ResultType>(originalValue);
  
      // Convert the converted value back to the original type. The original value is representable
      // using the new type if such round-tripping doesn't lose bits.
      InputType newValue = static_cast<InputType>(result);
  
      return isIdentical<BitsType>(originalValue, newValue);
  }
  
  template<typename ResultType>
  inline bool isRepresentableAs(int32_t value)
  {
      return isRepresentableAsImpl<ResultType, int32_t, int32_t>(value);
  }
  
  template<typename ResultType>
  inline bool isRepresentableAs(int64_t value)
  {
      return isRepresentableAsImpl<ResultType, int64_t, int64_t>(value);
  }
  
  template<typename ResultType>
  inline bool isRepresentableAs(size_t value)
  {
      return isRepresentableAsImpl<ResultType, size_t, size_t>(value);
  }
  
  template<typename ResultType>
  inline bool isRepresentableAs(double value)
  {
      return isRepresentableAsImpl<ResultType, double, int64_t>(value);
  }
  
  template<typename IntType>
  static IntType chillDiv(IntType numerator, IntType denominator)
  {
      if (!denominator)
          return 0;
      if (denominator == -1 && numerator == std::numeric_limits<IntType>::min())
          return std::numeric_limits<IntType>::min();
      return numerator / denominator;
  }
  
  template<typename IntType>
  static IntType chillMod(IntType numerator, IntType denominator)
  {
      if (!denominator)
          return 0;
      if (denominator == -1 && numerator == std::numeric_limits<IntType>::min())
          return 0;
      return numerator % denominator;
  }
  
  template<typename IntType>
  static IntType chillUDiv(IntType numerator, IntType denominator)
  {
      typedef typename std::make_unsigned<IntType>::type UnsignedIntType;
      UnsignedIntType unsignedNumerator = static_cast<UnsignedIntType>(numerator);
      UnsignedIntType unsignedDenominator = static_cast<UnsignedIntType>(denominator);
      if (!unsignedDenominator)
          return 0;
      return unsignedNumerator / unsignedDenominator;
  }
  
  template<typename IntType>
  static IntType chillUMod(IntType numerator, IntType denominator)
  {
      typedef typename std::make_unsigned<IntType>::type UnsignedIntType;
      UnsignedIntType unsignedNumerator = static_cast<UnsignedIntType>(numerator);
      UnsignedIntType unsignedDenominator = static_cast<UnsignedIntType>(denominator);
      if (!unsignedDenominator)
          return 0;
      return unsignedNumerator % unsignedDenominator;
  }
  
  template<typename IntType>
  static IntType rotateRight(IntType value, int32_t shift)
  {
      typedef typename std::make_unsigned<IntType>::type UnsignedIntType;
      UnsignedIntType uValue = static_cast<UnsignedIntType>(value);
      int32_t bits = sizeof(IntType) * 8;
      int32_t mask = bits - 1;
      shift &= mask;
      return (uValue >> shift) | (uValue << ((bits - shift) & mask));
  }
  
  template<typename IntType>
  static IntType rotateLeft(IntType value, int32_t shift)
  {
      typedef typename std::make_unsigned<IntType>::type UnsignedIntType;
      UnsignedIntType uValue = static_cast<UnsignedIntType>(value);
      int32_t bits = sizeof(IntType) * 8;
      int32_t mask = bits - 1;
      shift &= mask;
      return (uValue << shift) | (uValue >> ((bits - shift) & mask));
  }
  
  inline unsigned defaultOptLevel()
  {
      // This should almost always return 2, but we allow this default to be lowered for testing. Some
      // components will deliberately set the optLevel.
      return Options::defaultB3OptLevel();
  }
  
  std::optional<GPRReg> pinnedExtendedOffsetAddrRegister();
  
  } } // namespace JSC::B3
  
  #endif // ENABLE(B3_JIT)
  