[PATCH] D40728: [CallSiteSplitting] Refactor creating callsites.

[Jun Bum Lim via Phabricator via llvm-commits]

junbuml added inline comments.


================
Comment at: lib/Transforms/Scalar/CallSiteSplitting.cpp:143
+  BasicBlock *To = Pred;
+  while ((From = From->getSinglePredecessor())) {
+    recordCondition(CS, From, To, Conditions);
----------------
We should not revisit the same predecessor. Otherwise, it might get into infinite loop if  header is unreachable from the entry and we have a backedge from TBB to header : 
```
define i32 @test(i32* %a, i32 %v, i32 %p) {
Entry:
  br label %End
Header:
  %tobool2 = icmp eq i32 %p, 10
  br i1 %tobool2, label %Tail, label %TBB
TBB:
  %cmp = icmp eq i32 %v, 1
  br i1 %cmp, label %Tail, label %Header
Tail:
  %r = call i32 @callee(i32* %a, i32 %v, i32 %p)
  ret i32 %r
End:
  ret i32 %v
}
```


https://reviews.llvm.org/D40728