[rustc_data_structures][perf] Simplify base_n::push_str.#114306
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bors merged 1 commit intorust-lang:masterfrom Aug 1, 2023
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[rustc_data_structures][perf] Simplify base_n::push_str.#114306bors merged 1 commit intorust-lang:masterfrom
bors merged 1 commit intorust-lang:masterfrom
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This minor change removes the need to reverse resulting digits. Since reverse is O(|digit_num|) but bounded by 128, it's unlikely to be a noticeable in practice. At the same time, this code is also a 1 line shorter, so combined with tiny perf win, why not? I ran https://gist.github.com/ttsugriy/ed14860ef597ab315d4129d5f8adb191 on M1 macbook air and got a small improvement ``` Running benches/base_n_benchmark.rs (target/release/deps/base_n_benchmark-825fe5895b5c2693) push_str/old time: [14.180 µs 14.313 µs 14.462 µs] Performance has improved. Found 5 outliers among 100 measurements (5.00%) 4 (4.00%) high mild 1 (1.00%) high severe push_str/new time: [13.741 µs 13.839 µs 13.973 µs] Performance has improved. Found 8 outliers among 100 measurements (8.00%) 3 (3.00%) high mild 5 (5.00%) high severe ```
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…iaskrgr Rollup of 7 pull requests Successful merges: - rust-lang#100455 (Implement RefUnwindSafe for Backtrace) - rust-lang#113428 (coverage: Replace `ExpressionOperandId` with enum `Operand`) - rust-lang#114283 (Use parking lot's rwlock even without parallel-rustc) - rust-lang#114288 (Improve diagnostic for wrong borrow on binary operations) - rust-lang#114296 (interpret: fix alignment handling for Repeat expressions) - rust-lang#114306 ([rustc_data_structures][perf] Simplify base_n::push_str.) - rust-lang#114320 (Cover statements for stable_mir) r? `@ghost` `@rustbot` modify labels: rollup
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This minor change removes the need to reverse resulting digits. Since reverse is O(|digit_num|) but bounded by 128, it's unlikely to be a noticeable in practice. At the same time, this code is also a 1 line shorter, so combined with tiny perf win, why not?
I ran https://gist.github.com/ttsugriy/ed14860ef597ab315d4129d5f8adb191 on M1 macbook air and got a small improvement