1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
use crate::fmt;
use crate::mem::MaybeUninit;
use crate::num::fmt as numfmt;
use crate::ops::{Div, Rem, Sub};
use crate::ptr;
use crate::slice;
use crate::str;
#[doc(hidden)]
trait DisplayInt:
PartialEq + PartialOrd + Div<Output = Self> + Rem<Output = Self> + Sub<Output = Self> + Copy
{
fn zero() -> Self;
fn from_u8(u: u8) -> Self;
fn to_u8(&self) -> u8;
fn to_u16(&self) -> u16;
fn to_u32(&self) -> u32;
fn to_u64(&self) -> u64;
fn to_u128(&self) -> u128;
}
macro_rules! impl_int {
($($t:ident)*) => (
$(impl DisplayInt for $t {
fn zero() -> Self { 0 }
fn from_u8(u: u8) -> Self { u as Self }
fn to_u8(&self) -> u8 { *self as u8 }
fn to_u16(&self) -> u16 { *self as u16 }
fn to_u32(&self) -> u32 { *self as u32 }
fn to_u64(&self) -> u64 { *self as u64 }
fn to_u128(&self) -> u128 { *self as u128 }
})*
)
}
macro_rules! impl_uint {
($($t:ident)*) => (
$(impl DisplayInt for $t {
fn zero() -> Self { 0 }
fn from_u8(u: u8) -> Self { u as Self }
fn to_u8(&self) -> u8 { *self as u8 }
fn to_u16(&self) -> u16 { *self as u16 }
fn to_u32(&self) -> u32 { *self as u32 }
fn to_u64(&self) -> u64 { *self as u64 }
fn to_u128(&self) -> u128 { *self as u128 }
})*
)
}
impl_int! { i8 i16 i32 i64 i128 isize }
impl_uint! { u8 u16 u32 u64 u128 usize }
#[doc(hidden)]
trait GenericRadix: Sized {
const BASE: u8;
const PREFIX: &'static str;
fn digit(x: u8) -> u8;
fn fmt_int<T: DisplayInt>(&self, mut x: T, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let zero = T::zero();
let is_nonnegative = x >= zero;
let mut buf = [MaybeUninit::<u8>::uninit(); 128];
let mut curr = buf.len();
let base = T::from_u8(Self::BASE);
if is_nonnegative {
for byte in buf.iter_mut().rev() {
let n = x % base;
x = x / base;
byte.write(Self::digit(n.to_u8()));
curr -= 1;
if x == zero {
break;
};
}
} else {
for byte in buf.iter_mut().rev() {
let n = zero - (x % base);
x = x / base;
byte.write(Self::digit(n.to_u8()));
curr -= 1;
if x == zero {
break;
};
}
}
let buf = &buf[curr..];
let buf = unsafe {
str::from_utf8_unchecked(slice::from_raw_parts(
MaybeUninit::slice_as_ptr(buf),
buf.len(),
))
};
f.pad_integral(is_nonnegative, Self::PREFIX, buf)
}
}
#[derive(Clone, PartialEq)]
struct Binary;
#[derive(Clone, PartialEq)]
struct Octal;
#[derive(Clone, PartialEq)]
struct LowerHex;
#[derive(Clone, PartialEq)]
struct UpperHex;
macro_rules! radix {
($T:ident, $base:expr, $prefix:expr, $($x:pat => $conv:expr),+) => {
impl GenericRadix for $T {
const BASE: u8 = $base;
const PREFIX: &'static str = $prefix;
fn digit(x: u8) -> u8 {
match x {
$($x => $conv,)+
x => panic!("number not in the range 0..={}: {}", Self::BASE - 1, x),
}
}
}
}
}
radix! { Binary, 2, "0b", x @ 0 ..= 1 => b'0' + x }
radix! { Octal, 8, "0o", x @ 0 ..= 7 => b'0' + x }
radix! { LowerHex, 16, "0x", x @ 0 ..= 9 => b'0' + x, x @ 10 ..= 15 => b'a' + (x - 10) }
radix! { UpperHex, 16, "0x", x @ 0 ..= 9 => b'0' + x, x @ 10 ..= 15 => b'A' + (x - 10) }
macro_rules! int_base {
(fmt::$Trait:ident for $T:ident as $U:ident -> $Radix:ident) => {
#[stable(feature = "rust1", since = "1.0.0")]
impl fmt::$Trait for $T {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
$Radix.fmt_int(*self as $U, f)
}
}
};
}
macro_rules! integer {
($Int:ident, $Uint:ident) => {
int_base! { fmt::Binary for $Int as $Uint -> Binary }
int_base! { fmt::Octal for $Int as $Uint -> Octal }
int_base! { fmt::LowerHex for $Int as $Uint -> LowerHex }
int_base! { fmt::UpperHex for $Int as $Uint -> UpperHex }
int_base! { fmt::Binary for $Uint as $Uint -> Binary }
int_base! { fmt::Octal for $Uint as $Uint -> Octal }
int_base! { fmt::LowerHex for $Uint as $Uint -> LowerHex }
int_base! { fmt::UpperHex for $Uint as $Uint -> UpperHex }
};
}
integer! { isize, usize }
integer! { i8, u8 }
integer! { i16, u16 }
integer! { i32, u32 }
integer! { i64, u64 }
integer! { i128, u128 }
macro_rules! debug {
($($T:ident)*) => {$(
#[stable(feature = "rust1", since = "1.0.0")]
impl fmt::Debug for $T {
#[inline]
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
if f.debug_lower_hex() {
fmt::LowerHex::fmt(self, f)
} else if f.debug_upper_hex() {
fmt::UpperHex::fmt(self, f)
} else {
fmt::Display::fmt(self, f)
}
}
}
)*};
}
debug! {
i8 i16 i32 i64 i128 isize
u8 u16 u32 u64 u128 usize
}
static DEC_DIGITS_LUT: &[u8; 200] = b"0001020304050607080910111213141516171819\
2021222324252627282930313233343536373839\
4041424344454647484950515253545556575859\
6061626364656667686970717273747576777879\
8081828384858687888990919293949596979899";
macro_rules! impl_Display {
($($t:ident),* as $u:ident via $conv_fn:ident named $name:ident) => {
fn $name(mut n: $u, is_nonnegative: bool, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let mut buf = [MaybeUninit::<u8>::uninit(); 39];
let mut curr = buf.len() as isize;
let buf_ptr = MaybeUninit::slice_as_mut_ptr(&mut buf);
let lut_ptr = DEC_DIGITS_LUT.as_ptr();
unsafe {
assert!(crate::mem::size_of::<$u>() >= 2);
while n >= 10000 {
let rem = (n % 10000) as isize;
n /= 10000;
let d1 = (rem / 100) << 1;
let d2 = (rem % 100) << 1;
curr -= 4;
ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2);
ptr::copy_nonoverlapping(lut_ptr.offset(d2), buf_ptr.offset(curr + 2), 2);
}
let mut n = n as isize;
if n >= 100 {
let d1 = (n % 100) << 1;
n /= 100;
curr -= 2;
ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2);
}
if n < 10 {
curr -= 1;
*buf_ptr.offset(curr) = (n as u8) + b'0';
} else {
let d1 = n << 1;
curr -= 2;
ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2);
}
}
let buf_slice = unsafe {
str::from_utf8_unchecked(
slice::from_raw_parts(buf_ptr.offset(curr), buf.len() - curr as usize))
};
f.pad_integral(is_nonnegative, "", buf_slice)
}
$(#[stable(feature = "rust1", since = "1.0.0")]
impl fmt::Display for $t {
#[allow(unused_comparisons)]
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let is_nonnegative = *self >= 0;
let n = if is_nonnegative {
self.$conv_fn()
} else {
(!self.$conv_fn()).wrapping_add(1)
};
$name(n, is_nonnegative, f)
}
})*
};
}
macro_rules! impl_Exp {
($($t:ident),* as $u:ident via $conv_fn:ident named $name:ident) => {
fn $name(
mut n: $u,
is_nonnegative: bool,
upper: bool,
f: &mut fmt::Formatter<'_>
) -> fmt::Result {
let (mut n, mut exponent, trailing_zeros, added_precision) = {
let mut exponent = 0;
while n % 10 == 0 && n >= 10 {
n /= 10;
exponent += 1;
}
let (added_precision, subtracted_precision) = match f.precision() {
Some(fmt_prec) => {
let mut tmp = n;
let mut prec = 0;
while tmp >= 10 {
tmp /= 10;
prec += 1;
}
(fmt_prec.saturating_sub(prec), prec.saturating_sub(fmt_prec))
}
None => (0, 0)
};
for _ in 1..subtracted_precision {
n /= 10;
exponent += 1;
}
if subtracted_precision != 0 {
let rem = n % 10;
n /= 10;
exponent += 1;
if rem >= 5 {
n += 1;
}
}
(n, exponent, exponent, added_precision)
};
let mut buf = [MaybeUninit::<u8>::uninit(); 40];
let mut curr = buf.len() as isize;
let buf_ptr = MaybeUninit::slice_as_mut_ptr(&mut buf);
let lut_ptr = DEC_DIGITS_LUT.as_ptr();
while n >= 100 {
let d1 = ((n % 100) as isize) << 1;
curr -= 2;
unsafe {
ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2);
}
n /= 100;
exponent += 2;
}
let mut n = n as isize;
if n >= 10 {
curr -= 1;
unsafe {
*buf_ptr.offset(curr) = (n as u8 % 10_u8) + b'0';
}
n /= 10;
exponent += 1;
}
if exponent != trailing_zeros || added_precision != 0 {
curr -= 1;
unsafe {
*buf_ptr.offset(curr) = b'.';
}
}
let buf_slice = unsafe {
curr -= 1;
*buf_ptr.offset(curr) = (n as u8) + b'0';
let len = buf.len() - curr as usize;
slice::from_raw_parts(buf_ptr.offset(curr), len)
};
let mut exp_buf = [MaybeUninit::<u8>::uninit(); 3];
let exp_ptr = MaybeUninit::slice_as_mut_ptr(&mut exp_buf);
let exp_slice = unsafe {
*exp_ptr.offset(0) = if upper { b'E' } else { b'e' };
let len = if exponent < 10 {
*exp_ptr.offset(1) = (exponent as u8) + b'0';
2
} else {
let off = exponent << 1;
ptr::copy_nonoverlapping(lut_ptr.offset(off), exp_ptr.offset(1), 2);
3
};
slice::from_raw_parts(exp_ptr, len)
};
let parts = &[
numfmt::Part::Copy(buf_slice),
numfmt::Part::Zero(added_precision),
numfmt::Part::Copy(exp_slice)
];
let sign = if !is_nonnegative {
"-"
} else if f.sign_plus() {
"+"
} else {
""
};
let formatted = numfmt::Formatted{sign, parts};
f.pad_formatted_parts(&formatted)
}
$(
#[stable(feature = "integer_exp_format", since = "1.42.0")]
impl fmt::LowerExp for $t {
#[allow(unused_comparisons)]
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let is_nonnegative = *self >= 0;
let n = if is_nonnegative {
self.$conv_fn()
} else {
(!self.$conv_fn()).wrapping_add(1)
};
$name(n, is_nonnegative, false, f)
}
})*
$(
#[stable(feature = "integer_exp_format", since = "1.42.0")]
impl fmt::UpperExp for $t {
#[allow(unused_comparisons)]
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let is_nonnegative = *self >= 0;
let n = if is_nonnegative {
self.$conv_fn()
} else {
(!self.$conv_fn()).wrapping_add(1)
};
$name(n, is_nonnegative, true, f)
}
})*
};
}
#[cfg(any(target_pointer_width = "64", target_arch = "wasm32"))]
mod imp {
use super::*;
impl_Display!(
i8, u8, i16, u16, i32, u32, i64, u64, usize, isize
as u64 via to_u64 named fmt_u64
);
impl_Exp!(
i8, u8, i16, u16, i32, u32, i64, u64, usize, isize
as u64 via to_u64 named exp_u64
);
}
#[cfg(not(any(target_pointer_width = "64", target_arch = "wasm32")))]
mod imp {
use super::*;
impl_Display!(i8, u8, i16, u16, i32, u32, isize, usize as u32 via to_u32 named fmt_u32);
impl_Display!(i64, u64 as u64 via to_u64 named fmt_u64);
impl_Exp!(i8, u8, i16, u16, i32, u32, isize, usize as u32 via to_u32 named exp_u32);
impl_Exp!(i64, u64 as u64 via to_u64 named exp_u64);
}
impl_Exp!(i128, u128 as u128 via to_u128 named exp_u128);
fn parse_u64_into<const N: usize>(mut n: u64, buf: &mut [MaybeUninit<u8>; N], curr: &mut isize) {
let buf_ptr = MaybeUninit::slice_as_mut_ptr(buf);
let lut_ptr = DEC_DIGITS_LUT.as_ptr();
assert!(*curr > 19);
unsafe {
if n >= 1e16 as u64 {
let to_parse = n % 1e16 as u64;
n /= 1e16 as u64;
let d1 = ((to_parse / 1e14 as u64) % 100) << 1;
let d2 = ((to_parse / 1e12 as u64) % 100) << 1;
let d3 = ((to_parse / 1e10 as u64) % 100) << 1;
let d4 = ((to_parse / 1e8 as u64) % 100) << 1;
let d5 = ((to_parse / 1e6 as u64) % 100) << 1;
let d6 = ((to_parse / 1e4 as u64) % 100) << 1;
let d7 = ((to_parse / 1e2 as u64) % 100) << 1;
let d8 = ((to_parse / 1e0 as u64) % 100) << 1;
*curr -= 16;
ptr::copy_nonoverlapping(lut_ptr.offset(d1 as isize), buf_ptr.offset(*curr + 0), 2);
ptr::copy_nonoverlapping(lut_ptr.offset(d2 as isize), buf_ptr.offset(*curr + 2), 2);
ptr::copy_nonoverlapping(lut_ptr.offset(d3 as isize), buf_ptr.offset(*curr + 4), 2);
ptr::copy_nonoverlapping(lut_ptr.offset(d4 as isize), buf_ptr.offset(*curr + 6), 2);
ptr::copy_nonoverlapping(lut_ptr.offset(d5 as isize), buf_ptr.offset(*curr + 8), 2);
ptr::copy_nonoverlapping(lut_ptr.offset(d6 as isize), buf_ptr.offset(*curr + 10), 2);
ptr::copy_nonoverlapping(lut_ptr.offset(d7 as isize), buf_ptr.offset(*curr + 12), 2);
ptr::copy_nonoverlapping(lut_ptr.offset(d8 as isize), buf_ptr.offset(*curr + 14), 2);
}
if n >= 1e8 as u64 {
let to_parse = n % 1e8 as u64;
n /= 1e8 as u64;
let d1 = ((to_parse / 1e6 as u64) % 100) << 1;
let d2 = ((to_parse / 1e4 as u64) % 100) << 1;
let d3 = ((to_parse / 1e2 as u64) % 100) << 1;
let d4 = ((to_parse / 1e0 as u64) % 100) << 1;
*curr -= 8;
ptr::copy_nonoverlapping(lut_ptr.offset(d1 as isize), buf_ptr.offset(*curr + 0), 2);
ptr::copy_nonoverlapping(lut_ptr.offset(d2 as isize), buf_ptr.offset(*curr + 2), 2);
ptr::copy_nonoverlapping(lut_ptr.offset(d3 as isize), buf_ptr.offset(*curr + 4), 2);
ptr::copy_nonoverlapping(lut_ptr.offset(d4 as isize), buf_ptr.offset(*curr + 6), 2);
}
let mut n = n as u32;
if n >= 1e4 as u32 {
let to_parse = n % 1e4 as u32;
n /= 1e4 as u32;
let d1 = (to_parse / 100) << 1;
let d2 = (to_parse % 100) << 1;
*curr -= 4;
ptr::copy_nonoverlapping(lut_ptr.offset(d1 as isize), buf_ptr.offset(*curr + 0), 2);
ptr::copy_nonoverlapping(lut_ptr.offset(d2 as isize), buf_ptr.offset(*curr + 2), 2);
}
let mut n = n as u16;
if n >= 100 {
let d1 = (n % 100) << 1;
n /= 100;
*curr -= 2;
ptr::copy_nonoverlapping(lut_ptr.offset(d1 as isize), buf_ptr.offset(*curr), 2);
}
if n < 10 {
*curr -= 1;
*buf_ptr.offset(*curr) = (n as u8) + b'0';
} else {
let d1 = n << 1;
*curr -= 2;
ptr::copy_nonoverlapping(lut_ptr.offset(d1 as isize), buf_ptr.offset(*curr), 2);
}
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl fmt::Display for u128 {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt_u128(*self, true, f)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl fmt::Display for i128 {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let is_nonnegative = *self >= 0;
let n = if is_nonnegative {
self.to_u128()
} else {
(!self.to_u128()).wrapping_add(1)
};
fmt_u128(n, is_nonnegative, f)
}
}
fn fmt_u128(n: u128, is_nonnegative: bool, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let mut buf = [MaybeUninit::<u8>::uninit(); 39];
let mut curr = buf.len() as isize;
let (n, rem) = udiv_1e19(n);
parse_u64_into(rem, &mut buf, &mut curr);
if n != 0 {
let target = (buf.len() - 19) as isize;
unsafe {
ptr::write_bytes(
MaybeUninit::slice_as_mut_ptr(&mut buf).offset(target),
b'0',
(curr - target) as usize,
);
}
curr = target;
let (n, rem) = udiv_1e19(n);
parse_u64_into(rem, &mut buf, &mut curr);
if n != 0 {
let target = (buf.len() - 38) as isize;
let buf_ptr = MaybeUninit::slice_as_mut_ptr(&mut buf);
unsafe {
ptr::write_bytes(buf_ptr.offset(target), b'0', (curr - target) as usize);
curr = target - 1;
*buf_ptr.offset(curr) = (n as u8) + b'0';
}
}
}
let buf_slice = unsafe {
str::from_utf8_unchecked(slice::from_raw_parts(
MaybeUninit::slice_as_mut_ptr(&mut buf).offset(curr),
buf.len() - curr as usize,
))
};
f.pad_integral(is_nonnegative, "", buf_slice)
}
fn udiv_1e19(n: u128) -> (u128, u64) {
const DIV: u64 = 1e19 as u64;
const FACTOR: u128 = 156927543384667019095894735580191660403;
let quot = if n < 1 << 83 {
((n >> 19) as u64 / (DIV >> 19)) as u128
} else {
u128_mulhi(n, FACTOR) >> 62
};
let rem = (n - quot * DIV as u128) as u64;
(quot, rem)
}
#[inline]
fn u128_mulhi(x: u128, y: u128) -> u128 {
let x_lo = x as u64;
let x_hi = (x >> 64) as u64;
let y_lo = y as u64;
let y_hi = (y >> 64) as u64;
let carry = (x_lo as u128 * y_lo as u128) >> 64;
let m = x_lo as u128 * y_hi as u128 + carry;
let high1 = m >> 64;
let m_lo = m as u64;
let high2 = (x_hi as u128 * y_lo as u128 + m_lo as u128) >> 64;
x_hi as u128 * y_hi as u128 + high1 + high2
}