[Issue 9646] std.algorithm.splitter for strings has opportunities for improvement

[d-bugmail--- via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=9646

Iain Buclaw  changed:

   What|Removed |Added

   Priority|P2  |P4

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[Issue 9646] std.algorithm.splitter for strings has opportunities for improvement

[d-bugmail--- via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=9646

Seb  changed:

   What|Removed |Added

 CC||greensunn...@gmail.com

--- Comment #5 from Seb  ---
New numbers:

DMD (2.079.0):

std.algorithm.splitter took 2 secs, 736 ms, 348 μs, and 3 hnsecs
MySplitter took 3 secs, 176 ms, 18 μs, and 9 hnsecs

LDC (1.8.0):

>  ldc -O4 -mcpu=native -release -flto=full

std.algorithm.splitter took 1 sec, 954 ms, 444 μs, and 9 hnsecs
MySplitter took 1 sec, 635 ms, 394 μs, and 8 hnsecs

So I there's still an opportunity for improvement with LDC.

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[Issue 9646] std.algorithm.splitter for strings has opportunities for improvement

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=9646

--- Comment #4 from github-bugzi...@puremagic.com ---
Commit pushed to stable at https://github.com/dlang/phobos

https://github.com/dlang/phobos/commit/a9d5b8ca779d2dd89c8b49abae385e793d469e5d
Improve speed of find for random access needles (strings)

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[Issue 9646] std.algorithm.splitter for strings has opportunities for improvement

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=9646

Jack Stouffer  changed:

   What|Removed |Added

   Keywords||performance
 CC||j...@jackstouffer.com

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[Issue 9646] std.algorithm.splitter for strings has opportunities for improvement

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=9646

q...@web.de changed:

   What|Removed |Added

 CC||q...@web.de

--- Comment #3 from q...@web.de ---
For an update. This is still an issue for LDC 1.0.0 and DMD 2.071.0.

One problem is certainly that find does not get inlined. While everything of
MySplitter gets inlined. Maybe this is more of a dmd than a phobos bug.

Does LDC use the LLVM inliner?

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[Issue 9646] std.algorithm.splitter for strings has opportunities for improvement

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=9646

--- Comment #2 from github-bugzi...@puremagic.com ---
Commit pushed to master at https://github.com/dlang/phobos

https://github.com/dlang/phobos/commit/a9d5b8ca779d2dd89c8b49abae385e793d469e5d
Improve speed of find for random access needles (strings)

For find a string within a string, std.algorithm.searching.find was
unnecessarily slow. The reason is it created intermediate slices. A
naively written nested-for-loop implementation was a few times
faster.

For random access ranges (which strings are) this uses an index based
algorithm, which does not need to create an intermediate slice. Speed
is now comparable to the nested-for-loop implementation even in rather
pathological cases.

This might help with issue 9646.

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