lib/CodeGen/StrongPHIElimination.cpp

   1 //===- StrongPhiElimination.cpp - Eliminate PHI nodes by inserting copies -===//
   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 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #define DEBUG_TYPE "strongphielim"
  14 #include "llvm/CodeGen/Passes.h"
  15 #include "llvm/CodeGen/LiveIntervalAnalysis.h"
  16 #include "llvm/CodeGen/MachineDominators.h"
  17 #include "llvm/CodeGen/MachineFunctionPass.h"
  18 #include "llvm/Support/ErrorHandling.h"
  19 using namespace llvm;
  20
  21 namespace {
  22   class StrongPHIElimination : public MachineFunctionPass {
  23   public:
  24     static char ID; // Pass identification, replacement for typeid
  25     StrongPHIElimination() : MachineFunctionPass(ID) {
  26       initializeStrongPHIEliminationPass(*PassRegistry::getPassRegistry());
  27     }
  28
  29     virtual void getAnalysisUsage(AnalysisUsage&) const;
  30     bool runOnMachineFunction(MachineFunction&);
  31   };
  32 } // namespace
  33
  34 char StrongPHIElimination::ID = 0;
  35 INITIALIZE_PASS_BEGIN(StrongPHIElimination, "strong-phi-node-elimination",
  36   "Eliminate PHI nodes for register allocation, intelligently", false, false)
  37 INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)
  38 INITIALIZE_PASS_DEPENDENCY(SlotIndexes)
  39 INITIALIZE_PASS_DEPENDENCY(LiveIntervals)
  40 INITIALIZE_PASS_END(StrongPHIElimination, "strong-phi-node-elimination",
  41   "Eliminate PHI nodes for register allocation, intelligently", false, false)
  42
  43 char &llvm::StrongPHIEliminationID = StrongPHIElimination::ID;
  44
  45 void StrongPHIElimination::getAnalysisUsage(AnalysisUsage& AU) const {
  46   AU.setPreservesCFG();
  47   AU.addRequired<MachineDominatorTree>();
  48   AU.addRequired<SlotIndexes>();
  49   AU.addPreserved<SlotIndexes>();
  50   AU.addRequired<LiveIntervals>();
  51   AU.addPreserved<LiveIntervals>();
  52   MachineFunctionPass::getAnalysisUsage(AU);
  53 }
  54
  55 bool StrongPHIElimination::runOnMachineFunction(MachineFunction& Fn) {
  56   llvm_unreachable("Strong phi elimination is not implemented");
  57 }