mirror of
https://github.com/RPCS3/llvm.git
synced 2026-01-31 01:25:19 +01:00
bd0f067b12
ComputeValueKnownInPredecessors has a "visited" set to prevent infinite loops, since a value can be visited more than once. However, the implementation didn't prevent the algorithm from taking exponential time. Instead of removing elements from the RecursionSet one at a time, we should keep around the whole set until ComputeValueKnownInPredecessors finishes, then discard it. The testcase is synthetic because I was having trouble effectively reducing the original. But it's basically the same idea. Instead of failing, we could theoretically cache the result instead. But I don't think it would help substantially in practice. Differential Revision: https://reviews.llvm.org/D54239 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@346562 91177308-0d34-0410-b5e6-96231b3b80d8