Recommit r236670: [opaque pointer type] Pass explicit pointer type through GEP constant folding""

Clang regressions were caused by more stringent assertion checking
introduced by this change. Small fix needed to clang has been committed
in r236751.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236752 91177308-0d34-0410-b5e6-96231b3b80d8

lib/IR/ConstantFold.cpp

@@ -2028,7 +2028,7 @@ static bool isIndexInRangeOfSequentialType(const SequentialType *STy,
 }
 
 template<typename IndexTy>
-static Constant *ConstantFoldGetElementPtrImpl(Constant *C,
+static Constant *ConstantFoldGetElementPtrImpl(Type *PointeeTy, Constant *C,
                                                bool inBounds,
                                                ArrayRef<IndexTy> Idxs) {
   if (Idxs.empty()) return C;
@@ -2165,9 +2165,9 @@ static Constant *ConstantFoldGetElementPtrImpl(Constant *C,
   // factored out into preceding dimensions.
   bool Unknown = false;
   SmallVector<Constant *, 8> NewIdxs;
-  Type *Ty = C->getType();
+  Type *Ty = PointeeTy;
-  Type *Prev = nullptr;
+  Type *Prev = C->getType();
-  for (unsigned i = 0, e = Idxs.size(); i != e;
+  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])) {
       if (isa<ArrayType>(Ty) || isa<VectorType>(Ty))
@@ -2229,7 +2229,7 @@ static Constant *ConstantFoldGetElementPtrImpl(Constant *C,
   if (!Unknown && !inBounds)
     if (auto *GV = dyn_cast<GlobalVariable>(C))
       if (!GV->hasExternalWeakLinkage() && isInBoundsIndices(Idxs))
-        return ConstantExpr::getInBoundsGetElementPtr(nullptr, C, Idxs);
+        return ConstantExpr::getInBoundsGetElementPtr(PointeeTy, C, Idxs);
 
   return nullptr;
 }
@@ -2237,11 +2237,27 @@ static Constant *ConstantFoldGetElementPtrImpl(Constant *C,
 Constant *llvm::ConstantFoldGetElementPtr(Constant *C,
                                           bool inBounds,
                                           ArrayRef<Constant *> Idxs) {
-  return ConstantFoldGetElementPtrImpl(C, inBounds, Idxs);
+  return ConstantFoldGetElementPtrImpl(
+      cast<PointerType>(C->getType()->getScalarType())->getElementType(), C,
+      inBounds, Idxs);
 }
 
 Constant *llvm::ConstantFoldGetElementPtr(Constant *C,
                                           bool inBounds,
                                           ArrayRef<Value *> Idxs) {
-  return ConstantFoldGetElementPtrImpl(C, inBounds, Idxs);
+  return ConstantFoldGetElementPtrImpl(
+      cast<PointerType>(C->getType()->getScalarType())->getElementType(), C,
+      inBounds, Idxs);
+}
+
+Constant *llvm::ConstantFoldGetElementPtr(Type *Ty, Constant *C,
+                                          bool inBounds,
+                                          ArrayRef<Constant *> Idxs) {
+  return ConstantFoldGetElementPtrImpl(Ty, C, inBounds, Idxs);
+}
+
+Constant *llvm::ConstantFoldGetElementPtr(Type *Ty, Constant *C,
+                                          bool inBounds,
+                                          ArrayRef<Value *> Idxs) {
+  return ConstantFoldGetElementPtrImpl(Ty, C, inBounds, Idxs);
 }

lib/IR/ConstantFold.h

@@ -51,6 +51,10 @@ namespace llvm {
                                       ArrayRef<Constant *> Idxs);
   Constant *ConstantFoldGetElementPtr(Constant *C, bool inBounds,
                                       ArrayRef<Value *> Idxs);
+  Constant *ConstantFoldGetElementPtr(Type *Ty, Constant *C, bool inBounds,
+                                      ArrayRef<Constant *> Idxs);
+  Constant *ConstantFoldGetElementPtr(Type *Ty, Constant *C, bool inBounds,
+                                      ArrayRef<Value *> Idxs);
 } // End llvm namespace
 
 #endif

lib/IR/Constants.cpp

@@ -2015,14 +2015,16 @@ Constant *ConstantExpr::getSelect(Constant *C, Constant *V1, Constant *V2,
 Constant *ConstantExpr::getGetElementPtr(Type *Ty, Constant *C,
                                          ArrayRef<Value *> Idxs, bool InBounds,
                                          Type *OnlyIfReducedTy) {
-  if (Constant *FC = ConstantFoldGetElementPtr(C, InBounds, Idxs))
-    return FC;          // Fold a few common cases.
-
   if (!Ty)
     Ty = cast<PointerType>(C->getType()->getScalarType())->getElementType();
   else
-    assert(Ty ==
+    assert(
-           cast<PointerType>(C->getType()->getScalarType())->getElementType());
+        Ty ==
+        cast<PointerType>(C->getType()->getScalarType())->getContainedType(0u));
+
+  if (Constant *FC = ConstantFoldGetElementPtr(Ty, C, InBounds, Idxs))
+    return FC;          // Fold a few common cases.
+
   // Get the result type of the getelementptr!
   Type *DestTy = GetElementPtrInst::getIndexedType(Ty, Idxs);
   assert(DestTy && "GEP indices invalid!");

lib/Transforms/IPO/GlobalOpt.cpp

@@ -564,7 +564,7 @@ static GlobalVariable *SRAGlobal(GlobalVariable *GV, const DataLayout &DL) {
     if (Val >= NewGlobals.size()) Val = 0; // Out of bound array access.
 
     Value *NewPtr = NewGlobals[Val];
-    Type *NewTy = NewGlobals[Val]->getType();
+    Type *NewTy = NewGlobals[Val]->getValueType();
 
     // Form a shorter GEP if needed.
     if (GEP->getNumOperands() > 3) {
@@ -575,7 +575,6 @@ static GlobalVariable *SRAGlobal(GlobalVariable *GV, const DataLayout &DL) {
           Idxs.push_back(CE->getOperand(i));
         NewPtr =
             ConstantExpr::getGetElementPtr(NewTy, cast<Constant>(NewPtr), Idxs);
-        NewTy = GetElementPtrInst::getIndexedType(NewTy, Idxs);
       } else {
         GetElementPtrInst *GEPI = cast<GetElementPtrInst>(GEP);
         SmallVector<Value*, 8> Idxs;
@@ -583,8 +582,7 @@ static GlobalVariable *SRAGlobal(GlobalVariable *GV, const DataLayout &DL) {
         for (unsigned i = 3, e = GEPI->getNumOperands(); i != e; ++i)
           Idxs.push_back(GEPI->getOperand(i));
         NewPtr = GetElementPtrInst::Create(
-            NewPtr->getType()->getPointerElementType(), NewPtr, Idxs,
+            NewTy, NewPtr, Idxs, GEPI->getName() + "." + Twine(Val), GEPI);
-            GEPI->getName() + "." + Twine(Val), GEPI);
       }
     }
     GEP->replaceAllUsesWith(NewPtr);