Lowered the workload of string appending bechmarks a bit further, to get them under 1ms in `O` and 10ms in `Onone` builds.
Fine tuned the legacy factor to match original `O` runtimes — the changes are non-linear because of complications from double loop and amortized array growth costs.
These string appending benchmarks along with
* ArrayPlusEqualFiveElementCollection and
* ArrayPlusEqualSingleElementCollection
are likely to show different performance in `Osize` and `Onone` builds because of the non-linearity of their original implementation.
Cleaned up doubled inner loops and applied legacyFactor to the resulting, more rational, workload sizes.
Factors for string appending benchmarks are not 10, but 11 to compensate for smaller amortized Array resizes. Similarily ArrayPlusEqualFiveElementCollection’s factor is 49.
ArrayAppendStrings had setup overhead of 10ms (42%). ArrayAppendLazyMap had setup overhead of 24 μs (1%).
ArrayAppendOptionals and ArrayAppendArrayOfInt also had barely visible, small overhead of ~18μs, that was mostly hidden in measurement noise, but I’ve extracted the setup from all places that had 10 000 element array initializations, in preparation for more precise measurement in the future.
* Remove case destructuring to _
* Remove some Iterator.Element
* Which idiot wrote this? Oh.
* Switch NibbleSort to just use default impls... shouldn't change perf
Add substring-view-oriented array append benchmarks. Put a
getString/getSubstring call into the innermost loop to prevent some
constant folding towards triviality.
