ICC and GCC produce pretty nice scalar code, but their vectorization abilities are far from perfect. Compiler vectorization tends to also be less stable, sligh

ICC and GCC produce pretty nice scalar code, but their vectorization abilities are far from perfect. Compiler vectorization tends to also be less stable, slightest changes can make the compiler to drop the optimizations in a later build. It might not ideal to use intrinsics, but that's how you get predictable performance.