[PATCH] D21464: [PM] WIP: Introduce basic update capabilities to the new PM's CGSCC pass manager, including both plumbing and logic to handle function pass updates.

[Sanjoy Das via llvm-commits]

sanjoy added inline comments.

================
Comment at: include/llvm/Analysis/CGSCCPassManager.h:77
@@ +76,3 @@
+///
+/// 1) Sink to the bottom as the graph is refined. This means that any
+///    iteration continues in the bottom-most element remaining after the
----------------
Can you clarify here what happens when there isn't a well defined "bottom"?  I.e.

```
A -> B -> C -> A
A -> C
```

becomes

```
A -> B
A -> C
```



http://reviews.llvm.org/D21464