rust/library at e3af6dc23915f027b9de0721aae86f794a053627 - rust

History

Guillaume Gomez 4b08b2e400

Rollup merge of #128166 - ChaiTRex:isqrt, r=tgross35

Improved `checked_isqrt` and `isqrt` methods

### Improved tests of `isqrt` and `checked_isqrt` implementations

* Inputs chosen more thoroughly and systematically.
* Checks that `isqrt` and `checked_isqrt` have equivalent results for signed types, either equivalent numerically or equivalent as a panic and a `None`.
* Checks that `isqrt` has numerically-equivalent results for unsigned types and their `NonZero` counterparts.

### Added benchmarks for `isqrt` implementations

### Greatly sped up `checked_isqrt` and `isqrt` methods

* Uses a lookup table for 8-bit integers and then the Karatsuba square root algorithm for larger integers.
* Includes optimization hints that give the compiler the exact numeric range of results.

### Feature tracking issue

`isqrt` is an unstable feature tracked at #116226.

<details><summary>Benchmarked improvements</summary>

### Command used to benchmark

    ./x bench library/core -- int_sqrt

### Before

    benchmarks:
        num::int_sqrt::i128::isqrt           439591.65/iter  +/- 6652.70
        num::int_sqrt::i16::isqrt              5302.97/iter   +/- 160.93
        num::int_sqrt::i32::isqrt             62999.11/iter  +/- 2022.05
        num::int_sqrt::i64::isqrt            125248.81/iter  +/- 1674.43
        num::int_sqrt::i8::isqrt                123.56/iter     +/- 1.87
        num::int_sqrt::isize::isqrt          125356.56/iter  +/- 1017.03
        num::int_sqrt::non_zero_u128::isqrt  437443.75/iter  +/- 3535.43
        num::int_sqrt::non_zero_u16::isqrt     8604.58/iter    +/- 94.76
        num::int_sqrt::non_zero_u32::isqrt    62933.33/iter   +/- 517.30
        num::int_sqrt::non_zero_u64::isqrt   125076.38/iter +/- 11340.61
        num::int_sqrt::non_zero_u8::isqrt       221.51/iter     +/- 1.58
        num::int_sqrt::non_zero_usize::isqrt 136005.21/iter  +/- 2020.35
        num::int_sqrt::u128::isqrt           439014.55/iter  +/- 3920.45
        num::int_sqrt::u16::isqrt              8575.08/iter   +/- 148.06
        num::int_sqrt::u32::isqrt             63008.89/iter   +/- 803.67
        num::int_sqrt::u64::isqrt            125088.09/iter   +/- 879.29
        num::int_sqrt::u8::isqrt                230.18/iter     +/- 2.04
        num::int_sqrt::usize::isqrt          125237.51/iter  +/- 4747.83
### After

    benchmarks:
        num::int_sqrt::i128::isqrt           105184.89/iter +/- 1171.38
        num::int_sqrt::i16::isqrt              1910.26/iter   +/- 78.50
        num::int_sqrt::i32::isqrt             34260.34/iter  +/- 960.84
        num::int_sqrt::i64::isqrt             45939.19/iter +/- 2525.65
        num::int_sqrt::i8::isqrt                 22.87/iter    +/- 0.45
        num::int_sqrt::isize::isqrt           45884.17/iter  +/- 595.49
        num::int_sqrt::non_zero_u128::isqrt  106344.27/iter  +/- 780.99
        num::int_sqrt::non_zero_u16::isqrt     2790.19/iter   +/- 53.43
        num::int_sqrt::non_zero_u32::isqrt    33613.99/iter  +/- 362.96
        num::int_sqrt::non_zero_u64::isqrt    46235.42/iter  +/- 429.69
        num::int_sqrt::non_zero_u8::isqrt        31.78/iter    +/- 0.75
        num::int_sqrt::non_zero_usize::isqrt  46208.75/iter  +/- 375.27
        num::int_sqrt::u128::isqrt           106385.94/iter +/- 1649.95
        num::int_sqrt::u16::isqrt              2747.69/iter   +/- 28.72
        num::int_sqrt::u32::isqrt             33627.09/iter  +/- 475.68
        num::int_sqrt::u64::isqrt             46182.29/iter  +/- 311.16
        num::int_sqrt::u8::isqrt                 33.10/iter    +/- 0.30
        num::int_sqrt::usize::isqrt           46165.00/iter  +/- 388.41

</details>

Tracking Issue for {u8,i8,...}::isqrt #116226

try-job: test-various

2024-08-29 16:21:46 +02:00

alloc

Rollup merge of #129715 - Amjad50:update-compiler-builtins, r=tgross35

2024-08-28 19:12:56 -07:00

backtrace @ 72265bea21

…

core

Rollup merge of #128166 - ChaiTRex:isqrt, r=tgross35

2024-08-29 16:21:46 +02:00

panic_abort

…

panic_unwind