[PATCH] D16893: Keep CodeGenPrepare from preserving the dominator tree

[George Burgess IV via llvm-commits]

george.burgess.iv added a comment.

> LGTM.


Thank you! :) Like said, http://reviews.llvm.org/D16984 seems to absorb this change, so I'll commit this if we decide to abandon that.

> As CGP is the last pass run before SDAG, how exactly did you find this bug out of interest?


I wrote a script that more or less appends `-basicaa -verify-memoryssa` to all opt runlines in our test suite. This caused a CGP test that was originally just running `-loop-unroll -codegenprepare` to segfault, because the domtree was pointing to deleted basic blocks when it was handed to MemorySSA.


http://reviews.llvm.org/D16893