On Tuesday 09 May 2017, René J. V. Bertin wrote: > Thiago Macieira wrote: > > QString is already SIMD accelearated and has been since Qt 4.5. > > I'm perverse but not to the point that I'd consider using QString for math > operations :) > > > If you want any inline operations to become SIMD accelerated, compile > > your code with -O3. > > That'd only be as good as the compiler's auto-vectorisation, which rarely > has a significant impact on anything but the simpler operations. Anything you can write with SIMD arrays is simple enough that the compiler can also auto-vectorize it as well. Just pretend the arrays you have are SIMD arrays and write small simple loops that does the individual operations on them, and they will be auto-vectorized
> Also, to get SIMD support and auto-vectorisation you need the correct > -march CPU flag, no? > You would need that too with any SIMD-library. But at least on x64 SSE2 comes for free, so some vectorization is always enabled. (same with amd64 and neon) Best regards `Allan _______________________________________________ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
