Add a MachinePostDominator pass

This is used in the AMDIL and R600 backends.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164029 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/MachinePostDominators.h

@@ -0,0 +1,85 @@
+//=- llvm/CodeGen/MachineDominators.h ----------------------------*- C++ -*-==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file exposes interfaces to post dominance information for
+// target-specific code.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CODEGEN_MACHINEPOSTDOMINATORS_H
+#define LLVM_CODEGEN_MACHINEPOSTDOMINATORS_H
+
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineDominators.h"
+#include "llvm/Analysis/Dominators.h"
+#include "llvm/Analysis/DominatorInternals.h"
+
+namespace llvm {
+
+///
+/// PostDominatorTree Class - Concrete subclass of DominatorTree that is used
+/// to compute the a post-dominator tree.
+///
+struct MachinePostDominatorTree : public MachineFunctionPass {
+  static char ID;
+
+  DominatorTreeBase<MachineBasicBlock> *DT;
+
+  MachinePostDominatorTree();
+
+  ~MachinePostDominatorTree();
+
+  FunctionPass *createMachinePostDominatorTreePass();
+
+  const std::vector<MachineBasicBlock *> &getRoots() const {
+    return DT->getRoots();
+  }
+
+  MachineDomTreeNode *getRootNode() const {
+    return DT->getRootNode();
+  }
+
+  MachineDomTreeNode *operator[](MachineBasicBlock *BB) const {
+    return DT->getNode(BB);
+  }
+
+  MachineDomTreeNode *getNode(MachineBasicBlock *BB) const {
+    return DT->getNode(BB);
+  }
+
+  bool dominates(MachineDomTreeNode *A, MachineDomTreeNode *B) const {
+    return DT->dominates(A, B);
+  }
+
+  bool dominates(MachineBasicBlock *A, MachineBasicBlock *B) const {
+    return DT->dominates(A, B);
+  }
+
+  bool
+  properlyDominates(const MachineDomTreeNode *A, MachineDomTreeNode *B) const {
+    return DT->properlyDominates(A, B);
+  }
+
+  bool
+  properlyDominates(MachineBasicBlock *A, MachineBasicBlock *B) const {
+    return DT->properlyDominates(A, B);
+  }
+
+  MachineBasicBlock *findNearestCommonDominator(MachineBasicBlock *A,
+                                                       MachineBasicBlock *B) {
+    return DT->findNearestCommonDominator(A, B);
+  }
+
+  virtual bool runOnMachineFunction(MachineFunction &MF);
+  virtual void getAnalysisUsage(AnalysisUsage &AU) const;
+  virtual void print(llvm::raw_ostream &OS, const Module *M = 0) const;
+};
+} //end of namespace llvm
+
+#endif

include/llvm/InitializePasses.h

@@ -167,6 +167,7 @@ void initializeMachineBlockPlacementStatsPass(PassRegistry&);
 void initializeMachineBranchProbabilityInfoPass(PassRegistry&);
 void initializeMachineCSEPass(PassRegistry&);
 void initializeMachineDominatorTreePass(PassRegistry&);
+void initializeMachinePostDominatorTreePass(PassRegistry&);
 void initializeMachineLICMPass(PassRegistry&);
 void initializeMachineLoopInfoPass(PassRegistry&);
 void initializeMachineLoopRangesPass(PassRegistry&);

lib/CodeGen/CMakeLists.txt

@@ -45,6 +45,7 @@ add_llvm_library(LLVMCodeGen
   MachineCopyPropagation.cpp
   MachineCSE.cpp
   MachineDominators.cpp
+  MachinePostDominators.cpp
   MachineFunction.cpp
   MachineFunctionAnalysis.cpp
   MachineFunctionPass.cpp

lib/CodeGen/CodeGen.cpp

@@ -41,6 +41,7 @@ void llvm::initializeCodeGen(PassRegistry &Registry) {
   initializeMachineCopyPropagationPass(Registry);
   initializeMachineCSEPass(Registry);
   initializeMachineDominatorTreePass(Registry);
+  initializeMachinePostDominatorTreePass(Registry);
   initializeMachineLICMPass(Registry);
   initializeMachineLoopInfoPass(Registry);
   initializeMachineModuleInfoPass(Registry);

lib/CodeGen/MachinePostDominators.cpp

@@ -0,0 +1,55 @@
+//===- MachinePostDominators.cpp -Machine Post Dominator Calculation ------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements simple dominator construction algorithms for finding
+// post dominators on machine functions.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/MachinePostDominators.h"
+
+using namespace llvm;
+
+char MachinePostDominatorTree::ID = 0;
+
+//declare initializeMachinePostDominatorTreePass
+INITIALIZE_PASS(MachinePostDominatorTree, "machinepostdomtree",
+                "MachinePostDominator Tree Construction", true, true)
+
+MachinePostDominatorTree::MachinePostDominatorTree() : MachineFunctionPass(ID) {
+  initializeMachinePostDominatorTreePass(*PassRegistry::getPassRegistry());
+  DT = new DominatorTreeBase<MachineBasicBlock>(true); //true indicate
+                                                       // postdominator
+}
+
+FunctionPass *
+MachinePostDominatorTree::createMachinePostDominatorTreePass() {
+  return new MachinePostDominatorTree();
+}
+
+bool
+MachinePostDominatorTree::runOnMachineFunction(MachineFunction &F) {
+  DT->recalculate(F);
+  return false;
+}
+
+MachinePostDominatorTree::~MachinePostDominatorTree() {
+  delete DT;
+}
+
+void
+MachinePostDominatorTree::getAnalysisUsage(AnalysisUsage &AU) const {
+  AU.setPreservesAll();
+  MachineFunctionPass::getAnalysisUsage(AU);
+}
+
+void
+MachinePostDominatorTree::print(llvm::raw_ostream &OS, const Module *M) const {
+  DT->print(OS);
+}