dcbd5f5134
Add unicode fast path to `is_printable` Before, it would enter the full expensive check even for normal ascii characters. Now, it skips the check for the ascii characters in `32..127`. This range was checked manually from the current behavior. I ran the `tracing` test suite in miri, and it was really slow. I looked at a profile, and miri spent most of the time in `core::char::methods::escape_debug_ext`, where half of that was dominated by `core::unicode::printable::is_printable`. So I optimized it here. The tracing profile:  |
||
|---|---|---|
| .. | ||
| alloc | ||
| backtrace@4e5a3f7292 | ||
| core | ||
| panic_abort | ||
| panic_unwind | ||
| portable-simd | ||
| proc_macro | ||
| profiler_builtins | ||
| rtstartup | ||
| rustc-std-workspace-alloc | ||
| rustc-std-workspace-core | ||
| rustc-std-workspace-std | ||
| std | ||
| stdarch@28335054b1 | ||
| test | ||
| unwind | ||
