On Wed, 2018-06-20 at 17:11 -0400, NightStrike wrote: > > If I could perhaps jump in here for a moment... Just today I hit upon > a series of small (in lines of code) loops that gcc can't vectorize, > and intel vectorizes like a madman. They all involve a lot of heavy > use of std::vector<std::vector<float>>. Comparisons were with gcc > 8.1, intel 2018.u1, an AMD Opteron 6386 SE, with the program running > as sched_FIFO, mlockall, affinity set to its own core, and all > interrupts vectored off that core. So, as close to not-noisy as > possible.
There are a quite a number of bugzilla reports with examples where GCC does not vectorize a loop. I wonder if this example is related to PR 61247. Steve Ellcey
