diff options
Diffstat (limited to 'vendor/lukechampine.com/uint128')
| -rw-r--r-- | vendor/lukechampine.com/uint128/LICENSE | 21 | ||||
| -rw-r--r-- | vendor/lukechampine.com/uint128/README.md | 46 | ||||
| -rw-r--r-- | vendor/lukechampine.com/uint128/uint128.go | 417 |
3 files changed, 484 insertions, 0 deletions
diff --git a/vendor/lukechampine.com/uint128/LICENSE b/vendor/lukechampine.com/uint128/LICENSE new file mode 100644 index 00000000..a14c6cf2 --- /dev/null +++ b/vendor/lukechampine.com/uint128/LICENSE @@ -0,0 +1,21 @@ +The MIT License (MIT) + +Copyright (c) 2019 Luke Champine + +Permission is hereby granted, free of charge, to any person obtaining a copy +of this software and associated documentation files (the "Software"), to deal +in the Software without restriction, including without limitation the rights +to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in +all copies or substantial portions of the Software. + +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 AND NONINFRINGEMENT. IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +THE SOFTWARE. diff --git a/vendor/lukechampine.com/uint128/README.md b/vendor/lukechampine.com/uint128/README.md new file mode 100644 index 00000000..1ea5d7df --- /dev/null +++ b/vendor/lukechampine.com/uint128/README.md @@ -0,0 +1,46 @@ +uint128 +------- + +[](https://godoc.org/github.com/lukechampine/uint128) +[](https://goreportcard.com/report/github.com/lukechampine/uint128) + +``` +go get lukechampine.com/uint128 +``` + +`uint128` provides a high-performance `Uint128` type that supports standard arithmetic +operations. Unlike `math/big`, operations on `Uint128` values always produce new values +instead of modifying a pointer receiver. A `Uint128` value is therefore immutable, just +like `uint64` and friends. + +The name `uint128.Uint128` stutters, so I recommend either using a "dot import" +or aliasing `uint128.Uint128` to give it a project-specific name. Embedding the type +is not recommended, because methods will still return `uint128.Uint128`; this means that, +if you want to extend the type with new methods, your best bet is probably to copy the +source code wholesale and rename the identifier. ¯\\\_(ツ)\_/¯ + + +# Benchmarks + +Addition, multiplication, and subtraction are on par with their native 64-bit +equivalents. Division is slower: ~20x slower when dividing a `Uint128` by a +`uint64`, and ~100x slower when dividing by a `Uint128`. However, division is +still faster than with `big.Int` (for the same operands), especially when +dividing by a `uint64`. + +``` +BenchmarkArithmetic/Add-4 2000000000 0.45 ns/op 0 B/op 0 allocs/op +BenchmarkArithmetic/Sub-4 2000000000 0.67 ns/op 0 B/op 0 allocs/op +BenchmarkArithmetic/Mul-4 2000000000 0.42 ns/op 0 B/op 0 allocs/op +BenchmarkArithmetic/Lsh-4 2000000000 1.06 ns/op 0 B/op 0 allocs/op +BenchmarkArithmetic/Rsh-4 2000000000 1.06 ns/op 0 B/op 0 allocs/op + +BenchmarkDivision/native_64/64-4 2000000000 0.39 ns/op 0 B/op 0 allocs/op +BenchmarkDivision/Div_128/64-4 2000000000 6.28 ns/op 0 B/op 0 allocs/op +BenchmarkDivision/Div_128/128-4 30000000 45.2 ns/op 0 B/op 0 allocs/op +BenchmarkDivision/big.Int_128/64-4 20000000 98.2 ns/op 8 B/op 1 allocs/op +BenchmarkDivision/big.Int_128/128-4 30000000 53.4 ns/op 48 B/op 1 allocs/op + +BenchmarkString/Uint128-4 10000000 173 ns/op 48 B/op 1 allocs/op +BenchmarkString/big.Int-4 5000000 350 ns/op 144 B/op 3 allocs/op +``` diff --git a/vendor/lukechampine.com/uint128/uint128.go b/vendor/lukechampine.com/uint128/uint128.go new file mode 100644 index 00000000..0b74b9fc --- /dev/null +++ b/vendor/lukechampine.com/uint128/uint128.go @@ -0,0 +1,417 @@ +package uint128 // import "lukechampine.com/uint128" + +import ( + "encoding/binary" + "math" + "math/big" + "math/bits" +) + +// Zero is a zero-valued uint128. +var Zero Uint128 + +// Max is the largest possible uint128 value. +var Max = New(math.MaxUint64, math.MaxUint64) + +// A Uint128 is an unsigned 128-bit number. +type Uint128 struct { + Lo, Hi uint64 +} + +// IsZero returns true if u == 0. +func (u Uint128) IsZero() bool { + // NOTE: we do not compare against Zero, because that is a global variable + // that could be modified. + return u == Uint128{} +} + +// Equals returns true if u == v. +// +// Uint128 values can be compared directly with ==, but use of the Equals method +// is preferred for consistency. +func (u Uint128) Equals(v Uint128) bool { + return u == v +} + +// Equals64 returns true if u == v. +func (u Uint128) Equals64(v uint64) bool { + return u.Lo == v && u.Hi == 0 +} + +// Cmp compares u and v and returns: +// +// -1 if u < v +// 0 if u == v +// +1 if u > v +// +func (u Uint128) Cmp(v Uint128) int { + if u == v { + return 0 + } else if u.Hi < v.Hi || (u.Hi == v.Hi && u.Lo < v.Lo) { + return -1 + } else { + return 1 + } +} + +// Cmp64 compares u and v and returns: +// +// -1 if u < v +// 0 if u == v +// +1 if u > v +// +func (u Uint128) Cmp64(v uint64) int { + if u.Hi == 0 && u.Lo == v { + return 0 + } else if u.Hi == 0 && u.Lo < v { + return -1 + } else { + return 1 + } +} + +// And returns u&v. +func (u Uint128) And(v Uint128) Uint128 { + return Uint128{u.Lo & v.Lo, u.Hi & v.Hi} +} + +// And64 returns u&v. +func (u Uint128) And64(v uint64) Uint128 { + return Uint128{u.Lo & v, u.Hi & 0} +} + +// Or returns u|v. +func (u Uint128) Or(v Uint128) Uint128 { + return Uint128{u.Lo | v.Lo, u.Hi | v.Hi} +} + +// Or64 returns u|v. +func (u Uint128) Or64(v uint64) Uint128 { + return Uint128{u.Lo | v, u.Hi | 0} +} + +// Xor returns u^v. +func (u Uint128) Xor(v Uint128) Uint128 { + return Uint128{u.Lo ^ v.Lo, u.Hi ^ v.Hi} +} + +// Xor64 returns u^v. +func (u Uint128) Xor64(v uint64) Uint128 { + return Uint128{u.Lo ^ v, u.Hi ^ 0} +} + +// Add returns u+v. +func (u Uint128) Add(v Uint128) Uint128 { + lo, carry := bits.Add64(u.Lo, v.Lo, 0) + hi, carry := bits.Add64(u.Hi, v.Hi, carry) + if carry != 0 { + panic("overflow") + } + return Uint128{lo, hi} +} + +// AddWrap returns u+v with wraparound semantics; for example, +// Max.AddWrap(From64(1)) == Zero. +func (u Uint128) AddWrap(v Uint128) Uint128 { + lo, carry := bits.Add64(u.Lo, v.Lo, 0) + hi, _ := bits.Add64(u.Hi, v.Hi, carry) + return Uint128{lo, hi} +} + +// Add64 returns u+v. +func (u Uint128) Add64(v uint64) Uint128 { + lo, carry := bits.Add64(u.Lo, v, 0) + hi, carry := bits.Add64(u.Hi, 0, carry) + if carry != 0 { + panic("overflow") + } + return Uint128{lo, hi} +} + +// AddWrap64 returns u+v with wraparound semantics; for example, +// Max.AddWrap64(1) == Zero. +func (u Uint128) AddWrap64(v uint64) Uint128 { + lo, carry := bits.Add64(u.Lo, v, 0) + hi := u.Hi + carry + return Uint128{lo, hi} +} + +// Sub returns u-v. +func (u Uint128) Sub(v Uint128) Uint128 { + lo, borrow := bits.Sub64(u.Lo, v.Lo, 0) + hi, borrow := bits.Sub64(u.Hi, v.Hi, borrow) + if borrow != 0 { + panic("underflow") + } + return Uint128{lo, hi} +} + +// SubWrap returns u-v with wraparound semantics; for example, +// Zero.SubWrap(From64(1)) == Max. +func (u Uint128) SubWrap(v Uint128) Uint128 { + lo, borrow := bits.Sub64(u.Lo, v.Lo, 0) + hi, _ := bits.Sub64(u.Hi, v.Hi, borrow) + return Uint128{lo, hi} +} + +// Sub64 returns u-v. +func (u Uint128) Sub64(v uint64) Uint128 { + lo, borrow := bits.Sub64(u.Lo, v, 0) + hi, borrow := bits.Sub64(u.Hi, 0, borrow) + if borrow != 0 { + panic("underflow") + } + return Uint128{lo, hi} +} + +// SubWrap64 returns u-v with wraparound semantics; for example, +// Zero.SubWrap64(1) == Max. +func (u Uint128) SubWrap64(v uint64) Uint128 { + lo, borrow := bits.Sub64(u.Lo, v, 0) + hi := u.Hi - borrow + return Uint128{lo, hi} +} + +// Mul returns u*v, panicking on overflow. +func (u Uint128) Mul(v Uint128) Uint128 { + hi, lo := bits.Mul64(u.Lo, v.Lo) + p0, p1 := bits.Mul64(u.Hi, v.Lo) + p2, p3 := bits.Mul64(u.Lo, v.Hi) + hi, c0 := bits.Add64(hi, p1, 0) + hi, c1 := bits.Add64(hi, p3, c0) + if (u.Hi != 0 && v.Hi != 0) || p0 != 0 || p2 != 0 || c1 != 0 { + panic("overflow") + } + return Uint128{lo, hi} +} + +// MulWrap returns u*v with wraparound semantics; for example, +// Max.MulWrap(Max) == 1. +func (u Uint128) MulWrap(v Uint128) Uint128 { + hi, lo := bits.Mul64(u.Lo, v.Lo) + hi += u.Hi*v.Lo + u.Lo*v.Hi + return Uint128{lo, hi} +} + +// Mul64 returns u*v, panicking on overflow. +func (u Uint128) Mul64(v uint64) Uint128 { + hi, lo := bits.Mul64(u.Lo, v) + p0, p1 := bits.Mul64(u.Hi, v) + hi, c0 := bits.Add64(hi, p1, 0) + if p0 != 0 || c0 != 0 { + panic("overflow") + } + return Uint128{lo, hi} +} + +// MulWrap64 returns u*v with wraparound semantics; for example, +// Max.MulWrap64(2) == Max.Sub64(1). +func (u Uint128) MulWrap64(v uint64) Uint128 { + hi, lo := bits.Mul64(u.Lo, v) + hi += u.Hi * v + return Uint128{lo, hi} +} + +// Div returns u/v. +func (u Uint128) Div(v Uint128) Uint128 { + q, _ := u.QuoRem(v) + return q +} + +// Div64 returns u/v. +func (u Uint128) Div64(v uint64) Uint128 { + q, _ := u.QuoRem64(v) + return q +} + +// QuoRem returns q = u/v and r = u%v. +func (u Uint128) QuoRem(v Uint128) (q, r Uint128) { + if v.Hi == 0 { + var r64 uint64 + q, r64 = u.QuoRem64(v.Lo) + r = From64(r64) + } else { + // generate a "trial quotient," guaranteed to be within 1 of the actual + // quotient, then adjust. + n := uint(bits.LeadingZeros64(v.Hi)) + v1 := v.Lsh(n) + u1 := u.Rsh(1) + tq, _ := bits.Div64(u1.Hi, u1.Lo, v1.Hi) + tq >>= 63 - n + if tq != 0 { + tq-- + } + q = From64(tq) + // calculate remainder using trial quotient, then adjust if remainder is + // greater than divisor + r = u.Sub(v.Mul64(tq)) + if r.Cmp(v) >= 0 { + q = q.Add64(1) + r = r.Sub(v) + } + } + return +} + +// QuoRem64 returns q = u/v and r = u%v. +func (u Uint128) QuoRem64(v uint64) (q Uint128, r uint64) { + if u.Hi < v { + q.Lo, r = bits.Div64(u.Hi, u.Lo, v) + } else { + q.Hi, r = bits.Div64(0, u.Hi, v) + q.Lo, r = bits.Div64(r, u.Lo, v) + } + return +} + +// Mod returns r = u%v. +func (u Uint128) Mod(v Uint128) (r Uint128) { + _, r = u.QuoRem(v) + return +} + +// Mod64 returns r = u%v. +func (u Uint128) Mod64(v uint64) (r uint64) { + _, r = u.QuoRem64(v) + return +} + +// Lsh returns u<<n. +func (u Uint128) Lsh(n uint) (s Uint128) { + if n > 64 { + s.Lo = 0 + s.Hi = u.Lo << (n - 64) + } else { + s.Lo = u.Lo << n + s.Hi = u.Hi<<n | u.Lo>>(64-n) + } + return +} + +// Rsh returns u>>n. +func (u Uint128) Rsh(n uint) (s Uint128) { + if n > 64 { + s.Lo = u.Hi >> (n - 64) + s.Hi = 0 + } else { + s.Lo = u.Lo>>n | u.Hi<<(64-n) + s.Hi = u.Hi >> n + } + return +} + +// LeadingZeros returns the number of leading zero bits in u; the result is 128 +// for u == 0. +func (u Uint128) LeadingZeros() int { + if u.Hi > 0 { + return bits.LeadingZeros64(u.Hi) + } + return 64 + bits.LeadingZeros64(u.Lo) +} + +// TrailingZeros returns the number of trailing zero bits in u; the result is +// 128 for u == 0. +func (u Uint128) TrailingZeros() int { + if u.Lo > 0 { + return bits.TrailingZeros64(u.Lo) + } + return 64 + bits.TrailingZeros64(u.Hi) +} + +// OnesCount returns the number of one bits ("population count") in u. +func (u Uint128) OnesCount() int { + return bits.OnesCount64(u.Hi) + bits.OnesCount64(u.Lo) +} + +// RotateLeft returns the value of u rotated left by (k mod 128) bits. +func (u Uint128) RotateLeft(k int) Uint128 { + const n = 128 + s := uint(k) & (n - 1) + return u.Lsh(s).Or(u.Rsh(n - s)) +} + +// RotateRight returns the value of u rotated left by (k mod 128) bits. +func (u Uint128) RotateRight(k int) Uint128 { + return u.RotateLeft(-k) +} + +// Reverse returns the value of u with its bits in reversed order. +func (u Uint128) Reverse() Uint128 { + return Uint128{bits.Reverse64(u.Hi), bits.Reverse64(u.Lo)} +} + +// ReverseBytes returns the value of u with its bytes in reversed order. +func (u Uint128) ReverseBytes() Uint128 { + return Uint128{bits.ReverseBytes64(u.Hi), bits.ReverseBytes64(u.Lo)} +} + +// Len returns the minimum number of bits required to represent u; the result is +// 0 for u == 0. +func (u Uint128) Len() int { + return 128 - u.LeadingZeros() +} + +// String returns the base-10 representation of u as a string. +func (u Uint128) String() string { + if u.IsZero() { + return "0" + } + buf := []byte("0000000000000000000000000000000000000000") // log10(2^128) < 40 + for i := len(buf); ; i -= 19 { + q, r := u.QuoRem64(1e19) // largest power of 10 that fits in a uint64 + var n int + for ; r != 0; r /= 10 { + n++ + buf[i-n] += byte(r % 10) + } + if q.IsZero() { + return string(buf[i-n:]) + } + u = q + } +} + +// PutBytes stores u in b in little-endian order. It panics if len(b) < 16. +func (u Uint128) PutBytes(b []byte) { + binary.LittleEndian.PutUint64(b[:8], u.Lo) + binary.LittleEndian.PutUint64(b[8:], u.Hi) +} + +// Big returns u as a *big.Int. +func (u Uint128) Big() *big.Int { + i := new(big.Int).SetUint64(u.Hi) + i = i.Lsh(i, 64) + i = i.Xor(i, new(big.Int).SetUint64(u.Lo)) + return i +} + +// New returns the Uint128 value (lo,hi). +func New(lo, hi uint64) Uint128 { + return Uint128{lo, hi} +} + +// From64 converts v to a Uint128 value. +func From64(v uint64) Uint128 { + return New(v, 0) +} + +// FromBytes converts b to a Uint128 value. +func FromBytes(b []byte) Uint128 { + return New( + binary.LittleEndian.Uint64(b[:8]), + binary.LittleEndian.Uint64(b[8:]), + ) +} + +// FromBig converts i to a Uint128 value. It panics if i is negative or +// overflows 128 bits. +func FromBig(i *big.Int) (u Uint128) { + if i.Sign() < 0 { + panic("value cannot be negative") + } else if i.BitLen() > 128 { + panic("value overflows Uint128") + } + u.Lo = i.Uint64() + u.Hi = new(big.Int).Rsh(i, 64).Uint64() + return u +} |