Mirror of forum.nim-lang.org

8471 :: complex lib inline

• rforcen (orginal) [2021-10-01T12:02:18+02:00] view original

  i was experiencing some performance drawbacks with complex numbers, so i tried adding , inline:on at the starting push statement, i.e: {.push checks: off, line_dir: off, stack_trace: off, debugger: off, inline:on.}

  and now performance x10 and comparable to rust & go,

  is there any reason for not using inline here?

---

• Araq (orginal) [2021-10-01T12:24:03+02:00] view original

  Nah, it's simply an oversight. PRs are welcome.

---

• juancarlospaco (orginal) [2021-10-01T16:50:47+02:00] view original

  I am kind of confused..., I was told to send PRs adding {.inline.} to a few tiny proc that improved performance, then you said to stop, and instead try to integrate LTO when build for Release, so I PR that, but got closed, because you said is not a good idea, I understand what LTO does to the generated intermediate representation, I feel that is more work to open a new issue then PR directly adding {.inline.}, but what we should do when you feel a small func improves with {.inline.} ?, so I do not understand, sorry, sometimes you contradict yourself...

---

• Araq (orginal) [2021-10-01T17:39:44+02:00] view original

  You can apply .inline for procs where it's been shown to be beneficial. What you think is "small" might not be small...

---

• cblake (orginal) [2021-10-01T18:40:17+02:00] view original

  I tried to do complex in https://github.com/nim-lang/Nim/pull/8876/commits/826b8915dc33825b47834f8682c84b12e4672f52 3 years ago. It was part of https://github.com/nim-lang/Nim/pull/8876 which it looks like I just withdrew out of probably foolish impatience -- and LTO or even better PGO was/is an alternative with often more information.

  @rforcen - you should just try again PR-wise with just complex and learn from any errors in my attempt. But it also sounds like you should learn how to use nim c -t-flto and/or PGO modes of compiling. These can both indeed sometimes pay off with 2+X multiples in performance and are both more general and more automatic than inline annotations.

---