chromium/v8/src/bigint/div-helpers.h

// Copyright 2021 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef V8_BIGINT_DIV_HELPERS_H_
#define V8_BIGINT_DIV_HELPERS_H_

#include <memory>

#include "src/bigint/bigint.h"
#include "src/bigint/util.h"

namespace v8 {
namespace bigint {

void LeftShift(RWDigits Z, Digits X, int shift);
void RightShift(RWDigits Z, Digits X, int shift);

inline void PutAt(RWDigits Z, Digits A, int count) { … }

// Division algorithms typically need to left-shift their inputs into
// "bit-normalized" form (i.e. top bit is set). The inputs are considered
// read-only, and V8 relies on that by allowing concurrent reads from them,
// so by default, {ShiftedDigits} allocate temporary storage for their
// contents. In-place modification is opt-in for cases where callers can
// guarantee that it is safe.
// When callers allow in-place shifting and wish to undo it, they have to do
// so manually using {Reset()}.
// If {shift} is not given, it is auto-detected from {original}'s
// leading zeros.
class ShiftedDigits : public Digits { … };

}  // namespace bigint
}  // namespace v8

#endif  // V8_BIGINT_DIV_HELPERS_H_