GVN.cpp

bool GVN::iterateOnFunction(Function &F) {
  cleanupGlobalSets();
  
  // Top-down walk of the dominator tree
  bool Changed = false;
#if 0
  // Needed for value numbering with phi construction to work.
  ReversePostOrderTraversal<Function*> RPOT(&F);
  for (ReversePostOrderTraversal<Function*>::rpo_iterator RI = RPOT.begin(),
       RE = RPOT.end(); RI != RE; ++RI)
    Changed |= processBlock(*RI);
#else
  for (df_iterator<DomTreeNode*> DI = df_begin(DT->getRootNode()),
       DE = df_end(DT->getRootNode()); DI != DE; ++DI)
    Changed |= processBlock(DI->getBlock());
#endif

  return Changed;
}

void GVN::cleanupGlobalSets() {
  VN.clear();
  LeaderTable.clear();
  TableAllocator.Reset();
}

/// verifyRemoved - Verify that the specified instruction does not occur in our
/// internal data structures.
void GVN::verifyRemoved(const Instruction *Inst) const {
  VN.verifyRemoved(Inst);

  // Walk through the value number scope to make sure the instruction isn't
  // ferreted away in it.
  for (DenseMap<uint32_t, LeaderTableEntry>::const_iterator
       I = LeaderTable.begin(), E = LeaderTable.end(); I != E; ++I) {
    const LeaderTableEntry *Node = &I->second;
    assert(Node->Val != Inst && "Inst still in value numbering scope!");
    
    while (Node->Next) {
      Node = Node->Next;
      assert(Node->Val != Inst && "Inst still in value numbering scope!");
    }
  }
}