Commit 650437f2 authored by Tanya Lattner's avatar Tanya Lattner
Browse files

Merge 98977 from mainline. 

llvm-svn: 99292
parent 3e7b9913

llvm/include/llvm/CodeGen/MachineJumpTableInfo.h

+0 −4
Original line number Diff line number Diff line
@@ -83,10 +83,6 @@ public: 
  ///

  unsigned createJumpTableIndex(const std::vector<MachineBasicBlock*> &DestBBs);

  

  /// getJumpTableIndex - Return the index for an existing jump table.

  ///

  unsigned getJumpTableIndex(const std::vector<MachineBasicBlock*> &DestBBs);

  

  /// isEmpty - Return true if there are no jump tables.

  ///

  bool isEmpty() const { return JumpTables.empty(); }

llvm/lib/CodeGen/BranchFolding.cpp

+6 −28
Original line number Diff line number Diff line
@@ -203,7 +203,7 @@ bool BranchFolder::OptimizeFunction(MachineFunction &MF, 
    MadeChange |= MadeChangeThisIteration;

  }



  // See if any jump tables have become mergable or dead as the code generator

  // See if any jump tables have become dead as the code generator

  // did its thing.

  MachineJumpTableInfo *JTI = MF.getJumpTableInfo();

  if (JTI == 0) {
@@ -211,27 +211,8 @@ bool BranchFolder::OptimizeFunction(MachineFunction &MF, 
    return MadeChange;

  }

  

  const std::vector<MachineJumpTableEntry> &JTs = JTI->getJumpTables();

  // Figure out how these jump tables should be merged.

  std::vector<unsigned> JTMapping;

  JTMapping.reserve(JTs.size());



  // We always keep the 0th jump table.

  JTMapping.push_back(0);



  // Scan the jump tables, seeing if there are any duplicates.  Note that this

  // is N^2, which should be fixed someday.

  for (unsigned i = 1, e = JTs.size(); i != e; ++i) {

    if (JTs[i].MBBs.empty())

      JTMapping.push_back(i);

    else

      JTMapping.push_back(JTI->getJumpTableIndex(JTs[i].MBBs));

  }



  // If a jump table was merge with another one, walk the function rewriting

  // references to jump tables to reference the new JT ID's.  Keep track of

  // whether we see a jump table idx, if not, we can delete the JT.

  BitVector JTIsLive(JTs.size());

  // Walk the function to find jump tables that are live.

  BitVector JTIsLive(JTI->getJumpTables().size());

  for (MachineFunction::iterator BB = MF.begin(), E = MF.end();

       BB != E; ++BB) {

    for (MachineBasicBlock::iterator I = BB->begin(), E = BB->end();
@@ -239,17 +220,14 @@ bool BranchFolder::OptimizeFunction(MachineFunction &MF, 
      for (unsigned op = 0, e = I->getNumOperands(); op != e; ++op) {

        MachineOperand &Op = I->getOperand(op);

        if (!Op.isJTI()) continue;

        unsigned NewIdx = JTMapping[Op.getIndex()];

        Op.setIndex(NewIdx);



        // Remember that this JT is live.

        JTIsLive.set(NewIdx);

        JTIsLive.set(Op.getIndex());

      }

  }



  // Finally, remove dead jump tables.  This happens either because the

  // indirect jump was unreachable (and thus deleted) or because the jump

  // table was merged with some other one.

  // Finally, remove dead jump tables.  This happens when the

  // indirect jump was unreachable (and thus deleted).

  for (unsigned i = 0, e = JTIsLive.size(); i != e; ++i)

    if (!JTIsLive.test(i)) {

      JTI->RemoveJumpTable(i);

llvm/lib/CodeGen/MachineFunction.cpp

+0 −11
Original line number Diff line number Diff line
@@ -603,17 +603,6 @@ unsigned MachineJumpTableInfo::createJumpTableIndex( 
  return JumpTables.size()-1;

}



/// getJumpTableIndex - Return the index for an existing jump table entry in

/// the jump table info.

unsigned MachineJumpTableInfo::getJumpTableIndex(

                               const std::vector<MachineBasicBlock*> &DestBBs) {

  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i)

    if (JumpTables[i].MBBs == DestBBs)

      return i;

  assert(false && "getJumpTableIndex failed to find matching table");

  return ~0;

}



/// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update

/// the jump tables to branch to New instead.

bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,