[PATCH] D51976: [DebugInfo][Dexter] Speculated BB presents illegal variable value to debugger

[Adrian Prantl via Phabricator via llvm-commits]

aprantl added a comment.

In https://reviews.llvm.org/D51976#1236852, @CarlosAlbertoEnciso wrote:

> In https://reviews.llvm.org/D51976#1235508, @aprantl wrote:
>
> > Having read the real testcase now, I understand why you are dropping the debug info now. I would like to point out that we could do better. If we extended llvm.dbg.value to take more than one LLVM SSA Value, then we could produce a DIExpression that selects either %add or %sub depending on the value of %cmp. Let me know if you are interested in implementing this, it should be relatively straight forward to do and would come in useful in all sorts of other situations, too.
>
>
> That is a very good idea and I am interested in implementing it. A good opportunity to improve my knowledge in that area. I can see the associated benefits.
>
> I would suggest if that is OK with you, to finish with the current issue. And then as a general improvement, to revisit the 'select' case as an independent issue, to implement what you have described. If you feel otherwise, I would proceed with the changes proposed to the 'llvm.dbg.value'.


Sure. Dropping the debug info is always the safe/correct option and will improve the status quo. It would be good to leave a comment in the that explains why we are dropping it and that properly handling it needs a missing feature in LLVM IR.

> In the meantime, I am updating the patch.




https://reviews.llvm.org/D51976