[DomTree] Add constructor to create a new DT based on current DT/CFG and a set of Updates.

Summary:
Add the posibility of creating a new DT using a set of Updates.
This will essentially create a DT based on a CFG snapshot/view.

Additional refactoring for either this patch or follow-ups:
- create an utility for building BUI.
- replace BUI with a GraphDiff.

Reviewers: kuhar

Subscribers: sanjoy, jlebar, llvm-commits

Differential Revision: https://reviews.llvm.org/D50671

llvm-svn: 339947

1 files changed, 5 insertions, 0 deletions

diff --git a/llvm/lib/IR/Dominators.cpp b/llvm/lib/IR/Dominators.cpp
index dc4fa9eee66..c78f220439a 100644
--- a/llvm/lib/IR/Dominators.cpp
+++ b/llvm/lib/IR/Dominators.cpp
@@ -71,8 +71,13 @@ template class llvm::cfg::Update<BasicBlock *>;
 
 template void llvm::DomTreeBuilder::Calculate<DomTreeBuilder::BBDomTree>(
     DomTreeBuilder::BBDomTree &DT);
+template void
+llvm::DomTreeBuilder::CalculateWithUpdates<DomTreeBuilder::BBDomTree>(
+    DomTreeBuilder::BBDomTree &DT, BBUpdates U);
+
 template void llvm::DomTreeBuilder::Calculate<DomTreeBuilder::BBPostDomTree>(
     DomTreeBuilder::BBPostDomTree &DT);
+// No CalculateWithUpdates<PostDomTree> instantiation, unless a usecase arises.
 
 template void llvm::DomTreeBuilder::InsertEdge<DomTreeBuilder::BBDomTree>(
     DomTreeBuilder::BBDomTree &DT, BasicBlock *From, BasicBlock *To);