Esempi in C++ (Cpp) per iterator::dropAllReferences

Esempio n. 1

File: SimplifyCFGPass.cpp Progetto: Sciumo/llvm

/// RemoveUnreachableBlocksFromFn - Remove blocks that are not reachable, even 
/// if they are in a dead cycle.  Return true if a change was made, false 
/// otherwise.
static bool RemoveUnreachableBlocksFromFn(Function &F) {
  SmallPtrSet<BasicBlock*, 128> Reachable;
  bool Changed = MarkAliveBlocks(F.begin(), Reachable);
  
  // If there are unreachable blocks in the CFG...
  if (Reachable.size() == F.size())
    return Changed;
  
  assert(Reachable.size() < F.size());
  NumSimpl += F.size()-Reachable.size();
  
  // Loop over all of the basic blocks that are not reachable, dropping all of
  // their internal references...
  for (Function::iterator BB = ++F.begin(), E = F.end(); BB != E; ++BB) {
    if (Reachable.count(BB))
      continue;
    
    for (succ_iterator SI = succ_begin(BB), SE = succ_end(BB); SI != SE; ++SI)
      if (Reachable.count(*SI))
        (*SI)->removePredecessor(BB);
    BB->dropAllReferences();
  }
  
  for (Function::iterator I = ++F.begin(); I != F.end();)
    if (!Reachable.count(I))
      I = F.getBasicBlockList().erase(I);
    else
      ++I;
  
  return true;
}