// © 2018 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
//
// From the double-conversion library. Original license:
//
// Copyright 2010 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * 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.
//     * Neither the name of Google Inc. nor the names of its
//       contributors may be used to endorse or promote products derived
//       from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// ICU PATCH: ifdef around UCONFIG_NO_FORMATTING
#include "unicode/utypes.h"
#if !UCONFIG_NO_FORMATTING

// ICU PATCH: Customize header file paths for ICU.

#include "double-conversion-diy-fp.h"
#include "double-conversion-utils.h"

// ICU PATCH: Wrap in ICU namespace
U_NAMESPACE_BEGIN

namespace double_conversion {

void DiyFp::Multiply(const DiyFp& other) {
  // Simply "emulates" a 128 bit multiplication.
  // However: the resulting number only contains 64 bits. The least
  // significant 64 bits are only used for rounding the most significant 64
  // bits.
  const uint64_t kM32 = 0xFFFFFFFFU;
  uint64_t a = f_ >> 32;
  uint64_t b = f_ & kM32;
  uint64_t c = other.f_ >> 32;
  uint64_t d = other.f_ & kM32;
  uint64_t ac = a * c;
  uint64_t bc = b * c;
  uint64_t ad = a * d;
  uint64_t bd = b * d;
  uint64_t tmp = (bd >> 32) + (ad & kM32) + (bc & kM32);
  // By adding 1U << 31 to tmp we round the final result.
  // Halfway cases will be round up.
  tmp += 1U << 31;
  uint64_t result_f = ac + (ad >> 32) + (bc >> 32) + (tmp >> 32);
  e_ += other.e_ + 64;
  f_ = result_f;
}

}  // namespace double_conversion

// ICU PATCH: Close ICU namespace
U_NAMESPACE_END
#endif // ICU PATCH: close #if !UCONFIG_NO_FORMATTING