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 private:
  30   bool runOnMachineFunction(MachineFunction &Fn) {
  31     llvm_unreachable("Strong phi elimination is not implemented");
  32   }
  33
  34   virtual void getAnalysisUsage(AnalysisUsage &AU) const {
  35     AU.setPreservesCFG();
  36     AU.addRequired<MachineDominatorTree>();
  37     AU.addRequired<SlotIndexes>();
  38     AU.addPreserved<SlotIndexes>();
  39     AU.addRequired<LiveIntervals>();
  40     AU.addPreserved<LiveIntervals>();
  41     MachineFunctionPass::getAnalysisUsage(AU);
  42   }
  43 };
  44 } // namespace
  45
  46 char StrongPHIElimination::ID = 0;
  47 INITIALIZE_PASS_BEGIN(StrongPHIElimination, "strong-phi-node-elimination",
  48   "Eliminate PHI nodes for register allocation, intelligently", false, false)
  49 INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)
  50 INITIALIZE_PASS_DEPENDENCY(SlotIndexes)
  51 INITIALIZE_PASS_DEPENDENCY(LiveIntervals)
  52 INITIALIZE_PASS_END(StrongPHIElimination, "strong-phi-node-elimination",
  53   "Eliminate PHI nodes for register allocation, intelligently", false, false)
  54
  55 char &llvm::StrongPHIEliminationID = StrongPHIElimination::ID;
  56