[PATCH] D34095: [DAG] Prevent CombineTo from deleting already deleted nodes

[Nirav Dave via Phabricator via llvm-commits]

niravd added a comment.

Phabricator is still dropping comments from emails after the initial line. Reproducing here:

Justin Bogner said:

Can we do this without checking for ISD::DELETED_NODE? It's UB to read
N->getOpcode() if N was deleted, which we're currently working around by
unpoisoning the memory in ASAN, since we have this kind of code for
legacy reasons. I'd rather not introduce more places where we're doing
this.


https://reviews.llvm.org/D34095