[PATCH] D30869: [JumpThread] We want to fold (not thread) when all predecessor go to single BB's successor. .

[Sanjoy Das via Phabricator via llvm-commits]

sanjoy accepted this revision.
sanjoy added a comment.
This revision is now accepted and ready to land.

lgtm with nits



================
Comment at: lib/Transforms/Scalar/JumpThreading.cpp:1294
+  // not thread. By doing so, we do not need to duplicate the current block and
+  // also miss potential opportunities in case we dont/cant duplicate.
+  if (OnlyDest && OnlyDest != MultipleDestSentinel) {
----------------
s/dont/don't
s/cant/can't


================
Comment at: lib/Transforms/Scalar/JumpThreading.cpp:1299
+      for (BasicBlock *SuccBB : successors(BB)) {
+        if (SuccBB == OnlyDest)
+          continue;
----------------
In this case, it may be cleaner to write the loop as:

```
for (BasicBlock *SuccBB : successors(BB))
  if (SuccBB != OnlyDest)
    SuccBB->removePredecessor(BB, true);  // Unreachable successor
```



https://reviews.llvm.org/D30869