https://issues.dlang.org/show_bug.cgi?id=18629

Basile B. <b2.temp@gmx.com> changed:

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           Hardware|x86_64                      |All
                 OS|Linux                       |All
           Severity|enhancement                 |normal

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https://issues.dlang.org/show_bug.cgi?id=18629

greenify <greeenify@gmail.com> changed:

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                 CC|                            |greeenify@gmail.com
           Assignee|nobody@puremagic.com        |greeenify@gmail.com

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https://issues.dlang.org/show_bug.cgi?id=18629

John Colvin <john.loughran.colvin@gmail.com> changed:

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                 CC|                            |john.loughran.colvin@gmail.
                   |                            |com

--- Comment #1 from John Colvin <john.loughran.colvin@gmail.com> ---
Created attachment 1684
  --> https://issues.dlang.org/attachment.cgi?id=1684&action=edit
benchmark

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https://issues.dlang.org/show_bug.cgi?id=18629

--- Comment #2 from John Colvin <john.loughran.colvin@gmail.com> ---
If you compile with LDC and full optimisations (substitute isn't in LDC's phobos, see attached file for a working example) then the disparity goes away (without bounds checking v3 is even faster). This is normal for range-based code, dmd isn't good at optimising it.

Except that's not the end of the story. If you append extra nonsense to the end of the input string (-version=LongerString in the attached file)then the substitute version gets a lot slower again, so perhaps substitute really is doing something slow and stupid.

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https://issues.dlang.org/show_bug.cgi?id=18629

Carsten Blüggel <chilli@posteo.net> changed:

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                 CC|                            |chilli@posteo.net

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https://issues.dlang.org/show_bug.cgi?id=18629

Iain Buclaw <ibuclaw@gdcproject.org> changed:

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           Priority|P1                          |P3

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