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

4 files changed, 36 insertions, 16 deletions

diff --git a/lib/IR/ConstantFold.cpp b/lib/IR/ConstantFold.cpp
index 2a524937391..8afb3e489de 100644
--- a/lib/IR/ConstantFold.cpp
+++ b/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 *Prev = nullptr;
-  for (unsigned i = 0, e = Idxs.size(); i != e;
+  Type *Ty = PointeeTy;
+  Type *Prev = C->getType();
+  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);
 }
diff --git a/lib/IR/ConstantFold.h b/lib/IR/ConstantFold.h
index a516abe024e..42a9c6ba908 100644
--- a/lib/IR/ConstantFold.h
+++ b/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
diff --git a/lib/IR/Constants.cpp b/lib/IR/Constants.cpp
index 20a5206c230..b598c2807ce 100644
--- a/lib/IR/Constants.cpp
+++ b/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 ==
-           cast<PointerType>(C->getType()->getScalarType())->getElementType());
+    assert(
+        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!");
diff --git a/lib/Transforms/IPO/GlobalOpt.cpp b/lib/Transforms/IPO/GlobalOpt.cpp
index b8c4f5da39e..cc4a79fa67d 100644
--- a/lib/Transforms/IPO/GlobalOpt.cpp
+++ b/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,
-            GEPI->getName() + "." + Twine(Val), GEPI);
+            NewTy, NewPtr, Idxs, GEPI->getName() + "." + Twine(Val), GEPI);
       }
     }
     GEP->replaceAllUsesWith(NewPtr);