1 files changed, 18 insertions, 20 deletions

diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp
index 5f895eb..d1c4d59 100644
--- a/lib/Transforms/Utils/Local.cpp
+++ b/lib/Transforms/Utils/Local.cpp
@@ -355,22 +355,27 @@ bool llvm::RecursivelyDeleteDeadPHINode(PHINode *PN) {
 /// instructions in other blocks as well in this block.
 bool llvm::SimplifyInstructionsInBlock(BasicBlock *BB, const TargetData *TD) {
   bool MadeChange = false;
-  for (BasicBlock::iterator BI = BB->begin(), E = BB->end(); BI != E; ) {
+
+#ifndef NDEBUG
+  // In debug builds, ensure that the terminator of the block is never replaced
+  // or deleted by these simplifications. The idea of simplification is that it
+  // cannot introduce new instructions, and there is no way to replace the
+  // terminator of a block without introducing a new instruction.
+  AssertingVH<Instruction> TerminatorVH(--BB->end());
+#endif
+
+  for (BasicBlock::iterator BI = BB->begin(), E = --BB->end(); BI != E; ) {
+    assert(!BI->isTerminator());
     Instruction *Inst = BI++;
-    
-    if (Value *V = SimplifyInstruction(Inst, TD)) {
-      WeakVH BIHandle(BI);
-      ReplaceAndSimplifyAllUses(Inst, V, TD);
+
+    WeakVH BIHandle(BI);
+    if (recursivelySimplifyInstruction(Inst, TD)) {
       MadeChange = true;
       if (BIHandle != BI)
         BI = BB->begin();
       continue;
     }
 
-    if (Inst->isTerminator())
-      break;
-
-    WeakVH BIHandle(BI);
     MadeChange |= RecursivelyDeleteTriviallyDeadInstructions(Inst);
     if (BIHandle != BI)
       BI = BB->begin();
@@ -408,17 +413,11 @@ void llvm::RemovePredecessorAndSimplify(BasicBlock *BB, BasicBlock *Pred,
   WeakVH PhiIt = &BB->front();
   while (PHINode *PN = dyn_cast<PHINode>(PhiIt)) {
     PhiIt = &*++BasicBlock::iterator(cast<Instruction>(PhiIt));
+    Value *OldPhiIt = PhiIt;
 
-    Value *PNV = SimplifyInstruction(PN, TD);
-    if (PNV == 0) continue;
+    if (!recursivelySimplifyInstruction(PN, TD))
+      continue;
 
-    // If we're able to simplify the phi to a single value, substitute the new
-    // value into all of its uses.
-    assert(PNV != PN && "SimplifyInstruction broken!");
-    
-    Value *OldPhiIt = PhiIt;
-    ReplaceAndSimplifyAllUses(PN, PNV, TD);
-    
     // If recursive simplification ended up deleting the next PHI node we would
     // iterate to, then our iterator is invalid, restart scanning from the top
     // of the block.
@@ -763,9 +762,8 @@ unsigned llvm::getOrEnforceKnownAlignment(Value *V, unsigned PrefAlign,
   assert(V->getType()->isPointerTy() &&
          "getOrEnforceKnownAlignment expects a pointer!");
   unsigned BitWidth = TD ? TD->getPointerSizeInBits() : 64;
-  APInt Mask = APInt::getAllOnesValue(BitWidth);
   APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
-  ComputeMaskedBits(V, Mask, KnownZero, KnownOne, TD);
+  ComputeMaskedBits(V, KnownZero, KnownOne, TD);
   unsigned TrailZ = KnownZero.countTrailingOnes();
   
   // Avoid trouble with rediculously large TrailZ values, such as