[InlineFunction] Only check pointer arguments for a call

[shchenz]

Summary

This is found from code review of D127202. See comment https://reviews.llvm.org/D127202#3607812

This patch does not reply on D127202. Making this patch depend on D127202 is to show the improvement in the testcase.

[shchenz]

typo fix

[nikic]

LGTM

llvm/lib/Transforms/Utils/InlineFunction.cpp

1046–1050

Minor phrasing suggestion.

llvm/lib/Transforms/Utils/InlineFunction.cpp

if (const Instruction *I = dyn_cast<Instruction>(VMI->first)) {
           if (AAResults::onlyAccessesInaccessibleMem(MRB))
             continue;
 
           if (AAResults::onlyAccessesArgPointees(MRB))
             IsArgMemOnlyCall = true;
         }
 
         for (Value *Arg : Call->args()) {
-          // We need to check the underlying objects of all arguments, not just
-          // the pointer arguments, because we might be passing pointers as
-          // integers, etc.
-          // However, if we know that the call only accesses pointer arguments,
-          // then we only need to check the pointer arguments.
-          if (IsArgMemOnlyCall && !Arg->getType()->isPointerTy())
+          // Only care about pointer arguments. If a noalias argument is
+          // accessed through a non-pointer argument, it must be captured
+          // first (e.g. via ptrtoint), and we protect against captures below.
+          if (!Arg->getType()->isPointerTy())
             continue;
 
           PtrArgs.push_back(Arg);
         }
       }
 
       // If we found no pointers, then this instruction is not suitable for
       // pairing with an instruction to receive aliasing metadata.
       // However, if this is a call, this we might just alias with none of the