[PATCH] D35105: [SjLj] Replace recursive block marking algorithm with iterative algorithm

[Matthias Braun via Phabricator via llvm-commits]

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

Looks good to me. Possible improvement below.



================
Comment at: lib/CodeGen/SjLjEHPrepare.cpp:125-132
   if (!LiveBBs.insert(BB).second)
     return; // already been here.
 
-  for (BasicBlock *PredBB : predecessors(BB))
-    MarkBlocksLiveIn(PredBB, LiveBBs);
+  df_iterator_default_set<BasicBlock*> Visited;
+
+  for (BasicBlock *B : inverse_depth_first_ext(BB, Visited))
+    LiveBBs.insert(B);
----------------
Maybe
```
  for (BasicBlock *B : inverse_depth_first_ext(BB, LiveBBs)) {
    /* Empty: We want to produce the visited set. */
  }
```
works as well? So we can leave out the first if and only need a single set.


https://reviews.llvm.org/D35105