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v/vlib/math/unsigned/uint256.v
2022-01-17 11:35:02 +02:00

377 lines
8.1 KiB
V

module unsigned
import math.bits
pub const (
uint256_zero = Uint256{Uint128{}, Uint128{}}
uint256_max = Uint256{uint128_max, uint128_max}
)
// Uint256 is an unsigned 256-bit number
pub struct Uint256 {
pub mut:
lo Uint128 = uint128_zero // lower 128 bit half
hi Uint128 = uint128_zero // upper 128 bit half
}
pub fn uint256_from_128(v Uint128) Uint256 {
return Uint256{v, uint128_zero}
}
pub fn uint256_from_64(v u64) Uint256 {
return uint256_from_128(uint128_from_64(v))
}
pub fn (u Uint256) is_zero() bool {
return u.lo.is_zero() && u.hi.is_zero()
}
pub fn (u Uint256) equals(v Uint256) bool {
return u.lo.equals(v.lo) && u.hi.equals(v.hi)
}
pub fn (u Uint256) euqals_128(v Uint128) bool {
return u.lo.equals(v) && u.hi.is_zero()
}
pub fn (u Uint256) cmp(v Uint256) int {
h := u.hi.cmp(v.hi)
if h != 0 {
return h
}
return u.lo.cmp(v.lo)
}
pub fn (u Uint256) cmp_128(v Uint128) int {
if !u.hi.is_zero() {
return 1
}
return u.lo.cmp(v)
}
pub fn (u Uint256) not() Uint256 {
return Uint256{u.lo.not(), u.hi.not()}
}
pub fn (u Uint256) and(v Uint256) Uint256 {
return Uint256{u.lo.and(v.lo), u.hi.and(v.hi)}
}
pub fn (u Uint256) and_128(v Uint128) Uint256 {
return Uint256{u.lo.and(v), uint128_zero}
}
pub fn (u Uint256) or_(v Uint256) Uint256 {
return Uint256{u.lo.or_(v.lo), u.hi.or_(v.hi)}
}
pub fn (u Uint256) or_128(v Uint128) Uint256 {
return Uint256{u.lo.or_(v), u.hi}
}
pub fn (u Uint256) xor(v Uint256) Uint256 {
return Uint256{u.lo.xor(v.lo), u.hi.xor(v.hi)}
}
pub fn (u Uint256) xor_128(v Uint128) Uint256 {
return Uint256{u.lo.xor(v), u.hi}
}
pub fn add_256(x Uint256, y Uint256, carry u64) (Uint256, u64) {
mut sum := Uint256{}
mut carry_out := u64(0)
sum.lo, carry_out = add_128(x.lo, y.lo, carry)
sum.hi, carry_out = add_128(x.hi, y.hi, carry_out)
return sum, carry_out
}
pub fn sub_256(x Uint256, y Uint256, borrow u64) (Uint256, u64) {
mut diff := Uint256{}
mut borrow_out := u64(0)
diff.lo, borrow_out = sub_128(x.lo, y.lo, borrow)
diff.hi, borrow_out = sub_128(x.hi, y.hi, borrow_out)
return diff, borrow_out
}
pub fn mul_256(x Uint256, y Uint256) (Uint256, Uint256) {
mut hi := Uint256{}
mut lo := Uint256{}
lo.hi, lo.lo = mul_128(x.lo, y.lo)
hi.hi, hi.lo = mul_128(x.hi, y.hi)
t0, t1 := mul_128(x.lo, y.hi)
t2, t3 := mul_128(x.hi, y.lo)
mut c0 := u64(0)
mut c1 := u64(0)
lo.hi, c0 = add_128(lo.hi, t1, 0)
lo.hi, c1 = add_128(lo.hi, t3, 0)
hi.lo, c0 = add_128(hi.lo, t0, c0)
hi.lo, c1 = add_128(hi.lo, t2, c1)
hi.hi = hi.hi.add_64(c0 + c1)
return hi, lo
}
pub fn (u Uint256) add(v Uint256) Uint256 {
sum, _ := add_256(u, v, 0)
return sum
}
pub fn (u Uint256) overflowing_add(v Uint256) (Uint256, u64) {
sum, overflow := add_256(u, v, 0)
return sum, overflow
}
pub fn (u Uint256) add_128(v Uint128) Uint256 {
lo, c0 := add_128(u.lo, v, 0)
return Uint256{lo, u.hi.add_64(c0)}
}
pub fn (u Uint256) sub(v Uint256) Uint256 {
diff, _ := sub_256(u, v, 0)
return diff
}
pub fn (u Uint256) sub_128(v Uint128) Uint256 {
lo, b0 := sub_128(u.lo, v, 0)
return Uint256{lo, u.hi.sub_64(b0)}
}
pub fn (u Uint256) mul(v Uint256) Uint256 {
mut hi, mut lo := mul_128(u.lo, v.lo)
hi = hi.add(u.hi.mul(v.lo))
hi = hi.add(u.lo.mul(v.hi))
return Uint256{lo, hi}
}
pub fn (u Uint256) mul_128(v Uint128) Uint256 {
hi, lo := mul_128(u.lo, v)
return Uint256{lo, hi.add(u.hi.mul(v))}
}
pub fn (u Uint256) quo_rem(v Uint256) (Uint256, Uint256) {
if v.hi.is_zero() {
q, r := u.quo_rem_128(v.lo)
return q, uint256_from_128(r)
}
n := u64(v.hi.leading_zeros())
u1, v1 := u.rsh(1), v.lsh(u32(n))
mut tq, _ := div_128(u1.hi, u1.lo, v1.hi)
tq = tq.rsh(u32(127 - n))
if !tq.is_zero() {
tq = tq.sub_64(1)
}
mut q, mut r := uint256_from_128(tq), u.sub(v.mul_128(tq))
if r.cmp(v) >= 0 {
q = q.add_128(Uint128{1, 0})
r = r.sub(v)
}
return q, r
}
pub fn (u Uint256) quo_rem_128(v Uint128) (Uint256, Uint128) {
if u.hi.cmp(v) < 0 {
lo, r := div_128(u.hi, u.lo, v)
return Uint256{lo, uint128_zero}, r
}
hi, r := div_128(uint128_zero, u.hi, v)
lo, r2 := div_128(r, u.lo, v)
return Uint256{lo, hi}, r2
}
pub fn (u Uint256) quo_rem_64(v u64) (Uint256, u64) {
mut q := Uint256{}
mut r := u64(0)
q.lo.hi, r = bits.div_64(r, u.lo.hi, v)
q.lo.lo, r = bits.div_64(r, u.lo.lo, v)
return q, r
}
pub fn (u Uint256) rsh(n_ u32) Uint256 {
mut n := n_
if n > 128 {
return Uint256{u.hi.rsh(n - 128), uint128_zero}
}
if n > 64 {
n -= 64
return Uint256{Uint128{u.lo.hi >> n | u.hi.lo << (64 - n), u.hi.lo >> n | u.hi.hi << (64 - n)}, Uint128{u.hi.hi >> n, 0}}
}
return Uint256{Uint128{u.lo.lo >> n | u.lo.hi << (64 - n), u.lo.hi >> n | u.hi.lo << (64 - n)}, Uint128{u.hi.lo >> n | u.hi.hi << (64 - n), u.hi.hi >> n}}
}
pub fn (u Uint256) lsh(n_ u32) Uint256 {
mut n := n_
if n > 128 {
return Uint256{u.lo.lsh(n - 128), uint128_zero}
}
if n > 64 {
n -= 64
return Uint256{Uint128{u.lo.lo << n, 0}, Uint128{u.lo.hi << n | u.lo.lo >> (64 - n), u.hi.lo << n | u.lo.hi >> (64 - n)}}
}
return Uint256{Uint128{u.lo.lo << n, u.lo.hi << n | u.lo.lo >> (64 - n)}, Uint128{u.hi.lo << n | u.lo.hi >> (64 - n), u.hi.hi << n | u.hi.lo >> (64 - n)}}
}
pub fn (u Uint256) div(v Uint256) Uint256 {
q, _ := u.quo_rem(v)
return q
}
pub fn (u Uint256) div_128(v Uint128) Uint256 {
q, _ := u.quo_rem_128(v)
return q
}
pub fn (u Uint256) div_64(v u64) Uint256 {
q, _ := u.quo_rem_64(v)
return q
}
pub fn (u Uint256) mod(v Uint256) Uint256 {
_, r := u.quo_rem(v)
return r
}
pub fn (u Uint256) mod_128(v Uint128) Uint128 {
_, r := u.quo_rem_128(v)
return r
}
pub fn (u Uint256) mod_64(v u64) u64 {
_, r := u.quo_rem_64(v)
return r
}
pub fn (u Uint256) rotate_left(k int) Uint256 {
mut n := u32(k) & 255
if n < 64 {
if n == 0 {
return u
}
return Uint256{Uint128{u.lo.lo << n | u.hi.hi >> (64 - n), u.lo.hi << n | u.lo.lo >> (64 - n)}, Uint128{u.hi.lo << n | u.lo.hi >> (64 - n), u.hi.hi << n | u.hi.lo >> (64 - n)}}
}
n -= 64
if n < 64 {
if n == 0 {
return Uint256{Uint128{u.hi.hi, u.lo.lo}, Uint128{u.lo.hi, u.hi.lo}}
}
return Uint256{Uint128{u.hi.hi << n | u.hi.lo >> (64 - n), u.lo.lo << n | u.hi.hi >> (64 - n)}, Uint128{u.lo.hi << n | u.lo.lo >> (64 - n), u.hi.lo << n | u.lo.hi >> (64 - n)}}
}
n -= 64
if n < 64 {
if n == 0 {
return Uint256{u.hi, u.lo}
}
return Uint256{Uint128{u.hi.lo << n | u.lo.hi >> (64 - n), u.hi.hi << n | u.hi.lo >> (64 - n)}, Uint128{}}
}
n -= 64
if n == 0 {
return Uint256{Uint128{u.lo.hi, u.hi.lo}, Uint128{u.hi.hi, u.lo.lo}}
}
return Uint256{Uint128{u.lo.hi << n | u.lo.lo >> (64 - n), u.hi.lo << n | u.lo.hi >> (64 - n)}, Uint128{u.hi.hi << n | u.hi.lo >> (64 - n), u.lo.lo << n | u.hi.hi >> (64 - n)}}
}
pub fn (u Uint256) rotate_right(k int) Uint256 {
return u.rotate_left(-k)
}
pub fn (u Uint256) len() int {
if !u.hi.is_zero() {
return 128 + u.hi.len()
}
return u.lo.len()
}
pub fn (u Uint256) leading_zeros() int {
if !u.hi.is_zero() {
return u.hi.leading_zeros()
}
return 128 + u.lo.leading_zeros()
}
pub fn (u Uint256) trailing_zeros() int {
if !u.lo.is_zero() {
return u.lo.trailing_zeros()
}
return 128 + u.hi.trailing_zeros()
}
pub fn (u Uint256) ones_count() int {
return u.lo.ones_count() + u.hi.ones_count()
}
pub fn (u_ Uint256) str() string {
mut u := u_
if u.hi.is_zero() {
if u.lo.is_zero() {
return '0'
}
return u.lo.str()
}
mut buf := '000000000000000000000000000000000000000000000000000000000000000000000000000000'.bytes()
for i := buf.len; true; i -= 19 {
q, mut r := u.quo_rem_64(u64(1e19))
mut n := 0
for ; r != 0; r /= 10 {
n++
buf[i - n] += byte(r % 10)
}
if q.is_zero() {
return buf[i - n..].bytestr()
}
u = q
}
return ''
}
pub fn uint256_from_dec_str(value string) ?Uint256 {
mut res := unsigned.uint256_zero
for b_ in value.bytes() {
b := b_ - '0'.bytes()[0]
if b > 9 {
return error('invalid character "$b"')
}
r := res.mul_128(uint128_from_64(10))
r2 := r.add_128(uint128_from_64(u64(b)))
res = r2
}
return res
}
pub fn (u Uint256) / (v Uint256) Uint256 {
return u.div(v)
}
pub fn (u Uint256) % (v Uint256) Uint256 {
return u.mod(v)
}
pub fn (u Uint256) + (v Uint256) Uint256 {
return u.add(v)
}
pub fn (u Uint256) - (v Uint256) Uint256 {
return u.sub(v)
}
pub fn (u Uint256) * (v Uint256) Uint256 {
return u.mul(v)
}