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4918 :: v0.20: -d:release does not turn off runtime checks?

• quokka70 (orginal) [2019-06-07T18:53:52+02:00] view original

  Hi,

  I am trying out v0.20. Thanks for all the work!

  I recompiled some CPU intensive code I wrote and was surprised to find out that running time trebled on typical input. Poking around, I found that the generated C code shows array range checks:

  /* with 'nimble build -d:release */
          if ((NU)(i) >= (NU)((*data).itemNodes ? (*data).itemNodes->Sup.len : 0)) raiseIndexError2(i,((*data).itemNodes ? (*data).itemNodes->Sup.len : 0)-1);
          l = (*data).itemNodes->data[i].llink;
          if ((NU)(i) >= (NU)((*data).itemNodes ? (*data).itemNodes->Sup.len : 0)) raiseIndexError2(i,((*data).itemNodes ? (*data).itemNodes->Sup.len : 0)-1);
          r = (*data).itemNodes->data[i].rlink;
  Run

  When I disable runtime checks explicitly the range checks disappear, as expected, and my running times return to what they were before.

  /* with `nimble build -d:release --checks:off */
          l = (*data).itemNodes->data[i].llink;
          r = (*data).itemNodes->data[i].rlink;
  Run

  The compiler manual at https://nim-lang.org/docs/nimc.html says that the release switch "[t]urns off runtime checks and turns on the optimizer." It worked that way for me in the 0.19 series.

  Am I seeing this behavior because I use nimble to build and not "nim c"?

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• cantanima (orginal) [2019-06-07T19:00:44+02:00] view original

  Are you using -d:danger? That is the new switch for turning off runtime checks.

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• quokka70 (orginal) [2019-06-07T19:03:08+02:00] view original

  Oh!

  I read through the blog post announcing 0.20 but somehow missed this. I should have found it with a search but didn't look hard enough.

  Thanks for that and sorry for the line noise.

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• Araq (orginal) [2019-06-07T19:59:50+02:00] view original

  Well no, thank you for telling us I forgot to update the documentation!

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