[PATCH] D42551: [Debug] Add dbg.value intrinsics for PHIs created during LCSSA.

[Matt Davis via Phabricator via llvm-commits]

mattd added a comment.

In https://reviews.llvm.org/D42551#988531, @vsk wrote:

> In https://reviews.llvm.org/D42551#988523, @davide wrote:
>
> > In https://reviews.llvm.org/D42551#988512, @vsk wrote:
> >
> > > In https://reviews.llvm.org/D42551#988510, @aprantl wrote:
> > >
> > > > I don't think this is correct. What if the first nonphi instruction is the terminator?
> > >
> > >
> > > Oh I see. What about just inserting the dbg.value before the terminator? That should work for landingpad etc.
> >
> >
> > I think the correct fix is that of skipping phis and `landingpads` (& maybe something else that requires to be the first instruction in a block?, don't remember, check langref or the verifier) and then insert the dbg value.
>
>
> BasicBlock::getFirstInsertionPt() seems to do it. Wdyt? http://llvm.org/doxygen/BasicBlock_8cpp_source.html#l00200


That looks correct, as that routine checks both landing pad and phis.


Repository:
  rL LLVM

https://reviews.llvm.org/D42551