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use std::intrinsics::assume;
use ll;
use ll::limb::Limb;
use ll::limb_ptr::{Limbs, LimbsMut};
struct Base {
digits_per_limb: u32,
big_base: Limb,
}
include!(concat!(env!("OUT_DIR"), "/bases_table.rs"));
#[inline(always)]
fn div_unnorm(n: Limb, d: Limb) -> (Limb, Limb) {
(n / d, n % d)
}
#[inline]
pub unsafe fn num_base_digits(p: Limbs, n: i32, base: u32) -> usize {
debug_assert!(base >= 2);
assume(base >= 2);
if n == 0 { return 1; }
let cnt = (*p.offset((n - 1) as isize)).leading_zeros() as usize;
let total_bits = (Limb::BITS * (n as usize)) - cnt;
if base == 2 {
total_bits
} else if base.is_power_of_two() {
let bits_per_digit = BASES.get_unchecked(base as usize).big_base.0 as usize;
if bits_per_digit.is_power_of_two() {
(total_bits + bits_per_digit - 1) >> bits_per_digit.trailing_zeros()
} else {
(total_bits + bits_per_digit - 1) / bits_per_digit
}
} else {
let total_bits = total_bits as f64;
let lg2b = (base as f64).log2();
let digits = total_bits / lg2b;
return digits.ceil() as usize;
}
}
#[inline]
pub fn base_digits_to_len(num: usize, base: u32) -> usize {
debug_assert!(base >= 2);
if num == 0 { return 0; }
let digits_per_limb = BASES[base as usize].digits_per_limb as usize;
(num / digits_per_limb) + 1
}
pub unsafe fn to_base<F: FnMut(u8)>(base: u32, np: Limbs, nn: i32, mut out_byte: F) {
debug_assert!(nn >= 0);
debug_assert!(base < BASES.len() as u32);
debug_assert!(base >= 2);
assume(base < BASES.len() as u32);
assume(base >= 2);
if nn <= 0 {
out_byte(0);
return;
}
if base.is_power_of_two() {
let bits_per_digit = BASES.get_unchecked(base as usize).big_base.0 as usize;
assume(bits_per_digit > 0);
let mut n1 = *np.offset((nn - 1) as isize);
let cnt = n1.leading_zeros() as usize;
let mut bits = Limb::BITS * (nn as usize) - cnt;
let cnt = bits % bits_per_digit;
if cnt != 0 {
bits += bits_per_digit - cnt;
}
let mut bit_pos : isize = (bits - (nn as usize - 1) * Limb::BITS) as isize;
let mut i = nn - 1;
loop {
bit_pos -= bits_per_digit as isize;
while bit_pos >= 0 {
let b = ((n1 >> (bit_pos as usize)) & ((Limb(1) << bits_per_digit) - 1)).0 as u8;
out_byte(b);
bit_pos -= bits_per_digit as isize;
}
i -= 1;
if i < 0 { break; }
let n0 = (n1 << ((-bit_pos) as usize)) & ((Limb(1) << bits_per_digit) - 1);
n1 = *np.offset(i as isize);
bit_pos += Limb::BITS as isize;
let b = (n0 | (n1 >> (bit_pos as usize))).0 as u8;
out_byte(b);
}
return;
}
to_base_impl(0, base, np, nn, out_byte);
}
unsafe fn to_base_impl<F: FnMut(u8)>(mut len: u32, base: u32, np: Limbs, mut nn: i32, mut out_byte: F) {
debug_assert!(base > 2);
let buf_len = num_base_digits(np, nn, base);
let mut buf : Vec<u8> = vec![0; buf_len];
let mut r : Vec<Limb> = vec![Limb(0); (nn + 1) as usize];
let rp = LimbsMut::new(&mut r[0], 0, r.len() as i32);
ll::copy_incr(np, rp.offset(1), nn);
let mut sz = 0;
let s : *mut u8 = &mut buf[0];
let mut s = s.offset(buf_len as isize);
let base = Limb(base as ll::limb::BaseInt);
macro_rules! base_impl (
($base:expr, $s:expr, $rp:expr, $sz:ident, $nn:ident) => (
{
let digits_per_limb = BASES.get_unchecked($base.0 as usize).digits_per_limb;
let big_base = BASES.get_unchecked($base.0 as usize).big_base;
while $nn > 1 {
ll::divrem_1($rp, 1, $rp.offset(1).as_const(), $nn, big_base);
$nn -= if *$rp.offset($nn as isize) == 0 { 1 } else { 0 };
let mut frac = *$rp + 1;
$s = $s.offset(-(digits_per_limb as isize));
let mut i = digits_per_limb;
loop {
let (digit, f) = frac.mul_hilo($base);
frac = f;
*$s = digit.0 as u8;
$s = $s.offset(1);
$sz += 1;
i -= 1;
if i == 0 { break; }
}
$s = $s.offset(-(digits_per_limb as isize));
}
let mut ul = *$rp.offset(1);
while ul != 0 {
let (q, r) = div_unnorm(ul, base);
$s = $s.offset(-1);
*$s = r.0 as u8;
ul = q;
$sz += 1;
}
}
)
);
if base == 10 {
base_impl!(Limb(10), s, rp, sz, nn);
} else {
base_impl!(base, s, rp, sz, nn);
}
let mut l = sz;
while l < len {
out_byte(0);
len -= 1;
}
while l != 0 {
out_byte(*s);
s = s.offset(1);
l -= 1;
}
}
pub unsafe fn from_base(mut out: LimbsMut, bp: *const u8, bs: i32, base: u32) -> usize {
debug_assert!(bs > 0);
debug_assert!(base < BASES.len() as u32);
debug_assert!(base >= 2);
assume(base < BASES.len() as u32);
assume(base >= 2);
if bs <= 0 {
*out = Limb(0);
return 1;
}
if base.is_power_of_two() {
let bits_per_digit = BASES.get_unchecked(base as usize).big_base.0 as usize;
assume(bits_per_digit > 0);
let mut size = 0;
let mut b = bp.offset((bs - 1) as isize);
let mut res_digit = Limb(0);
let mut next_bitpos = 0;
while b >= bp {
let digit = Limb((*b) as ll::limb::BaseInt);
res_digit = res_digit | (digit << next_bitpos);
next_bitpos += bits_per_digit;
if next_bitpos >= Limb::BITS {
next_bitpos -= Limb::BITS;
*out.offset(size as isize) = res_digit;
size += 1;
res_digit = digit >> (bits_per_digit - next_bitpos);
}
b = b.offset(-1);
}
if res_digit > 0 {
*out.offset(size as isize) = res_digit;
size += 1;
}
return size;
}
from_base_small(out, bp, bs, base)
}
unsafe fn from_base_small(mut out: LimbsMut, mut bp: *const u8, bs: i32, base: u32) -> usize {
debug_assert!(base > 2);
assume(base > 2);
let big_base = BASES.get_unchecked(base as usize).big_base;
let digits_per_limb = BASES.get_unchecked(base as usize).digits_per_limb;
let mut i = digits_per_limb;
let mut size : usize = 0;
while i < (bs as u32) {
let mut res_digit = Limb((*bp) as ll::limb::BaseInt);
bp = bp.offset(1);
if base == 10 {
let mut j = digits_per_limb - 1;
while j > 0 {
res_digit = res_digit * 10 + ((*bp) as ll::limb::BaseInt);
bp = bp.offset(1);
j -= 1;
}
} else {
let mut j = digits_per_limb - 1;
while j > 0 {
res_digit = res_digit * (base as ll::limb::BaseInt) + ((*bp) as ll::limb::BaseInt);
bp = bp.offset(1);
j -= 1;
}
}
if size == 0 {
if res_digit != 0 {
*out = res_digit;
size = 1;
}
} else {
let mut carry = ll::mul_1(out, out.as_const(), size as i32, big_base);
carry = carry + ll::add_1(out, out.as_const(), size as i32, res_digit);
if carry != 0 {
*out.offset(size as isize) = carry;
size += 1;
}
}
i += digits_per_limb;
}
let mut big_base = base as ll::limb::BaseInt;
let mut res_digit = Limb((*bp) as ll::limb::BaseInt);
bp = bp.offset(1);
if base == 10 {
let mut j = (bs as u32) - (i - digits_per_limb) - 1;
while j > 0 {
res_digit = res_digit * 10 + ((*bp) as ll::limb::BaseInt);
big_base *= 10;
bp = bp.offset(1);
j -= 1;
}
} else {
let mut j = (bs as u32) - (i - digits_per_limb) - 1;
while j > 0 {
res_digit = res_digit * (base as ll::limb::BaseInt) + ((*bp) as ll::limb::BaseInt);
bp = bp.offset(1);
big_base *= base as ll::limb::BaseInt;
j -= 1;
}
}
if size == 0 {
if res_digit != 0 {
*out = res_digit;
size = 1;
}
} else {
let mut carry = ll::mul_1(out, out.as_const(), size as i32, Limb(big_base));
carry = carry + ll::add_1(out, out.as_const(), size as i32, res_digit);
if carry != 0 {
*out.offset(size as isize) = carry;
size += 1;
}
}
return size;
}