Re: [boost] [Fusion] port to c++0x

Subject: Re: [boost] [Fusion] port to c++0x
From: Larry Evans (cppljevans_at_[hidden])
Date: 2009-10-03 16:08:43

On 09/26/09 10:40, Christopher Schmidt wrote:
[snip]
> I used gcc 4.4.1 (TDM-1 mingw32) and ptime to measure performance. It is 
> pretty interesting that the instantiation of the horizontal tuple type 
> is just slightly slower. The at-operations differ all the more 
> surprisingly.
> 
> ===  g++ -std=c++0x -c test.cpp ===
> Execution time: 5.274 s
> ===  g++ -std=c++0x -c test.cpp -DAT ===
> Execution time: 11.821 s
> ===  g++ -std=c++0x -c test.cpp -DMETA_AT ===
> Execution time: 12.161 s
> ===  g++ -std=c++0x -c test.cpp -DAT -DMETA_AT ===
> Execution time: 19.565 s
> ===  g++ -std=c++0x -c test.cpp -DVERTICAL ===
> Execution time: 4.884 s
> ===  g++ -std=c++0x -c test.cpp -DAT -DVERTICAL ===
> Execution time: 7.136 s
> ===  g++ -std=c++0x -c test.cpp -DMETA_AT -DVERTICAL ===
> Execution time: 5.835 s
> ===  g++ -std=c++0x -c test.cpp -DAT -DMETA_AT -DVERTICAL ===
> Execution time: 8.156 s
[snip]
There's now a tuple.benchmark.zip in boost vault under the
variadic_templates directory.  It uses the compiler's
-ftime-report flag to report times.  The zip file also
contains a short makefile (suffix .mk).

The report shows a large difference between gcc4.4 and
gcc4.5 in the HORIZONTAL implementation.  It shows
with 4.5 there's not nearly as large a difference
compared to the VERTICAL implementation.

-regards,
Larry