[Dominators] Add DomTreeUpdater constructor from DT* and PDT*
Summary:
Previously, if a function accepts an optional DT pointer,
```
void Foo (.., DominatorTree * DT = nullptr) {
...
if(DT)
DomTreeUpdater(*DT, ...).insertEdge(A, B);
if(DT){
DomTreeUpdater DTU(*DT, ...);
... // Construct the update vector and applyUpdates
}
...
if(DT){
DomTreeUpdater DTU(*DT, ...);
... // Construct the update vector and applyUpdates
}
}
```
After this patch, it can be simplified as
```
void Foo (.., DominatorTree * DT = nullptr) {
DomTreeUpdater DTU(DT, ...);
...
DTU.insertEdge(A, B);
if(DT){
... // Construct the update vector and applyUpdates
}
...
if(DT){
... // Construct the update vector and applyUpdates
}
}
```
Patch by Chijun Sima <simachijun@gmail.com>.
Reviewers: kuhar, brzycki, dmgreen
Reviewed By: kuhar
Author: NutshellySima
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D48923
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336294 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed