Minimal refactor of TargetTransformInfoImpl.h to avoid Clang Static Analyser's core.CallAndMessage (NFC)

[markus]

Summary

Don't expose OpTy way earlier than needed and we don't have the problem of having to assign nullptr if we are looking at the wrong type of instruction.

[bjope]

LGTM!

This seem to help out avoiding complaints from clangsa that the OpTy passed on to getCastInstrCost could be a nullptr (implementations of getCastInstrCost doesn't seem to check that the Src/Dst Type pointers are non-null. One could perhaps question the API (if those pointers must not be null then I guess one could have passed the Type arguments by reference instead of passing the pointer). This patch in itself seem good anyway.

llvm/include/llvm/Analysis/TargetTransformInfoImpl.h

if (CB && !isa<IntrinsicInst>(U)) {
 
         return TTI::TCC_Basic * (F->getFunctionType()->getNumParams() + 1);
       }
       // For indirect or other calls, scale cost by number of arguments.
       return TTI::TCC_Basic * (CB->arg_size() + 1);
     }
 
     Type *Ty = U->getType();
-    Type *OpTy =
-      U->getNumOperands() == 1 ? U->getOperand(0)->getType() : nullptr;
     unsigned Opcode = Operator::getOpcode(U);
     auto *I = dyn_cast<Instruction>(U);
     switch (Opcode) {
     default:
       break;
     case Instruction::Call: {
       assert(isa<IntrinsicInst>(U) && "Unexpected non-intrinsic call");
       auto *Intrinsic = cast<IntrinsicInst>(U);
InstructionCost getUserCost(const User *U, ArrayRef<const Value *> Operands,
     case Instruction::FPToUI:
     case Instruction::FPToSI:
     case Instruction::Trunc:
     case Instruction::FPTrunc:
     case Instruction::BitCast:
     case Instruction::FPExt:
     case Instruction::SExt:
     case Instruction::ZExt:
-    case Instruction::AddrSpaceCast:
+    case Instruction::AddrSpaceCast: {
+      Type *OpTy = U->getOperand(0)->getType();
       return TargetTTI->getCastInstrCost(
           Opcode, Ty, OpTy, TTI::getCastContextHint(I), CostKind, I);
+    }
     case Instruction::Store: {
       auto *SI = cast<StoreInst>(U);
       Type *ValTy = U->getOperand(0)->getType();
       return TargetTTI->getMemoryOpCost(Opcode, ValTy, SI->getAlign(),
                                         SI->getPointerAddressSpace(),
                                         CostKind, I);
     }
     case Instruction::Load: {