Re: C++11 in LibreOffice

On Thu, 2012-07-19 at 16:04 +0200, Michael Stahl wrote:
> i'm saying it doesn't benefit from the "sophisticated" optimizations that
> vendor compilers like SunStudio or Intel do that speed up your BLAS
> stuff with gigabytes of floating point arrays by X times because office
> suites don't contain gigabytes of floating point arrays.

        So - Kohei has been working for years to turn Calc spreadsheets into
gigabyte arrays of floating point numbers - precisely to take advantage
of this sort of optimisation :-)

        Having said that, I totally agree, our problems are 95% algorithmic,
and fiddling with compiler optimiser settings is the last refuge of the
desperate man ;-)

        The thing that concerns me about gcc vs. MSVC++ is not the speed of the
generated code, but it's size (which impacts startup performance, I/O
load, memory use etc.). If you checkout the tables you linked the binary
size column is quite stark:

        http://www.willus.com/ccomp_benchmark2.shtml?p18+s12
        http://www.willus.com/ccomp_benchmark2.shtml?p14+s12

        in several cases a 2x growth. So - clearly this would need benchmarking
various ways to see what the story is there with -Os etc.

        IMHO it's well worth looking at a gcc cross-compiled solution for
Windows though; if only to use really fast, fully repeatable, Free
Software tooling; though it'd be nice to use an enterprise / maintained
cross-compiler - where is cygnus when you need them :-)

        All the best,

                Michael.

-- 
michael.meeks@suse.com  <><, Pseudo Engineer, itinerant idiot