[Dominators] Make IsPostDominator a template parameter

Summary:
DominatorTreeBase used to have IsPostDominators (bool) member to indicate if the tree is a dominator or a postdominator tree. This made it possible to switch between the two 'modes' at runtime, but it isn't used in practice anywhere.

This patch makes IsPostDominator a template argument. This way, it is easier to switch between different algorithms at compile-time based on this argument and design external utilities around it. It also makes it impossible to incidentally assign a postdominator tree to a dominator tree (and vice versa), and to further simplify template code in GenericDominatorTreeConstruction.

Reviewers: dberlin, sanjoy, davide, grosser

Reviewed By: dberlin

Subscribers: mzolotukhin, llvm-commits

Differential Revision: https://reviews.llvm.org/D35315

llvm-svn: 308040

1 files changed, 3 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/MachineDominators.cpp b/llvm/lib/CodeGen/MachineDominators.cpp
index 65e9e5d..845e823 100644
--- a/llvm/lib/CodeGen/MachineDominators.cpp
+++ b/llvm/lib/CodeGen/MachineDominators.cpp
@@ -31,7 +31,7 @@ static cl::opt<bool, true> VerifyMachineDomInfoX(
 
 namespace llvm {
 template class DomTreeNodeBase<MachineBasicBlock>;
-template class DominatorTreeBase<MachineBasicBlock>;
+template class DominatorTreeBase<MachineBasicBlock, false>; // DomTreeBase
 }
 
 char MachineDominatorTree::ID = 0;
@@ -49,7 +49,7 @@ void MachineDominatorTree::getAnalysisUsage(AnalysisUsage &AU) const {
 bool MachineDominatorTree::runOnMachineFunction(MachineFunction &F) {
   CriticalEdgesToSplit.clear();
   NewBBs.clear();
-  DT.reset(new DominatorTreeBase<MachineBasicBlock>(false));
+  DT.reset(new DomTreeBase<MachineBasicBlock>());
   DT->recalculate(F);
   return false;
 }
@@ -144,7 +144,7 @@ void MachineDominatorTree::verifyDomTree() const {
     return;
   MachineFunction &F = *getRoot()->getParent();
 
-  DominatorTreeBase<MachineBasicBlock> OtherDT(false);
+  DomTreeBase<MachineBasicBlock> OtherDT;
   OtherDT.recalculate(F);
   if (getRootNode()->getBlock() != OtherDT.getRootNode()->getBlock() ||
       DT->compare(OtherDT)) {