)]}'
{
  "commit": "691a130e0f14459d9358a71ffd52a01295e6200a",
  "tree": "6ba9746b4d5e8fde1a4b0edac2700f98fdbcb93f",
  "parents": [
    "7a186da65b3754509bff2d7bafcc28a095279320"
  ],
  "author": {
    "name": "Alexis Engelke",
    "email": "engelke@in.tum.de",
    "time": "Thu Apr 09 22:31:15 2026 +0200"
  },
  "committer": {
    "name": "GitHub",
    "email": "noreply@github.com",
    "time": "Thu Apr 09 20:31:15 2026 +0000"
  },
  "message": "[ADT] Refactor post order traversal (#191047)\n\nCurrently, po_iterator holds the traversal state. This makes copying\nand moving po_iterator fairly expensive and the code cannot be optimized\naway in several cases (most of it isn\u0027t even inlined in a default\nbuild).\n\nTherefore, refactor post-order traversal to hold the state in a wrapper\nclass with cheap iterators. Additionally, replace po_storage base class\nwith a CRTP implementation where users can provide their own storage.\n\nBenefits:\n\n- Performance in stage2-O3 improves by 0.19% instructions:u and even\n  more substantially in cycles/wall-time.\n\n- Users that use a custom storage/iteration limitation can do so in a\n  more clean way by subclassing PostIteratorTraversalBase. See e.g.\n  LoopBlocksTraversal.\n\n- For graphs with block numbers, reserving can now be implemented\n  reasonably easy (not done yet).\n\nImplications:\n\n- PostOrderTraversal::iterator is no longer a forward iterator. This\n  property was never really used, though.\n\n- PostOrderTraversal must be live while iterators are live. For typical\n  uses (for (X x : post_order(...))), this is no problem, but could end\n  up being problematic if the iterator is wrapped (e.g.\n  for (X x : make_filter_range(post_order(...), ...)) -- problematic,\n  because make_filter_range doesn\u0027t preserve the range but only the two\n  iterators, which become invalid as the for loop is entered). This is a\n  limitation of the way LLVM implements ranges.",
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