[sYnfo]

FYI vien [0] figured out that simply compiling with "-static -fno-pie" and _exit(0)-ing at the end puts the solution presented here to 15000 points and hence #4 on the leaderboard. Pretty funny.

[0] https://news.ycombinator.com/user?id=vient

[a_t48]

Optimizing the leftovers loop to

    #pragma clang loop vectorize(enable)
    #pragma clang loop interleave(enable)
    for (; offset < length; offset += 4) {
        const auto x = ((uint32_t\*)start)[offset / 4];
        count += ((x & 0xFF) == 0x7F);
        count += ((x & 0xFF00) == 0x7F00);
        count += ((x & 0xFF0000) == 0x7F0000);
        count += ((x & 0xFF000000) == 0x7F000000);
    }

also gives some points. It'd probably be more if I could be bothered to break apart your assembly. :)