// © 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

// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

// OWNER 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

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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// 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