The main problem with the article is that the idea to influence backend code generation decisions via specific highlevel code constructs is mostly just mystical bullshit (some compilers do detect specific patterns - usually for bit twiddling hacks, but not on a basic level like control flow optimization).

Using a highlevel language construct like "y += (x > 0) as usize;" doesn't "switch on" branchless code just because the source code looks branchless, compilers are not that dumb anymore.

E.g. I bet that writing

    if (x > 0) {
        y += 1;
    }

...generates the exact same code after optimization, otherwise I would consider that an LLVM bug.

The only reliable way is to mostly bypass the optimizer via simd intrinsics, or drop down to assembler, everything else is just cargo culting.

(fwiw I can't shake the feeling now that the article is recycled, I'm pretty sure I saw those exact same code examples in another "branchless" blog post, but maybe for a different language - because the next question was ineviatably "then why is the code using "if" slower? answer: because it also behaves differently). Or maybe I'm just having a strong dejavu ;)