Unexpect slowdown in basic example (provided)

[Wheest]

Hello all,

I'm looking at integrating the library into a project I've working on.

However, I want to make sure that I set off on the right foot.

Thus, I have made a very simple minimum working example, using CMake, git submodules, and an old example I found lying around.

You can find the MWE here, which I will improve in responses to this thread.

However, I'm finding an ~15x slowdown using SIMD, which is not what I would expect.

Standard: 2 ms
SIMD: 37 ms

Before integrating, I want to make sure I avoid stumbling blocks such as this.

Does anyone have any insight into what's going on?

Cheers

[Wheest]

I've updated my basic example also using Intel Instincts, with the same programming pattern.

Running ./simd_mwe 524288 100 on a test machine:

Standard: 90 ms
libsimdpp (4): 1569 ms
libsimdpp (8): 1428 ms
SSE Intrinsics (4): 55 ms
SSE Intrinsics (8): 28 ms

Is compiling with -march=native, and making the libsimdpp header available to the file not enough to use the correct instructions?