github.com/shogo82148/std@v1.22.1-0.20240327122250-4e474527810c/runtime/internal/math/math.go (about)

     1  // Copyright 2018 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package math
     6  
     7  const MaxUintptr = ^uintptr(0)
     8  
     9  // MulUintptr returns a * b and whether the multiplication overflowed.
    10  // On supported platforms this is an intrinsic lowered by the compiler.
    11  func MulUintptr(a, b uintptr) (uintptr, bool)
    12  
    13  // Mul64 returns the 128-bit product of x and y: (hi, lo) = x * y
    14  // with the product bits' upper half returned in hi and the lower
    15  // half returned in lo.
    16  // This is a copy from math/bits.Mul64
    17  // On supported platforms this is an intrinsic lowered by the compiler.
    18  func Mul64(x, y uint64) (hi, lo uint64)
    19  
    20  // Add64 returns the sum with carry of x, y and carry: sum = x + y + carry.
    21  // The carry input must be 0 or 1; otherwise the behavior is undefined.
    22  // The carryOut output is guaranteed to be 0 or 1.
    23  //
    24  // This function's execution time does not depend on the inputs.
    25  // On supported platforms this is an intrinsic lowered by the compiler.
    26  func Add64(x, y, carry uint64) (sum, carryOut uint64)