Add comment as follow up to r245712

[oota-llvm.git] / lib / IR / ConstantFold.cpp

diff --git a/lib/IR/ConstantFold.cpp b/lib/IR/ConstantFold.cpp
index 8afb3e489de266927bfbc355eb817dc6787574e6..f63ce9bbf038a1fda1da0a987341727618729f24 100644 (file)
--- a/lib/IR/ConstantFold.cpp
+++ b/lib/IR/ConstantFold.cpp
@@ -632,8 +632,8 @@ Constant *llvm::ConstantFoldCastInstruction(unsigned opc, Constant *V,
     if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
       if (CE->getOpcode() == Instruction::GetElementPtr &&
           CE->getOperand(0)->isNullValue()) {
-        Type *Ty =
-          cast<PointerType>(CE->getOperand(0)->getType())->getElementType();
+        GEPOperator *GEPO = cast<GEPOperator>(CE);
+        Type *Ty = GEPO->getSourceElementType();
         if (CE->getNumOperands() == 2) {
           // Handle a sizeof-like expression.
           Constant *Idx = CE->getOperand(1);
@@ -1385,7 +1385,7 @@ static ICmpInst::Predicate areGlobalsPotentiallyEqual(const GlobalValue *GV1,
     if (GV->hasExternalWeakLinkage() || GV->hasWeakAnyLinkage())
       return true;
     if (const auto *GVar = dyn_cast<GlobalVariable>(GV)) {
-      Type *Ty = GVar->getType()->getPointerElementType();
+      Type *Ty = GVar->getValueType();
       // A global with opaque type might end up being zero sized.
       if (!Ty->isSized())
         return true;
@@ -1997,17 +1997,17 @@ static bool isInBoundsIndices(ArrayRef<IndexTy> Idxs) {
 }
 
 /// \brief Test whether a given ConstantInt is in-range for a SequentialType.
-static bool isIndexInRangeOfSequentialType(const SequentialType *STy,
+static bool isIndexInRangeOfSequentialType(SequentialType *STy,
                                            const ConstantInt *CI) {
-  if (const PointerType *PTy = dyn_cast<PointerType>(STy))
-    // Only handle pointers to sized types, not pointers to functions.
-    return PTy->getElementType()->isSized();
+  // And indicies are valid when indexing along a pointer
+  if (isa<PointerType>(STy))
+    return true;
 
   uint64_t NumElements = 0;
   // Determine the number of elements in our sequential type.
-  if (const ArrayType *ATy = dyn_cast<ArrayType>(STy))
+  if (auto *ATy = dyn_cast<ArrayType>(STy))
     NumElements = ATy->getNumElements();
-  else if (const VectorType *VTy = dyn_cast<VectorType>(STy))
+  else if (auto *VTy = dyn_cast<VectorType>(STy))
     NumElements = VTy->getNumElements();
 
   assert((isa<ArrayType>(STy) || NumElements > 0) &&
@@ -2163,10 +2163,10 @@ static Constant *ConstantFoldGetElementPtrImpl(Type *PointeeTy, Constant *C,
   // Check to see if any array indices are not within the corresponding
   // notional array or vector bounds. If so, try to determine if they can be
   // factored out into preceding dimensions.
-  bool Unknown = false;
   SmallVector<Constant *, 8> NewIdxs;
   Type *Ty = PointeeTy;
   Type *Prev = C->getType();
+  bool Unknown = !isa<ConstantInt>(Idxs[0]);
   for (unsigned i = 1, e = Idxs.size(); i != e;
        Prev = Ty, Ty = cast<CompositeType>(Ty)->getTypeAtIndex(Idxs[i]), ++i) {
     if (ConstantInt *CI = dyn_cast<ConstantInt>(Idxs[i])) {
@@ -2178,7 +2178,7 @@ static Constant *ConstantFoldGetElementPtrImpl(Type *PointeeTy, Constant *C,
             // dimension.
             NewIdxs.resize(Idxs.size());
             uint64_t NumElements = 0;
-            if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty))
+            if (auto *ATy = dyn_cast<ArrayType>(Ty))
               NumElements = ATy->getNumElements();
             else
               NumElements = cast<VectorType>(Ty)->getNumElements();
@@ -2221,7 +2221,7 @@ static Constant *ConstantFoldGetElementPtrImpl(Type *PointeeTy, Constant *C,
   if (!NewIdxs.empty()) {
     for (unsigned i = 0, e = Idxs.size(); i != e; ++i)
       if (!NewIdxs[i]) NewIdxs[i] = cast<Constant>(Idxs[i]);
-    return ConstantExpr::getGetElementPtr(nullptr, C, NewIdxs, inBounds);
+    return ConstantExpr::getGetElementPtr(PointeeTy, C, NewIdxs, inBounds);
   }
 
   // If all indices are known integers and normalized, we can do a simple