[llvm] Remove uses of hasSameElemenTypeAs() (NFC)

Always returns true with opaque pointers.

Author: nikic

llvm/lib/IR/Constants.cpp

@@ -2226,21 +2226,6 @@ Constant *ConstantExpr::getAddrSpaceCast(Constant *C, Type *DstTy,
                                          bool OnlyIfReduced) {
   assert(CastInst::castIsValid(Instruction::AddrSpaceCast, C, DstTy) &&
          "Invalid constantexpr addrspacecast!");
-
-  // Canonicalize addrspacecasts between different pointer types by first
-  // bitcasting the pointer type and then converting the address space.
-  PointerType *SrcScalarTy = cast<PointerType>(C->getType()->getScalarType());
-  PointerType *DstScalarTy = cast<PointerType>(DstTy->getScalarType());
-  if (!SrcScalarTy->hasSameElementTypeAs(DstScalarTy)) {
-    Type *MidTy = PointerType::getWithSamePointeeType(
-        DstScalarTy, SrcScalarTy->getAddressSpace());
-    if (VectorType *VT = dyn_cast<VectorType>(DstTy)) {
-      // Handle vectors of pointers.
-      MidTy = FixedVectorType::get(MidTy,
-                                   cast<FixedVectorType>(VT)->getNumElements());
-    }
-    C = getBitCast(C, MidTy);
-  }
   return getFoldedCast(Instruction::AddrSpaceCast, C, DstTy, OnlyIfReduced);
 }
 

llvm/lib/IR/Instructions.cpp

@@ -3397,15 +3397,9 @@ unsigned CastInst::isEliminableCastPair(
         "Illegal addrspacecast, bitcast sequence!");
       // Allowed, use first cast's opcode
       return firstOp;
-    case 14: {
-      // bitcast, addrspacecast -> addrspacecast if the element type of
-      // bitcast's source is the same as that of addrspacecast's destination.
-      PointerType *SrcPtrTy = cast<PointerType>(SrcTy->getScalarType());
-      PointerType *DstPtrTy = cast<PointerType>(DstTy->getScalarType());
-      if (SrcPtrTy->hasSameElementTypeAs(DstPtrTy))
-        return Instruction::AddrSpaceCast;
-      return 0;
-    }
+    case 14:
+      // bitcast, addrspacecast -> addrspacecast
+      return Instruction::AddrSpaceCast;
     case 15:
       // FIXME: this state can be merged with (1), but the following assert
       // is useful to check the correcteness of the sequence due to semantic

llvm/lib/Transforms/Scalar/InferAddressSpaces.cpp

@@ -1251,20 +1251,6 @@ bool InferAddressSpacesImpl::rewriteWithNewAddressSpaces(
         if (AddrSpaceCastInst *ASC = dyn_cast<AddrSpaceCastInst>(CurUser)) {
           unsigned NewAS = NewV->getType()->getPointerAddressSpace();
           if (ASC->getDestAddressSpace() == NewAS) {
-            if (!cast<PointerType>(ASC->getType()->getScalarType())
-                     ->hasSameElementTypeAs(
-                         cast<PointerType>(NewV->getType()->getScalarType()))) {
-              BasicBlock::iterator InsertPos;
-              if (Instruction *NewVInst = dyn_cast<Instruction>(NewV))
-                InsertPos = std::next(NewVInst->getIterator());
-              else if (Instruction *VInst = dyn_cast<Instruction>(V))
-                InsertPos = std::next(VInst->getIterator());
-              else
-                InsertPos = ASC->getIterator();
-
-              NewV = CastInst::Create(Instruction::BitCast, NewV,
-                                      ASC->getType(), "", &*InsertPos);
-            }
             ASC->replaceAllUsesWith(NewV);
             DeadInstructions.push_back(ASC);
             continue;