rust/library/core/tests
bors 46ad16b70f Auto merge of #85630 - gilescope:to_digit_speedup3, r=nagisa
to_digit simplification (less jumps)

I just realised we might be able to make use of the fact that changing case in ascii is easy to help simplify to_digit some more.

It looks a bit cleaner and it looks like it's less jumps and there's less instructions in the generated assembly:

https://godbolt.org/z/84Erh5dhz

The benchmarks don't really tell me much. Maybe a slight improvement on the var radix.

Before:
```
test char::methods::bench_to_digit_radix_10                     ... bench:      53,819 ns/iter (+/- 8,314)
test char::methods::bench_to_digit_radix_16                     ... bench:      57,265 ns/iter (+/- 10,730)
test char::methods::bench_to_digit_radix_2                      ... bench:      55,077 ns/iter (+/- 5,431)
test char::methods::bench_to_digit_radix_36                     ... bench:      56,549 ns/iter (+/- 3,248)
test char::methods::bench_to_digit_radix_var                    ... bench:      43,848 ns/iter (+/- 3,189)

test char::methods::bench_to_digit_radix_10                     ... bench:      51,707 ns/iter (+/- 10,946)
test char::methods::bench_to_digit_radix_16                     ... bench:      52,835 ns/iter (+/- 2,689)
test char::methods::bench_to_digit_radix_2                      ... bench:      51,012 ns/iter (+/- 2,746)
test char::methods::bench_to_digit_radix_36                     ... bench:      53,210 ns/iter (+/- 8,645)
test char::methods::bench_to_digit_radix_var                    ... bench:      40,386 ns/iter (+/- 4,711)

test char::methods::bench_to_digit_radix_10                     ... bench:      54,088 ns/iter (+/- 5,677)
test char::methods::bench_to_digit_radix_16                     ... bench:      55,972 ns/iter (+/- 17,229)
test char::methods::bench_to_digit_radix_2                      ... bench:      52,083 ns/iter (+/- 2,425)
test char::methods::bench_to_digit_radix_36                     ... bench:      54,132 ns/iter (+/- 1,548)
test char::methods::bench_to_digit_radix_var                    ... bench:      41,250 ns/iter (+/- 5,299)
```
After:
```
test char::methods::bench_to_digit_radix_10                     ... bench:      48,907 ns/iter (+/- 19,449)
test char::methods::bench_to_digit_radix_16                     ... bench:      52,673 ns/iter (+/- 8,122)
test char::methods::bench_to_digit_radix_2                      ... bench:      48,509 ns/iter (+/- 2,885)
test char::methods::bench_to_digit_radix_36                     ... bench:      50,526 ns/iter (+/- 4,610)
test char::methods::bench_to_digit_radix_var                    ... bench:      38,618 ns/iter (+/- 3,180)

test char::methods::bench_to_digit_radix_10                     ... bench:      54,202 ns/iter (+/- 6,994)
test char::methods::bench_to_digit_radix_16                     ... bench:      56,585 ns/iter (+/- 8,448)
test char::methods::bench_to_digit_radix_2                      ... bench:      50,548 ns/iter (+/- 1,674)
test char::methods::bench_to_digit_radix_36                     ... bench:      52,749 ns/iter (+/- 2,576)
test char::methods::bench_to_digit_radix_var                    ... bench:      40,215 ns/iter (+/- 3,327)

test char::methods::bench_to_digit_radix_10                     ... bench:      50,233 ns/iter (+/- 22,272)
test char::methods::bench_to_digit_radix_16                     ... bench:      50,841 ns/iter (+/- 19,981)
test char::methods::bench_to_digit_radix_2                      ... bench:      50,386 ns/iter (+/- 4,555)
test char::methods::bench_to_digit_radix_36                     ... bench:      52,369 ns/iter (+/- 2,737)
test char::methods::bench_to_digit_radix_var                    ... bench:      40,417 ns/iter (+/- 2,766)
```

I removed the likely as it resulted in a few less instructions. (It's not been in there long - I added it in the last to_digit iteration).
2021-06-10 23:14:11 +00:00
..
fmt Format Struct { .. } on one line even with {:#?}. 2021-04-21 13:50:56 +02:00
hash
iter Update expressions where we can use array's IntoIterator implementation 2021-06-02 16:09:04 +06:00
num Preserve signed zero on roundtrip 2021-03-22 17:02:09 -07:00
ops Expand the docs for ops::ControlFlow a bit 2021-02-06 22:36:05 -08:00
alloc.rs
any.rs Add test for issue 84666. 2021-06-03 16:13:45 +02:00
array.rs Update expressions where we can use array's IntoIterator implementation 2021-06-02 16:09:04 +06:00
ascii.rs Make ui test that are run-pass and do not test the compiler itself library tests 2020-11-30 02:47:32 +01:00
atomic.rs enable atomic_min/max tests in Miri 2021-03-02 19:58:55 +01:00
bool.rs Make ui test that are run-pass and do not test the compiler itself library tests 2020-11-30 02:47:32 +01:00
cell.rs Constantify UnsafeCell::into_inner and related 2020-11-04 11:41:57 +01:00
char.rs Further simplification of to_digit 2021-06-10 20:16:35 +01:00
clone.rs Fix borrow and deref 2021-03-03 11:23:29 +01:00
cmp.rs Make ui test that are run-pass and do not test the compiler itself library tests 2020-11-30 02:47:32 +01:00
const_ptr.rs Revert tests added by PR 81167. 2021-06-04 16:44:28 -04:00
intrinsics.rs move test to intergrated test in library/core 2020-09-24 14:46:57 +00:00
lazy.rs Make OnceCell<T> transparent to dropck 2020-08-18 00:34:54 +02:00
lib.rs Unify feature flags as step_trait 2021-05-26 18:07:10 -04:00
macros.rs Make ui test that are run-pass and do not test the compiler itself library tests 2020-11-30 02:47:32 +01:00
manually_drop.rs
mem.rs Allow use of deprecated std::raw in a test for that feature 2021-04-15 19:16:18 +02:00
nonzero.rs Added impl Rem<NonZeroU{0}> for u{0} which cannot panic 2020-12-17 18:42:19 +02:00
ops.rs Expand the docs for ops::ControlFlow a bit 2021-02-06 22:36:05 -08:00
option.rs Simple library test updates 2021-05-06 11:37:45 -07:00
pattern.rs
pin.rs Make some methods of Pin<&mut T> unstable const 2020-09-18 19:23:50 +02:00
ptr.rs Bump cfgs 2021-04-04 14:57:05 -04:00
result.rs Simple library test updates 2021-05-06 11:37:45 -07:00
slice.rs Implement indexing slices with pairs of ops::Bound<usize> 2021-04-13 09:57:24 -04:00
str_lossy.rs
str.rs
task.rs Move const tests for Poll to library\core 2020-09-04 01:04:34 +02:00
time.rs Fixup tests: Duration::MIN -> ::ZERO 2020-10-27 13:57:51 -07:00
tuple.rs
unicode.rs Make ui test that are run-pass and do not test the compiler itself library tests 2020-11-30 02:47:32 +01:00