Split dominance calculation and post dominance calculation stuff

Dominance calculation goes to VMCore library to be used by Verifier.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@3210 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 6 insertions, 267 deletions

diff --git a/lib/Analysis/PostDominators.cpp b/lib/Analysis/PostDominators.cpp
index 1aff600d65..24355d4d6d 100644
--- a/lib/Analysis/PostDominators.cpp
+++ b/lib/Analysis/PostDominators.cpp
@@ -1,93 +1,24 @@
-//===- DominatorSet.cpp - Dominator Set Calculation --------------*- C++ -*--=//
+//===- PostDominators.cpp - Post-Dominator Calculation --------------------===//
 //
-// This file provides a simple class to calculate the dominator set of a
-// function.
+// This file implements the post-dominator construction algorithms.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Analysis/Dominators.h"
 #include "llvm/Transforms/Utils/UnifyFunctionExitNodes.h"
 #include "llvm/Support/CFG.h"
-#include "llvm/Assembly/Writer.h"
 #include "Support/DepthFirstIterator.h"
-#include "Support/STLExtras.h"
 #include "Support/SetOperations.h"
-#include <algorithm>
 using std::set;
 
 //===----------------------------------------------------------------------===//
-//  DominatorSet Implementation
+//  PostDominatorSet Implementation
 //===----------------------------------------------------------------------===//
 
-static RegisterAnalysis<DominatorSet>
-A("domset", "Dominator Set Construction", true);
 static RegisterAnalysis<PostDominatorSet>
 B("postdomset", "Post-Dominator Set Construction", true);
-
-AnalysisID DominatorSet::ID = A;
 AnalysisID PostDominatorSet::ID = B;
 
-// dominates - Return true if A dominates B.  This performs the special checks
-// neccesary if A and B are in the same basic block.
-//
-bool DominatorSetBase::dominates(Instruction *A, Instruction *B) const {
-  BasicBlock *BBA = A->getParent(), *BBB = B->getParent();
-  if (BBA != BBB) return dominates(BBA, BBB);
-  
-  // Loop through the basic block until we find A or B.
-  BasicBlock::iterator I = BBA->begin();
-  for (; &*I != A && &*I != B; ++I) /*empty*/;
-  
-  // A dominates B if it is found first in the basic block...
-  return &*I == A;
-}
-
-// runOnFunction - This method calculates the forward dominator sets for the
-// specified function.
-//
-bool DominatorSet::runOnFunction(Function &F) {
-  Doms.clear();   // Reset from the last time we were run...
-  Root = &F.getEntryNode();
-  assert(pred_begin(Root) == pred_end(Root) &&
-	 "Root node has predecessors in function!");
-
-  bool Changed;
-  do {
-    Changed = false;
-
-    DomSetType WorkingSet;
-    df_iterator<Function*> It = df_begin(&F), End = df_end(&F);
-    for ( ; It != End; ++It) {
-      BasicBlock *BB = *It;
-      pred_iterator PI = pred_begin(BB), PEnd = pred_end(BB);
-      if (PI != PEnd) {                // Is there SOME predecessor?
-	// Loop until we get to a predecessor that has had it's dom set filled
-	// in at least once.  We are guaranteed to have this because we are
-	// traversing the graph in DFO and have handled start nodes specially.
-	//
-	while (Doms[*PI].size() == 0) ++PI;
-	WorkingSet = Doms[*PI];
-
-	for (++PI; PI != PEnd; ++PI) { // Intersect all of the predecessor sets
-	  DomSetType &PredSet = Doms[*PI];
-	  if (PredSet.size())
-	    set_intersect(WorkingSet, PredSet);
-	}
-      }
-	
-      WorkingSet.insert(BB);           // A block always dominates itself
-      DomSetType &BBSet = Doms[BB];
-      if (BBSet != WorkingSet) {
-	BBSet.swap(WorkingSet);        // Constant time operation!
-	Changed = true;                // The sets changed.
-      }
-      WorkingSet.clear();              // Clear out the set for next iteration
-    }
-  } while (Changed);
-  return false;
-}
-
-
 // Postdominator set construction.  This converts the specified function to only
 // have a single exit node (return stmt), then calculates the post dominance
 // sets for the function.
@@ -151,146 +82,22 @@ void PostDominatorSet::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.addRequired(UnifyFunctionExitNodes::ID);
 }
 
-static std::ostream &operator<<(std::ostream &o, const set<BasicBlock*> &BBs) {
-  for (set<BasicBlock*>::const_iterator I = BBs.begin(), E = BBs.end();
-       I != E; ++I) {
-    o << "  ";
-    WriteAsOperand(o, *I, false);
-    o << "\n";
-   }
-  return o;
-}
-
-void DominatorSetBase::print(std::ostream &o) const {
-  for (const_iterator I = begin(), E = end(); I != E; ++I)
-    o << "=============================--------------------------------\n"
-      << "\nDominator Set For Basic Block\n" << I->first
-      << "-------------------------------\n" << I->second << "\n";
-}
-
 //===----------------------------------------------------------------------===//
-//  ImmediateDominators Implementation
+//  ImmediatePostDominators Implementation
 //===----------------------------------------------------------------------===//
 
-static RegisterAnalysis<ImmediateDominators>
-C("idom", "Immediate Dominators Construction", true);
 static RegisterAnalysis<ImmediatePostDominators>
 D("postidom", "Immediate Post-Dominators Construction", true);
-
-AnalysisID ImmediateDominators::ID = C;
 AnalysisID ImmediatePostDominators::ID = D;
 
-// calcIDoms - Calculate the immediate dominator mapping, given a set of
-// dominators for every basic block.
-void ImmediateDominatorsBase::calcIDoms(const DominatorSetBase &DS) {
-  // Loop over all of the nodes that have dominators... figuring out the IDOM
-  // for each node...
-  //
-  for (DominatorSet::const_iterator DI = DS.begin(), DEnd = DS.end(); 
-       DI != DEnd; ++DI) {
-    BasicBlock *BB = DI->first;
-    const DominatorSet::DomSetType &Dominators = DI->second;
-    unsigned DomSetSize = Dominators.size();
-    if (DomSetSize == 1) continue;  // Root node... IDom = null
-
-    // Loop over all dominators of this node.  This corresponds to looping over
-    // nodes in the dominator chain, looking for a node whose dominator set is
-    // equal to the current nodes, except that the current node does not exist
-    // in it.  This means that it is one level higher in the dom chain than the
-    // current node, and it is our idom!
-    //
-    DominatorSet::DomSetType::const_iterator I = Dominators.begin();
-    DominatorSet::DomSetType::const_iterator End = Dominators.end();
-    for (; I != End; ++I) {   // Iterate over dominators...
-      // All of our dominators should form a chain, where the number of elements
-      // in the dominator set indicates what level the node is at in the chain.
-      // We want the node immediately above us, so it will have an identical 
-      // dominator set, except that BB will not dominate it... therefore it's
-      // dominator set size will be one less than BB's...
-      //
-      if (DS.getDominators(*I).size() == DomSetSize - 1) {
-	IDoms[BB] = *I;
-	break;
-      }
-    }
-  }
-}
-
-void ImmediateDominatorsBase::print(std::ostream &o) const {
-  for (const_iterator I = begin(), E = end(); I != E; ++I)
-    o << "=============================--------------------------------\n"
-      << "\nImmediate Dominator For Basic Block\n" << *I->first
-      << "is: \n" << *I->second << "\n";
-}
-
-
 //===----------------------------------------------------------------------===//
-//  DominatorTree Implementation
+//  PostDominatorTree Implementation
 //===----------------------------------------------------------------------===//
 
-static RegisterAnalysis<DominatorTree>
-E("domtree", "Dominator Tree Construction", true);
 static RegisterAnalysis<PostDominatorTree>
 F("postdomtree", "Post-Dominator Tree Construction", true);
-
-AnalysisID DominatorTree::ID = E;
 AnalysisID PostDominatorTree::ID = F;
 
-// DominatorTreeBase::reset - Free all of the tree node memory.
-//
-void DominatorTreeBase::reset() { 
-  for (NodeMapType::iterator I = Nodes.begin(), E = Nodes.end(); I != E; ++I)
-    delete I->second;
-  Nodes.clear();
-}
-
-
-void DominatorTree::calculate(const DominatorSet &DS) {
-  Nodes[Root] = new Node(Root, 0);   // Add a node for the root...
-
-  // Iterate over all nodes in depth first order...
-  for (df_iterator<BasicBlock*> I = df_begin(Root), E = df_end(Root);
-       I != E; ++I) {
-    BasicBlock *BB = *I;
-    const DominatorSet::DomSetType &Dominators = DS.getDominators(BB);
-    unsigned DomSetSize = Dominators.size();
-    if (DomSetSize == 1) continue;  // Root node... IDom = null
-      
-    // Loop over all dominators of this node. This corresponds to looping over
-    // nodes in the dominator chain, looking for a node whose dominator set is
-    // equal to the current nodes, except that the current node does not exist
-    // in it. This means that it is one level higher in the dom chain than the
-    // current node, and it is our idom!  We know that we have already added
-    // a DominatorTree node for our idom, because the idom must be a
-    // predecessor in the depth first order that we are iterating through the
-    // function.
-    //
-    DominatorSet::DomSetType::const_iterator I = Dominators.begin();
-    DominatorSet::DomSetType::const_iterator End = Dominators.end();
-    for (; I != End; ++I) {   // Iterate over dominators...
-      // All of our dominators should form a chain, where the number of
-      // elements in the dominator set indicates what level the node is at in
-      // the chain.  We want the node immediately above us, so it will have
-      // an identical dominator set, except that BB will not dominate it...
-      // therefore it's dominator set size will be one less than BB's...
-      //
-      if (DS.getDominators(*I).size() == DomSetSize - 1) {
-        // We know that the immediate dominator should already have a node, 
-        // because we are traversing the CFG in depth first order!
-        //
-        Node *IDomNode = Nodes[*I];
-        assert(IDomNode && "No node for IDOM?");
-        
-        // Add a new tree node for this BasicBlock, and link it as a child of
-        // IDomNode
-        Nodes[BB] = IDomNode->addChild(new Node(BB, IDomNode));
-        break;
-      }
-    }
-  }
-}
-
-
 void PostDominatorTree::calculate(const PostDominatorSet &DS) {
   Nodes[Root] = new Node(Root, 0);   // Add a node for the root...
 
@@ -339,74 +146,15 @@ void PostDominatorTree::calculate(const PostDominatorSet &DS) {
   }
 }
 
-static std::ostream &operator<<(std::ostream &o,
-                                const DominatorTreeBase::Node *Node) {
-  return o << Node->getNode()
-           << "\n------------------------------------------\n";
-}
-
-static void PrintDomTree(const DominatorTreeBase::Node *N, std::ostream &o,
-                         unsigned Lev) {
-  o << "Level #" << Lev << ":  " << N;
-  for (DominatorTreeBase::Node::const_iterator I = N->begin(), E = N->end(); 
-       I != E; ++I) {
-    PrintDomTree(*I, o, Lev+1);
-  }
-}
-
-void DominatorTreeBase::print(std::ostream &o) const {
-  o << "=============================--------------------------------\n"
-    << "Inorder Dominator Tree:\n";
-  PrintDomTree(Nodes.find(getRoot())->second, o, 1);
-}
-
-
 //===----------------------------------------------------------------------===//
-//  DominanceFrontier Implementation
+//  PostDominanceFrontier Implementation
 //===----------------------------------------------------------------------===//
 
-static RegisterAnalysis<DominanceFrontier>
-G("domfrontier", "Dominance Frontier Construction", true);
 static RegisterAnalysis<PostDominanceFrontier>
 H("postdomfrontier", "Post-Dominance Frontier Construction", true);
-
-AnalysisID DominanceFrontier::ID = G;
 AnalysisID PostDominanceFrontier::ID = H;
 
 const DominanceFrontier::DomSetType &
-DominanceFrontier::calculate(const DominatorTree &DT, 
-                             const DominatorTree::Node *Node) {
-  // Loop over CFG successors to calculate DFlocal[Node]
-  BasicBlock *BB = Node->getNode();
-  DomSetType &S = Frontiers[BB];       // The new set to fill in...
-
-  for (succ_iterator SI = succ_begin(BB), SE = succ_end(BB);
-       SI != SE; ++SI) {
-    // Does Node immediately dominate this successor?
-    if (DT[*SI]->getIDom() != Node)
-      S.insert(*SI);
-  }
-
-  // At this point, S is DFlocal.  Now we union in DFup's of our children...
-  // Loop through and visit the nodes that Node immediately dominates (Node's
-  // children in the IDomTree)
-  //
-  for (DominatorTree::Node::const_iterator NI = Node->begin(), NE = Node->end();
-       NI != NE; ++NI) {
-    DominatorTree::Node *IDominee = *NI;
-    const DomSetType &ChildDF = calculate(DT, IDominee);
-
-    DomSetType::const_iterator CDFI = ChildDF.begin(), CDFE = ChildDF.end();
-    for (; CDFI != CDFE; ++CDFI) {
-      if (!Node->dominates(DT[*CDFI]))
-	S.insert(*CDFI);
-    }
-  }
-
-  return S;
-}
-
-const DominanceFrontier::DomSetType &
 PostDominanceFrontier::calculate(const PostDominatorTree &DT, 
                                  const DominatorTree::Node *Node) {
   // Loop over CFG successors to calculate DFlocal[Node]
@@ -439,12 +187,3 @@ PostDominanceFrontier::calculate(const PostDominatorTree &DT,
 
   return S;
 }
-
-void DominanceFrontierBase::print(std::ostream &o) const {
-  for (const_iterator I = begin(), E = end(); I != E; ++I) {
-    o << "=============================--------------------------------\n"
-      << "\nDominance Frontier For Basic Block\n";
-    WriteAsOperand(o, I->first, false);
-    o << " is: \n" << I->second << "\n";
-  }
-}