Enable first-class aggregates support.

Remove the GetResultInst instruction. It is still accepted in LLVM assembly
and bitcode, where it is now auto-upgraded to ExtractValueInst. Also, remove
support for return instructions with multiple values. These are auto-upgraded
to use InsertValueInst instructions.

The IRBuilder still accepts multiple-value returns, and auto-upgrades them
to InsertValueInst instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53941 91177308-0d34-0410-b5e6-96231b3b80d8

10 files changed, 68 insertions, 261 deletions

diff --git a/lib/Transforms/IPO/IPConstantPropagation.cpp b/lib/Transforms/IPO/IPConstantPropagation.cpp
index fa004fda1e..42c02e6a45 100644
--- a/lib/Transforms/IPO/IPConstantPropagation.cpp
+++ b/lib/Transforms/IPO/IPConstantPropagation.cpp
@@ -255,9 +255,7 @@ bool IPCP::PropagateConstantReturn(Function &F) {
 
       // Find the index of the retval to replace with
       int index = -1;
-      if (GetResultInst *GR = dyn_cast<GetResultInst>(Ins))
-        index = GR->getIndex();
-      else if (ExtractValueInst *EV = dyn_cast<ExtractValueInst>(Ins))
+      if (ExtractValueInst *EV = dyn_cast<ExtractValueInst>(Ins))
         if (EV->hasIndices())
           index = *EV->idx_begin();
 
diff --git a/lib/Transforms/IPO/StructRetPromotion.cpp b/lib/Transforms/IPO/StructRetPromotion.cpp
index 94bf4c6d5f..aa74944850 100644
--- a/lib/Transforms/IPO/StructRetPromotion.cpp
+++ b/lib/Transforms/IPO/StructRetPromotion.cpp
@@ -97,9 +97,6 @@ bool SRETPromotion::PromoteReturn(CallGraphNode *CGN) {
     dyn_cast<StructType>(FArgType->getElementType());
   assert (STy && "Invalid sret parameter element type");
 
-  if (nestedStructType(STy))
-    return false;
-
   // Check if it is ok to perform this promotion.
   if (isSafeToUpdateAllCallers(F) == false) {
     NumRejectedSRETUses++;
@@ -114,25 +111,13 @@ bool SRETPromotion::PromoteReturn(CallGraphNode *CGN) {
   NFirstArg->replaceAllUsesWith(TheAlloca);
 
   // [2] Find and replace ret instructions
-  SmallVector<Value *,4> RetVals;
   for (Function::iterator FI = F->begin(), FE = F->end();  FI != FE; ++FI) 
     for(BasicBlock::iterator BI = FI->begin(), BE = FI->end(); BI != BE; ) {
       Instruction *I = BI;
       ++BI;
       if (isa<ReturnInst>(I)) {
-        RetVals.clear();
-        for (unsigned idx = 0; idx < STy->getNumElements(); ++idx) {
-          SmallVector<Value*, 2> GEPIdx;
-          GEPIdx.push_back(ConstantInt::get(Type::Int32Ty, 0));
-          GEPIdx.push_back(ConstantInt::get(Type::Int32Ty, idx));
-          Value *NGEPI = GetElementPtrInst::Create(TheAlloca, GEPIdx.begin(),
-                                                   GEPIdx.end(),
-                                                   "mrv.gep", I);
-          Value *NV = new LoadInst(NGEPI, "mrv.ld", I);
-          RetVals.push_back(NV);
-        }
-    
-        ReturnInst *NR = ReturnInst::Create(&RetVals[0], RetVals.size(), I);
+        Value *NV = new LoadInst(TheAlloca, "mrv.ld", I);
+        ReturnInst *NR = ReturnInst::Create(NV);
         I->replaceAllUsesWith(NR);
         I->eraseFromParent();
       }
@@ -315,7 +300,7 @@ void SRETPromotion::updateCallSites(Function *F, Function *NF) {
     ArgAttrsVec.clear();
     New->takeName(Call);
 
-    // Update all users of sret parameter to extract value using getresult.
+    // Update all users of sret parameter to extract value using extractvalue.
     for (Value::use_iterator UI = FirstCArg->use_begin(), 
            UE = FirstCArg->use_end(); UI != UE; ) {
       User *U2 = *UI++;
@@ -325,7 +310,8 @@ void SRETPromotion::updateCallSites(Function *F, Function *NF) {
       else if (GetElementPtrInst *UGEP = dyn_cast<GetElementPtrInst>(U2)) {
         ConstantInt *Idx = dyn_cast<ConstantInt>(UGEP->getOperand(2));
         assert (Idx && "Unexpected getelementptr index!");
-        Value *GR = new GetResultInst(New, Idx->getZExtValue(), "gr", UGEP);
+        Value *GR = ExtractValueInst::Create(New, Idx->getZExtValue(),
+                                             "evi", UGEP);
         for (Value::use_iterator GI = UGEP->use_begin(),
                GE = UGEP->use_end(); GI != GE; ++GI) {
           if (LoadInst *L = dyn_cast<LoadInst>(*GI)) {
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 861badf8f0..da98d0a0fc 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -11476,9 +11476,7 @@ bool InstCombiner::DoOneIteration(Function &F, unsigned Iteration) {
     }
 
     // See if we can trivially sink this instruction to a successor basic block.
-    // FIXME: Remove GetResultInst test when first class support for aggregates
-    // is implemented.
-    if (I->hasOneUse() && !isa<GetResultInst>(I)) {
+    if (I->hasOneUse()) {
       BasicBlock *BB = I->getParent();
       BasicBlock *UserParent = cast<Instruction>(I->use_back())->getParent();
       if (UserParent != BB) {
diff --git a/lib/Transforms/Scalar/JumpThreading.cpp b/lib/Transforms/Scalar/JumpThreading.cpp
index 4e57f0e74c..1d3bfbfe7c 100644
--- a/lib/Transforms/Scalar/JumpThreading.cpp
+++ b/lib/Transforms/Scalar/JumpThreading.cpp
@@ -440,20 +440,7 @@ void JumpThreading::ThreadEdge(BasicBlock *BB, BasicBlock *PredBB,
     
     // We found a use of I outside of BB.  Create a new stack slot to
     // break this inter-block usage pattern.
-    if (!isa<StructType>(I->getType())) {
-      DemoteRegToStack(*I);
-      continue;
-    }
-    
-    // Alternatively, I must be a call or invoke that returns multiple retvals.
-    // We can't use 'DemoteRegToStack' because that will create loads and
-    // stores of aggregates which is not valid yet.  If I is a call, we can just
-    // pull all the getresult instructions up to this block.  If I is an invoke,
-    // we are out of luck.
-    BasicBlock::iterator IP = I; ++IP;
-    for (Value::use_iterator UI = I->use_begin(), E = I->use_end();
-         UI != E; ++UI)
-      cast<GetResultInst>(UI)->moveBefore(IP);
+    DemoteRegToStack(*I);
   }
  
   // We are going to have to map operands from the original BB block to the new
diff --git a/lib/Transforms/Scalar/LoopRotation.cpp b/lib/Transforms/Scalar/LoopRotation.cpp
index 38364c1587..f0dd40bd33 100644
--- a/lib/Transforms/Scalar/LoopRotation.cpp
+++ b/lib/Transforms/Scalar/LoopRotation.cpp
@@ -249,35 +249,11 @@ bool LoopRotate::rotateLoop(Loop *Lp, LPPassManager &LPM) {
     // create new PHINode for this instruction.
     Instruction *NewHeaderReplacement = NULL;
     if (usedOutsideOriginalHeader(In)) {
-      // FIXME: remove this when we have first-class aggregates.
-      if (isa<StructType>(In->getType())) {
-        // Can't create PHI nodes for this type.  If there are any getResults
-        // not defined in this block, move them back to this block.  PHI
-        // nodes will be created for all getResults later.
-        BasicBlock::iterator InsertPoint;
-        if (InvokeInst *II = dyn_cast<InvokeInst>(In)) {
-          InsertPoint = II->getNormalDest()->getFirstNonPHI();
-        } else {
-          InsertPoint = I;  // call
-          ++InsertPoint;
-        }
-        for (Value::use_iterator UI = In->use_begin(), UE = In->use_end();
-             UI != UE; ++UI) {
-          GetResultInst *InGR = cast<GetResultInst>(UI);
-          if (InGR->getParent() != OrigHeader) {
-            // Move InGR to immediately after the call or in the normal dest of
-            // the invoke.  It will be picked up, cloned and PHI'd on the next
-            // iteration.
-            InGR->moveBefore(InsertPoint);
-          }
-        }
-      } else {
-        PHINode *PN = PHINode::Create(In->getType(), In->getName(),
-                                      NewHeader->begin());
-        PN->addIncoming(In, OrigHeader);
-        PN->addIncoming(C, OrigPreHeader);
-        NewHeaderReplacement = PN;
-      }
+      PHINode *PN = PHINode::Create(In->getType(), In->getName(),
+                                    NewHeader->begin());
+      PN->addIncoming(In, OrigHeader);
+      PN->addIncoming(C, OrigPreHeader);
+      NewHeaderReplacement = PN;
     }
     LoopHeaderInfo.push_back(RenameData(In, C, NewHeaderReplacement));
   }
diff --git a/lib/Transforms/Scalar/SCCP.cpp b/lib/Transforms/Scalar/SCCP.cpp
index ff88137af8..d52cef607c 100644
--- a/lib/Transforms/Scalar/SCCP.cpp
+++ b/lib/Transforms/Scalar/SCCP.cpp
@@ -384,7 +384,6 @@ private:
   void visitTerminatorInst(TerminatorInst &TI);
 
   void visitCastInst(CastInst &I);
-  void visitGetResultInst(GetResultInst &GRI);
   void visitSelectInst(SelectInst &I);
   void visitBinaryOperator(Instruction &I);
   void visitCmpInst(CmpInst &I);
@@ -669,41 +668,6 @@ void SCCPSolver::visitCastInst(CastInst &I) {
                                            VState.getConstant(), I.getType()));
 }
 
-void SCCPSolver::visitGetResultInst(GetResultInst &GRI) {
-  Value *Aggr = GRI.getOperand(0);
-
-  // If the operand to the getresult is an undef, the result is undef.
-  if (isa<UndefValue>(Aggr))
-    return;
-  
-  Function *F;
-  if (CallInst *CI = dyn_cast<CallInst>(Aggr))
-    F = CI->getCalledFunction();
-  else
-    F = cast<InvokeInst>(Aggr)->getCalledFunction();
-
-  // TODO: If IPSCCP resolves the callee of this function, we could propagate a
-  // result back!
-  if (F == 0 || TrackedMultipleRetVals.empty()) {
-    markOverdefined(&GRI);
-    return;
-  }
-  
-  // See if we are tracking the result of the callee.
-  std::map<std::pair<Function*, unsigned>, LatticeVal>::iterator
-    It = TrackedMultipleRetVals.find(std::make_pair(F, GRI.getIndex()));
-
-  // If not tracking this function (for example, it is a declaration) just move
-  // to overdefined.
-  if (It == TrackedMultipleRetVals.end()) {
-    markOverdefined(&GRI);
-    return;
-  }
-  
-  // Otherwise, the value will be merged in here as a result of CallSite
-  // handling.
-}
-
 void SCCPSolver::visitExtractValueInst(ExtractValueInst &EVI) {
   Value *Aggr = EVI.getAggregateOperand();
 
@@ -1267,11 +1231,6 @@ CallOverdefined:
     // currently handled conservatively.
     for (Value::use_iterator UI = I->use_begin(), E = I->use_end();
          UI != E; ++UI) {
-      if (GetResultInst *GRI = dyn_cast<GetResultInst>(*UI)) {
-        mergeInValue(GRI, 
-                TrackedMultipleRetVals[std::make_pair(F, GRI->getIndex())]);
-        continue;
-      }
       if (ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(*UI)) {
         if (EVI->getNumIndices() == 1) {
           mergeInValue(EVI, 
diff --git a/lib/Transforms/Utils/InlineFunction.cpp b/lib/Transforms/Utils/InlineFunction.cpp
index 22dab69846..a198356fd2 100644
--- a/lib/Transforms/Utils/InlineFunction.cpp
+++ b/lib/Transforms/Utils/InlineFunction.cpp
@@ -442,17 +442,7 @@ bool llvm::InlineFunction(CallSite CS, CallGraph *CG, const TargetData *TD) {
     // uses of the returned value.
     if (!TheCall->use_empty()) {
       ReturnInst *R = Returns[0];
-      if (isa<StructType>(TheCall->getType()) &&
-          TheCall->getType() != R->getOperand(0)->getType()) {
-        // Multiple-value return statements.
-        while (!TheCall->use_empty()) {
-          GetResultInst *GR = cast<GetResultInst>(TheCall->use_back());
-          Value *RV = R->getOperand(GR->getIndex());
-          GR->replaceAllUsesWith(RV);
-          GR->eraseFromParent();
-        }
-      } else
-        TheCall->replaceAllUsesWith(R->getReturnValue());
+      TheCall->replaceAllUsesWith(R->getReturnValue());
     }
     // Since we are now done with the Call/Invoke, we can delete it.
     TheCall->eraseFromParent();
@@ -508,63 +498,27 @@ bool llvm::InlineFunction(CallSite CS, CallGraph *CG, const TargetData *TD) {
   // Handle all of the return instructions that we just cloned in, and eliminate
   // any users of the original call/invoke instruction.
   const Type *RTy = CalledFunc->getReturnType();
-  const StructType *STy = dyn_cast<StructType>(RTy);
-
-  // We do special handling for multiple-value return statements. If this is
-  // a plain aggregate return, don't do the special handling.
-  if (!Returns.empty() && Returns[0]->getNumOperands() != 0 &&
-      Returns[0]->getOperand(0)->getType() == STy)
-    STy = 0;
 
-  if (Returns.size() > 1 || STy) {
+  if (Returns.size() > 1) {
     // The PHI node should go at the front of the new basic block to merge all
     // possible incoming values.
-    SmallVector<PHINode *, 4> PHIs;
+    PHINode *PHI = 0;
     if (!TheCall->use_empty()) {
-      if (STy) {
-        unsigned NumRetVals = STy->getNumElements();
-        // Create new phi nodes such that phi node number in the PHIs vector
-        // match corresponding return value operand number.
-        Instruction *InsertPt = AfterCallBB->begin();
-        for (unsigned i = 0; i < NumRetVals; ++i) {
-            PHINode *PHI = PHINode::Create(STy->getElementType(i),
-                                           TheCall->getName() + "." + utostr(i), 
-                                           InsertPt);
-          PHIs.push_back(PHI);
-        }
-        // TheCall results are used by GetResult instructions. 
-        while (!TheCall->use_empty()) {
-          GetResultInst *GR = cast<GetResultInst>(TheCall->use_back());
-          GR->replaceAllUsesWith(PHIs[GR->getIndex()]);
-          GR->eraseFromParent();
-        }
-      } else {
-        PHINode *PHI = PHINode::Create(RTy, TheCall->getName(),
-                                       AfterCallBB->begin());
-        PHIs.push_back(PHI);
-        // Anything that used the result of the function call should now use the
-        // PHI node as their operand.
-        TheCall->replaceAllUsesWith(PHI); 
-      } 
+      PHI = PHINode::Create(RTy, TheCall->getName(),
+                            AfterCallBB->begin());
+      // Anything that used the result of the function call should now use the
+      // PHI node as their operand.
+      TheCall->replaceAllUsesWith(PHI); 
     }
 
     // Loop over all of the return instructions adding entries to the PHI node as
     // appropriate.
-    if (!PHIs.empty()) {
-      // There is atleast one return value.
-      unsigned NumRetVals = 1; 
-      if (STy)
-        NumRetVals = STy->getNumElements();
-      for (unsigned j = 0; j < NumRetVals; ++j) {
-        PHINode *PHI = PHIs[j];
-        // Each PHI node will receive one value from each return instruction.
-        for(unsigned i = 0, e = Returns.size(); i != e; ++i) {
-          ReturnInst *RI = Returns[i];
-          assert(RI->getReturnValue(j)->getType() == PHI->getType() &&
-                 "Ret value not consistent in function!");
-          PHI->addIncoming(RI->getReturnValue(j /*PHI number matches operand number*/), 
-                           RI->getParent());
-        }
+    if (PHI) {
+      for (unsigned i = 0, e = Returns.size(); i != e; ++i) {
+        ReturnInst *RI = Returns[i];
+        assert(RI->getReturnValue()->getType() == PHI->getType() &&
+               "Ret value not consistent in function!");
+        PHI->addIncoming(RI->getReturnValue(), RI->getParent());
       }
     }
 
diff --git a/lib/Transforms/Utils/LCSSA.cpp b/lib/Transforms/Utils/LCSSA.cpp
index d94cd594ba..55d7a48593 100644
--- a/lib/Transforms/Utils/LCSSA.cpp
+++ b/lib/Transforms/Utils/LCSSA.cpp
@@ -217,27 +217,7 @@ void LCSSA::getLoopValuesUsedOutsideLoop(Loop *L,
         }
         
         if (*BB != UserBB && !inLoop(UserBB)) {
-          const StructType *STy = dyn_cast<StructType>(I->getType());
-          if (STy) {
-            // I is a call or an invoke that returns multiple values.
-            // These values are accessible through getresult only.
-            // If the getresult value is not in the BB then move it
-            // immediately here. It will be processed in next iteration.
-            BasicBlock::iterator InsertPoint;
-            if (InvokeInst *II = dyn_cast<InvokeInst>(I)) {
-              InsertPoint = II->getNormalDest()->getFirstNonPHI();
-            } else {
-              InsertPoint = I;
-              InsertPoint++;
-            }
-            for (Value::use_iterator TmpI = I->use_begin(), 
-                   TmpE = I->use_end(); TmpI != TmpE; ++TmpI) {
-              GetResultInst *GR = cast<GetResultInst>(TmpI);
-              if (GR->getParent() != *BB)
-                GR->moveBefore(InsertPoint);
-            }
-          } else
-            AffectedValues.insert(I);
+          AffectedValues.insert(I);
           break;
         }
       }
diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp
index 2fc859e88d..d04fce6892 100644
--- a/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -1357,40 +1357,31 @@ static bool SimplifyCondBranchToTwoReturns(BranchInst *BI) {
     return true;
   }
     
-  // Otherwise, build up the result values for the new return.
-  SmallVector<Value*, 4> TrueResult;
-  SmallVector<Value*, 4> FalseResult;
+  // Otherwise, figure out what the true and false return values are
+  // so we can insert a new select instruction.
+  Value *TrueValue = TrueRet->getReturnValue();
+  Value *FalseValue = FalseRet->getReturnValue();
+  
+  // Unwrap any PHI nodes in the return blocks.
+  if (PHINode *TVPN = dyn_cast_or_null<PHINode>(TrueValue))
+    if (TVPN->getParent() == TrueSucc)
+      TrueValue = TVPN->getIncomingValueForBlock(BI->getParent());
+  if (PHINode *FVPN = dyn_cast_or_null<PHINode>(FalseValue))
+    if (FVPN->getParent() == FalseSucc)
+      FalseValue = FVPN->getIncomingValueForBlock(BI->getParent());
+  
+  // In order for this transformation to be safe, we must be able to
+  // unconditionally execute both operands to the return.  This is
+  // normally the case, but we could have a potentially-trapping
+  // constant expression that prevents this transformation from being
+  // safe.
+  if (ConstantExpr *TCV = dyn_cast_or_null<ConstantExpr>(TrueValue))
+    if (TCV->canTrap())
+      return false;
+  if (ConstantExpr *FCV = dyn_cast_or_null<ConstantExpr>(FalseValue))
+    if (FCV->canTrap())
+      return false;
   
-  for (unsigned i = 0, e = TrueRet->getNumOperands(); i != e; ++i) {
-    // Otherwise, figure out what the true and false return values are
-    // so we can insert a new select instruction.
-    Value *TrueValue = TrueRet->getOperand(i);
-    Value *FalseValue = FalseRet->getOperand(i);
-    
-    // Unwrap any PHI nodes in the return blocks.
-    if (PHINode *TVPN = dyn_cast<PHINode>(TrueValue))
-      if (TVPN->getParent() == TrueSucc)
-        TrueValue = TVPN->getIncomingValueForBlock(BI->getParent());
-    if (PHINode *FVPN = dyn_cast<PHINode>(FalseValue))
-      if (FVPN->getParent() == FalseSucc)
-        FalseValue = FVPN->getIncomingValueForBlock(BI->getParent());
-    
-    // In order for this transformation to be safe, we must be able to
-    // unconditionally execute both operands to the return.  This is
-    // normally the case, but we could have a potentially-trapping
-    // constant expression that prevents this transformation from being
-    // safe.
-    if (ConstantExpr *TCV = dyn_cast<ConstantExpr>(TrueValue))
-      if (TCV->canTrap())
-        return false;
-    if (ConstantExpr *FCV = dyn_cast<ConstantExpr>(FalseValue))
-      if (FCV->canTrap())
-        return false;
-    
-    TrueResult.push_back(TrueValue);
-    FalseResult.push_back(FalseValue);
-  }
-
   // Okay, we collected all the mapped values and checked them for sanity, and
   // defined to really do this transformation.  First, update the CFG.
   TrueSucc->removePredecessor(BI->getParent());
@@ -1398,20 +1389,20 @@ static bool SimplifyCondBranchToTwoReturns(BranchInst *BI) {
   
   // Insert select instructions where needed.
   Value *BrCond = BI->getCondition();
-  for (unsigned i = 0, e = TrueRet->getNumOperands(); i != e; ++i) {
+  if (TrueValue) {
     // Insert a select if the results differ.
-    if (TrueResult[i] == FalseResult[i] || isa<UndefValue>(FalseResult[i]))
-      continue;
-    if (isa<UndefValue>(TrueResult[i])) {
-      TrueResult[i] = FalseResult[i];
-      continue;
+    if (TrueValue == FalseValue || isa<UndefValue>(FalseValue)) {
+    } else if (isa<UndefValue>(TrueValue)) {
+      TrueValue = FalseValue;
+    } else {
+      TrueValue = SelectInst::Create(BrCond, TrueValue,
+                                     FalseValue, "retval", BI);
     }
-    
-    TrueResult[i] = SelectInst::Create(BrCond, TrueResult[i],
-                                       FalseResult[i], "retval", BI);
   }
 
-  Value *RI = ReturnInst::Create(&TrueResult[0], TrueResult.size(), BI);
+  Value *RI = !TrueValue ?
+              ReturnInst::Create(BI) :
+              ReturnInst::Create(TrueValue, BI);
       
   DOUT << "\nCHANGING BRANCH TO TWO RETURNS INTO SELECT:"
        << "\n  " << *BI << "NewRet = " << *RI
diff --git a/lib/Transforms/Utils/UnifyFunctionExitNodes.cpp b/lib/Transforms/Utils/UnifyFunctionExitNodes.cpp
index c024d32374..ba58fbd987 100644
--- a/lib/Transforms/Utils/UnifyFunctionExitNodes.cpp
+++ b/lib/Transforms/Utils/UnifyFunctionExitNodes.cpp
@@ -110,32 +110,13 @@ bool UnifyFunctionExitNodes::runOnFunction(Function &F) {
   //
   BasicBlock *NewRetBlock = BasicBlock::Create("UnifiedReturnBlock", &F);
 
-  SmallVector<Value *, 4> Phis;
-  unsigned NumRetVals = ReturningBlocks[0]->getTerminator()->getNumOperands();
-  if (NumRetVals == 0)
+  PHINode *PN = 0;
+  if (F.getReturnType() == Type::VoidTy) {
     ReturnInst::Create(NULL, NewRetBlock);
-  else if (const StructType *STy = dyn_cast<StructType>(F.getReturnType())) {
-    Instruction *InsertPt = NULL;
-    if (NumRetVals == 0)
-      InsertPt = NewRetBlock->getFirstNonPHI();
-    PHINode *PN = NULL;
-    for (unsigned i = 0; i < NumRetVals; ++i) {
-      if (InsertPt)
-        PN = PHINode::Create(STy->getElementType(i), "UnifiedRetVal." 
-                         + utostr(i), InsertPt);
-      else
-        PN = PHINode::Create(STy->getElementType(i), "UnifiedRetVal." 
-                         + utostr(i), NewRetBlock);
-      Phis.push_back(PN);
-      InsertPt = PN;
-    }
-    ReturnInst::Create(&Phis[0], NumRetVals, NewRetBlock);
-  }
-  else {
+  } else {
     // If the function doesn't return void... add a PHI node to the block...
-    PHINode *PN = PHINode::Create(F.getReturnType(), "UnifiedRetVal");
+    PN = PHINode::Create(F.getReturnType(), "UnifiedRetVal");
     NewRetBlock->getInstList().push_back(PN);
-    Phis.push_back(PN);
     ReturnInst::Create(PN, NewRetBlock);
   }
 
@@ -148,11 +129,8 @@ bool UnifyFunctionExitNodes::runOnFunction(Function &F) {
 
     // Add an incoming element to the PHI node for every return instruction that
     // is merging into this new block...
-    if (!Phis.empty()) {
-      for (unsigned i = 0; i < NumRetVals; ++i) 
-        cast<PHINode>(Phis[i])->addIncoming(BB->getTerminator()->getOperand(i), 
-                                            BB);
-    }
+    if (PN)
+      PN->addIncoming(BB->getTerminator()->getOperand(0), BB);
 
     BB->getInstList().pop_back();  // Remove the return insn
     BranchInst::Create(NewRetBlock, BB);