Sink the collection of return instructions until after *all*

[oota-llvm.git] / lib / Transforms / Utils / Local.cpp

diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp
index e65e5675acdcf8c4d1e7c126f45bbb8b053e4bce..d1c4d5968231f6046de76523de61e6de950fc7c0 100644 (file)
--- a/lib/Transforms/Utils/Local.cpp
+++ b/lib/Transforms/Utils/Local.cpp
@@ -355,7 +355,17 @@ 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++;
 
     WeakVH BIHandle(BI);
@@ -366,9 +376,6 @@ bool llvm::SimplifyInstructionsInBlock(BasicBlock *BB, const TargetData *TD) {
       continue;
     }
 
-    if (Inst->isTerminator())
-      break;
-
     MadeChange |= RecursivelyDeleteTriviallyDeadInstructions(Inst);
     if (BIHandle != BI)
       BI = BB->begin();
@@ -755,9 +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