lib/CodeGen/MachinePostDominators.cpp

   1 //===- MachinePostDominators.cpp -Machine Post Dominator Calculation ------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file implements simple dominator construction algorithms for finding
  11 // post dominators on machine functions.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/CodeGen/MachinePostDominators.h"
  16
  17 using namespace llvm;
  18
  19 char MachinePostDominatorTree::ID = 0;
  20
  21 //declare initializeMachinePostDominatorTreePass
  22 INITIALIZE_PASS(MachinePostDominatorTree, "machinepostdomtree",
  23                 "MachinePostDominator Tree Construction", true, true)
  24
  25 MachinePostDominatorTree::MachinePostDominatorTree() : MachineFunctionPass(ID) {
  26   initializeMachinePostDominatorTreePass(*PassRegistry::getPassRegistry());
  27   DT = new DominatorTreeBase<MachineBasicBlock>(true); //true indicate
  28                                                        // postdominator
  29 }
  30
  31 FunctionPass *
  32 MachinePostDominatorTree::createMachinePostDominatorTreePass() {
  33   return new MachinePostDominatorTree();
  34 }
  35
  36 bool
  37 MachinePostDominatorTree::runOnMachineFunction(MachineFunction &F) {
  38   DT->recalculate(F);
  39   return false;
  40 }
  41
  42 MachinePostDominatorTree::~MachinePostDominatorTree() {
  43   delete DT;
  44 }
  45
  46 void
  47 MachinePostDominatorTree::getAnalysisUsage(AnalysisUsage &AU) const {
  48   AU.setPreservesAll();
  49   MachineFunctionPass::getAnalysisUsage(AU);
  50 }
  51
  52 void
  53 MachinePostDominatorTree::print(llvm::raw_ostream &OS, const Module *M) const {
  54   DT->print(OS);
  55 }