Fix massive LiveVariables regression (due to LiveVariables rewrite) by addressing two performance problems:
- Speed of "merge()", which merged data flow facts. This was doing a set canonicalization on every insertion, which was super slow.
To fix this, we use ImmutableSetRef.
- Visit CFGBlocks in reverse postorder. This is a huge speedup, as on some test cases the algorithm would take many iterations
to converge.
This contains a bunch of copy-paste from UninitializedValues.cpp and ThreadSafety.cpp. The idea
was to get something working first, and then refactor the common logic for all three files into
a separate analysis/library entry point.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@139968 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed