4 ms·

Interesting analysis, but in what ways can we realistically affect the instructions used without involving assembly?

• linkregister 10y ago
  Perhaps writing longer functions would cause the compiler to use more registers, since it needs to keep track of more variables. Though I think this is not the point. I think the author was just pointing this out as an interesting exercise rather than a call to action. The hottest 5 instructions for the call to std::fill were generated by the compiler that inexplicably didn't end up using a rep (or variant) instruction. But we don't know if in this case, fewer x86_64 instructions profiles faster or slower.
  • greglindahl 10y ago
    Compilers routinely inline code, even between source files. Programmers don't need to stress about that. And I don't think REP is ever the fastest, although it's sometimes the shortest code.