//===----------------------------------------------------------------------===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

// Copyright (c) Microsoft Corporation.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

// Copyright 2018 Ulf Adams

// Copyright (c) Microsoft Corporation. All rights reserved.

// Boost Software License - Version 1.0 - August 17th, 2003

// Permission is hereby granted, free of charge, to any person or organization

// obtaining a copy of the software and accompanying documentation covered by

// this license (the "Software") to use, reproduce, display, distribute,

// execute, and transmit the Software, and to prepare derivative works of the

// Software, and to permit third-parties to whom the Software is furnished to

// do so, all subject to the following:

// The copyright notices in the Software and this entire statement, including

// the above license grant, this restriction and the following disclaimer,

// must be included in all copies of the Software, in whole or in part, and

// all derivative works of the Software, unless such copies or derivative

// works are solely in the form of machine-executable object code generated by

// a source language processor.

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT

// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE

// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,

// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER

// DEALINGS IN THE SOFTWARE.

#ifndef _LIBCPP_SRC_INCLUDE_RYU_DS2_INTRINSICS_H

#define _LIBCPP_SRC_INCLUDE_RYU_DS2_INTRINSICS_H

// Avoid formatting to keep the changes with the original code minimal.

// clang-format off

#include "__config"

_LIBCPP_BEGIN_NAMESPACE_STD

#if defined(_M_X64) && defined(_MSC_VER)

#define _LIBCPP_INTRINSIC128 1

[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline uint64_t __ryu_umul128(const uint64_t __a, const uint64_t __b, uint64_t* const __productHi) {

  return _umul128(__a, __b, __productHi);

}

[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline uint64_t __ryu_shiftright128(const uint64_t __lo, const uint64_t __hi, const uint32_t __dist) {

  // For the __shiftright128 intrinsic, the shift value is always

  // modulo 64.

  // In the current implementation of the double-precision version

  // of Ryu, the shift value is always < 64.

  // (The shift value is in the range [49, 58].)

  // Check this here in case a future change requires larger shift

  // values. In this case this function needs to be adjusted.

  _LIBCPP_ASSERT(__dist < 64, "");

  return __shiftright128(__lo, __hi, static_cast<unsigned char>(__dist));

}

// ^^^ intrinsics available ^^^ / vvv __int128 available vvv

#elif defined(__SIZEOF_INT128__) && ( \

    (defined(__clang__) && !defined(_MSC_VER)) || \

    (defined(__GNUC__) && !defined(__clang__) && !defined(__CUDACC__)))

#define _LIBCPP_INTRINSIC128 1

  // We have __uint128 support in clang or gcc

[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline uint64_t __ryu_umul128(const uint64_t __a, const uint64_t __b, uint64_t* const __productHi) {

  auto __temp = __a * (unsigned __int128)__b;

  *__productHi = __temp >> 64;

  return static_cast<uint64_t>(__temp);

}

[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline uint64_t __ryu_shiftright128(const uint64_t __lo, const uint64_t __hi, const uint32_t __dist) {

  // In the current implementation of the double-precision version

  // of Ryu, the shift value is always < 64.

  // (The shift value is in the range [49, 58].)

  // Check this here in case a future change requires larger shift

  // values. In this case this function needs to be adjusted.

  _LIBCPP_ASSERT(__dist < 64, "");

  auto __temp = __lo | ((unsigned __int128)__hi << 64);

  // For x64 128-bit shfits using the `shrd` instruction and two 64-bit

  // registers, the shift value is modulo 64.  Thus the `& 63` is free.

  return static_cast<uint64_t>(__temp >> (__dist & 63));

}

#else // ^^^ __int128 available ^^^ / vvv intrinsics unavailable vvv

[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline _LIBCPP_ALWAYS_INLINE uint64_t __ryu_umul128(const uint64_t __a, const uint64_t __b, uint64_t* const __productHi) {

  // TRANSITION, VSO-634761

  // The casts here help MSVC to avoid calls to the __allmul library function.

  const uint32_t __aLo = static_cast<uint32_t>(__a);

  const uint32_t __aHi = static_cast<uint32_t>(__a >> 32);

  const uint32_t __bLo = static_cast<uint32_t>(__b);

  const uint32_t __bHi = static_cast<uint32_t>(__b >> 32);

  const uint64_t __b00 = static_cast<uint64_t>(__aLo) * __bLo;

  const uint64_t __b01 = static_cast<uint64_t>(__aLo) * __bHi;

  const uint64_t __b10 = static_cast<uint64_t>(__aHi) * __bLo;

  const uint64_t __b11 = static_cast<uint64_t>(__aHi) * __bHi;

  const uint32_t __b00Lo = static_cast<uint32_t>(__b00);

  const uint32_t __b00Hi = static_cast<uint32_t>(__b00 >> 32);

  const uint64_t __mid1 = __b10 + __b00Hi;

  const uint32_t __mid1Lo = static_cast<uint32_t>(__mid1);

  const uint32_t __mid1Hi = static_cast<uint32_t>(__mid1 >> 32);

  const uint64_t __mid2 = __b01 + __mid1Lo;

  const uint32_t __mid2Lo = static_cast<uint32_t>(__mid2);

  const uint32_t __mid2Hi = static_cast<uint32_t>(__mid2 >> 32);

  const uint64_t __pHi = __b11 + __mid1Hi + __mid2Hi;

  const uint64_t __pLo = (static_cast<uint64_t>(__mid2Lo) << 32) | __b00Lo;

  *__productHi = __pHi;

  return __pLo;

}

[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline uint64_t __ryu_shiftright128(const uint64_t __lo, const uint64_t __hi, const uint32_t __dist) {

  // We don't need to handle the case __dist >= 64 here (see above).

  _LIBCPP_ASSERT(__dist < 64, "");

#ifdef _LIBCPP_64_BIT

  _LIBCPP_ASSERT(__dist > 0, "");

  return (__hi << (64 - __dist)) | (__lo >> __dist);

#else // ^^^ 64-bit ^^^ / vvv 32-bit vvv

  // Avoid a 64-bit shift by taking advantage of the range of shift values.

  _LIBCPP_ASSERT(__dist >= 32, "");

  return (__hi << (64 - __dist)) | (static_cast<uint32_t>(__lo >> 32) >> (__dist - 32));

#endif // ^^^ 32-bit ^^^

}

#endif // ^^^ intrinsics unavailable ^^^

#ifndef _LIBCPP_64_BIT

// Returns the high 64 bits of the 128-bit product of __a and __b.

[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline uint64_t __umulh(const uint64_t __a, const uint64_t __b) {

  // Reuse the __ryu_umul128 implementation.

  // Optimizers will likely eliminate the instructions used to compute the

  // low part of the product.

  uint64_t __hi;

  (void) __ryu_umul128(__a, __b, &__hi);

  return __hi;

}

// On 32-bit platforms, compilers typically generate calls to library

// functions for 64-bit divisions, even if the divisor is a constant.

//

// TRANSITION, LLVM-37932

//

// The functions here perform division-by-constant using multiplications

// in the same way as 64-bit compilers would do.

//

// NB:

// The multipliers and shift values are the ones generated by clang x64

// for expressions like x/5, x/10, etc.

[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline uint64_t __div5(const uint64_t __x) {

  return __umulh(__x, 0xCCCCCCCCCCCCCCCDu) >> 2;

}

[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline uint64_t __div10(const uint64_t __x) {

  return __umulh(__x, 0xCCCCCCCCCCCCCCCDu) >> 3;

}

[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline uint64_t __div100(const uint64_t __x) {

  return __umulh(__x >> 2, 0x28F5C28F5C28F5C3u) >> 2;

}

[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline uint64_t __div1e8(const uint64_t __x) {

  return __umulh(__x, 0xABCC77118461CEFDu) >> 26;

}

[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline uint64_t __div1e9(const uint64_t __x) {

  return __umulh(__x >> 9, 0x44B82FA09B5A53u) >> 11;

}

[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline uint32_t __mod1e9(const uint64_t __x) {

  // Avoid 64-bit math as much as possible.

  // Returning static_cast<uint32_t>(__x - 1000000000 * __div1e9(__x)) would

  // perform 32x64-bit multiplication and 64-bit subtraction.

  // __x and 1000000000 * __div1e9(__x) are guaranteed to differ by

  // less than 10^9, so their highest 32 bits must be identical,

  // so we can truncate both sides to uint32_t before subtracting.

  // We can also simplify static_cast<uint32_t>(1000000000 * __div1e9(__x)).

  // We can truncate before multiplying instead of after, as multiplying

  // the highest 32 bits of __div1e9(__x) can't affect the lowest 32 bits.

  return static_cast<uint32_t>(__x) - 1000000000 * static_cast<uint32_t>(__div1e9(__x));

}

#else // ^^^ 32-bit ^^^ / vvv 64-bit vvv

[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline uint64_t __div5(const uint64_t __x) {

  return __x / 5;

}

[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline uint64_t __div10(const uint64_t __x) {

  return __x / 10;

}

[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline uint64_t __div100(const uint64_t __x) {

  return __x / 100;

}

[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline uint64_t __div1e8(const uint64_t __x) {

  return __x / 100000000;

}

[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline uint64_t __div1e9(const uint64_t __x) {

  return __x / 1000000000;

}

[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline uint32_t __mod1e9(const uint64_t __x) {

  return static_cast<uint32_t>(__x - 1000000000 * __div1e9(__x));

}

#endif // ^^^ 64-bit ^^^

[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline uint32_t __pow5Factor(uint64_t __value) {

  uint32_t __count = 0;

  for (;;) {

    _LIBCPP_ASSERT(__value != 0, "");

    const uint64_t __q = __div5(__value);

    const uint32_t __r = static_cast<uint32_t>(__value) - 5 * static_cast<uint32_t>(__q);

    if (__r != 0) {

      break;

    }

    __value = __q;

    ++__count;

  }

  return __count;

}

// Returns true if __value is divisible by 5^__p.

[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline bool __multipleOfPowerOf5(const uint64_t __value, const uint32_t __p) {

  // I tried a case distinction on __p, but there was no performance difference.

  return __pow5Factor(__value) >= __p;

}

// Returns true if __value is divisible by 2^__p.

[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline bool __multipleOfPowerOf2(const uint64_t __value, const uint32_t __p) {

  _LIBCPP_ASSERT(__value != 0, "");

  _LIBCPP_ASSERT(__p < 64, "");

  // __builtin_ctzll doesn't appear to be faster here.

  return (__value & ((1ull << __p) - 1)) == 0;

}

_LIBCPP_END_NAMESPACE_STD

// clang-format on

#endif // _LIBCPP_SRC_INCLUDE_RYU_DS2_INTRINSICS_H