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	Update backtrace to 0.3.73	2024-06-06 22:50:45 -07:00
core	Rollup merge of #128166 - ChaiTRex:isqrt, r=tgross35	2024-08-29 16:21:46 +02:00
panic_abort	step cfg(bootstrap)	2024-07-28 14:46:29 -04:00
panic_unwind	Auto merge of #128083 - Mark-Simulacrum:bump-bootstrap, r=albertlarsan68	2024-07-30 17:49:08 +00:00
portable-simd	Fix doc nits	2024-07-26 13:26:33 +01:00
proc_macro	library: Stabilize new_uninit for Box, Rc, and Arc	2024-08-27 10:17:05 -07:00
profiler_builtins	Build library/profiler_builtins from ci-llvm if appropriate	2024-08-24 21:21:34 +10:00
rtstartup	Let InstCombine remove Clone shims inside Clone shims	2024-07-25 15:14:42 -04:00
rustc-std-workspace-alloc
rustc-std-workspace-core
rustc-std-workspace-std
std	Rollup merge of #129715 - Amjad50:update-compiler-builtins, r=tgross35	2024-08-28 19:12:56 -07:00
stdarch@d9466edb4c	Update stdarch submodule	2024-08-21 00:20:27 -07:00
sysroot	Auto merge of #125016 - nicholasbishop:bishop-cb-112, r=tgross35	2024-07-29 07:41:33 +00:00
test	Reduce merged doctest source code size	2024-08-13 20:14:56 +02:00
unwind	Auto merge of #128083 - Mark-Simulacrum:bump-bootstrap, r=albertlarsan68	2024-07-30 17:49:08 +00:00
windows_targets	Add windows-targets crate to std's sysroot	2024-08-09 10:43:43 +00:00
Cargo.lock	Update compiler_builtins to 0.1.123	2024-08-29 08:38:19 +08:00
Cargo.toml	Exclude windows-targets from the workspace	2024-08-09 11:06:39 +00:00