Updates to support

* Changes in PHI node structure

llvm-svn: 25

lib/Bytecode/Reader/InstructionReader.cpp

@@ -104,24 +104,29 @@ bool BytecodeParser::ParseInstruction(const uchar *&Buf, const uchar *EndBuf,
   } else if (Raw.Opcode == Instruction::PHINode) {
     PHINode *PN = new PHINode(Raw.Ty);
     switch (Raw.NumOperands) {
-    case 0: cerr << "Invalid phi node encountered!\n"; 
+    case 0: 
+    case 1: 
+    case 3: cerr << "Invalid phi node encountered!\n"; 
             delete PN; 
 	    return true;
-    case 1: PN->addIncoming(getValue(Raw.Ty, Raw.Arg1)); break;
-    case 2: PN->addIncoming(getValue(Raw.Ty, Raw.Arg1)); 
-            PN->addIncoming(getValue(Raw.Ty, Raw.Arg2)); break;
-    case 3: PN->addIncoming(getValue(Raw.Ty, Raw.Arg1)); 
-            PN->addIncoming(getValue(Raw.Ty, Raw.Arg2)); 
-            PN->addIncoming(getValue(Raw.Ty, Raw.Arg3)); break;
+    case 2: PN->addIncoming(getValue(Raw.Ty, Raw.Arg1),
+			    (BasicBlock*)getValue(Type::LabelTy, Raw.Arg2)); 
+      break;
     default:
-      PN->addIncoming(getValue(Raw.Ty, Raw.Arg1)); 
-      PN->addIncoming(getValue(Raw.Ty, Raw.Arg2));
-      {
+      PN->addIncoming(getValue(Raw.Ty, Raw.Arg1), 
+		      (BasicBlock*)getValue(Type::LabelTy, Raw.Arg2));
+      if (Raw.VarArgs->size() & 1) {
+	cerr << "PHI Node with ODD number of arguments!\n";
+	delete PN;
+	return true;
+      } else {
         vector<unsigned> &args = *Raw.VarArgs;
-        for (unsigned i = 0; i < args.size(); i++)
-          PN->addIncoming(getValue(Raw.Ty, args[i]));
+        for (unsigned i = 0; i < args.size(); i+=2)
+          PN->addIncoming(getValue(Raw.Ty, args[i]),
+			  (BasicBlock*)getValue(Type::LabelTy, args[i+1]));
       }
-      delete Raw.VarArgs;
+      delete Raw.VarArgs; 
+      break;
     }
     Res = PN;
     return false;

lib/Transforms/IPO/InlineSimple.cpp

@@ -158,7 +158,7 @@ bool InlineMethod(BasicBlock::InstListType::iterator CIIt) {
 	assert(RI->getReturnValue() && "Ret should have value!");
 	assert(RI->getReturnValue()->getType() == PHI->getType() && 
 	       "Ret value not consistent in method!");
-	PHI->addIncoming((Value*)RI->getReturnValue());
+	PHI->addIncoming((Value*)RI->getReturnValue(), (BasicBlock*)BB);
       }
 
       // Add a branch to the code that was after the original Call.

lib/Transforms/Scalar/DCE.cpp

@@ -77,14 +77,14 @@ static bool RemoveSingularPHIs(BasicBlock *BB) {
   Instruction *I = BB->getInstList().front();
   if (I->getInstType() != Instruction::PHINode) return false;  // No PHI nodes
 
-  cerr << "Killing PHIs from " << BB;
-  cerr << "Pred #0 = " << *pred_begin(BB);
+  //cerr << "Killing PHIs from " << BB;
+  //cerr << "Pred #0 = " << *pred_begin(BB);
 
-  cerr << "Method == " << BB->getParent();
+  //cerr << "Method == " << BB->getParent();
 
   do {
     PHINode *PN = (PHINode*)I;
-    assert(PN->getOperand(1) == 0 && "PHI node should only have one value!");
+    assert(PN->getOperand(2) == 0 && "PHI node should only have one value!");
     Value *V = PN->getOperand(0);
 
     PN->replaceAllUsesWith(V);      // Replace PHI node with its single value.
@@ -134,29 +134,25 @@ static void ReplaceUsesWithConstant(Instruction *I) {
 //
 static void RemovePredecessorFromBlock(BasicBlock *BB, BasicBlock *Pred) {
   pred_iterator PI(pred_begin(BB)), EI(pred_end(BB));
-  unsigned pred_idx = 0, max_idx;
+  unsigned max_idx;
 
-  cerr << "RPFB: " << Pred << "From Block: " << BB;
+  //cerr << "RPFB: " << Pred << "From Block: " << BB;
   
-  // Find out what index the predecessor is...
-  for (; *PI != BB; ++PI, ++pred_idx) {
-    assert(PI != EI && "Pred is not a predecessor of BB!");
-  }
-
   // Loop over the rest of the predecssors until we run out, or until we find
   // out that there are more than 2 predecessors.
-  for (max_idx = pred_idx; PI != EI && max_idx < 2; ++PI, ++max_idx) /*empty*/;
+  for (max_idx = 0; PI != EI && max_idx < 3; ++PI, ++max_idx) /*empty*/;
 
   // If there are exactly two predecessors, then we want to nuke the PHI nodes
   // altogether.
-  bool NukePHIs = max_idx == 1;
+  bool NukePHIs = max_idx == 2;
+  assert(max_idx != 0 && "PHI Node in block with 0 predecessors!?!?!");
   
   // Okay, now we know that we need to remove predecessor #pred_idx from all
   // PHI nodes.  Iterate over each PHI node fixing them up
   BasicBlock::InstListType::iterator II(BB->getInstList().begin());
   for (; (*II)->getInstType() == Instruction::PHINode; ++II) {
     PHINode *PN = (PHINode*)*II;
-    PN->removeIncomingValue(pred_idx);
+    PN->removeIncomingValue(BB);
 
     if (NukePHIs) {  // Destroy the PHI altogether??
       assert(PN->getOperand(1) == 0 && "PHI node should only have one value!");
@@ -282,7 +278,7 @@ static bool DoDCEPass(Method *M) {
 	BasicBlock::InstListType::iterator DI = Pred->getInstList().end();
 	assert(Pred->getTerminator() && 
 	       "Degenerate basic block encountered!");  // Empty bb???      
-	delete Pred->getInstList().remove(--DI);
+	delete Pred->getInstList().remove(--DI);        // Destroy uncond branch
 	
 	// Move all definitions in the succecessor to the predecessor...
 	while (!BB->getInstList().empty()) {
@@ -290,12 +286,16 @@ static bool DoDCEPass(Method *M) {
 	  Instruction *Def = BB->getInstList().remove(DI); // Remove from front
 	  Pred->getInstList().push_back(Def);              // Add to end...
 	}
-	
+
 	// Remove basic block from the method... and advance iterator to the
 	// next valid block...
 	BB = BBs.remove(BBIt);
 	--BBIt;  // remove puts us on the NEXT bb.  We want the prev BB
 	Changed = true;
+
+	// Make all PHI nodes that refered to BB now refer to Pred as their
+	// source...
+	BB->replaceAllUsesWith(Pred);
 	
 	// Inherit predecessors name if it exists...
 	if (BB->hasName() && !Pred->hasName()) Pred->setName(BB->getName());

lib/VMCore/InstrTypes.cpp

@@ -45,7 +45,9 @@ PHINode::PHINode(const PHINode &PN)
   : Instruction(PN.getType(), Instruction::PHINode) {
   
   for (unsigned i = 0; i < PN.IncomingValues.size(); i++)
-    IncomingValues.push_back(Use(PN.IncomingValues[i], this));
+    IncomingValues.push_back(
+	make_pair(Use(PN.IncomingValues[i].first, this),
+		  BasicBlockUse(PN.IncomingValues[i].second, this)));
 }
 
 void PHINode::dropAllReferences() {
@@ -54,20 +56,37 @@ void PHINode::dropAllReferences() {
 
 bool PHINode::setOperand(unsigned i, Value *Val) {
   assert(Val && "PHI node must only reference nonnull definitions!");
-  if (i >= IncomingValues.size()) return false;
+  if (i >= IncomingValues.size()*2) return false;
 
-  IncomingValues[i] = Val;
+  if (i & 1) {
+    assert(Val->getValueType() == BasicBlockVal && "Not a BB!");
+    IncomingValues[i/2].second = (BasicBlock*)Val;
+  } else {
+    IncomingValues[i/2].first  = Val;
+  }
   return true;
 }
 
-void PHINode::addIncoming(Value *D) {
-  IncomingValues.push_back(Use(D, this));
+void PHINode::addIncoming(Value *D, BasicBlock *BB) {
+  IncomingValues.push_back(make_pair(Use(D, this), BasicBlockUse(BB, this)));
 }
 
+struct FindBBEntry {
+  const BasicBlock *BB;
+  inline FindBBEntry(const BasicBlock *bb) : BB(bb) {}
+  inline bool operator()(const pair<Use,BasicBlockUse> &Entry) {
+    return Entry.second == BB;
+  }
+};
+
+
 // removeIncomingValue - Remove an incoming value.  This is useful if a
 // predecessor basic block is deleted.
-Value *PHINode::removeIncomingValue(unsigned idx) {
-  Value *Removed = IncomingValues[idx];
-  IncomingValues.erase(IncomingValues.begin()+idx);
+Value *PHINode::removeIncomingValue(const BasicBlock *BB) {
+  vector<PairTy>::iterator Idx = find_if(IncomingValues.begin(), 
+					 IncomingValues.end(), FindBBEntry(BB));
+  assert(Idx != IncomingValues.end() && "BB not in PHI node!");
+  Value *Removed = Idx->first;
+  IncomingValues.erase(Idx);
   return Removed;
 }

lib/VMCore/Value.cpp

@@ -27,6 +27,12 @@ Value::Value(const Type *ty, ValueTy vty, const string &name = "") : Name(name){
 
 Value::~Value() {
 #ifndef NDEBUG      // Only in -g mode...
+  // Check to make sure that there are no uses of this value that are still
+  // around when the value is destroyed.  If there are, then we have a dangling
+  // reference and something is wrong.  This code is here to print out what is
+  // still being referenced.  The value in question should be printed as 
+  // a <badref>
+  //
   if (Uses.begin() != Uses.end()) {
     for (use_const_iterator I = Uses.begin(); I != Uses.end(); I++)
       cerr << "Use still stuck around after Def is destroyed:" << *I << endl;