Crash during inline call promotion due to VTablePtr not of PointerType

[NickLewisL3H]

Crash when compiling Linux Kernel Library files: lkl/net/core/dev.c, lkl/net/core/sock_reuseport.c, lkl/drivers/net/virtio_net.c, lkl/net/ipv4/af_inet.c

Added debug msgs show:

Internal error when inlining callee: __dev_xmit_skb into __dev_queue_xmit: VTablePtr not of PointerType
Internal error when inlining callee: __dev_xmit_skb into __dev_queue_xmit: VTablePtr not of PointerType
Internal error when inlining callee: run_bpf into reuseport_select_sock: VTablePtr not of PointerType
Internal error when inlining callee: bpf_prog_run_xdp into receive_mergeable: VTablePtr not of PointerType
Internal error when inlining callee: bpf_prog_run_xdp into receive_small: VTablePtr not of PointerType
Internal error when inlining callee: call_gro_receive into inet_gro_receive: VTablePtr not of PointerType

All creduce to the same or very similar code:

void *a;
void b(void *c) { *(long *)c = a; }
struct d {
  int (*e)()
} f(struct d *c) {
  c->e();
}
void g() {
  struct d *h = ({
    typeof(0) *i = ({
      union {
        typeof(&g) j;
        char k[1]
      } l;
      b(l.k);
      l.j;
    });
    i;
  });
  f(h);
}

[NickLewisL3H]

A workaround for the crash just forgoes call promotion in these cases:

--- a/llvm/lib/Transforms/Utils/CallPromotionUtils.cpp
+++ b/llvm/lib/Transforms/Utils/CallPromotionUtils.cpp
@@ -560,7 +560,10 @@ bool llvm::tryPromoteCall(CallBase &CB) {
       VTablePtrLoad, VTablePtrLoad->getParent(), BBI, 0, nullptr, nullptr);
   if (!VTablePtr)
     return false; // No vtable found.
-  APInt VTableOffsetGVBase(DL.getPointerAddrSizeInBits(VTablePtr->getType()),
+  Type *VTablePtrType = VTablePtr->getType();
+  if (!VTablePtrType->isPointerTy())
+    return false; //Not of pointer type.
+  APInt VTableOffsetGVBase(DL.getPointerAddrSizeInBits(VTablePtrType),
                            0);
   Value *VTableGVBase = VTablePtr->stripAndAccumulateConstantOffsets(
       DL, VTableOffsetGVBase, /* AllowNonInbounds */ true);

but this does not fully address the cause of the problem (in stripAndAccumulateConstantOffsets?)