)]}'
{
  "commit": "aee71dd70b3779c66950ce6a952deca13d48e55e",
  "tree": "ba5e077b2478755d5a423c9898c23b9bd3819cdd",
  "parents": [
    "cd1976dbef0a4a474cccb9e7fcb1e9cf2310df66"
  ],
  "author": {
    "name": "Martin Möhrmann",
    "email": "moehrmann@google.com",
    "time": "Fri Apr 27 21:58:59 2018 +0200"
  },
  "committer": {
    "name": "Martin Möhrmann",
    "email": "moehrmann@google.com",
    "time": "Tue May 08 21:15:16 2018 +0000"
  },
  "message": "cmd/compile: optimize map-clearing range idiom\n\nreplace map clears of the form:\n\n        for k :\u003d range m {\n                delete(m, k)\n        }\n\n(where m is map with key type that is reflexive for \u003d\u003d)\nwith a new runtime function that clears the maps backing\narray with a memclr and reinitializes the hmap struct.\n\nMap key types that for example contain floats are not\nreplaced by this optimization since NaN keys cannot\nbe deleted from maps using delete.\n\nname                           old time/op  new time/op  delta\nGoMapClear/Reflexive/1         92.2ns ± 1%  47.1ns ± 2%  -48.89%  (p\u003d0.000 n\u003d9+9)\nGoMapClear/Reflexive/10         108ns ± 1%    48ns ± 2%  -55.68%  (p\u003d0.000 n\u003d10+10)\nGoMapClear/Reflexive/100        303ns ± 2%   110ns ± 3%  -63.56%  (p\u003d0.000 n\u003d10+10)\nGoMapClear/Reflexive/1000      3.58µs ± 3%  1.23µs ± 2%  -65.49%  (p\u003d0.000 n\u003d9+10)\nGoMapClear/Reflexive/10000     28.2µs ± 3%  10.3µs ± 2%  -63.55%  (p\u003d0.000 n\u003d9+10)\nGoMapClear/NonReflexive/1       121ns ± 2%   124ns ± 7%     ~     (p\u003d0.097 n\u003d10+10)\nGoMapClear/NonReflexive/10      137ns ± 2%   139ns ± 3%   +1.53%  (p\u003d0.033 n\u003d10+10)\nGoMapClear/NonReflexive/100     331ns ± 3%   334ns ± 2%     ~     (p\u003d0.342 n\u003d10+10)\nGoMapClear/NonReflexive/1000   3.64µs ± 3%  3.64µs ± 2%     ~     (p\u003d0.887 n\u003d9+10)\nGoMapClear/NonReflexive/10000  28.1µs ± 2%  28.4µs ± 3%     ~     (p\u003d0.247 n\u003d10+10)\n\nFixes #20138\n\nChange-Id: I181332a8ef434a4f0d89659f492d8711db3f3213\nReviewed-on: https://go-review.googlesource.com/110055\nReviewed-by: Keith Randall \u003ckhr@golang.org\u003e\n",
  "tree_diff": [
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