[all-commits] [llvm/llvm-project] 9f8652: [ASTMatcher] Fix a performance regression: memoriz...

[Haojian Wu via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 9f865246a81759cdcb056c883e6f92fe6693b3d3
      https://github.com/llvm/llvm-project/commit/9f865246a81759cdcb056c883e6f92fe6693b3d3
  Author: Haojian Wu <hokein.wu at gmail.com>
  Date:   2020-06-30 (Tue, 30 Jun 2020)

  Changed paths:
    M clang/lib/ASTMatchers/ASTMatchFinder.cpp

  Log Message:
  -----------
  [ASTMatcher] Fix a performance regression: memorize the child match.

D80025 introduced a performance regression: in some cases, it makes
clang-tidy readability-container-size-empty ~80x slower (running on an internal
huge TU, before that patch 12s vs after 950s).

after this patch, we go back to 12s.

Differential Revision: https://reviews.llvm.org/D82771