November 26, 2010
http://d.puremagic.com/issues/show_bug.cgi?id=5276

           Summary: Template compilation slower than G++ 4.5
           Product: D
           Version: D2
          Platform: x86
        OS/Version: Windows
            Status: NEW
          Keywords: performance
          Severity: enhancement
          Priority: P2
         Component: DMD
        AssignedTo: nobody@puremagic.com
        ReportedBy: bearophile_hugs@eml.cc


--- Comment #0 from bearophile_hugs@eml.cc 2010-11-25 20:17:36 PST ---
Created an attachment (id=832)
D2 version of the benchmark

This performance bug may share the same cause of bug 4900
If this turns out to be true then we may close this as resolved duplicated.

In attach there are two programs that perform many computations at compile time using just templates, one written in C++ and one in D2.

This is not idiomatic D code, because for this purpose CTFE is better, but it may be good enough as first performance benchmark for templates.

Compilation time (N=7): G++ 0.95 seconds, dmd 12.4 seconds.

G++ uses about 34 MB RAM, DMD about 130+ MB RAM.
I have used MinGW 4.5.1 and DMD 2.050.

Compilation:
g++ nqueens_cpp.cpp -o nqueens_cpp
dmd nqueens_d.d

See also: http://cpptruths.blogspot.com/2010/03/faster-meta-programs-using-gcc-45-and.html

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November 26, 2010
http://d.puremagic.com/issues/show_bug.cgi?id=5276



--- Comment #1 from bearophile_hugs@eml.cc 2010-11-25 20:18:22 PST ---
Created an attachment (id=833)
C++ G++ 4.5 version of the benchmark

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