[InstCombine] Make combineLoadToNewType a method; NFC

So it can be reused as part of other combines.
In particular for D71164.

Author: nikic

llvm/lib/Transforms/InstCombine/InstCombineInternal.h

@@ -467,6 +467,9 @@ class LLVM_LIBRARY_VISIBILITY InstCombiner
   /// \return true if successful.
   bool replacePointer(Instruction &I, Value *V);
 
+  LoadInst *combineLoadToNewType(LoadInst &LI, Type *NewTy,
+                                 const Twine &Suffix = "");
+
 private:
   bool shouldChangeType(unsigned FromBitWidth, unsigned ToBitWidth) const;
   bool shouldChangeType(Type *From, Type *To) const;

llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp

@@ -449,8 +449,8 @@ static bool isSupportedAtomicType(Type *Ty) {
 ///
 /// Note that this will create all of the instructions with whatever insert
 /// point the \c InstCombiner currently is using.
-static LoadInst *combineLoadToNewType(InstCombiner &IC, LoadInst &LI, Type *NewTy,
-                                      const Twine &Suffix = "") {
+LoadInst *InstCombiner::combineLoadToNewType(LoadInst &LI, Type *NewTy,
+                                             const Twine &Suffix) {
   assert((!LI.isAtomic() || isSupportedAtomicType(NewTy)) &&
          "can't fold an atomic load to requested type");
 
@@ -460,16 +460,16 @@ static LoadInst *combineLoadToNewType(InstCombiner &IC, LoadInst &LI, Type *NewT
   if (!(match(Ptr, m_BitCast(m_Value(NewPtr))) &&
         NewPtr->getType()->getPointerElementType() == NewTy &&
         NewPtr->getType()->getPointerAddressSpace() == AS))
-    NewPtr = IC.Builder.CreateBitCast(Ptr, NewTy->getPointerTo(AS));
+    NewPtr = Builder.CreateBitCast(Ptr, NewTy->getPointerTo(AS));
 
   unsigned Align = LI.getAlignment();
   if (!Align)
     // If old load did not have an explicit alignment specified,
     // manually preserve the implied (ABI) alignment of the load.
     // Else we may inadvertently incorrectly over-promise alignment.
-    Align = IC.getDataLayout().getABITypeAlignment(LI.getType());
+    Align = getDataLayout().getABITypeAlignment(LI.getType());
 
-  LoadInst *NewLoad = IC.Builder.CreateAlignedLoad(
+  LoadInst *NewLoad = Builder.CreateAlignedLoad(
       NewTy, NewPtr, Align, LI.isVolatile(), LI.getName() + Suffix);
   NewLoad->setAtomic(LI.getOrdering(), LI.getSyncScopeID());
   copyMetadataForLoad(*NewLoad, LI);
@@ -607,9 +607,8 @@ static Instruction *combineLoadToOperationType(InstCombiner &IC, LoadInst &LI) {
           return SI && SI->getPointerOperand() != &LI &&
                  !SI->getPointerOperand()->isSwiftError();
         })) {
-      LoadInst *NewLoad = combineLoadToNewType(
-          IC, LI,
-          Type::getIntNTy(LI.getContext(), DL.getTypeStoreSizeInBits(Ty)));
+      LoadInst *NewLoad = IC.combineLoadToNewType(
+          LI, Type::getIntNTy(LI.getContext(), DL.getTypeStoreSizeInBits(Ty)));
       // Replace all the stores with stores of the newly loaded value.
       for (auto UI = LI.user_begin(), UE = LI.user_end(); UI != UE;) {
         auto *SI = cast<StoreInst>(*UI++);
@@ -631,7 +630,7 @@ static Instruction *combineLoadToOperationType(InstCombiner &IC, LoadInst &LI) {
     if (auto* CI = dyn_cast<CastInst>(LI.user_back()))
       if (CI->isNoopCast(DL))
         if (!LI.isAtomic() || isSupportedAtomicType(CI->getDestTy())) {
-          LoadInst *NewLoad = combineLoadToNewType(IC, LI, CI->getDestTy());
+          LoadInst *NewLoad = IC.combineLoadToNewType(LI, CI->getDestTy());
           CI->replaceAllUsesWith(NewLoad);
           IC.eraseInstFromFunction(*CI);
           return &LI;
@@ -659,8 +658,8 @@ static Instruction *unpackLoadToAggregate(InstCombiner &IC, LoadInst &LI) {
     // If the struct only have one element, we unpack.
     auto NumElements = ST->getNumElements();
     if (NumElements == 1) {
-      LoadInst *NewLoad = combineLoadToNewType(IC, LI, ST->getTypeAtIndex(0U),
-                                               ".unpack");
+      LoadInst *NewLoad = IC.combineLoadToNewType(LI, ST->getTypeAtIndex(0U),
+                                                  ".unpack");
       AAMDNodes AAMD;
       LI.getAAMetadata(AAMD);
       NewLoad->setAAMetadata(AAMD);
@@ -709,7 +708,7 @@ static Instruction *unpackLoadToAggregate(InstCombiner &IC, LoadInst &LI) {
     auto *ET = AT->getElementType();
     auto NumElements = AT->getNumElements();
     if (NumElements == 1) {
-      LoadInst *NewLoad = combineLoadToNewType(IC, LI, ET, ".unpack");
+      LoadInst *NewLoad = IC.combineLoadToNewType(LI, ET, ".unpack");
       AAMDNodes AAMD;
       LI.getAAMetadata(AAMD);
       NewLoad->setAAMetadata(AAMD);
@@ -1352,7 +1351,7 @@ static bool removeBitcastsFromLoadStoreOnMinMax(InstCombiner &IC,
     return false;
 
   IC.Builder.SetInsertPoint(LI);
-  LoadInst *NewLI = combineLoadToNewType(IC, *LI, CmpLoadTy);
+  LoadInst *NewLI = IC.combineLoadToNewType(*LI, CmpLoadTy);
   // Replace all the stores with stores of the newly loaded value.
   for (auto *UI : LI->users()) {
     auto *USI = cast<StoreInst>(UI);