Fangrui Song 13a97305ba [JumpThreading] Skip unconditional PredBB when threading jumps through two basic blocks ...

Fixes https://bugs.llvm.org/show_bug.cgi?id=44922 (caused by 4698bf145d)

ThreadThroughTwoBasicBlocks assumes PredBBBranch is conditional. The following code can segfault.

  AddPHINodeEntriesForMappedBlock(PredBBBranch->getSuccessor(1), PredBB, NewBB,
                                  ValueMapping);

We can also allow unconditional PredBB, but the produced code is not
better.

Reviewed By: kazu

Differential Revision: https://reviews.llvm.org/D74747

2020-02-18 11:01:46 -08:00

1.4 KiB

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