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// Copyright 2016 Dtoa Developers
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
#[macro_export]
macro_rules! dtoa {(
floating_type: $fty:ty,
significand_type: $sigty:ty,
exponent_type: $expty:ty,
$($diyfp_param:ident: $diyfp_value:tt,)*
) => {
diyfp! {
floating_type: $fty,
significand_type: $sigty,
exponent_type: $expty,
$($diyfp_param: $diyfp_value,)*
};
/*
inline void GrisuRound(char* buffer, int len, uint64_t delta, uint64_t rest, uint64_t ten_kappa, uint64_t wp_w) {
while (rest < wp_w && delta - rest >= ten_kappa &&
(rest + ten_kappa < wp_w || /// closer
wp_w - rest > rest + ten_kappa - wp_w)) {
buffer[len - 1]--;
rest += ten_kappa;
}
}
*/
#[inline]
unsafe fn grisu_round(buffer: *mut u8, len: isize, delta: $sigty, mut rest: $sigty, ten_kappa: $sigty, wp_w: $sigty) {
while rest < wp_w && delta - rest >= ten_kappa &&
(rest + ten_kappa < wp_w || // closer
wp_w - rest > rest + ten_kappa - wp_w) {
*buffer.offset(len - 1) -= 1;
rest += ten_kappa;
}
}
/*
inline unsigned CountDecimalDigit32(uint32_t n) {
// Simple pure C++ implementation was faster than __builtin_clz version in this situation.
if (n < 10) return 1;
if (n < 100) return 2;
if (n < 1000) return 3;
if (n < 10000) return 4;
if (n < 100000) return 5;
if (n < 1000000) return 6;
if (n < 10000000) return 7;
if (n < 100000000) return 8;
// Will not reach 10 digits in DigitGen()
//if (n < 1000000000) return 9;
//return 10;
return 9;
}
*/
#[inline]
fn count_decimal_digit32(n: u32) -> usize {
if n < 10 { 1 }
else if n < 100 { 2 }
else if n < 1000 { 3 }
else if n < 10000 { 4 }
else if n < 100000 { 5 }
else if n < 1000000 { 6 }
else if n < 10000000 { 7 }
else if n < 100000000 { 8 }
// Will not reach 10 digits in digit_gen()
else { 9 }
}
/*
inline void DigitGen(const DiyFp& W, const DiyFp& Mp, uint64_t delta, char* buffer, int* len, int* K) {
static const uint32_t kPow10[] = { 1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000 };
const DiyFp one(uint64_t(1) << -Mp.e, Mp.e);
const DiyFp wp_w = Mp - W;
uint32_t p1 = static_cast<uint32_t>(Mp.f >> -one.e);
uint64_t p2 = Mp.f & (one.f - 1);
unsigned kappa = CountDecimalDigit32(p1); // kappa in [0, 9]
*len = 0;
*/
// Returns length and k.
#[inline]
unsafe fn digit_gen(w: DiyFp, mp: DiyFp, mut delta: $sigty, buffer: *mut u8, mut k: isize) -> (isize, isize) {
static POW10: [$sigty; 10] = [ 1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000 ];
let one = DiyFp::new(1 << -mp.e, mp.e);
let wp_w = mp - w;
let mut p1 = (mp.f >> -one.e) as u32;
let mut p2 = mp.f & (one.f - 1);
let mut kappa = count_decimal_digit32(p1); // kappa in [0, 9]
let mut len = 0;
/*
while (kappa > 0) {
uint32_t d = 0;
switch (kappa) {
case 9: d = p1 / 100000000; p1 %= 100000000; break;
case 8: d = p1 / 10000000; p1 %= 10000000; break;
case 7: d = p1 / 1000000; p1 %= 1000000; break;
case 6: d = p1 / 100000; p1 %= 100000; break;
case 5: d = p1 / 10000; p1 %= 10000; break;
case 4: d = p1 / 1000; p1 %= 1000; break;
case 3: d = p1 / 100; p1 %= 100; break;
case 2: d = p1 / 10; p1 %= 10; break;
case 1: d = p1; p1 = 0; break;
default:;
}
if (d || *len)
buffer[(*len)++] = static_cast<char>('0' + static_cast<char>(d));
kappa--;
uint64_t tmp = (static_cast<uint64_t>(p1) << -one.e) + p2;
if (tmp <= delta) {
*K += kappa;
GrisuRound(buffer, *len, delta, tmp, static_cast<uint64_t>(kPow10[kappa]) << -one.e, wp_w.f);
return;
}
}
*/
while kappa > 0 {
let mut d = 0u32;
match kappa {
9 => { d = p1 / 100000000; p1 %= 100000000; }
8 => { d = p1 / 10000000; p1 %= 10000000; }
7 => { d = p1 / 1000000; p1 %= 1000000; }
6 => { d = p1 / 100000; p1 %= 100000; }
5 => { d = p1 / 10000; p1 %= 10000; }
4 => { d = p1 / 1000; p1 %= 1000; }
3 => { d = p1 / 100; p1 %= 100; }
2 => { d = p1 / 10; p1 %= 10; }
1 => { d = p1; p1 = 0; }
_ => {}
}
if d != 0 || len != 0 {
*buffer.offset(len) = b'0' + d as u8;
len += 1;
}
kappa -= 1;
let tmp = (p1 as $sigty << -one.e) + p2;
if tmp <= delta {
k += kappa as isize;
grisu_round(buffer, len, delta, tmp, POW10[kappa] << -one.e, wp_w.f);
return (len, k);
}
}
// kappa = 0
/*
for (;;) {
p2 *= 10;
delta *= 10;
char d = static_cast<char>(p2 >> -one.e);
if (d || *len)
buffer[(*len)++] = static_cast<char>('0' + d);
p2 &= one.f - 1;
kappa--;
if (p2 < delta) {
*K += kappa;
int index = -static_cast<int>(kappa);
GrisuRound(buffer, *len, delta, p2, one.f, wp_w.f * (index < 9 ? kPow10[-static_cast<int>(kappa)] : 0));
return;
}
}
*/
loop {
p2 *= 10;
delta *= 10;
let d = (p2 >> -one.e) as u8;
if d != 0 || len != 0 {
*buffer.offset(len) = b'0' + d;
len += 1;
}
p2 &= one.f - 1;
kappa = kappa.wrapping_sub(1);
if p2 < delta {
k += kappa as isize;
let index = -(kappa as isize);
grisu_round(buffer, len, delta, p2, one.f, wp_w.f * if index < 9 { POW10[-(kappa as isize) as usize] } else { 0 });
return (len, k);
}
}
}
/*
inline void Grisu2(double value, char* buffer, int* length, int* K) {
const DiyFp v(value);
DiyFp w_m, w_p;
v.NormalizedBoundaries(&w_m, &w_p);
const DiyFp c_mk = GetCachedPower(w_p.e, K);
const DiyFp W = v.Normalize() * c_mk;
DiyFp Wp = w_p * c_mk;
DiyFp Wm = w_m * c_mk;
Wm.f++;
Wp.f--;
DigitGen(W, Wp, Wp.f - Wm.f, buffer, length, K);
}
*/
// Returns length and k.
#[inline]
unsafe fn grisu2(value: $fty, buffer: *mut u8) -> (isize, isize) {
let v = DiyFp::from(value);
let (w_m, w_p) = v.normalized_boundaries();
let (c_mk, k) = get_cached_power(w_p.e);
let w = v.normalize() * c_mk;
let mut wp = w_p * c_mk;
let mut wm = w_m * c_mk;
wm.f += 1;
wp.f -= 1;
digit_gen(w, wp, wp.f - wm.f, buffer, k)
}
/*
inline char* WriteExponent(int K, char* buffer) {
if (K < 0) {
*buffer++ = '-';
K = -K;
}
if (K >= 100) {
*buffer++ = static_cast<char>('0' + static_cast<char>(K / 100));
K %= 100;
const char* d = GetDigitsLut() + K * 2;
*buffer++ = d[0];
*buffer++ = d[1];
}
else if (K >= 10) {
const char* d = GetDigitsLut() + K * 2;
*buffer++ = d[0];
*buffer++ = d[1];
}
else
*buffer++ = static_cast<char>('0' + static_cast<char>(K));
return buffer;
}
*/
#[inline]
unsafe fn write_exponent(mut k: isize, mut buffer: *mut u8) -> *mut u8 {
if k < 0 {
*buffer = b'-';
buffer = buffer.offset(1);
k = -k;
}
if k >= 100 {
*buffer = b'0' + (k / 100) as u8;
k %= 100;
let d = DEC_DIGITS_LUT.as_ptr().offset(k * 2);
ptr::copy_nonoverlapping(d, buffer.offset(1), 2);
buffer.offset(3)
} else if k >= 10 {
let d = DEC_DIGITS_LUT.as_ptr().offset(k * 2);
ptr::copy_nonoverlapping(d, buffer, 2);
buffer.offset(2)
} else {
*buffer = b'0' + k as u8;
buffer.offset(1)
}
}
/*
inline char* Prettify(char* buffer, int length, int k, int maxDecimalPlaces) {
const int kk = length + k; // 10^(kk-1) <= v < 10^kk
*/
#[inline]
unsafe fn prettify(buffer: *mut u8, length: isize, k: isize) -> *mut u8 {
let kk = length + k; // 10^(kk-1) <= v < 10^kk
/*
if (0 <= k && kk <= 21) {
// 1234e7 -> 12340000000
for (int i = length; i < kk; i++)
buffer[i] = '0';
buffer[kk] = '.';
buffer[kk + 1] = '0';
return &buffer[kk + 2];
}
*/
if 0 <= k && kk <= 21 {
// 1234e7 -> 12340000000
for i in length..kk {
*buffer.offset(i) = b'0';
}
*buffer.offset(kk) = b'.';
*buffer.offset(kk + 1) = b'0';
buffer.offset(kk + 2)
}
/*
else if (0 < kk && kk <= 21) {
// 1234e-2 -> 12.34
std::memmove(&buffer[kk + 1], &buffer[kk], static_cast<size_t>(length - kk));
buffer[kk] = '.';
if (0 > k + maxDecimalPlaces) {
// When maxDecimalPlaces = 2, 1.2345 -> 1.23, 1.102 -> 1.1
// Remove extra trailing zeros (at least one) after truncation.
for (int i = kk + maxDecimalPlaces; i > kk + 1; i--)
if (buffer[i] != '0')
return &buffer[i + 1];
return &buffer[kk + 2]; // Reserve one zero
}
else
return &buffer[length + 1];
}
*/
else if 0 < kk && kk <= 21 {
// 1234e-2 -> 12.34
ptr::copy(buffer.offset(kk), buffer.offset(kk + 1), (length - kk) as usize);
*buffer.offset(kk) = b'.';
if 0 > k + MAX_DECIMAL_PLACES {
// When MAX_DECIMAL_PLACES = 2, 1.2345 -> 1.23, 1.102 -> 1.1
// Remove extra trailing zeros (at least one) after truncation.
for i in (kk + 2 .. kk + MAX_DECIMAL_PLACES + 1).rev() {
if *buffer.offset(i) != b'0' {
return buffer.offset(i + 1);
}
}
buffer.offset(kk + 2) // Reserve one zero
} else {
buffer.offset(length + 1)
}
}
/*
else if (-6 < kk && kk <= 0) {
// 1234e-6 -> 0.001234
const int offset = 2 - kk;
std::memmove(&buffer[offset], &buffer[0], static_cast<size_t>(length));
buffer[0] = '0';
buffer[1] = '.';
for (int i = 2; i < offset; i++)
buffer[i] = '0';
if (length - kk > maxDecimalPlaces) {
// When maxDecimalPlaces = 2, 0.123 -> 0.12, 0.102 -> 0.1
// Remove extra trailing zeros (at least one) after truncation.
for (int i = maxDecimalPlaces + 1; i > 2; i--)
if (buffer[i] != '0')
return &buffer[i + 1];
return &buffer[3]; // Reserve one zero
}
else
return &buffer[length + offset];
}
*/
else if -6 < kk && kk <= 0 {
// 1234e-6 -> 0.001234
let offset = 2 - kk;
ptr::copy(buffer, buffer.offset(offset), length as usize);
*buffer = b'0';
*buffer.offset(1) = b'.';
for i in 2..offset {
*buffer.offset(i) = b'0';
}
if length - kk > MAX_DECIMAL_PLACES {
// When MAX_DECIMAL_PLACES = 2, 0.123 -> 0.12, 0.102 -> 0.1
// Remove extra trailing zeros (at least one) after truncation.
for i in (3 .. MAX_DECIMAL_PLACES + 2).rev() {
if *buffer.offset(i) != b'0' {
return buffer.offset(i + 1);
}
}
buffer.offset(3) // Reserve one zero
} else {
buffer.offset(length + offset)
}
}
/*
else if (kk < -maxDecimalPlaces) {
// Truncate to zero
buffer[0] = '0';
buffer[1] = '.';
buffer[2] = '0';
return &buffer[3];
}
*/
else if kk < -MAX_DECIMAL_PLACES {
*buffer = b'0';
*buffer.offset(1) = b'.';
*buffer.offset(2) = b'0';
buffer.offset(3)
}
/*
else if (length == 1) {
// 1e30
buffer[1] = 'e';
return WriteExponent(kk - 1, &buffer[2]);
}
*/
else if length == 1 {
// 1e30
*buffer.offset(1) = b'e';
write_exponent(kk - 1, buffer.offset(2))
}
/*
else {
// 1234e30 -> 1.234e33
std::memmove(&buffer[2], &buffer[1], static_cast<size_t>(length - 1));
buffer[1] = '.';
buffer[length + 1] = 'e';
return WriteExponent(kk - 1, &buffer[0 + length + 2]);
}
*/
else {
// 1234e30 -> 1.234e33
ptr::copy(buffer.offset(1), buffer.offset(2), (length - 1) as usize);
*buffer.offset(1) = b'.';
*buffer.offset(length + 1) = b'e';
write_exponent(kk - 1, buffer.offset(length + 2))
}
}
/*
inline char* dtoa(double value, char* buffer, int maxDecimalPlaces = 324) {
RAPIDJSON_ASSERT(maxDecimalPlaces >= 1);
Double d(value);
if (d.IsZero()) {
if (d.Sign())
*buffer++ = '-'; // -0.0, Issue #289
buffer[0] = '0';
buffer[1] = '.';
buffer[2] = '0';
return &buffer[3];
}
else {
if (value < 0) {
*buffer++ = '-';
value = -value;
}
int length, K;
Grisu2(value, buffer, &length, &K);
return Prettify(buffer, length, K, maxDecimalPlaces);
}
}
*/
#[inline]
unsafe fn dtoa<W: io::Write>(mut wr: W, mut value: $fty) -> io::Result<usize> {
if value == 0.0 {
if value.is_sign_negative() {
try!(wr.write_all(b"-0.0"));
Ok(4)
} else {
try!(wr.write_all(b"0.0"));
Ok(3)
}
} else {
let negative = value < 0.0;
if negative {
try!(wr.write_all(b"-"));
value = -value;
}
let mut buffer: [u8; 24] = mem::uninitialized();
let buf_ptr = buffer.as_mut_ptr();
let (length, k) = grisu2(value, buf_ptr);
let end = prettify(buf_ptr, length, k);
let len = end as usize - buf_ptr as usize;
try!(wr.write_all(slice::from_raw_parts(buf_ptr, len)));
if negative {
Ok(len + 1)
} else {
Ok(len)
}
}
}
}}