[PATCH] D58170: [DTU] Refine the logic of deduplication

[Chijun Sima via Phabricator via llvm-commits]

NutshellySima added a comment.

Further explanation:
The motivation of this patch is that currently there can be bugs like that mentioned in summary.
But after inspecting that JT and other utils never submit updates that have been applied, we can get the information of whether a specific edge <From, To> exists in the previous CFG.
For example, if we observe a sequence of updates of an edge<From, To> to be

  1. Insert --> 2. Delete --> 3. Delete --> 4. Insert --> 5. Delete

Because it is supposed that "never submit updates that have been applied", so we can infer from `1. Insert` that <From, To> does not exist in the previous CFG. We can then inspect the current CFG to see if there is an edge<From, To>.  If there is one, it is sure that an insertion happens. Otherwise, the 5 operations result in a no-op.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D58170/new/

https://reviews.llvm.org/D58170