[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, 4 insertions, 4 deletions

diff --git a/llvm/lib/Analysis/IteratedDominanceFrontier.cpp b/llvm/lib/Analysis/IteratedDominanceFrontier.cpp
index 0e02850df34..3992657417c 100644
--- a/llvm/lib/Analysis/IteratedDominanceFrontier.cpp
+++ b/llvm/lib/Analysis/IteratedDominanceFrontier.cpp
@@ -17,8 +17,8 @@
 #include <queue>
 
 namespace llvm {
-template <class NodeTy>
-void IDFCalculator<NodeTy>::calculate(
+template <class NodeTy, bool IsPostDom>
+void IDFCalculator<NodeTy, IsPostDom>::calculate(
     SmallVectorImpl<BasicBlock *> &PHIBlocks) {
   // Use a priority queue keyed on dominator tree level so that inserted nodes
   // are handled from the bottom of the dominator tree upwards.
@@ -88,6 +88,6 @@ void IDFCalculator<NodeTy>::calculate(
   }
 }
 
-template class IDFCalculator<BasicBlock *>;
-template class IDFCalculator<Inverse<BasicBlock *>>;
+template class IDFCalculator<BasicBlock *, false>;
+template class IDFCalculator<Inverse<BasicBlock *>, true>;
 }