https://issues.dlang.org/show_bug.cgi?id=17485
Issue ID: 17485
Summary: bringToFront and/or upperBound slow
Product: D
Version: D2
Hardware: x86
OS: Mac OS X
Status: NEW
Severity: enhancement
Priority: P1
Component: phobos
Assignee: [email protected]
Reporter: [email protected]
See this thread:
https://forum.dlang.org/post/[email protected]
Not any idea why it doesn't go fast, or his other issue with -boundscheck=off
on ldc, but tinkering with the code, I couldn't get much except:
1. It's not the interaction of SortedRange with bringToFront
2. It's not an issue with using functors instead of lambdas
3. It's not an issue with the initial setup, as that should take nowhere near
the 10 seconds I found it takes (consistent with his testing).
4. It *may* be an issue with the comparison, but I switched away from using ==,
and didn't get any better performance.
Ali's message in the thread may give a clue as to why std::rotate is so good
and something we should try and dissect to copy it's speedups:
https://stackoverflow.com/questions/21160875/why-is-stdrotate-so-fast
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