[PATCH] D29243: Cache reverse graph edges during dominator construction to avoidhaving to look them up later.

[Davide Italiano via Phabricator via llvm-commits]

davide added a comment.

LGTM, thanks.



================
Comment at: include/llvm/Support/GenericDomTreeConstruction.h:206
     WInfo.Semi = WInfo.Parent;
-    typedef GraphTraits<Inverse<NodeT> > InvTraits;
-    for (typename InvTraits::ChildIteratorType CI =
-         InvTraits::child_begin(W),
-         E = InvTraits::child_end(W); CI != E; ++CI) {
-      typename InvTraits::NodeRef N = *CI;
-      if (DT.Info.count(N)) {  // Only if this predecessor is reachable!
+    for (auto *N : WInfo.ReverseChildren) {
         unsigned SemiU = DT.Info[Eval<GraphT>(DT, N, i + 1)].Semi;
----------------
dberlin wrote:
> davide wrote:
> > Nit: I prefer the explicit type when non-obvious from the right hand side, and I just recently realized LLVM coding convention suggests this too. Anyway, this is just splitting hair, so, up to you.
> Making this an explicit type is a bit annoying. The real type is really GraphTraits<Inverse<NodeT> >::NodeRef
> 
> You would think it's just NodeT * (since that's what is in the SmallVector) ,but  using NodeT causes it to screw up the inference of Calculate everywhere.
> 
> So i'm going to leave it auto :)
> 
Oh, sure.


https://reviews.llvm.org/D29243